Substances that are recognized by the immune system and induce an immune reaction.
Infections with unicellular organisms formerly members of the subkingdom Protozoa.
Substances elaborated by bacteria that have antigenic activity.
Proteins, glycoprotein, or lipoprotein moieties on surfaces of tumor cells that are usually identified by monoclonal antibodies. Many of these are of either embryonic or viral origin.
Antigens on surfaces of cells, including infectious or foreign cells or viruses. They are usually protein-containing groups on cell membranes or walls and may be isolated.
Proteins found in any species of protozoan.
Substances elaborated by viruses that have antigenic activity.
Any part or derivative of any protozoan that elicits immunity; malaria (Plasmodium) and trypanosome antigens are presently the most frequently encountered.
One of the three domains of life (the others being BACTERIA and ARCHAEA), also called Eukarya. These are organisms whose cells are enclosed in membranes and possess a nucleus. They comprise almost all multicellular and many unicellular organisms, and are traditionally divided into groups (sometimes called kingdoms) including ANIMALS; PLANTS; FUNGI; and various algae and other taxa that were previously part of the old kingdom Protista.
Deoxyribonucleic acid that makes up the genetic material of protozoa.
A phylum of EUKARYOTES characterized by the presence of cilia at some time during the life cycle. It comprises three classes: KINETOFRAGMINOPHOREA; OLIGOHYMENOPHOREA; and POLYMENOPHOREA.
The functional hereditary units of protozoa.
Ribonucleic acid in protozoa having regulatory and catalytic roles as well as involvement in protein synthesis.
Polyomavirus antigens which cause infection and cellular transformation. The large T antigen is necessary for the initiation of viral DNA synthesis, repression of transcription of the early region and is responsible in conjunction with the middle T antigen for the transformation of primary cells. Small T antigen is necessary for the completion of the productive infection cycle.
Antigens determined by leukocyte loci found on chromosome 6, the major histocompatibility loci in humans. They are polypeptides or glycoproteins found on most nucleated cells and platelets, determine tissue types for transplantation, and are associated with certain diseases.
Substances of fungal origin that have antigenic activity.
Differentiation antigens residing on mammalian leukocytes. CD stands for cluster of differentiation, which refers to groups of monoclonal antibodies that show similar reactivity with certain subpopulations of antigens of a particular lineage or differentiation stage. The subpopulations of antigens are also known by the same CD designation.
The complete genetic complement contained in a set of CHROMOSOMES in a protozoan.
Infections with unicellular organisms formerly members of the subkingdom Protozoa. The infections may be experimental or veterinary.
Any part or derivative of a helminth that elicits an immune reaction. The most commonly seen helminth antigens are those of the schistosomes.
The major group of transplantation antigens in the mouse.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
A glycoprotein that is secreted into the luminal surface of the epithelia in the gastrointestinal tract. It is found in the feces and pancreaticobiliary secretions and is used to monitor the response to colon cancer treatment.
Those proteins recognized by antibodies from serum of animals bearing tumors induced by viruses; these proteins are presumably coded for by the nucleic acids of the same viruses that caused the neoplastic transformation.
A species of parasitic protozoa causing ENTAMOEBIASIS and amebic dysentery (DYSENTERY, AMEBIC). Characteristics include a single nucleus containing a small central karyosome and peripheral chromatin that is finely and regularly beaded.
A subclass of HLA-D antigens that consist of alpha and beta chains. The inheritance of HLA-DR antigens differs from that of the HLA-DQ ANTIGENS and HLA-DP ANTIGENS.
Molecules on the surface of T-lymphocytes that recognize and combine with antigens. The receptors are non-covalently associated with a complex of several polypeptides collectively called CD3 antigens (ANTIGENS, CD3). Recognition of foreign antigen and the major histocompatibility complex is accomplished by a single heterodimeric antigen-receptor structure, composed of either alpha-beta (RECEPTORS, ANTIGEN, T-CELL, ALPHA-BETA) or gamma-delta (RECEPTORS, ANTIGEN, T-CELL, GAMMA-DELTA) chains.
Antibodies produced by a single clone of cells.
A species of parasitic EUKARYOTES that attaches itself to the intestinal mucosa and feeds on mucous secretions. The organism is roughly pear-shaped and motility is somewhat erratic, with a slow oscillation about the long axis.
The agent of South American trypanosomiasis or CHAGAS DISEASE. Its vertebrate hosts are man and various domestic and wild animals. Insects of several species are vectors.
A group of antigens that includes both the major and minor histocompatibility antigens. The former are genetically determined by the major histocompatibility complex. They determine tissue type for transplantation and cause allograft rejections. The latter are systems of allelic alloantigens that can cause weak transplant rejection.
Nuclear antigen with a role in DNA synthesis, DNA repair, and cell cycle progression. PCNA is required for the coordinated synthesis of both leading and lagging strands at the replication fork during DNA replication. PCNA expression correlates with the proliferation activity of several malignant and non-malignant cell types.
A genus of flagellate protozoa comprising several species that are pathogenic for humans. Organisms of this genus have an amastigote and a promastigote stage in their life cycles. As a result of enzymatic studies this single genus has been divided into two subgenera: Leishmania leishmania and Leishmania viannia. Species within the Leishmania leishmania subgenus include: L. aethiopica, L. arabica, L. donovani, L. enrietti, L. gerbilli, L. hertigi, L. infantum, L. major, L. mexicana, and L. tropica. The following species are those that compose the Leishmania viannia subgenus: L. braziliensis, L. guyanensis, L. lainsoni, L. naiffi, and L. shawi.
Sites on an antigen that interact with specific antibodies.
Large, transmembrane, non-covalently linked glycoproteins (alpha and beta). Both chains can be polymorphic although there is more structural variation in the beta chains. The class II antigens in humans are called HLA-D ANTIGENS and are coded by a gene on chromosome 6. In mice, two genes named IA and IE on chromosome 17 code for the H-2 antigens. The antigens are found on B-lymphocytes, macrophages, epidermal cells, and sperm and are thought to mediate the competence of and cellular cooperation in the immune response. The term IA antigens used to refer only to the proteins encoded by the IA genes in the mouse, but is now used as a generic term for any class II histocompatibility antigen.
A glycoprotein that is a kallikrein-like serine proteinase and an esterase, produced by epithelial cells of both normal and malignant prostate tissue. It is an important marker for the diagnosis of prostate cancer.
The lipopolysaccharide-protein somatic antigens, usually from gram-negative bacteria, important in the serological classification of enteric bacilli. The O-specific chains determine the specificity of the O antigens of a given serotype. O antigens are the immunodominant part of the lipopolysaccharide molecule in the intact bacterial cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
IMMUNOGLOBULINS on the surface of B-LYMPHOCYTES. Their MESSENGER RNA contains an EXON with a membrane spanning sequence, producing immunoglobulins in the form of type I transmembrane proteins as opposed to secreted immunoglobulins (ANTIBODIES) which do not contain the membrane spanning segment.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Immunoglobulins produced in a response to PROTOZOAN ANTIGENS.
Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.
A trisaccharide antigen expressed on glycolipids and many cell-surface glycoproteins. In the blood the antigen is found on the surface of NEUTROPHILS; EOSINOPHILS; and MONOCYTES. In addition, CD15 antigen is a stage-specific embryonic antigen.
A genus of protozoa parasitic to birds and mammals. T. gondii is one of the most common infectious pathogenic animal parasites of man.
Carbohydrate antigens expressed by malignant tissue. They are useful as tumor markers and are measured in the serum by means of a radioimmunoassay employing monoclonal antibodies.
A group of three related eukaryotic phyla whose members possess an alveolar membrane system, consisting of flattened membrane-bound sacs lying beneath the outer cell membrane.
A phylum of unicellular parasitic EUKARYOTES characterized by the presence of complex apical organelles generally consisting of a conoid that aids in penetrating host cells, rhoptries that possibly secrete a proteolytic enzyme, and subpellicular microtubules that may be related to motility.
A genus of flagellate protozoans found in the blood and lymph of vertebrates and invertebrates, both hosts being required to complete the life cycle.
Substances that are destructive to protozoans.
An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.
A species of ciliate protozoa used extensively in genetic research.
A specific HLA-A surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-A*02 allele family.
A hemoflagellate subspecies of parasitic protozoa that causes nagana in domestic and game animals in Africa. It apparently does not infect humans. It is transmitted by bites of tsetse flies (Glossina).
Differentiation antigens found on thymocytes and on cytotoxic and suppressor T-lymphocytes. CD8 antigens are members of the immunoglobulin supergene family and are associative recognition elements in MHC (Major Histocompatibility Complex) Class I-restricted interactions.
The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.
An order of flagellate protozoa. Characteristics include the presence of one or two flagella arising from a depression in the cell body and a single mitochondrion that extends the length of the body.
Serological reactions in which an antiserum against one antigen reacts with a non-identical but closely related antigen.
Infections of the INTESTINES with PARASITES, commonly involving PARASITIC WORMS. Infections with roundworms (NEMATODE INFECTIONS) and tapeworms (CESTODE INFECTIONS) are also known as HELMINTHIASIS.
Suspensions of attenuated or killed protozoa administered for the prevention or treatment of infectious protozoan disease.
Sets of cell surface antigens located on BLOOD CELLS. They are usually membrane GLYCOPROTEINS or GLYCOLIPIDS that are antigenically distinguished by their carbohydrate moieties.
Those hepatitis B antigens found on the surface of the Dane particle and on the 20 nm spherical and tubular particles. Several subspecificities of the surface antigen are known. These were formerly called the Australia antigen.
Complex of at least five membrane-bound polypeptides in mature T-lymphocytes that are non-covalently associated with one another and with the T-cell receptor (RECEPTORS, ANTIGEN, T-CELL). The CD3 complex includes the gamma, delta, epsilon, zeta, and eta chains (subunits). When antigen binds to the T-cell receptor, the CD3 complex transduces the activating signals to the cytoplasm of the T-cell. The CD3 gamma and delta chains (subunits) are separate from and not related to the gamma/delta chains of the T-cell receptor (RECEPTORS, ANTIGEN, T-CELL, GAMMA-DELTA).
A suborder of monoflagellate parasitic protozoa that lives in the blood and tissues of man and animals. Representative genera include: Blastocrithidia, Leptomonas, CRITHIDIA, Herpetomonas, LEISHMANIA, Phytomonas, and TRYPANOSOMA. Species of this suborder may exist in two or more morphologic stages formerly named after genera exemplifying these forms - amastigote (LEISHMANIA), choanomastigote (CRITHIDIA), promastigote (Leptomonas), opisthomastigote (Herpetomonas), epimastigote (Blastocrithidia), and trypomastigote (TRYPANOSOMA).
Polymorphic class I human histocompatibility (HLA) surface antigens present on almost all nucleated cells. At least 20 antigens have been identified which are encoded by the A locus of multiple alleles on chromosome 6. They serve as targets for T-cell cytolytic responses and are involved with acceptance or rejection of tissue/organ grafts.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.
Morphologic alteration of small B LYMPHOCYTES or T LYMPHOCYTES in culture into large blast-like cells able to synthesize DNA and RNA and to divide mitotically. It is induced by INTERLEUKINS; MITOGENS such as PHYTOHEMAGGLUTININS, and by specific ANTIGENS. It may also occur in vivo as in GRAFT REJECTION.
A genus of parasitic flagellate EUKARYOTES distinguished by the presence of four anterior flagella, an undulating membrane, and a trailing flagellum.
A parasitic hemoflagellate of the subgenus Leishmania leishmania that infects man and animals and causes cutaneous leishmaniasis (LEISHMANIASIS, CUTANEOUS) of the Old World. Transmission is by Phlebotomus sandflies.
Membrane glycoproteins consisting of an alpha subunit and a BETA 2-MICROGLOBULIN beta subunit. In humans, highly polymorphic genes on CHROMOSOME 6 encode the alpha subunits of class I antigens and play an important role in determining the serological specificity of the surface antigen. Class I antigens are found on most nucleated cells and are generally detected by their reactivity with alloantisera. These antigens are recognized during GRAFT REJECTION and restrict cell-mediated lysis of virus-infected cells.
Invertebrate organisms that live on or in another organism (the host), and benefit at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.
The property of antibodies which enables them to react with some ANTIGENIC DETERMINANTS and not with others. Specificity is dependent on chemical composition, physical forces, and molecular structure at the binding site.
A genus of free-living amoebae found in fresh water. The cysts usually pass harmlessly through the intestinal tract of man and may thus be found in feces. Occasionally, these organisms cause respiratory tract infections or generalized fatal meningoencephalitis.
Human immune-response or Class II antigens found mainly, but not exclusively, on B-lymphocytes and produced from genes of the HLA-D locus. They are extremely polymorphic families of glycopeptides, each consisting of two chains, alpha and beta. This group of antigens includes the -DR, -DQ and -DP designations, of which HLA-DR is most studied; some of these glycoproteins are associated with certain diseases, possibly of immune etiology.
A genus of ameboid protozoa characterized by the presence of beaded chromatin on the inner surface of the nuclear membrane. Its organisms are parasitic in invertebrates and vertebrates, including humans.
Molecules on the surface of B- and T-lymphocytes that recognize and combine with specific antigens.
A genus of parasitic protozoans found in the digestive tract of invertebrates, especially insects. Organisms of this genus have an amastigote and choanomastigote stage in their life cycle.
High-molecular weight glycoproteins uniquely expressed on the surface of LEUKOCYTES and their hemopoietic progenitors. They contain a cytoplasmic protein tyrosine phosphatase activity which plays a role in intracellular signaling from the CELL SURFACE RECEPTORS. The CD45 antigens occur as multiple isoforms that result from alternative mRNA splicing and differential usage of three exons.
Established cell cultures that have the potential to propagate indefinitely.
Antigens of the virion of the HEPATITIS B VIRUS or the Dane particle, its surface (HEPATITIS B SURFACE ANTIGENS), core (HEPATITIS B CORE ANTIGENS), and other associated antigens, including the HEPATITIS B E ANTIGENS.
The first stomach of ruminants. It lies on the left side of the body, occupying the whole of the left side of the abdomen and even stretching across the median plane of the body to the right side. It is capacious, divided into an upper and a lower sac, each of which has a blind sac at its posterior extremity. The rumen is lined by mucous membrane containing no digestive glands, but mucus-secreting glands are present in large numbers. Coarse, partially chewed food is stored and churned in the rumen until the animal finds circumstances convenient for rumination. When this occurs, little balls of food are regurgitated through the esophagus into the mouth, and are subjected to a second more thorough mastication, swallowed, and passed on into other parts of the compound stomach. (From Black's Veterinary Dictionary, 17th ed)
A species of TRICHOMONAS that produces a refractory vaginal discharge in females, as well as bladder and urethral infections in males.
55-kDa antigens found on HELPER-INDUCER T-LYMPHOCYTES and on a variety of other immune cell types. CD4 antigens are members of the immunoglobulin supergene family and are implicated as associative recognition elements in MAJOR HISTOCOMPATIBILITY COMPLEX class II-restricted immune responses. On T-lymphocytes they define the helper/inducer subset. CD4 antigens also serve as INTERLEUKIN-15 receptors and bind to the HIV receptors, binding directly to the HIV ENVELOPE PROTEIN GP120.
Serum that contains antibodies. It is obtained from an animal that has been immunized either by ANTIGEN injection or infection with microorganisms containing the antigen.
An infection of the SMALL INTESTINE caused by the flagellated protozoan GIARDIA LAMBLIA. It is spread via contaminated food and water and by direct person-to-person contact.
The processes triggered by interactions of ANTIBODIES with their ANTIGENS.
Glycoproteins expressed on cortical thymocytes and on some dendritic cells and B-cells. Their structure is similar to that of MHC Class I and their function has been postulated as similar also. CD1 antigens are highly specific markers for human LANGERHANS CELLS.
A parasitic hemoflagellate of the subgenus Leishmania leishmania that infects man and animals and causes visceral leishmaniasis (LEISHMANIASIS, VISCERAL). The sandfly genera Phlebotomus and Lutzomyia are the vectors.
Protozoan infection found in animals and man. It is caused by several different genera of COCCIDIA.
Immunoglobulins produced in a response to BACTERIAL ANTIGENS.
Deliberate stimulation of the host's immune response. ACTIVE IMMUNIZATION involves administration of ANTIGENS or IMMUNOLOGIC ADJUVANTS. PASSIVE IMMUNIZATION involves administration of IMMUNE SERA or LYMPHOCYTES or their extracts (e.g., transfer factor, immune RNA) or transplantation of immunocompetent cell producing tissue (thymus or bone marrow).
The production of ANTIBODIES by proliferating and differentiated B-LYMPHOCYTES under stimulation by ANTIGENS.
Class I human histocompatibility (HLA) surface antigens encoded by more than 30 detectable alleles on locus B of the HLA complex, the most polymorphic of all the HLA specificities. Several of these antigens (e.g., HLA-B27, -B7, -B8) are strongly associated with predisposition to rheumatoid and other autoimmune disorders. Like other class I HLA determinants, they are involved in the cellular immune reactivity of cytolytic T lymphocytes.
Antigens expressed primarily on the membranes of living cells during sequential stages of maturation and differentiation. As immunologic markers they have high organ and tissue specificity and are useful as probes in studies of normal cell development as well as neoplastic transformation.
Lymphoid cells concerned with humoral immunity. They are short-lived cells resembling bursa-derived lymphocytes of birds in their production of immunoglobulin upon appropriate stimulation.
The relationship between an invertebrate and another organism (the host), one of which lives at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.
A genus of free-living soil amoebae that produces no flagellate stage. Its organisms are pathogens for several infections in humans and have been found in the eye, bone, brain, and respiratory tract.
A genus of coccidian parasites of the family CRYPTOSPORIDIIDAE, found in the intestinal epithelium of many vertebrates including humans.
A melanosome-specific protein that plays a role in the expression, stability, trafficking, and processing of GP100 MELANOMA ANTIGEN, which is critical to the formation of Stage II MELANOSOMES. The protein is used as an antigen marker for MELANOMA cells.
A species of parasitic protozoa that infects humans and most domestic mammals. Its oocysts measure five microns in diameter. These organisms exhibit alternating cycles of sexual and asexual reproduction.
Antigens associated with specific proteins of the human adult T-cell immunodeficiency virus (HIV); also called HTLV-III-associated and lymphadenopathy-associated virus (LAV) antigens.
A costimulatory ligand expressed by ANTIGEN-PRESENTING CELLS that binds to CTLA-4 ANTIGEN with high specificity and to CD28 ANTIGEN with low specificity. The interaction of CD80 with CD28 ANTIGEN provides a costimulatory signal to T-LYMPHOCYTES, while its interaction with CTLA-4 ANTIGEN may play a role in inducing PERIPHERAL TOLERANCE.
The acquired form of infection by Toxoplasma gondii in animals and man.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Infection of the striated muscle of mammals by parasites of the genus SARCOCYSTIS. Disease symptoms such as vomiting, diarrhea, muscle weakness, and paralysis are produced by sarcocystin, a toxin produced by the organism.
The sum of the weight of all the atoms in a molecule.
A parasitic hemoflagellate of the subgenus Leishmania leishmania that infects man and animals including rodents. The Leishmania mexicana complex causes both cutaneous (LEISHMANIASIS, CUTANEOUS) and diffuse cutaneous leishmaniasis (LEISHMANIASIS, DIFFUSE CUTANEOUS) and includes the subspecies amazonensis, garnhami, mexicana, pifanoi, and venezuelensis. L. m. mexicana causes chiclero ulcer, a form of cutaneous leishmaniasis (LEISHMANIASIS, CUTANEOUS) in the New World. The sandfly, Lutzomyia, appears to be the vector.
An encapsulated lymphatic organ through which venous blood filters.
A supergroup (some say phylum) of ameboid EUKARYOTES, comprising ARCHAMOEBAE; LOBOSEA; and MYCETOZOA.
A protozoan parasite that is the etiologic agent of East Coast fever (THEILERIASIS). Transmission is by ticks of the Physicephalus and Hyalomma genera.
Proteins prepared by recombinant DNA technology.
Nuclear antigens encoded by VIRAL GENES found in HUMAN HERPESVIRUS 4. At least six nuclear antigens have been identified.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
Immunologic techniques based on the use of: (1) enzyme-antibody conjugates; (2) enzyme-antigen conjugates; (3) antienzyme antibody followed by its homologous enzyme; or (4) enzyme-antienzyme complexes. These are used histologically for visualizing or labeling tissue specimens.
A species of gram-negative, aerobic bacteria that is the causative agent of LEGIONNAIRES' DISEASE. It has been isolated from numerous environmental sites as well as from human lung tissue, respiratory secretions, and blood.
Differentiation antigens expressed on B-lymphocytes and B-cell precursors. They are involved in regulation of B-cell proliferation.
A genus of protozoan parasites of the subclass COCCIDIA. Various species are parasitic in the epithelial cells of the liver and intestines of man and other animals.
Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).
A species of parasitic protozoa found in the intestines of humans and other primates. It was classified as a yeast in 1912. Over the years, questions arose about this designation. In 1967, many physiological and morphological B. hominis characteristics were reported that fit a protozoan classification. Since that time, other papers have corroborated this work and the organism is now recognized as a protozoan parasite of humans causing intestinal disease with potentially disabling symptoms.
Intestinal infection with organisms of the genus CRYPTOSPORIDIUM. It occurs in both animals and humans. Symptoms include severe DIARRHEA.
A vegetative stage in the life cycle of sporozoan protozoa. It is characteristic of members of the phyla APICOMPLEXA and MICROSPORIDIA.
The major interferon produced by mitogenically or antigenically stimulated LYMPHOCYTES. It is structurally different from TYPE I INTERFERON and its major activity is immunoregulation. It has been implicated in the expression of CLASS II HISTOCOMPATIBILITY ANTIGENS in cells that do not normally produce them, leading to AUTOIMMUNE DISEASES.
Antigens stimulating the formation of, or combining with heterophile antibodies. They are cross-reacting antigens found in phylogenetically unrelated species.
Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.
Infection with the protozoan parasite TRYPANOSOMA CRUZI, a form of TRYPANOSOMIASIS endemic in Central and South America. It is named after the Brazilian physician Carlos Chagas, who discovered the parasite. Infection by the parasite (positive serologic result only) is distinguished from the clinical manifestations that develop years later, such as destruction of PARASYMPATHETIC GANGLIA; CHAGAS CARDIOMYOPATHY; and dysfunction of the ESOPHAGUS or COLON.
The hepatitis B antigen within the core of the Dane particle, the infectious hepatitis virion.
A member of the tumor necrosis factor receptor superfamily with specificity for CD40 LIGAND. It is found on mature B-LYMPHOCYTES and some EPITHELIAL CELLS, lymphoid DENDRITIC CELLS. Evidence suggests that CD40-dependent activation of B-cells is important for generation of memory B-cells within the germinal centers. Mutations of the gene for CD40 antigen result in HYPER-IGM IMMUNODEFICIENCY SYNDROME, TYPE 3. Signaling of the receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.
Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.
Technique involving the diffusion of antigen or antibody through a semisolid medium, usually agar or agarose gel, with the result being a precipitin reaction.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
Specialized cells of the hematopoietic system that have branch-like extensions. They are found throughout the lymphatic system, and in non-lymphoid tissues such as SKIN and the epithelia of the intestinal, respiratory, and reproductive tracts. They trap and process ANTIGENS, and present them to T-CELLS, thereby stimulating CELL-MEDIATED IMMUNITY. They are different from the non-hematopoietic FOLLICULAR DENDRITIC CELLS, which have a similar morphology and immune system function, but with respect to humoral immunity (ANTIBODY PRODUCTION).
Endogenous tissue constituents that have the ability to interact with AUTOANTIBODIES and cause an immune response.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
A genus of ciliate protozoa commonly used in genetic, cytological, and other research.
Commonly known as parasitic worms, this group includes the ACANTHOCEPHALA; NEMATODA; and PLATYHELMINTHS. Some authors consider certain species of LEECHES that can become temporarily parasitic as helminths.
Infection with amoebae of the genus ENTAMOEBA. Infection with E. histolytica causes DYSENTERY, AMEBIC and LIVER ABSCESS, AMEBIC.
A class of immunoglobulin bearing mu chains (IMMUNOGLOBULIN MU-CHAINS). IgM can fix COMPLEMENT. The name comes from its high molecular weight and originally being called a macroglobulin.
Infections or infestations with parasitic organisms. They are often contracted through contact with an intermediate vector, but may occur as the result of direct exposure.
A group of differentiation surface antigens, among the first to be discovered on thymocytes and T-lymphocytes. Originally identified in the mouse, they are also found in other species including humans, and are expressed on brain neurons and other cells.
Manifestations of the immune response which are mediated by antigen-sensitized T-lymphocytes via lymphokines or direct cytotoxicity. This takes place in the absence of circulating antibody or where antibody plays a subordinate role.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
A glycolipid, cross-species antigen that induces production of antisheep hemolysin. It is present on the tissue cells of many species but absent in humans. It is found in many infectious agents.
The complex formed by the binding of antigen and antibody molecules. The deposition of large antigen-antibody complexes leading to tissue damage causes IMMUNE COMPLEX DISEASES.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
A sex-specific cell surface antigen produced by the sex-determining gene of the Y chromosome in mammals. It causes syngeneic grafts from males to females to be rejected and interacts with somatic elements of the embryologic undifferentiated gonad to produce testicular organogenesis.
A species of free-living soil amoebae in the family Acanthamoebidae. It can cause ENCEPHALITIS and KERATITIS in humans.
A genus of flagellate EUKARYOTES possessing three long anterior flagella.
A heterogeneous group of immunocompetent cells that mediate the cellular immune response by processing and presenting antigens to the T-cells. Traditional antigen-presenting cells include MACROPHAGES; DENDRITIC CELLS; LANGERHANS CELLS; and B-LYMPHOCYTES. FOLLICULAR DENDRITIC CELLS are not traditional antigen-presenting cells, but because they hold antigen on their cell surface in the form of IMMUNE COMPLEXES for B-cell recognition they are considered so by some authors.
A genus of protozoa found in reptiles, birds, and mammals, including humans. This heteroxenous parasite produces muscle cysts in intermediate hosts such as domestic herbivores (cattle, sheep, pigs) and rodents. Final hosts are predators such as dogs, cats, and man.
Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)
Infection of cattle, sheep, or goats with protozoa of the genus THEILERIA. This infection results in an acute or chronic febrile condition.
Serologic tests based on inactivation of complement by the antigen-antibody complex (stage 1). Binding of free complement can be visualized by addition of a second antigen-antibody system such as red cells and appropriate red cell antibody (hemolysin) requiring complement for its completion (stage 2). Failure of the red cells to lyse indicates that a specific antigen-antibody reaction has taken place in stage 1. If red cells lyse, free complement is present indicating no antigen-antibody reaction occurred in stage 1.
A group of the D-related HLA antigens found to differ from the DR antigens in genetic locus and therefore inheritance. These antigens are polymorphic glycoproteins comprising alpha and beta chains and are found on lymphoid and other cells, often associated with certain diseases.
An albumin obtained from the white of eggs. It is a member of the serpin superfamily.
A costimulatory ligand expressed by ANTIGEN-PRESENTING CELLS that binds to CD28 ANTIGEN with high specificity and to CTLA-4 ANTIGEN with low specificity. The interaction of CD86 with CD28 ANTIGEN provides a stimulatory signal to T-LYMPHOCYTES, while its interaction with CTLA-4 ANTIGEN may play a role in inducing PERIPHERAL TOLERANCE.
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
The study of parasites and PARASITIC DISEASES.
A species of POLYOMAVIRUS originally isolated from Rhesus monkey kidney tissue. It produces malignancy in human and newborn hamster kidney cell cultures.
A parasitic hemoflagellate of the subgenus Leishmania leishmania that infects man and animals and causes visceral leishmaniasis (LEISHMANIASIS, VISCERAL). Human infections are confined almost entirely to children. This parasite is commonly seen in dogs, other Canidae, and porcupines with humans considered only an accidental host. Transmission is by Phlebotomus sandflies.
A disease caused by any of a number of species of protozoa in the genus LEISHMANIA. There are four major clinical types of this infection: cutaneous (Old and New World) (LEISHMANIASIS, CUTANEOUS), diffuse cutaneous (LEISHMANIASIS, DIFFUSE CUTANEOUS), mucocutaneous (LEISHMANIASIS, MUCOCUTANEOUS), and visceral (LEISHMANIASIS, VISCERAL).
Immunized T-lymphocytes which can directly destroy appropriate target cells. These cytotoxic lymphocytes may be generated in vitro in mixed lymphocyte cultures (MLC), in vivo during a graft-versus-host (GVH) reaction, or after immunization with an allograft, tumor cell or virally transformed or chemically modified target cell. The lytic phenomenon is sometimes referred to as cell-mediated lympholysis (CML). These CD8-positive cells are distinct from NATURAL KILLER CELLS and NATURAL KILLER T-CELLS. There are two effector phenotypes: TC1 and TC2.
The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood MONOCYTES. Main types are PERITONEAL MACROPHAGES; ALVEOLAR MACROPHAGES; HISTIOCYTES; KUPFFER CELLS of the liver; and OSTEOCLASTS. They may further differentiate within chronic inflammatory lesions to EPITHELIOID CELLS or may fuse to form FOREIGN BODY GIANT CELLS or LANGHANS GIANT CELLS. (from The Dictionary of Cell Biology, Lackie and Dow, 3rd ed.)
White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.
Constituent of the 40S subunit of eukaryotic ribosomes. 18S rRNA is involved in the initiation of polypeptide synthesis in eukaryotes.
T-cell receptors composed of CD3-associated alpha and beta polypeptide chains and expressed primarily in CD4+ or CD8+ T-cells. Unlike immunoglobulins, the alpha-beta T-cell receptors recognize antigens only when presented in association with major histocompatibility (MHC) molecules.
A genus of protozoa that comprise the malaria parasites of mammals. Four species infect humans (although occasional infections with primate malarias may occur). These are PLASMODIUM FALCIPARUM; PLASMODIUM MALARIAE; PLASMODIUM OVALE, and PLASMODIUM VIVAX. Species causing infection in vertebrates other than man include: PLASMODIUM BERGHEI; PLASMODIUM CHABAUDI; P. vinckei, and PLASMODIUM YOELII in rodents; P. brasilianum, PLASMODIUM CYNOMOLGI; and PLASMODIUM KNOWLESI in monkeys; and PLASMODIUM GALLINACEUM in chickens.
A critical subpopulation of T-lymphocytes involved in the induction of most immunological functions. The HIV virus has selective tropism for the T4 cell which expresses the CD4 phenotypic marker, a receptor for HIV. In fact, the key element in the profound immunosuppression seen in HIV infection is the depletion of this subset of T-lymphocytes.
A species of ciliate protozoa used in genetic and cytological research.
Diagnostic procedures involving immunoglobulin reactions.
Immunoglobulins produced in response to VIRAL ANTIGENS.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
A critical subpopulation of regulatory T-lymphocytes involved in MHC Class I-restricted interactions. They include both cytotoxic T-lymphocytes (T-LYMPHOCYTES, CYTOTOXIC) and CD8+ suppressor T-lymphocytes.
A technique that combines protein electrophoresis and double immunodiffusion. In this procedure proteins are first separated by gel electrophoresis (usually agarose), then made visible by immunodiffusion of specific antibodies. A distinct elliptical precipitin arc results for each protein detectable by the antisera.
A parasitic hemoflagellate of the subgenus Leishmania leishmania that infects man and rodents. This taxonomic complex includes species which cause a disease called Oriental sore which is a form of cutaneous leishmaniasis (LEISHMANIASIS, CUTANEOUS) of the Old World.
Acquired infection of non-human animals by organisms of the genus TOXOPLASMA.
An inhibitory T CELL receptor that is closely related to CD28 ANTIGEN. It has specificity for CD80 ANTIGEN and CD86 ANTIGEN and acts as a negative regulator of peripheral T cell function. CTLA-4 antigen is believed to play role in inducing PERIPHERAL TOLERANCE.
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.
A genus of ciliate protozoa that is often large enough to be seen by the naked eye. Paramecia are commonly used in genetic, cytological, and other research.
A component of the B-cell antigen receptor that is involved in B-cell antigen receptor heavy chain transport to the PLASMA MEMBRANE. It is expressed almost exclusively in B-LYMPHOCYTES and serves as a useful marker for B-cell NEOPLASMS.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
The phenomenon of target cell destruction by immunologically active effector cells. It may be brought about directly by sensitized T-lymphocytes or by lymphoid or myeloid "killer" cells, or it may be mediated by cytotoxic antibody, cytotoxic factor released by lymphoid cells, or complement.
Infections with protozoa of the phylum CILIOPHORA.
Sialylated Lewis blood group carbohydrate antigen found in many adenocarcinomas of the digestive tract, especially pancreatic tumors.
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.
Elements of limited time intervals, contributing to particular results or situations.
The specific failure of a normally responsive individual to make an immune response to a known antigen. It results from previous contact with the antigen by an immunologically immature individual (fetus or neonate) or by an adult exposed to extreme high-dose or low-dose antigen, or by exposure to radiation, antimetabolites, antilymphocytic serum, etc.
The relationships of groups of organisms as reflected by their genetic makeup.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
Sensitive tests to measure certain antigens, antibodies, or viruses, using their ability to agglutinate certain erythrocytes. (From Stedman, 26th ed)
A melanosome-associated protein that plays a role in the maturation of the MELANOSOME.
A genus of protozoan parasites of the subclass COCCIDIA. Its species are parasitic in dogs, cattle, goats, and sheep, among others. N. caninum, a species that mainly infects dogs, is intracellular in neural and other cells of the body, multiplies by endodyogeny, has no parasitophorous vacuole, and has numerous rhoptries. It is known to cause lesions in many tissues, especially the brain and spinal cord as well as abortion in the expectant mother.
Proteins found in any species of bacterium.
Glycoproteins found on the membrane or surface of cells.
A group of dominantly and independently inherited antigens associated with the ABO blood factors. They are glycolipids present in plasma and secretions that may adhere to the erythrocytes. The phenotype Le(b) is the result of the interaction of the Le gene Le(a) with the genes for the ABO blood groups.
A species of monogenetic, parasitic protozoa usually found in insects.
A CELL CYCLE and tumor growth marker which can be readily detected using IMMUNOCYTOCHEMISTRY methods. Ki-67 is a nuclear antigen present only in the nuclei of cycling cells.
Immunoglobulins produced in a response to HELMINTH ANTIGENS.
Infestation with parasitic worms of the helminth class.
Antigens which may directly stimulate B lymphocytes without the cooperation of T lymphocytes.
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
Glycoprotein members of the immunoglobulin superfamily which participate in T-cell adhesion and activation. They are expressed on most peripheral T-lymphocytes, natural killer cells, and thymocytes, and function as co-receptors or accessory molecules in the T-cell receptor complex.

Cryptosporidium parvum sporozoite pellicle antigen recognized by a neutralizing monoclonal antibody is a beta-mannosylated glycolipid. (1/3739)

The protozoan parasite Cryptosporidium parvum is an important cause of diarrhea in humans, calves, and other mammals worldwide. No approved vaccines or parasite-specific drugs are currently available for the control of cryptosporidiosis. To effectively immunize against C. parvum, identification and characterization of protective antigens are required. We previously identified CPS-500, a conserved, neutralization-sensitive antigen of C. parvum sporozoites and merozoites defined by monoclonal antibody 18.44. In the present study, the biochemical characteristics and subcellular location of CPS-500 were determined. CPS-500 was chloroform extractable and eluted with acetone and methanol in silicic acid chromatography, consistent with being a polar glycolipid. Following chloroform extraction and silicic acid chromatography, CPS-500 was isolated by high-pressure liquid chromatography for glycosyl analysis, which indicated the presence of mannose and inositol. To identify which component of CPS-500 comprised the neutralization-sensitive epitope recognized by 18.44, the ability of the monoclonal antibody to bind CPS-500 treated with proteases, or with alpha- or beta-glycosidases, was determined. Monoclonal antibody 18.44 did not bind antigen treated with beta-D-mannosidase but did bind antigen treated with alpha-D-mannosidase, other alpha- or beta-glycosidases, or a panel of proteases. These data indicated that the target epitope was dependent on terminal beta-D-mannopyranosyl residues. By immunoelectron microscopy, 18.44 binding was localized to the pellicle and an intracytoplasmic tubulovesicular network in sporozoites. Monoclonal antibody 18.44 also bound to antigen deposited and released onto substrate over the course travelled by gliding sporozoites and merozoites. Surface localization, adhesion and release during locomotion, and neutralization sensitivity suggest that CPS-500 may be involved in motility and invasion processes of the infective zoite stages.  (+info)

Immunoglobulin subclass distribution and diagnostic value of Leishmania donovani antigen-specific immunoglobulin G3 in Indian kala-azar patients. (2/3739)

Visceral leishmaniasis, or kala-azar, a fatal tropical disease, remains problematic, as early diagnosis is difficult and treatment often results in drug resistance and relapse. We have developed a sensitive enzyme-linked immunosorbent assay (ELISA), using leishmanial membrane antigenic extracts (LAg) to detect specific antibody responses in 25 untreated Indian visceral leishmaniasis patients. To investigate the pathogenetic significance of isotype markers in kala-azar, relative levels of specific immunoglobulin G (IgG), IgM, IgA, IgE, and IgG subclasses were analyzed under clinically established diseased conditions. Since LAg showed higher sensitivity for specific IgG than lysate, the immunoglobulin isotype responses were evaluated, with LAg as antigen. Compared to 60 controls, which included patients with malaria, tuberculosis, leprosy, and typhoid and healthy subjects, visceral leishmaniasis patients showed significantly higher IgG (100% sensitivity, 85% specificity), IgM (48% sensitivity, 100% specificity), and IgE (44% sensitivity, 98.3% specificity) responses. Low levels of IgA in visceral leishmaniasis patients contrasted with a 13-fold-higher reactivity in sera from patients with leprosy. Among IgG subclasses, IgG1, -3, and -4 responses were significantly higher in visceral leishmaniasis patients than in the controls. IgG2 response, however, was significantly higher (twofold) in leprosy than even visceral leishmaniasis patients. The rank orders for sensitivity (IgG = IgG1 = IgG3 = IgG4 > IgG2 > IgM > IgE > IgA) and specificity (IgM = IgG3 > IgE > IgG4 > IgG2 > IgG > IgG1 > IgA) for LAg-specific antibody responses suggest the potentiality of IgG3 as a diagnostic marker for visceral leishmaniasis.  (+info)

Cytokine profile induced by Cryptosporidium antigen in peripheral blood mononuclear cells from immunocompetent and immunosuppressed persons with cryptosporidiosis. (3/3739)

The proliferative response of peripheral blood mononuclear cells (PBMC) to a crude extract from Cryptosporidium parvum (CCE) was studied in persons who acquired cryptosporidiosis in the same outbreak (15 immunocompetent subjects with prior cryptosporidiosis and 22 human immunodeficiency virus [HIV]-positive persons with various levels of immunosuppression and active cryptosporidiosis) and in individual patients (8 HIV-positive patients with active cryptosporidiosis and 15 HIV-positive persons without history of cryptosporidiosis). PBMC from HIV-positive persons showed less proliferation to CCE and mitogens than did PBMC from immunocompetent subjects with prior cryptosporidiosis, independent of CD4 cell count. In immunocompetent subjects, cytokine gene expression was consistent with cytokine production, whereas in HIV-positive subjects it was not. The production of interferon-gamma in CCE-stimulated PBMC from both immunocompetent and HIV-positive subjects with cryptosporidiosis and the lack of interferon-gamma in CCE-stimulated PBMC from HIV-positive subjects without cryptosporidiosis indicate that C. parvum mainly induces a Th1 response.  (+info)

HLA class II factors associated with Plasmodium falciparum merozoite surface antigen allele families. (4/3739)

In Plasmodium falciparum malaria, certain human leukocyte antigens (HLA) and the parasite's merozoite surface antigens 1 and 2 (MSA-1, MSA-2) have been shown to influence the course of the infection. This report is on associations of distinct HLA factors with the occurrence of particular MSA families in a group of patients with either severe or mild P. falciparum malaria in Gabon. Different distributions of HLA-DPB1 alleles were found in the 2 groups. DR *04 alleles were observed more frequently among patients with severe malaria. Several alleles of different loci were associated with distinct MSA allele families. In addition, carriers of the amino acid methionine at position 11 of the DPA1 allele were more often infected by MSA-1 K1 parasites and less frequently by MSA-1 RO33 parasites. Furthermore, associations of HLA factors with polyclonal infections were found.  (+info)

Susceptibility to infectious diseases: Leishmania as a paradigm. (5/3739)

The diverse response of individuals within populations to infectious pathogens remains poorly understood, although genetic determinants undoubtedly contribute in substantial ways to the outcome of infection. In a mouse model of infection with the intramacrophage protozoan Leishmania major, susceptibility correlates both with aberrant helper T cell differentiation biased towards the production of interleukin 4 and with the presence of an endogenous CD4 T cell repertoire that recognizes an immunodominant parasite antigen with high frequency. In the setting of the particular ecological niche occupied by Leishmania, this combination of otherwise unrelated factors synergizes to result in exquisite susceptibility to this single pathogen, without seemingly compromising host defenses against other agents. Similar paradigms could underlie susceptibility to other pathogenic organisms.  (+info)

Immunization of mice with DNA-based Pfs25 elicits potent malaria transmission-blocking antibodies. (6/3739)

Immunological intervention, in addition to vector control and malaria chemotherapy, will be needed to stop the resurgence of malaria, a disease with a devastating impact on the health of 300 to 500 million people annually. We have pursued a vaccination strategy, based on DNA immunization in mice with genes encoding two antigens present on the sexual stages of Plasmodium falciparum, Pfs25 and Pfg27, to induce biologically important antibodies that can block development of the parasite in the Anopheles mosquito and thus transmission of the disease. DNA encoding Pfs25 when administered by the intramuscular route, either alone or with DNA encoding Pfg27, had the most potent transmission-blocking effects, resulting in up to a 97% decrease in oocyst numbers in mosquito midguts and a 75% decrease in rate of infection. Immunization with DNA encoding a Pfg27-Pfs25 fusion protein was less effective and DNA encoding Pfg27 elicited antibodies in sera that had only modest effects on the infectivity of the parasite. These results show for the first time that DNA vaccination can result in potent transmission-blocking antibodies in mice and suggest that the Pfs25 gene should be included as part of a multicomponent DNA vaccine.  (+info)

Antibodies reactive with the N-terminal domain of Plasmodium falciparum serine repeat antigen inhibit cell proliferation by agglutinating merozoites and schizonts. (7/3739)

The serine repeat antigen (SERA) is a vaccine candidate antigen of Plasmodium falciparum. Immunization of mice with Escherichia coli-produced recombinant protein of the SERA N-terminal domain (SE47') induced an antiserum that was inhibitory to parasite growth in vitro. Affinity-purified mouse antibodies specific to the recombinant protein inhibited parasite growth between the schizont and ring stages but not between the ring and schizont stages. When Percoll-purified schizonts were cultured with the affinity-purified SE47'-specific antibodies, schizonts and merozoites were agglutinated. Indirect-immunofluorescence assays with unfixed parasite cells showed that SE47'-specific immunoglobulin G (IgG) bound to SERA molecules on rupturing schizonts and merozoites but the IgG did not react with the schizont-infected erythrocytes (RBC). Furthermore, double-fluorescence staining against SE47'-specific IgG and anti-human RBC membrane IgG showed that the RBC membrane disappeared from SE47'-specific-IgG-bound schizonts after cultivation. These observations suggest that the SE47'-specific antibodies inhibit parasite growth by cross-linking SERA molecules that are associated with merozoites in rupturing schizonts with partly broken RBC and parasitophorous vacuole membranes, blocking merozoite release.  (+info)

Role of gamma interferon in cellular immune response against murine Encephalitozoon cuniculi infection. (8/3739)

Microsporidia are obligate intracellular protozoan parasites that cause a wide variety of opportunistic infection in patients with AIDS. Because it is able to grow in vitro, Encephalitozoon cuniculi is currently the best-studied microsporidian. T cells mediate protective immunity against this parasite. Splenocytes obtained from infected mice proliferate in vitro in response to irradiated parasites. A transient state of hyporesponsiveness to parasite antigen and mitogen was observed at day 17 postinfection. This downregulatory response could be partially reversed by addition of nitric oxide (NO) antagonist to the culture. Mice infected with E. cuniculi secrete significant levels of gamma interferon (IFN-gamma). Treatment with antibody to IFN-gamma or interleukin-2 (IL-12) was able to neutralize the resistance to the parasite. Mutant animals lacking the IFN-gamma or IL-12 gene were highly susceptible to infection. However, mice unable to secrete NO withstood high doses of parasite challenge, similar to normal wild-type animals. These studies describe an IFN-gamma-mediated protection against E. cuniculi infection that is independent of NO production.  (+info)

Protective devices against vectors are used by travelers in malaria-endemic areas but their efficacy for protection against mosquitoes has rarely been evaluated. The level of exposure to malaria transmission of 205 soldiers deployed in Africa and the efficacy of their anti-vector prophylaxis was evaluated by comparison of their IgM and IgG responses against five pre-erythrocytic Plasmodium falciparum antigens (circumsporozoite protein, sporozoite threonine- and asparagine-rich protein, sporozoite- and liver-stage antigen, liver stage antigen 1, and SR11.1) before and at the end of their deployment, and three months after returning to France for 106 of these soldiers. The immune responses increased significantly during the mission in 35% (95% confidence interval = 28-42%) of the individuals. The permanent use of insecticide-treated bed nets and long-sleeve battle dress at night were associated with protective efficacy. The analysis of these antibody responses was sensitive enough to evaluate exposure to
Kaj je zdravilo HBVaxPro in za kaj ga uporabljamo. Kako jemati zdravilo HBVaxPro. Možni neželeni učinki. Hepatitis B, recombinant surface antigen - J07BC01 - MSD VACCINS - Navodilo za uporabo
Complete information for CHORDC1 gene (Protein Coding), Cysteine And Histidine Rich Domain Containing 1, including: function, proteins, disorders, pathways, orthologs, and expression. GeneCards - The Human Gene Compendium
A very interesting reference you might check is: Hale, JE and Beidler, DE, Anal. Biochem. 222, 29-33(1994). They describe the use of chelated metals (particularly Cobalt and Nickel) as Metal Affinity materials to select histidine rich sequences. Note that the system is also potentially reversible. Lot easier to make than an antibody! BTW, note that they use these chelated materials to pull out MAbs which have a high-histidine sequence near the carboxy terminus of the haevy chain. This paper should give you a number of leads. Jerry corey at MED.PITT.EDU (Seth Corey) wrote: ,this may be rehashed - but are their Ab , which blot and ip poly-his-tagged proteins? ,thanks ,Seth Corey ,p.s. where can one get myc-tagged and ha-tagged vectors? ...
Although Plasmodium falciparum apical membrane antigen 1 (AMA1) is a leading malaria vaccine candidate, extensive allelic diversity may compromise its vaccine potential. We have previously shown that naturally acquired antibodies to AMA1 were associated with protection from clinical malaria in this Kenyan population. To assess the impact of allelic diversity on naturally acquired immunity, we first sequenced the ectodomain-encoding region of P. falciparum ama1 from subjects with asymptomatic, mild, and severe malaria and measured allele frequency distributions. We then measured antibodies to three allelic AMA1 proteins (AMA1_3D7, AMA1_FVO, and AMA1_HB3) and used competition enzyme-linked immunosorbent assays (ELISAs) to analyze allele-specific antibodies. Seventy-eight unique haplotypes were identified from 129 alleles sampled. No clustering of allelic haplotypes with disease severity or year of sampling was observed. Differences in nucleotide frequencies in clinical (severe plus mild malaria) versus
The surface-accessible ectodomain region of the Plasmodium falciparum apical membrane antigen 1 (AMA1) is a malaria vaccine candidate. The amino acid sequence may be under selection from naturally acquired immune responses, and previous analyses with a small number of allele sequences indicate a non-neutral pattern of nucleotide variation. To investigate whether there is selection to maintain polymorphism within a population, and to identify the parts of the ectodomain under strongest selection, a sample of 51 alleles from a single endemic population was studied. Analyses using Fu and Lis D and F tests, Tajimas D test, and the McDonald-Kreitman test (with the chimpanzee parasite P. reichenowi as outgroup) show significant departure from neutrality and indicate the selective maintenance of alleles within the population. There is also evidence of a very high recombination rate throughout the sequence, as estimated by the recombination parameter, C, and by the rapid decline in linkage disequilibrium with
Abstract We have investigated seroreactivity against Plasmodium falciparum crude parasite antigens, the P. falciparum ring-infected erythrocyte surface antigen (Pf155/RESA), as well as against two synthetic peptides (EENV)6 and (EENVEHDA)3 that represent important epitopes of Pf155/RESA. The study population consisted of 421 children and adult Thais living in an area with moderate malaria transmission. We related these serologic findings to some important epidemiologic baseline data collected in the study area. The parasite rate in study subjects was 18.76%. Sixty-two percent were seropositive to crude P. falciparum antigens, 30.3% to the Pf155/RESA antigen, 23.05% to (EENV)6, and 20.17% to (EENVEHDA)3. Antibody responses to crude P. falciparum antigens and to Pf155/RESA were age dependent and increased with exposure. There was evidence that Pf155/RESA antibodies might play a role in protective immunity in this population. Since Pf155/RESA is a potential vaccine candidate antigen, the information
Plasmodium falciparum gametocytes contain specific antigens, some of which (Mr 230,000, 48,000, 45,000) are expressed on the surface of the newly emerged macrogamete. A different antigen (Mr 25,000) surrounds the surface of the ookinete and, although present to some extent in the developing gametocyte, is synthesized in high quantities by the macrogamete/zygote and expressed progressively on the transforming zygote surface. These antigens are targets of transmission blocking antibodies that are effective at two distinct points after gametogenesis: fertilization of the macrogamete and ookinete to oocyst development. The antigens involved in the fertilization blockade are the Mr 48 and 45 proteins, which are expressed on the macrogamete surface. The Mr 230 K coprecipitating protein probably plays no part in transmission block. mAb directed against the Mr 25 K ookinete surface protein blocked transmission without inhibiting ookinete formation, indicating that this protein has an important role in ...
Multiplex assays have been developed for detecting Abs to combinations of viral and bacterial pathogens (7, 13) and to different bacterial serotypes (8, 9). The multiplex assay described herein is to the first to measure Ab responses to P. falciparum malarial proteins, including sporozoite (CSP), liver-stage Ag (LSA-1), and asexual blood-stage Ags (MSP-142, AMA-1, EBA-175, MSP-3, and RESA) simultaneously. The assay for malaria proved to be rapid, allowing us to screen over 250 samples against the nine Ags in an afternoon. The assay also requires small amounts of Ag and minimal amounts of plasma. It has a wider dynamic range and is as sensitive as ELISA. Thus, this multiplex immunoassay is a useful new tool for research on malaria.. A major concern with multiplexing microspheres coated with different Ags is that combining Ags might result in Ab competition or blocking. In this study, no significant difference was found when antigen-coated spheres were used alone or in combination (Fig. 2). ...
Evaluation of P. falciparum antigen Pf332 as a target for parasite neutralizing immune responses. This project is based on the P. falciparum antigen Pf332, which we identified in 1989 together with Mattei et al. at the Pasteur Institute in Paris. Subsequent data on Pf332, obtained mainly by our groups by laboratory experiments and epidemiological investigations, indicate that the antigen stands out as an attractive target for vaccine development. However, the previous research on Pf332 has involved mainly a 157 amino acids long fragment (EB200) of the antigen; the complete 5506 a.a. sequence became recently available from the sequencing of the P. falciparum genome.. ...
Originally, it was thought that in utero exposure to foreign Ags resulted in immunological tolerance, but accumulating evidence now shows that exposure to small doses of microbial Ags can lead to the priming of fetal lymphocytes (12, 14, 26, 27). In developing countries, women are often infected with parasites during pregnancy and expose the developing fetus to foreign Ags. Mechanisms underlying transplacental passage of parasite Ags are unclear, but malarial, filarial, and schistosomal Ags have been detected in CB (2, 10, 26, 28).. Developing germinal centers have been detected in human neonates at birth (29) and neonatal B cells have the ability to produce IgM and different IgG subclasses in vitro (6). In the current study, malaria-specific IgM was detected in 12% of 120 CBMC cultures. Previously, Xi et al. (30) detected IgM in 14% of CB samples collected in Yaoundé and demonstrated by Western blotting that the Abs reacted with a wide range of asexual stage Ags, with each newborn having its ...
The [email protected] Centre provides a platform for research students to deposit their Ph.D. theses and make it available to the entire scholarly community in open access ...
Our results demonstrate a clear dose-response relationship between titres of antibodies to two of the pre-erythrocytic antigens, CSP and TRAP, and time to re-infection with P. falciparum. By contrast, we did not observe such a relationship between antibody titres for LSA-1 and time to re-infection. This is biologically plausible given that LSA-1 antigens are only expressed inside hepatocytes in the liver, where they are inaccessible to antibodies; the presence of these functionally redundant LSA-1 antibodies in the blood is probably owing to immune recognition of the remains of eliminated parasites. The apparent correlation between LSA-1 antibody titres and protection from infection observed in field studies [11,12] is therefore probably owing to the correlation between anti-LSA-1 titres and titres of other effective pre-erythrocytic antibodies.. Despite the importance of the infection-blocking immune response, it is unclear whether it is primarily mediated by immune responses directed against ...
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Title: RTS,S/AS01E immunization increases antibody responses to vaccine-unrelated Plasmodium falciparum antigens associated with protection against clinical malaria in African children: A case-control study  Author: Gyan, B.; Dobaño, C.; Ubillos, I.; Jairoce, C.; Vidal, M.; Jiménez, A.; Santano, R.; Dosoo, D.; Nhabomba, A.J.; Ayestaran, A.; Aguilar, R.; Williams, N.A.; Díez-Padrisa, N.; Lanar, D.; Chauhan, V.; Chitnis, C.; Dutta, S.; Gaur, D.; Angov, E.; Asante, K.P.; Owusu-Agyei, S.; Valim, C.; Gamain, B.; Coppel, R.L.; Cavanagh, D.; Beeson, J.G.; Campo, J.J.; Moncunill, G. Date: 2019-08-14 ...
A dose escalating, placebo-controlled phase 1 trial was conducted to test the safety and immunogenicity of a vaccine containing recombinant Plasmodium falciparum apical membrane antigen 1 (AMA1) formulated in Montanide ISA720. Three groups of volunteers were vaccinated intramuscularly with 5 microg, 20 microg or 80 microg of AMA1, respectively, in 0.5 mL of formulation at 0, 3 and 6 months. Anti-AMA1 antibody levels and T cell stimulation indices were measured before and after each vaccination. No vaccine-related serious adverse events were recorded. Most subjects generated a mild to moderate, transient local reaction after the first vaccination. Three subjects developed a local reaction approximately 10 days following vaccination. Six of the 29 subjects seroconverted. Only one of these developed a high antibody titre. However, the interpretation of this trial was compromised by a loss of potency of the formulated vaccine during the course of the study ...
Malaria constitutes a major health problem and is strongly associated with socioeconomic ramifications in many temperate and most tropical countries. In Myanmar, malaria is ranked as the number one public health problem, and nearly 600,000 malaria patients seek medical attention at health institutions annually. Among malaria species in Myanmar, Plasmodium falciparum accounts for approximately 80% of infections and Plasmodium vivax for 17.8% of infections, whereas the remaining infections are due to Plasmodium malariae or mixed infections [1].. The sporozoites of malaria parasites are transmitted from the saliva of infected mosquitoes and stay for a while at the site of infection or travel to the liver and invade hepatocytes, where they develop into the exoerythrocytic stage called tissue schizont. During this stage, the parasites express liver stage-specific antigens. In P. falciparum, at least two of the relevant antigens, liver stage antigen-1 (PfLSA-1) and liver stage antigen-3 (PfLSA-3), ...
Plasmodium vivax apical membrane antigen-1(PvAMA-1) is a surface protein with polymorphic sites. This study was aimed to analyze the polymorphic amino acid residues at PvAMA-1 in different infected age groups. 92 blood samples were collected from south and southeast of Iran. The DNA coding for the domain I (DI), DII, and partial ...
The clinical symptoms of malaria are attributed to the blood stage life cycle of parasite in which merozoite invades erythrocyte, undergoes multiplication and exit to re-invade into new erythrocyte to continue its life cycle. The interaction of repertoire of parasite proteins with host cell receptors is essential for invasion process. Identification, characterization and localization of the proteins involved in invasion will enrich our understanding of this complex process. In the present study we have identified a novel Apical Rhoptry Neck Protein in Plasmodium falciparum, which harbours a predicted signal and transmembrane domain and is conserved across the species. The transcription and translation analysis confirmed its expression in schizont stage of asexual cycle of P. falciparum. Immunoflouresence microscopy in schizonts and merozoites revealed its localization in the neck of rhoptries of P. falciparum. Furthermore, PfARNP has been found at the tight junction during invasion of P. ...
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Malaria antigen-induced polarization of T cells into effectors Th1 and/or Th2 cells and their subsequent release of cytokines is known to affect antibody production. This thesis includes studies on early innate responses to the parasite, with a focus on γδT cells, and acquired specific responses in African sympatric ethnic tribes. In the last part of this thesis, a method for enrichment for the asexual blood stages of P. falciparum and their use in in vitro T-cell studies is presented.. To investigate mechanisms involved in parasite growth inhibition by γδT cells, an in vitro system was set up using blood stage parasites co-cultured with differently treated γδT cells. The results showed that Vγ9/δ2+ γδT cells inhibited the in vitro growth of P. falciparum parasites whereas CD4+ and CD8+ T cells did not. This inhibition was positively correlated with the expression of cytolytic molecules in the cell lines tested. Anti-granulysin antibodies reversed γδT cell-mediated inhibition, ...
Shanghai Wanxing Bio-Pharmaceuticals is currently evaluating one malaria vaccine candidate, PfCP2.9 adjuvanted with Montanide ISA 720. This trial is designed to test the safety and immunogenicity of 3 doses and 2 vaccination schedules.. This blood stage candidate malaria vaccine is being developed for the routine immunization of infants and children living in malaria-endemic areas. ...
Principal Investigator:HIRAYAMA Kenji, Project Period (FY):1994 - 1995, Research Category:Grant-in-Aid for General Scientific Research (C), Research Field:寄生虫学(含医用動物学)
Link to Pubmed [PMID] - 8552406. Parasite Immunol. 1995 Jul;17(7):341-52. Immunogens based upon sequences from the P. falciparum asexual blood stage antigen Pf332 were assessed for their capacity to induce antibodies inhibiting parasite growth or cytoadherence of infected erythrocytes in vitro. Selection of the Pf332 sequences was based on their reactivity with the human monoclonal antibody (MoAb) 33G2 which inhibits parasite growth as well as cytoadherence in vitro. Octameric multiple antigen peptides (MAP) were assembled based upon either a trimer of the minimal epitope recognized by the MoAb, VTEEI, or a Pf332 sequence including that motif, SVTEEIAEEDK. A dimer of SVTEEIAEEDK was also expressed in Escherichia coli, genetically fused to ZZ, two IgG-binding domains of staphylococcal protein A. Rabbit antibodies elicited by the immunogens reacted with Pf332 in immunofluorescence and in ELISA with Pf332 peptides which were also recognized by MoAb 33G2. The MAP with branched (VTEEI)3 peptide ...
Immunization with the F1 domain alone resulted in isolation of antibodies that are 2-fold more neutralizing than the F2-specific MAbs at 3 mg/ml (Fig. 4). This concentration reflects the fact that laboratory strains have adapted to be less dependent on glycophorin C for invasion than field strains (43). It is anticipated that the concentration of EBA-140 MAbs required to neutralize field strains will be lower, as field strains showed a greater range of dependence on glycophorin C for invasion than laboratory-adapted strains, up to a 47% reduction of invasion for field strains in glycophorin C knockdown RBCs compared to the 0% to 10% reduction seen in laboratory strains (43). In addition to EBA-140, the merozoite antigens EBA-175 (42, 44, 45), AMA-1 (46-51), RON2 (52), and RH5 (53-56) all have demonstrated the ability to elicit antibodies that potently neutralize growth in vitro. The concentrations of EBA-140 antibodies required here for neutralization are higher than those reported for some of ...
Our results demonstrate a clear dose-response relationship between titres of antibodies to two of the pre-erythrocytic antigens, CSP and TRAP, and time to re-infection with P. falciparum. By contrast, we did not observe such a relationship between antibody titres for LSA-1 and time to re-infection. This is biologically plausible given that LSA-1 antigens are only expressed inside hepatocytes in the liver, where they are inaccessible to antibodies; the presence of these functionally redundant LSA-1 antibodies in the blood is probably owing to immune recognition of the remains of eliminated parasites. The apparent correlation between LSA-1 antibody titres and protection from infection observed in field studies [11,12] is therefore probably owing to the correlation between anti-LSA-1 titres and titres of other effective pre-erythrocytic antibodies.. Despite the importance of the infection-blocking immune response, it is unclear whether it is primarily mediated by immune responses directed against ...
New efficient vaccines against infectious diseases are in demand. Some important factors impeding the vaccine development are the poor immunogenicity and the MHC restriction of the immune responses to a number of antigens. The use of novel vaccine adjuvants or carrier proteins, which are known to enhance the immunogenicity of the subunit antigens and provide T-cell help, can circumvent these problems. The potential of heat shock proteins (HSPs) to function as adjuvants when fused to or co-delivered with protein antigens, make them attractive vaccine candidates. In this thesis we have evaluated the potency of heat shock protein 70 (HSP70) as a possible vaccine adjuvant and studied the mechanisms behind the adjuvanticity.. The first article aims to evaluate the carrier effect of glutathione-S-transferase (GST) on a malarial antigen EB200 that induces a MHC restricted response in mice. Immunization of CBA and C57BL/6 mice, high and low responders to EB200, respectively, with the GST-EB200 fusion ...
The apDia Malaria Antigen ELISA is an in vitro diagnostic immunoassay (IVD) for the qualitative determination of Plasmodium spp LDH in blood samples.
Malaria Antigen CELISA,192 Test HRP-II Enzyme Immunoassay for the presence of infection.,medicine,medical supply,medical supplies,medical product
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This story has been passed around a lot the last few days, and Ive had several people ask me what Ive thought of it. Its on a really interesting possibility
R. Chattopadhyay, J. Russell, J. M. Carlton, J. C. Aguiar, E. Bilcikova, C. E. White, P. L. Blair, W. R. Weiss, D. Haddad, A. A. Witney, E. Abot, Y. Charoenvit, D. J. Carucci
The government has allowed antigen-based rapid testing for Covid-19 at hospitals and health institutes across Bangladesh. The Ministry of Health made the
The Plasmodium falciparum Merozoite Surface Protein 1(Pf MSP1), a predominant antigen on the surface of the asexual blood stage of the parasite, plays a role in erythrocyte invasion. It elicits immune responses during exposure to natural P. falciparum infections, hence, it is a potential vaccine candidate. However, its extensive sequence diversity causes antigenic variability. Parasites that express variants other than that targeted by immune protection mounted as a result of a vaccine variant, evade the resultant host immune protection. This compromises the efficacy of allele-specific vaccines formulated to protect against a single variant. Due to this, Pf MSP1 has been extensively studied, including in Kenya. However, the extent of Pf MSP1 diversity in children with multiple infections are unknown in Kilifi which is a moderate to high malaria transmission zone. Parasite genomic DNA was extracted from 421 blood samples in 33 children aged below 5 years who had at least 9 multiple infections. ...
The roles of allelic and conserved epitopes in vaccine-induced immunity to the C-terminal 42-kDa fragment of the Plasmodium falciparum merozoite surface protein 1 (MSP1) were investigated. The C-terminal fragment of MSP1 was expressed as a baculovirus recombinant protein, BVp42. Rabbits were immunized with BVp42, and antibodies were tested for reactivity to MSP1s of the homologous and heterologous allelic forms, represented by the FUP, FVO, FC27, and Honduras parasite isolates, by enzyme-linked immunosorbent assay and indirect immunofluorescence antibody assay. Despite the fact that allelic sequences accounted for approximately 50% of the BVp42 molecule, anti-BVp42 antibodies cross-reacted extensively with parasites carrying heterologous MSP1 alleles. Enzyme-linked immunosorbent inhibition assays confirmed that an overwhelming majority of the anti-BVp42 antibodies were cross-reactive, suggesting that determinants within conserved block 17 are dominant B-cell epitopes in the anti-BVp42 response. ...
Substantial evidence indicates that antibodies to Plasmodium falciparum merozoite antigens play a role in protection from malaria, although the precise targets and mechanisms mediating immunity remain unclear. Different malaria antigens induce distinct immunoglobulin G (IgG) subclass responses, but the importance of different responses in protective immunity from malaria is not known and the factors determining subclass responses in vivo are poorly understood. We examined IgG and IgG subclass responses to the merozoite antigens MSP1-19 (the 19-kDa C-terminal region of merozoite surface protein 1), MSP2 (merozoite surface protein 2), and AMA-1 (apical membrane antigen 1), including different polymorphic variants of these antigens, in a longitudinal cohort of children in Papua New Guinea. IgG1 and IgG3 were the predominant subclasses of antibodies to each antigen, and all antibody responses increased in association with age and exposure without evidence of increasing polarization toward one ...
Many studies on the role of merozoite surface protein 3 (MSP3) in immunity against malaria have focused on a conserved section of MSP3. New evidence suggests that polymorphic sequences within MSP3 are under immune selection. We report a detailed analysis of naturally-acquired antibodies to allele-specific and conserved parts of MSP3 in a Kenyan cohort. Indirect and competition ELISA to heterologous recombinant MSP3 proteins were used for antibody assays, and parasites were genotyped for msp3 alleles. Antibody reactivity to allele-specific and conserved epitopes of MSP3 was heterogeneous between individuals. Overall, the prevalence of allele-specific antibody reactivity was significantly higher (3D7-specific 54%, K1-specific 41%) than that to a recombinant protein representing a conserved portion of C-terminal MSP3 (24%, P | 0.01). The most abundant IgG subclass was IgG3, followed by IgG1. Allele-specific reactivity to the K1-type of MSP3 was associated with a lower risk of clinical malaria episodes
Plasmodium vivax merozoite surface protein-1 paralog (PvMSP1P) is a glycosylphosphatidylinositol-anchored protein expressed on the merozoite surface. This molecule is a target of natural immunity, as high anti-MSP1P-19 antibody levels were detected during P. vivax infection and the antibody inhibited PvMSP1P-erythrocyte binding. Recombinant PvMSP1P antigen results in production of a significant Th1 cytokine response in immunized mice. The present study was performed to characterize natural cellular immunity against PvMSP1P-19 and PvDBP region II in acute and recovery P. vivax infection. Peripheral blood mononuclear cells (PBMCs) from acute and recovery P. vivax infection were obtained for lymphocyte proliferation assay upon PvMSP1P-19 and PvDBP region II antigen stimulation. The culture supernatant was examined for the presence of the cytokines IL-2, TNF, IFN-γ and IL-10 by enzyme-linked immunosorbent assay (ELISA). To determine whether Th1 or Th2 have a memory response against PvMSP1P-19 and PvDBPII
Malaria presents a considerable threat to public health. Histidine-rich protein 2 (HRP 2) is the major protein released into human blood upon infection by Plasmodium falciparum. In this study, we aimed to evaluate the immunogenicity of HRP 2 exon II and the efficacy of novel monoclonal antibodies (mAbs) against HRP 2 for Point-of-Care Test (POCT). The recombinant protein was expressed in soluble form in E. coli and used to immunize mice for mAb production. Two IgG1 mAbs (1A5 and 1C10) with high affinity, specificity and sensitivity for both native and recombinant HRP 2 were selected after fusion of mouse spleen with myeloma cells. The affinity constant of 1A5 and 1C10 were 7.15 and 4.91 × 10-7 L/mol, respectively. Subsequently, an immunochromatograhic assay was used for screening of clinical samples in endemic regions of China and Myanmar. The immunochromatographic test retrospectively showed an overall sensitivity of 99.07%, and specificity of 100%. Sensitivity at parasite densities | 200, 200-2000,
The malaria genome encodes over 5,000 proteins and many of these have also been proposed to be potential vaccine candidates, although few of these have been tested clinically. RH5 is one of the leading blood-stage Plasmodium falciparum malaria vaccine antigens and Phase I/II clinical trials of vaccines containing this antigen are currently underway. Its likely mechanism of action is to elicit antibodies that can neutralize merozoites by blocking their invasion of red blood cells (RBC). However, many other antigens could also elicit neutralizing antibodies against the merozoite, and most of these have never been compared directly to RH5. The objective of this study was to compare a range of blood-stage antigens to RH5, to identify any antigens that outperform or synergize with anti-RH5 antibodies. We selected 55 gene products, covering 15 candidate antigens that have been described in the literature and 40 genes selected on the basis of bioinformatics functional prediction. We were able to make 20
The Plasmodium genome encodes for a number of 6-Cys proteins that contain a module of six cysteine residues forming three intramolecular disulphide bonds. These proteins have been well characterized at transmission as well as hepatic stages of the parasite life cycle. In the present study, a large complex of 6-Cys proteins: Pfs41, Pfs38 and Pfs12 and three other merozoite surface proteins: Glutamate-rich protein (GLURP), SERA5 and MSP-1 were identified on the Plasmodium falciparum merozoite surface. Recombinant 6-cys proteins i.e. Pfs38, Pfs12, Pfs41 as well as PfMSP-165 were expressed and purified using Escherichia coli expression system and antibodies were raised against each of these proteins. These antibodies were used to immunoprecipitate the native proteins and their associated partners from parasite lysate. ELISA, Far western, surface plasmon resonance and glycerol density gradient fractionation were carried out to confirm the respective interactions. Furthermore, erythrocyte binding assay with 6
Plasmodium vivax Duffy binding protein (DBP) is an essential ligand for reticulocyte invasion making it a premier asexual blood stage vaccine candidate. However, strain-specific immunity due to DBPII allelic variation may complicate vaccine efficacy, suggesting that an effective DBPII vaccine needs to target immune responses to conserved epitopes that are potential targets of strain-transcending neutralizing immunity. Anti DBPII monoclonal antibodies, which were previously characterized by COS7 cell binding assay as inhibitory and non-inhibitory to DBPII-erythrocyte binding, were mapped to DBPII gene fragment libraries using phage display. Inhibitory mAb 3C9 binds to a conserved conformation-dependent epitope in subdomain 3 while non-inhibitory mAb 3D10 binds to a linear epitope in subdomain 1 of DBPII. More definitive epitope mapping of mAb 3D10 was achieved using a random peptide library displayed on phage. Since DBP region II is mostly made up of alpha-helices, we used a randomized helical scaffold
|jats:p|Ring-infected erythrocyte surface antigen (RESA)-positive,Plasmodium falciparum-negative red blood cells (RBCs) are cells from which the malaria parasite has been removed by the host without the destruction of the erythrocyte (
Abs that inhibit Plasmodium falciparum invasion of erythrocytes form an important component of human immunity against malaria, but key target Ags are largely unknown. Phenotypic variation by P. falciparum mediates the evasion of inhibitory Abs, contributing to the capacity of P. falciparum to cause repeat and chronic infections. However, Ags involved in mediating immune evasion have not been defined, and studies of the function of human Abs are limited. In this study, we used novel approaches to determine the importance of P. falciparum erythrocyte-binding Ags (EBAs), which are important invasion ligands, as targets of human invasion-inhibitory Abs and define their role in contributing to immune evasion through variation in function. We evaluated the invasion-inhibitory activity of acquired Abs from malaria-exposed children and adults from Kenya, using P. falciparum with disruption of genes encoding EBA140, EBA175, and EBA181, either individually or combined as EBA140/EBA175 or EBA175/EBA181 double
Plasmodium falciparum histidine rich protein 2 (PfHRP2) antigen was measured semi-quantitatively in whole blood, plasma, and supernatants and red blood cells of cultures in vitro using the dipstick ParaSight-F test and also by a quantitative antigen-capture enzyme-linked immunosorbent assay (ELISA). In vitro, PfHRP2 was secreted mainly during the second half of the asexual cycle with a marked rise during schizont development and rupture. The total PfHRP2 secreted before schizogony corresponded to approximately 4% of that contained in the red blood cells. In samples from 55 patients with acute falciparum malaria, the level of detection by ELISA corresponded to parasitaemias of 100/microL for whole blood and 1600/microL for separated plasma. Whole blood PfHRP2 levels were correlated significantly with admission parasitaemia (r = 0.76, P | 0.0001) and the stage of parasite development (r = 0.43, P | 0.01). Although whole blood PfHRP2 concentrations were higher in severe malaria, plasma concentrations of
Background: Cerebral malaria (CM) is one of the major causes of death in African populations infected with Plasmodium falciparum. Only 1% of infected subjects develop CM. The reasons for these differences are not fully understood, but it is likely that the host humoral response against blood-stage antigens plays a role in protection from malaria, although the precise targets and mechanisms mediating immunity remain unclear. Objective: The purpose of this study was to distinguish between defined P. falciparum- specific Ab response patterns in patients presenting with mild malaria (MM) vs. CM. Methods: We used a panel of P. falciparum conserved antigens including crude blood-stage extracts schizont, merozoite and parasitised erythrocyte membranes and MSP-1p19, PfEB200, R23 and GST-5 recombinant antigens in a retrospective casecontrol study of symptomatic adults, one group presenting confirmed CM without fatal outcome and another group with MM. We further matched P. falciparum-specific Ab responses with
We examined the hypothesis that recovery from uncomplicated malaria in patients carrying drug-resistant Plasmodium falciparum is a measure of acquired functional immunity and may therefore be associated with humoral responses to candidate vaccine antigens. Gambian children with malaria were treated with chloroquine in 28-day trials, and recovery was defined primarily as the absence of severe clinical malaria at any time and absence of parasitemia with fever after 3 days. Plasma samples from these children were assayed by enzyme-linked immunosorbent assay for immunoglobulin G (IgG) to recombinant merozoite antigens: apical membrane antigen 1 (AMA-1) and the 19-kDa C-terminal region of merozoite surface protein 1 (MSP-1(19)), including antigenic variants of MSP-1(19) with double and triple substitutions. Antigen-specific IgG was more frequent in children who recovered, particularly that for MSP-1(19) (age-adjusted odds ratios: 0.32 [95% confidence interval, 0.05, 1.87; P = 0.168] for AMA-1, 0.19 ...
We examined the hypothesis that recovery from uncomplicated malaria in patients carrying drug-resistant Plasmodium falciparum is a measure of acquired functional immunity and may therefore be associated with humoral responses to candidate vaccine antigens. Gambian children with malaria were treated with chloroquine in 28-day trials, and recovery was defined primarily as the absence of severe clinical malaria at any time and absence of parasitemia with fever after 3 days. Plasma samples from these children were assayed by enzyme-linked immunosorbent assay for immunoglobulin G (IgG) to recombinant merozoite antigens: apical membrane antigen 1 (AMA-1) and the 19-kDa C-terminal region of merozoite surface protein 1 (MSP-1(19)), including antigenic variants of MSP-1(19) with double and triple substitutions. Antigen-specific IgG was more frequent in children who recovered, particularly that for MSP-1(19) (age-adjusted odds ratios: 0.32 [95% confidence interval, 0.05, 1.87; P = 0.168] for AMA-1, 0.19 ...
Abstract Background Reported malaria cases continue to decline globally, and this has been attributed to strategic implementation of multiple malaria control tools. Gains made would however need to be sustained through continuous monitoring to ensure malaria elimination and eradication. Entomological inoculation rate (EIR) is currently the standard tool for transmission monitoring but this is not sensitive enough, especially in areas of very low transmission. Transmission estimation models based on seroconversion rates (λ) of antibodies to Plasmodium falciparum blood stage antigens are gaining relevance. Estimates of λ, which is the measure of transmission intensity, correlate with EIR but are limited by long-term persistence of antibodies to blood stage antigens. Seroprevalence of antibodies to sporozoite antigens may be better alternatives since these antigens usually have shorter immune exposure times. The aim of this study was to develop transmission estimation models based on the ...
A chimeric proteins, PfMSP-Fu24, was constructed by genetically coupling immunodominant, conserved regions of two merozoite surface proteins, the 19-kDa region C-terminal region of merozoite surface protein 1 (PfMSP-119) and an 11-kDa conserved region of merozoite surface protein 3 (PfMSP-311), to augment the immunogenicity potential of these blood-stage malaria vaccine candidates. inhibitory antibody responses and inhibited growth of parasites in the presence as well as in the absence of human monocytes. These results suggest that PfMSP-Fu24 can form a constituent of a multistage malaria vaccine. INTRODUCTION is responsible for causing over 2 million deaths annually, and 90% of these deaths are reported to occur in children under the age of 5 years. An effective vaccine represents a high-priority intervention technique that could offer long-lasting safety from the condition (1,C5). Many malaria vaccines, like the liver-stage vaccine, RTS,S/ASO1, established that its feasible to interrupt the ...
A longitudinal study on immune responses in relation to protection against clinical malaria episodes will be conducted in Apac District, Uganda. Three cohorts will be recruited: children 1 to 5 years of age (n=250), children 6 to 10 years of age (n=125) and adults 25 and above (n=125). After finger prick sampling (~300µL) and examination at enrolment, participants will be followed up for one year. Follow-up will include fortnightly active case detection and three-monthly cross-sectional surveys. Clinical malaria attacks and the associated clinical and parasitological parameters will be related to immunological profiles determined utilizing a protein microarray as a capture substratum to profile the humoral immune response against a vast number of parasite antigens.. For individuals who experience a clinical malaria attack or who are diagnosed with high density parasitaemia (≥15,000 parasites/µL) during cross-sectional surveys, a 5mL blood sample is obtained to determine the diversity of ...
Micronemes are cellular organs, or organelles, possessed by Apicomplexa protozoans that are restricted to the apical third of the protozoan body. They are surrounded by a typical unit membrane. On electron microscopy they have an electron-dense matrix due to the high protein content. They are specialized secretory organelles important for gliding motility and host cell invasion. These organelles secrete several proteins such as the Plasmodium falciparum apical membrane antigen-1, or PfAMA1, and Erythrocyte family antigen, or EBA, family proteins. These proteins specialize in binding to erythrocyte surface receptors and facilitating erythrocyte entry. Only by this initial chemical exchange can the parasite enter into the erythrocyte via actin-myosin motor complex. It has been posited that this organelle works cooperatively with its counterpart organelle, the rhoptry, which also is a secretory organelle. It is possible that, while the microneme initiates erythrocyte-binding, the rhoptry secretes ...
|ns4:p||ns4:bold|Background|/ns4:bold|: RTS,S/AS01 |ns4:sub|E|/ns4:sub|, the most advanced malaria vaccine confers partial immunity. The vaccine-induced pre-erythrocytic immunity reduces exposure to blood-stage parasites, delaying acquisition of antibodies to blood-stage antigens. However, the duration of this effect is unknown.|/ns4:p||ns4:p| |ns4:bold|Methods:|/ns4:bold| We measured, by enzyme-linked immunosorbent assay, IgG-antibodies to 4 |ns4:italic|Plasmodium falciparum |/ns4:italic|blood-stage antigens (AMA1, MSP1|ns4:sub|42|/ns4:sub|, EBA175, and MSP3) on 314 children randomized to receive RTS,S/AS01 |ns4:sub|E|/ns4:sub| or Rabies vaccine at 5 - 17 months of age in a phase 2b trial in Kenya, and thereafter participated in a 7-year study of the duration of vaccine immunity.|/ns4:p||ns4:p| |ns4:bold|Results|/ns4:bold|: Antibody levels to MSP1|ns4:sub|42|/ns4:sub|, AMA1 and EBA175 were slightly lower among the RTS,S/AS01 |ns4:sub|E|/ns4:sub| recipients, relative to the Rabies-control vaccinees,
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Antibody responses to a panel of Plasmodium falciparum malaria blood-stage antigens in relation to clinical disease outcome in Sudan.
Monoclonal antibodies with broad reactivity against antigens on the parasite that causes malaria, Plasmodium falciparum, are isolated from two subjects and are found to have an unusual insertion of an immunoglobulin-like domain from a different chromosome, illustrating a new mechanism of antibody diversification. This paper reports the isolation of monoclonal antibodies with broad reactivity against Plasmodium falciparum antigens from two subjects living in a malaria-endemic region in Kilifi, Kenya. The antibodies are unusual in that they carry large insertions of an immunoglobulin-like domain from LAIR1, an Ig superfamily inhibitory receptor encoded on chromosome 19. The antibodies bind to polymorphic surface antigens on the parasite surface; binding depends on the mutated form of the insert. These findings illustrate a novel mechanism of antibody diversification, and the existence of conserved epitopes that may be suitable candidates for the development of a malaria vaccine. Plasmodium falciparum
Five new articles published this week in PLOS Medicine ranging from malaria to HIV to cardiovascular health. Arjen Dondorp and colleagues investigate whether the plasma level of Plasmodium falciparum histidine-rich protein 2 can be ...
Trypsin treatment of Leishmania promastigote antigen has proved to be indispensible in the direct agglutination test (DAT) for the diagnosis of visceral leishmaniasis (VL) and canine visceral leishmaniasis (CVL). In the present study four antigen batches were prepared with pronase (400 micrograms/ml …
Mymetics to apply its innovative virosome vaccine technology to develop a transmission-blocking Malaria vaccine candidate Fully funded by the PATH Malaria Vaccine Initiative (MVI), the study will...
Malaria pathogenesis results from the asexual replication of Plasmodium falciparum within human red blood cells, which relies on a precisely timed cascade of
Plasmodium falciparum STEVOR protein (41-60): binds red blood cell membrane proteins to prevent invasion by Plasmodium falciparum; amino acid sequence in first source
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Among 1521 microscopically positive P. falciparum samples screened, 50 were negative by HRP2 based RDT test. Molecular testing was carried out using these 50 RDT negative samples by assuming that 1471 RDT positive samples carried pfhrp2 gene. It was found that 2.4% (36/1521) and 1.8% (27/1521) of samples were negative for pfhrp2 and pfhrp3 genes, respectively. However, the frequency of pfhrp2 deletions varied between the sites ranging from 0-25% (2.4, 95% CI; 1.6-3.3). The frequency of both pfhrp2 and pfhrp3 gene deletion varied from 0-8% (1.6, 95% CI; 1.0-2.4 ...
Pfenex receives subcontract from Leidos to develop a production process for the malaria antigen Plasmodium falciparum reticulocyte-binding homolog 5 (Rh5).
Nanoparticle vaccines enhance humoral responses to a malaria antigen by expanding Tfh cells and inducing germinal center formation ...
These results have important implications for vaccine development, suggesting that an efficacious malaria vaccine should be multivalent and targeted at a select panel of key antigens, many of which have not been previously characterized.. ...
When and how often laboratory tests are done may depend on many factors. The timing of laboratory tests may rely on the results or completion of other tests, procedures, or treatments. Lab tests may be performed immediately in an emergency, or tests may be delayed as a condition is treated or monitored. A test may be suggested or become necessary when certain signs or symptoms appear. Due to changes in the way your body naturally functions through the course of a day, lab tests may need to be performed at a certain time of day. If you have prepared for a test by changing your food or fluid intake, lab tests may be timed in accordance with those changes. Timing of tests may be based on increased and decreased levels of medications, drugs or other substances in the body. The age or gender of the person being tested may affect when and how often a lab test is required. Chronic or progressive conditions may need ongoing monitoring through the use of lab tests. Conditions that worsen and improve may ...
Behind ever art is a man, behind the man is the race and behind the race is the social and natural environment and these influences are sure to be reflected on folklore. There is an enormous amount of influence of folklore in our old and modern Bengali literature. In Bangladesh folklore activities were much accelerated when The Bangla Academy in Dhaka in 1955 to promote research work on Bengali language and literature and collected, preserved, and published folklore materials. Mohammad Sayeedur started his professional life in Bangla academy Folklore division at 1962 by the guideline of Jainul abedin, Jashim uddin and others, who builds up a lot of collection of tangible and intangible folk heritage by himself, those which are the valuable national properties of our country. But now a day, his huge collections are being destroyed for lack of authority, space and proper preservation. In this Mohammod Sayeedur Folk Heritage Museum and Research centre, where the scientists of different countries ...
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Final results from Phase III trial suggest substantial public health benefits could be provided by the RTS,S malaria vaccine candidate in endemic regions in sub-Saharan Africa; vaccine efficacy enhanced by administration of a booster dose ...
avoid getting • start getting • keep getting • begin getting • help get • go get • mean getting • come get • try get • got get • want get ...
Er der en sammenhæng mellen dårlige tænder og sygdom? Er rodbehandlede tænder farlige? Kan man blive rask af kroniske sygdomme uden at interessere sig for tændernes sundhedstilstand? Se svarene her hos Vitamindoktor
Tłumaczenie presentation w bezpłatnym Angielski-Niemiecki słowniku LANGENSCHEIDT - wraz z przykładami, synonimami i wymową.
UPDATE: We will discontinue using quotation marks to identify parts of an article, but retain the capitalization; eg, This is discussed in the Methods section (not the
UPDATE: We will discontinue using quotation marks to identify parts of an article, but retain the capitalization; eg, This is discussed in the Methods section (not the
They could therefore be used to vaccinate against viral, bacterial, protozoan, and tumor antigens. Initially, the Togaviridae ...
In protozoa[edit]. Antigenic variation is employed by a number of different protozoan parasites. Trypanosoma brucei and ... Immunity to re-infection is based on recognition of the antigens carried by the pathogen, which are "remembered" by the ... Antigenic variation or antigenic alteration refers to the mechanism by which an infectious agent such as a protozoan, bacterium ... Segments of the silent cassettes recombine with the vlsE gene, generating variants of the surface lipoprotein antigen.[7] ...
Historically the role of this antigen other than its importance as a receptor for Plasmodium protozoa has not been appreciated ... This antigen along with other blood group antigens was used to identify the Basque people as a genetically separate group.[49] ... Because the Duffy antigen is uncommon in those of Black African descent, the presence of this antigen has been used to detect ... The Fy4 antigen, originally described on Fy (a-b-) RBCs, is now thought to be a distinct, unrelated antigen and is no longer ...
As a parasitic protozoan, C. luciliae lacks the ability to biosynthetically produce purine bases and therefore needs to salvage ... The high concentration of dsDNA and the absence of human nuclear antigens in the kinetoplast provides a specific substrate for ... C. luciliae is a eukaryotic single-cell protozoan. The family Trypanosomatidae belongs to the order Kinetoplastida and is ... "Guidelines for clinical use of the antinuclear antibody test and tests for specific autoantibodies to nuclear antigens. ...
Button LL, McMaster WR (February 1988). "Molecular cloning of the major surface antigen of leishmania". The Journal of ... This membrane-bound glycoprotein is present in the promastigote of various species of Leishmania protozoans. ...
Malaria is caused by a variety of species of the Plasmodium protozoan and the virus of the antigens are always changing which ...
... s are located on the apical third of the protozoan body. They are surrounded by a typical unit membrane. On electron ... These organelles secrete several proteins such as the Plasmodium falciparum apical membrane antigen-1, or PfAMA1, and ... Erythrocyte family antigen, or EBA, family proteins. These proteins specialize in binding to erythrocyte surface receptors and ...
The structure of the immunodominant SAG1 antigen reveals a homodimeric configuration. This family of surface antigens is found ... SAG1 is found on the surface of a protozoan parasite Toxoplasma gondii. This parasite infects almost any warm-blooded ... This particular antigen contains many cysteine residues which lead to disulphide bridge formation. This domain has a sequence ... He XL, Grigg ME, Boothroyd JC, Garcia KC (2002). "Structure of the immunodominant surface antigen from the Toxoplasma gondii ...
Antigen Antigenicity Immunogen Superantigen Allergen Hapten Epitope Linear Conformational Mimotope Tumor antigen Antigen- ... Pathogens Pathogenic bacteria Viruses Fungi Protozoa Parasites Tumors Allergens Self-proteins Autoimmunity Alloimmunity Cross- ... T cells Antigen receptor - T cell receptor (TCR) Subunits - [email protected] / [email protected] / [email protected] / [email protected] Co-receptors CD8 (CD8α / CD8β) CD4 ... CD18 Macrophage-1 antigen (CR3) - Heterodimer: CD11b / CD18 Integrin alphaXbeta2 (CR4) - Heterodimer: CD11c / CD18 Very late ...
That antigen could be from any species of virus/bacteria or even human disease antigens, for example cancer antigens. Vaccines ... Viruses have been explored as a means to treat infections caused by protozoa. One such protozoa that potential virotherapy ... Chimeric antigen receptor T cell (CAR T cell) are a type of immunotherapy that makes use of viral gene editing. CAR T cell use ... Tumor antigens and danger-associated molecular patterns are also released during the lysis process which helps recruit host ...
He continued to research antibodies and antigens. In 1918 he published his book on typhoid fever, and in 1921 he became Head of ... He contributed to Agents of Disease and Host Resistance(1935) concerned with bacteria, fungi, protozoa, rickettsiae and viruses ...
The most accurate diagnosis is by qPcr DNA antigen assay, not generally available by primary care physicians in the USA: most ... Human parasites include various protozoa and worms which may infect humans that cause parasitic diseases. Human parasites are ...
The protozoan reproduces asexually, the first division is longitudinal while the succeeding ones are approximately regular and ... i-antigens, of the parasite. Fish that survive amyloodiniosis may develop at least a partial immunity. Since 1931 (year of the ... The protozoan pathogenicity is associated with the trophont attachment to host tissues; trophonts constantly twist and turn, ... In this phase, the protozoan is round and encapsulated in a cellulose wall, which becomes thicker and confers upon it an ...
An important discovery was the malaria antigen gene "apical memberane antigen 1" (AMA-1), which has potential for use in ... The research focus was on protozoan infections, especially the cause of malaria (Plasmodium falciparum), which kill over ... In 1981 he became a senior researcher, looking into how to clone malaria antigens with the goal of making a vaccine. In 1984 he ... He supervised PhD candidate Alan Cowman and together they developed improved techniques to detect antigens expressed in E. coli ...
It has been suggested that absorption of trichophyton fungal antigens can give rise to immunoglobulin E (IgE) antibody ... Possible ocular hazards result from exposure to foreign bodies, allergens, bacteria, viruses, fungi and protozoa that can be ... of the population has allergic antibodies to fungal antigens, and half of them, that is 5% of the population, would be ...
Grand Challenge #5: Solve How to Design Antigens for Effective, Protective immunity The priority areas for this challenge ... and complex pathogens such as protozoa and fungi. Dr. Hongkui Deng of Peking University in China is currently working with his ...
Disadvantages are that the urine antigen test only detects antigen of Legionella pneumophila serogroup 1 (LP1); only a culture ... or other protozoa such as Tetrahymena pyriformis. Upon inhalation, the bacteria can infect alveolar macrophages, where the ... The side chains of the cell wall carry the bases responsible for the somatic antigen specificity of these organisms. The ... Many hospitals use the Legionella urinary antigen test for initial detection when Legionella pneumonia is suspected. Some of ...
Binding of antigens to IgE already bound by the FcεRI on mast cells causes cross-linking of the bound IgE and the aggregation ... IgE is utilized during immune defense against certain protozoan parasites such as Plasmodium falciparum. IgE may have evolved ... IgE also plays a pivotal role in responses to allergens, such as: anaphylactic reactions to drugs, bee stings, and antigen ... CD23 may also allow facilitated antigen presentation, an IgE-dependent mechanism whereby B cells expressing CD23 are able to ...
However, premunition is probably much more complex than simple antibody and antigen interaction. In the case of malaria, the ... Premunity is progressive development of immunity in individuals exposed to an infective agent, mainly belonging to protozoa and ... For malaria, premunition is maintained by repeated antigen exposure from infective bites. Thus, if an individual departs from ... However, Plasmodium can change its surface antigens, so the development of an antibody repertoire that can recognize multiple ...
De Lange T, Borst P. Genomic environment of the expression-linked extra copies of genes for surface antigens of Trypanosoma ... Ouellette M, Borst P. Drug resistance and P-glycoprotein gene amplification in the protozoan parasite Leishmania. Res Microbiol ... Novel expression-linked copies of the genes for variant surface antigens in trypanosomes. Nature. 1980;284:78-80. Boothroyd JC ... Introduction of PFG electrophoresis for the separation of chromosome-sized DNA molecules of several protozoa (20) (21). The ...
Unlike other parasitic protozoa (Giardia lamblia, Entamoeba histolytica etc.), Trichomonas vaginalis exists in only one ... such as rapid antigen testing and transcription-mediated amplification, have even greater sensitivity, but are not in ... It is the most common pathogenic protozoan infection of humans in industrialized countries. Infection rates in men and women ... Trichomonas vaginalis, a parasitic protozoan, is the etiologic agent of trichomoniasis, and is a sexually transmitted infection ...
NS1 antigen test. Protozoan infection. *toxoplasmosis *Sabin-Feldman dye test. Authority control. *NDL: 00565676 ...
... is a protozoan that causes coccidiosis in poultry. It is located in the middle part of the intestine, on either ... immunization of chickens against Eimeria maxima infection with a monoclonal antibody developed against a gametocyte antigen". ...
ELISA is able to detect more specific antigens. Molecular assays such as PCR are continuing on the rise to be used but require ... Theiler found that East Coast fever was not the same as redwater, but caused by a different protozoan. Sporozoites from the ... Research is being done to create a vaccine with a mixture of many antigens from sporozoite and schizont stage to increase ... When the genome of Babesia bovis, another protozoan parasite that infects red blood cells (erythrocytes) and causes Babesiosis ...
... in which the body produces antibodies in response to exposure to an antigen. In pioneering studies, both at the laboratory ... large cells that can surround and digest foreign substances like protozoa and bacteria. He applied these insights to patient- ...
Gynatren is contraindicated in patients with a history of allergic reaction to the bacterial antigens or phenol contained in ... Specific immunofluorescence was observed on those protozoa which had been treated with anti-lactobacillus serum and anti- ... The altered immune signaling favours local processing of antigens and a rapid induction of low-affinitiy, broad-specificity IgA ... Patrolling dendritic cells exposed to killed bacterial antigens at a muscular injection site however typically do not migrate ...
They are part of the lymphatic system, and provide a site for antigens from potentially harmful bacteria or other ... Other Protozoa (e.g. Cryptosporidium parvum, Cyclospora, Microsporidia, Entamoeba histolytica) Bacterial infections ...
... antigen, b-cell MeSH D12.776.377.715.548.950.500 - antigens, cd79 MeSH D12.776.377.715.647.100 - alpha-macroglobulins See List ... protozoan MeSH D12.776.377.715.548.114.254 - antibodies, viral MeSH D12.776.377.715.548.114.254.150 - deltaretrovirus ... antigen-antibody complex MeSH D12.776.377.715.548.114.301 - antitoxins MeSH D12.776.377.715.548.114.301.138 - antivenins MeSH ... antigens, polyomavirus transforming MeSH D12.776.624.664.520.420 - papillomavirus e7 proteins MeSH D12.776.624.664.520.750 - ...
OspA antigens, shed by live Borrelia bacteria into urine, are a promising technique being studied.[117] The use of nanotrap ... The CDC does not recommend urine antigen tests, PCR tests on urine, immunofluorescent staining for cell-wall-deficient forms of ... burgdorferi sensu stricto antigens in people have been identified in Colombia,[237] and Bolivia.[citation needed] ... antibodies to Borrelia antigens indicate disease, but lower titers can be misleading, because the IgM antibodies may remain ...
... is to conjugate the antigens. Conjugation is the attachment to the antigen of another substance which also generates an immune ... A more contemporary approach for "boosting" the immune response to simpler immunogenic molecules (known as antigens) ... In the future it might be possible to artificially design antibodies to fit specific antigens, then produce them in large ... response, thus amplifying the overall response and causing a more robust immune memory to the antigen. For example, a toxoid ...
... antigen - antigen presentation - antigen-presenting cell (APC) - antineoplastic - antiprotozoal - antiretroviral drugs - ... protozoa - provirus - pruritus - pseudo-Cushing's syndrome - pseudovirion - PUBMED - pulmonary - purified protein derivative ( ... human leukocyte antigens (HLA) - human papilloma virus (HPV) - human T cell lymphotropic virus type I (HTLV-I) - human T cell ...
Alphonse Laveran got the 1907 Nobel Prize for his research on the role of protozoans as disease agents (notably, his discovery ... as an antigen, Richard F. J. Pfeiffer introduced it in the abdomen of a guinea pig already vaccinated against this disease, and ... and they deduced that it can play the role of antigen, that is if they could overcome the delicate moment of its injection, ...
Normal body cells are not recognized and attacked by NK cells because they express intact self MHC antigens. Those MHC antigens ... Intracellular protozoa. *Plasmodium malariae. *Leishmania donovani. no. no. no Extracellular protozoa. *Entamoeba histolytica ... Dendritic cells are very important in the process of antigen presentation, and serve as a link between the innate and adaptive ... rid the body of neutralised antigen-antibody complexes.. There are three different complement systems: Classical, alternative, ...
The study of microscopic organisms, such as bacteria, viruses, archaea, fungi and protozoa. This discipline includes ... of the immune system in response to specific antigens invading the body. The theory has become the widely accepted model for ... protozoan, or another microbial agent which causes disease for a host organism by invading the host's tissues.. pathology. A ... which act as a critical part of the immune response by specifically recognizing and binding to particular antigens, such as ...
Binding of antigens to IgE already bound by the FcεRI on mast cells causes cross-linking of the bound IgE and the aggregation ... IgE is utilized during immune defense against certain protozoan parasites such as Plasmodium falciparum.[6] ... FcεRI is expressed on mast cells, basophils, and the antigen-presenting dendritic cells in both mice and humans. ... IgE also plays a pivotal role in responses to allergens, such as: anaphylactic drugs, bee stings, and antigen preparations used ...
... and many West Africans lack the Duffy antigen - a protein on the surface of the red blood cell that the parasite uses to invade ... Protozoan infection: SAR and Archaeplastida (A07, B50-B54,B58, 007, 084). SAR. ...
The leverage of ciliate protozoa". Dev. Biol. (NY). 7: 229-58. PMID 1804215. doi:10.1007/978-1-4615-6823-0_11.. ... has a 10-40-fold preference for hemimethylated DNA and interacts with the proliferating cell nuclear antigen (PCNA).[51] ...
Second, adjuvants may provide physical protection to antigens which grants the antigen a prolonged delivery. This means that ... or enhance antigen-specific immune responses when used in combination with specific vaccine antigens."[2] ... In immunology, an adjuvant is a substance that potentiates and/or modulates the immune responses to an antigen to improve them. ... Spurred into action, the DC picks up the antigen and speeds to a lymph node, where it sticks tightly to a helper T cell and ...
Rotavirus antigens for parenteral delivery, such as the P2-VP8 candidate, can be expressed as virus-like particles prepared in ... baculovirus, expressed antigens, DNA vaccines, and killed virus. These novel approaches are being pursued using animal models ...
Upon detection of microbial antigens, the host systemic immune system is activated. Immune cells not only recognise pathogen- ... and protozoan infections can also lead to sepsis.[3] Common locations for the primary infection include the lungs, brain, ... Superantigens simultaneously bind major histocompatibility complex and T-cell receptors in the absence of antigen presentation ...
Kaneda Y, Tanaka T, Saw T (1990). "Effects of berberine, a plant alkaloid, on the growth of anaerobic protozoa in axenic ... Accurate diagnosis requires an antigen test or, if that is unavailable, an ova and parasite examination of stool. Multiple ... është një parazit flagellated protozoan që kolonizon dhe riprodhohet në intestine të vogla, që shkakton giardiasis. Paraziti i ...
Template:Protozoan infection navs(edit talk links history). *Template:Psych navs(edit talk links history) ({{Psychology navs ...
These tests are based upon the ability of an antibody to bind specifically to an antigen. The antigen, usually a protein or ... Several human activities have led to the emergence of zoonotic human pathogens, including viruses, bacteria, protozoa, and ... For example, "Strep throat" is often diagnosed within minutes, and is based on the appearance of antigens made by the causative ... Signal of unknowns can be compared to that of standards allowing quantitation of the target antigen. To aid in the diagnosis of ...
Complement fixation test are methods of identifying different kinds of parasites by detecting the presence of their antigens on ... Examples of protozoan parasites: *Babesia divergens. *Balantidium coli. *Besnoitia besnoiti. *Cryptosporidium parvum ...
Infectious diseases - Parasitic disease: protozoan infection: Excavata (A06-A07, B55-B57, 007, 085-086) ... 2005). "Towards an RTS,S-based, multi-stage, multi-antigen vaccine against falciparum malaria: progress at the Walter Reed Army ...
Plasmid DNA vaccines are genetically engineered to contain a gene which encodes for an antigen or a protein produced by a ... Extrachromosomal DNA is found in Apicomplexa, which is a group of protozoa. The malaria parasite (genus Plasmodium), the AIDS- ... or antigens, on the bacteria that allow it to evade the immune response of its infected host. The linear plasmids which contain ...
For example, when an antigen-presenting cell expresses an antigen on MHC class II, a CD4+ cell will aid those cells through a ... In addition, IFN-γ can activate iNOS to produce NOx free radicals to directly kill intracellular bacteria and protozoa. Th1 ... that a host antigen is foreign. As a result, the CD8+ T cells treat the host cell presenting that antigen as infected, and go ... but unprocessed antigens do not interact with T cells and are not involved in their activation. The antigens that bind to MHC ...
"Migration of antigen-presenting B cells from peripheral to mucosal lymphoid tissues may induce intestinal antigen-specific IgA ...
In O and A antigens, there are two monomers of galactose on the antigens, whereas in the B antigens there are three monomers of ... Galactofuranose occurs in bacteria, fungi and protozoa,[7] and is recognized by a putative chordate immune lectin intelectin ... Galactose is a component of the antigens present on blood cells that determine blood type within the ABO blood group system. ...
Beekeepers have high levels of antibodies (mainly IgG) reacting to the major antigen of bee venom, phospholipase A2 (PLA).[30] ... The common agents of disease that affect adult honey bees include fungi, bacteria, protozoa, viruses, parasites, and poisons. ...
Most acantharean species of protozoa[69] and some fungi in mycorrhizae[70] have naturally multinucleated cells. Other examples ... Oct1 and PIKA antigens associates with specific chromosomes early in the cell cycle". The EMBO Journal. 17 (6): 1768-78. doi: ...
High correlation with protozoa Entamoeba gingivalis and Trichomonas tenax was then established. Progress in microscopy in the ... The presence of complement and antigen-antibody complexes is evident throughout the connective and epithelial tissue. It is in ...
This anergy may be limited to leishmania antigens or extend to mitogens and other antigens as the disease progresses.[61] In ... The protozoan is in the smaller of its two forms, called an amastigote, which is round, non-motile, and only 3-7 micrometers in ... is inversely correlated with antigen specific IFN-γ secretion but leishmania antigen specific IL-10 and IFN-γ secretion are not ... Leishmania antigen stimulation of PBMC from cured patients show a mixed T helper cell and regulatory T cell response.[57] Both ...
Vital Staining for Protozoa and Related Temporary Mounting Techniques ~ Howey, 2000. *Speaking of Fixation: Part 1 and Part 2 ... Immunohistochemistry: the use of antisera to label specific antigens. *Ruthenium(II) tris(bathophenanthroline disulfonate), a ...
It can also be diagnosed by detection of antigens in blood or urine samples by ELISA or PCR. Antigens can cross-react with ... "A protozoan general infection producing pseudotubercles in the lungs and focal necrosis in the liver, spleen and lymphnodes" ... Diagnosis is best established by urine antigen testing, as blood cultures may take up to 6 weeks for diagnostic growth to occur ... and serum antigen testing often comes back with a false negative before 4 weeks of disseminated infection.[15] ...
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Immunoblot Assay Using Recombinant Antigens as a Supplemental Test To Confirm the Presence of Antibodies to Trypanosoma cruzi ... Use of MAG1 Recombinant Antigen for Diagnosis of Toxoplasma gondii Infection in Humans Lucyna Holec, Elżbieta Hiszczyńska- ... Multiplex Assay for Simultaneous Measurement of Antibodies to Multiple Plasmodium falciparum Antigens Genevieve G. Fouda, Rose ...
The protozoan parasite Trypanosoma cruzi, causative agent of Chagas disease, depends upon a cell surface-expressed trans- ... Recombination-driven generation of the largest pathogen repository of antigen variants in the protozoan Trypanosoma cruzi *D. ... Recombination-driven generation of the largest pathogen repository of antigen variants in the protozoan Trypanosoma cruzi . BMC ... The protozoan parasite Trypanosoma cruzi, causative agent of Chagas disease, depends upon a cell surface-expressed trans- ...
Antigen detection kits are available for the positive identification of these species. One such rapid antigen detection test is ... INTESTINAL PROTOZOA. Lumen-Dwelling Protozoa Flagellates:. Giardia lamblia. Dientamoeba fragilis. Chilomastix mesnili. ... This list includes representatives from many diverse protozoan groups. The majority of these protozoa are non-pathogenic ... Intestinal protozoa are transmitted by the fecal-oral route and tend to exhibit similar life cycles consisting of a cyst stage ...
... a 5mL blood sample is obtained to determine the diversity of parasite antigens in the population in relation to antigen ... Correlating Protection Against Malaria With Serum Profiles Against Plasmodium Falciparum Antigen Repertoires. The safety and ... a protein microarray as a capture substratum to profile the humoral immune response against a vast number of parasite antigens. ...
Antigens, Protozoan / genetics* * Antigens, Protozoan / immunology* * Epitopes / genetics* * Epitopes / immunology* * Genetics ...
... protozoa; or antigens specific to these microbes; rheumatoid factor; antibodies, including, but not limited to IgG, IgM, IgA ... antigens associated with autoimmune disease; allergens; tumor antigens; streptococcus Group B antigen; HIV I or HIV II antigen ... antigens associated with autoimmune disease; allergens; tumor antigens; streptococcus Group B antigen; HIV I or HIV II antigen ... carcinoembryonic antigen; streptococcus Group A antigen; viral antigens; ...
Protozoan Immunol.,Obihiro University, 畜産学部, 教授 (10003071). Co-Investigator(Kenkyū-buntansha). SATO Motoyoshi Assist.Prof.,Dept ... When animals (mice, rats and cattle) were pretreated with Toxoplasma lysate antigens(TLA), lymphokines such as IFN,MAF,MIF,TOXO ... Protozoan Immunol.,Obihiro University, 畜産学部家畜生理学講座, 助教授 (10002263) MIURA Hiroyuki Prof.,Dept. Animal Science, Obihiro ... Publications] OGAWA,R.;SATO,M.;HIROSE,T.;SUZUKI,N.: Preventive effect of Toxoplasma lysate antigen (TLA) on fatal
Characterization of the Fine Specificity of Bovine CD8 T-Cell Responses to Defined Antigens from the Protozoan Parasite ... Characterization of the Fine Specificity of Bovine CD8 T-Cell Responses to Defined Antigens from the Protozoan Parasite ... Characterization of the Fine Specificity of Bovine CD8 T-Cell Responses to Defined Antigens from the Protozoan Parasite ...
Antigens, Protozoan / analysis* * Encephalitozoon cuniculi / genetics * Encephalitozoon cuniculi / immunology * Encephalitozoon ...
The molecular basis of antigen variation. The mode of..." Nematodes "...Intestinal helminths: Epidemiology, morbidity and ... Disease, symptoms and..." Blood Protozoa "...Trypanosomiasis, Leishmaniasis, Malaria, Babesiosis, Toxoplasmosis, Pneumocystsis ... Intestinal and Luminal Protozoa "...Amebiasis (amebic dysentery, amebic hepatitis), Giardiasis (lambliasis): Epidemiology, ...
Biochemical and genetic analysis of the distinct proliferating cell nuclear antigens of Toxoplasma gondii ... Clostridium septicum Alpha-Toxin Is Active against the Parasitic Protozoan Toxoplasma gondii and Targets Members of the SAG ... Insertional mutagenesis and marker rescue in a protozoan parasite: cloning of the uracil phosphoribosyltransferase locus from ... Insertional mutagenesis and marker rescue in a protozoan parasite: cloning of the uracil phosphoribosyltransferase locus from ...
Based on morphology and immunohistochemical staining, the organism was a Sarcocystis sp.-like protozoan. Rabies antigen and ... Two plasma samples taken from live free-living wildcats showed positive ELISA reactions to feline leukemia antigen. A feline ... A Sarcocystis sp.-like Protozoan and Concurrent Canine Distemper Virus Infection Associated with Encephalitis in A Raccoon ( ... KEYWORDS: Sarcocystis sp.-like protozoan, schizonts, raccoon, Procyon lotor, necrotizing encephalitis, canine distemper virus, ...
0 (Antibodies, Protozoan); 0 (Antigens, Protozoan); 0 (Biomarkers); 0 (Epitopes); 0 (HRP-2 antigen, Plasmodium falciparum); 0 ( ... 0 (Antigens, Protozoan); 0 (Single-Domain Antibodies); EC (Fructose-Bisphosphate Aldolase). ... IgY); 0 (Immunoglobulin G); 0 (Immunoglobulins); 0 (Protozoan Proteins); 0 (Recombinant Proteins); EC (L-Lactate ...
We have compared the ability of five Plasmodium falciparum microsatellites and three antigen-coding loci to differentiate ... 0/Antigens, Protozoan; 0/Antimalarials; 0/DNA, Protozoan; 0/Genetic Markers From MEDLINE®/PubMed®, a database of the U.S. ... Antigens, Protozoan / genetics*. Antimalarials / therapeutic use. DNA, Protozoan / genetics. Drug Resistance. Endemic Diseases ... We have compared the ability of five Plasmodium falciparum microsatellites and three antigen-coding loci to differentiate ...
0 (Adjuvants, Immunologic); 0 (Antigens, Protozoan); 0 (IFNG protein, mouse); 0 (IL10 protein, mouse); 0 (Imidazoles); 0 ( ... Many factors affect oral tolerance induction; some of them related to antigen, and some related to the animal. The age of the ... Oral tolerance is defined as a state of systemic hyporesponsiveness to an antigen that has been previously administered by the ... Lifelong Maintenance of Oral Tolerance and Immunity Profiles in Mice Depends on Early Exposure to Antigen.. ...
Also, genome-mining and new antigen discovery strategies may provide new tools for a more rational search of novel vaccine ... Many studies have validated the concept of using DNA vaccines for both protection and therapy against these protozoan parasites ... Comparative efficacy of DNA vaccines encoding various Trypanosoma cruzi antigens. *G. Sanchez-Burgos, G. Mezquita-Vega, J. ... Everybody needs sphingolipids, right! Mining for new drug targets in protozoan sphingolipid biosynthesis. *John G. M. Mina, ...
Cellular variations: antibiotics and antigens. * 1953, Oct. 22. The Fascinating World of Protozoa, H.S. ... 5. Protozoa in Biological Research and Theory. * 1949, Oct. 26. Cytoplasm, environment and genes in the control Paramecium ... Biology of Protozoa, Consortium of University of Washington, and Smithsonian. * 1970, May 7. Development and inheritance of ... 1. Introduction to Discussion of HSJ and Protozoa in History of Genetics, Prof. Churchills seminar 1979, May 3-22. Seminar to ...
... defense response to protozoan, negative regulation of cell population proliferation, negative regulation of myeloid dendritic ... Leukocyte antigen CD37Add BLAST. 281. Amino acid modifications. Feature key. Position(s). DescriptionActions. Graphical view. ... defense response to protozoan Source: MGI ,p>Inferred from Genetic Interaction,/p> ,p>Used to describe "traditional" genetic ... sp,Q61470,CD37_MOUSE Leukocyte antigen CD37 OS=Mus musculus OX=10090 GN=Cd37 PE=1 SV=1 ...
... the protozoan parasite, Leishmania major (6); and the nematode parasite Schistosoma mansoni (7). With several of these ... The effect of antigen dose on CD4+ T helper cell phenotype development in a T cell receptor-αβ-transgenic model. J. Exp. Med. ... Antigen-primed T cells from B cell-deficient JHD mice fail to provide B cell help. J. Immunol. 160: 1694. ... Lacto-N-fucopentaose III found on Schistosoma mansoni egg antigens functions as adjuvant for proteins by inducing Th2-type ...
... the classic DC specialized in the processing and presentation of the antigen; and the plasmacytoid DC that have a high ... Once internalized, DCs process antigens for presentation to T cells [50].. 4.1 Parasitic protozoan infections. Protozoan ... the PRRs from protozoa induce the presentation of antigens, the co-stimulation, and the expression of the cytokine IL-12, IFN-γ ... The endogenous antigens are processed by MHC class I, while exogenous antigens are processed by MHC class II. The lipidic ...
Publications] Yano A: Antigen presentation in protozoan infection.Progress of Medical Patasitology in Japan. 7. 297-308 (2003 ... Publications] Yano A: Roles of IFN-γ on stage conversion of an obligate intracellular protozoan parasite, Toxoplasma gondii. ... Publications] Yano A: Roles of IFN-γ on stage conversion of an obligate intracellular protozoan parasite, Toxoplasma gondii. ... Publications] Yano A: Roles of IFN-γ on stage conversion of an obligate intracellular protozoan parasite, Toxoplasma gondii. ...
In protozoa[edit]. Antigenic variation is employed by a number of different protozoan parasites. Trypanosoma brucei and ... Immunity to re-infection is based on recognition of the antigens carried by the pathogen, which are "remembered" by the ... Antigenic variation or antigenic alteration refers to the mechanism by which an infectious agent such as a protozoan, bacterium ... Segments of the silent cassettes recombine with the vlsE gene, generating variants of the surface lipoprotein antigen.[7] ...
The present invention relates to vaccine compositions which comprise at least one antigen chemically linked to a water- ... This includes antigens of bacteria, viruses, fungi and protozoans. It also includes plant antigens, such as various types of ... The chemical linkage of the antigen of choice to the solid support allows the antigen to remain in the body for a longer period ... When the present composition is used as the antigen in the first step, much smaller amounts of pure antigen may be employed to ...
The first section of this book discusses prions, viruses, protozoa, and helminth parasites both in host organisms and in food, ... with notes on parasitological and antigen detection methods; 5. Molecular and immunodiagnosis of human filarial nematode ... infections; 6. Molecular detection of parasitic protozoa; 7. Molecular diagnosis of parasitic nematodes; 8. Detection of ...
Research Interest: The molecular basis of antigen induced immune suppression and the modulation of the innate immune system ... Biology of the ciliated protozoa Tetrahymena and Ichthyophthirius ... Research Interest: Vaccine Development; Mitochondrial Dynamics; Evolution of Antigen Presentation in teleost fish; ...
Antigens, Protozoan Protozoan Proteins Protozoan Vaccines Vaccines, Attenuated Vaccines, DNA Vaccines, Synthetic ... Antigens, Protozoan Dog Diseases Dogs Humans Leishmania donovani Leishmaniasis, Visceral Neglected Diseases Protozoan Proteins ... Vaccines based on recombinant protein and antigen-encoding DNA plasmids have given promising results and few vaccines including ... and third generation vaccines derived from antigen-encoding DNA plasmids including heterologous prime-boost Leishmania vaccine ...
Surface antigen glycoproteins, SAG2C, -2D, -2X, and -2Y, are expressed on the surface of bradyzoites. These antigens have been ... i,Toxoplasma gondii,/i, is a protozoan parasite capable of infecting humans and animals. ... Toxoplasma gondii is a protozoan parasite capable of infecting humans and animals. Surface antigen glycoproteins, SAG2C, -2D, - ... The surface antigen of T. gondii that plays roles in the processes of host cell attachment and host immune evasion is dominated ...
... is caused by a protozoan parasite that affects the health of livestock. Livestock production in Ethiopia is severely hampered ... is caused by a protozoan parasite that affects the health of livestock. Livestock production in Ethiopia is severely hampered ... Goldszmid, R. S., Sher, A. (2010). Processing and presentation of antigens derived from intracellular protozoan parasites. Curr ... Jordan, K. A., Hunter, C. A. (2010). Regulation of CD8+ T cell responses to infection with parasitic protozoa. Exp. Parasitol. ...
  • Malaria protection is mainly antibody mediated, and antigens like P. falciparum erythrocyte membrane protein 1 (PfEMP1) expressed on the infected erythrocyte (IE) surface are important targets ( 4 ). (
  • Results were negative for serum anti-A IgM, antibody to hepatitis B core antigen (anti-HBc), antibody to hepatitis B surface antigen (anti-HBs), and antibody to hepatitis C virus (anti-HCV). (
  • Using crude soluble P. falciparum antigens, an ELISA-malaria antibody test detected anti-Plasmodium antibodies. (
  • Humoral (Antibody-Mediated) Immunity (Antibody Involves production of antibodies against foreign antigens. (
  • High quality infectious disease antigens are key reagents for analyzing antibody responses to bacteria, viruses, protozoa, and fungi. (
  • In 1950, the Duffy antigen was discovered in a multiply-transfused hemophiliac whose serum contained the first example of anti-Fya antibody . (
  • [10] In 1951, the antibody to a second antigen, Fyb, was discovered in serum . (
  • Each therapeutic antibody recognizes a different protein, or antigen, and in general can be used alone, in combination with chemotherapy or as a carrier of substances such as toxins or radiation. (
  • Antigen-antibody reactions serve as host defenses against microorganisms and other foreign bodies, or are used in laboratory tests for detecting the presence of either antigen or antibody. (
  • With a few exceptions, such as the autoantigens and the isoantigens of the blood groups, antigens produce antibody only in species other than the ones from which they are derived. (
  • The presence of antibody to one of these constituent antigens in human or animal sera is presumptive evidence of past or present contact with specific microorganisms, and this finds application in clinical diagnosis and epidemiological surveys. (
  • Since whole microorganisms are complex structures, vaccines may contain 10 or more distinct antigens, of which generally not more than one or two engender a protective antibody. (
  • Antigenic variation or antigenic alteration refers to the mechanism by which an infectious agent such as a protozoan , bacterium or virus alters the proteins or carbohydrates on its surface and thus avoids a host immune response . (
  • The surface antigen of T. gondii that plays roles in the processes of host cell attachment and host immune evasion is dominated by a SRS (SAG1-related sequence) family of proteins which includes the SAG1-like sequence branch and the SAG2-like sequence branch [ 5 ]. (
  • Therefore, surface antigens and cell adhesion proteins have been suggested as promising Development of anti-EmSAG antibodies against the vaccine candidates against parasitic infections [13, 14]. (
  • Receptors are cell surface proteins that can attach to antigens. (
  • etc.Antigens Most are proteins or large polysaccharides from a foreign organism. (
  • For instance, individuals produce innumerable "self" antigens and are constantly exposed to harmless foreign antigens, such as food proteins, pollen, or dust components. (
  • These may be proteins or polysaccharides derived from the outer surfaces of the cell (capsular antigens), from the cell interior (the somatic or O antigens), or from the flagella (the flagellar or H antigens). (
  • It is especially effective at destroying bacteria, extracellular viruses, and other antigens found in body fluids. (
  • A rapid induction of necrosis by L. pneumophila also occurs upon entry into the post-exponential phase of growth within both macrophages and protozoa, when the bacteria become cytotoxic. (
  • Before the lysis of the mammalian or protozoan plasma membrane, the bacteria egress into the cytoplasm. (
  • These invaders include viruses, bacteria, protozoa or even larger parasites. (
  • The first complete genome sequence for the protozoan parasite T. cruzi was reported in 2005, along with the genomes of the related parasites Trypanosoma brucei and Leishmania major . (
  • For individuals who experience a clinical malaria attack or who are diagnosed with high density parasitaemia (≥15,000 parasites/µL) during cross-sectional surveys, a 5mL blood sample is obtained to determine the diversity of parasite antigens in the population in relation to antigen recognition in the cohort. (
  • Antigenic variation is employed by a number of different protozoan parasites. (
  • The first section of this book discusses prions, viruses, protozoa, and helminth parasites both in host organisms and in food, drinking water and the environment. (
  • Trypanosomiasis is a disease caused by uni-cellular protozoan parasites which affects the health of humans and livestock. (
  • Many protozoa cause infections that often follow chronic courses, owing to coevolution between parasites and host immune system. (
  • A great challenge to research in immunology and parasitology is the development of strategies that favor immunity against protozoan parasites and prevent their evasion, chronic, or recurrent infections and associated pathologies. (
  • This special issue includes original papers and reviews that summarize current advances in our understanding on the mechanisms of immunity to protozoan parasites in humans and experimental animal models. (
  • Four papers of this special issue discuss molecules present at initial encounter between hosts and protozoan parasites plus the secretions of their insect vectors. (
  • Other PRRs, such as Nod-like receptors (NLR), only recently came into spotlight in immunity to protozoan parasites [ 5 ]. (
  • Longstanding experimental studies have suggested that the frequency of antigenic variation and transmissibility may be linked, antigen switching being higher in developmentally competent, fly-transmissible, parasites ("pleomorphs") than in serially passaged "monomorphic" lines that cannot transmit through flies. (
  • The in vitro culture of protozoan parasites involves highly complex procedures, which are subject to many variables. (
  • There are a number of issues involved in the culture of protozoan parasites that make these procedures highly complex and subject to many variables, some of which are known and some of which are still undefined. (
  • Certainly protozoan parasites have complex life cycles. (
  • At the present time, are there any advantages in the in vitro culture of protozoan parasites, especially when revolutionary developments are going on in the field of molecular biology? (
  • However, compared to mammalian cells, protozoan parasites express about one hundred times more GPI glycolipids per cell. (
  • GPIs are commonly employed by the parasites to anchor surface antigens on the extracellular membrane, although not protein-linked or free GPIs can also be found. (
  • Rapid card tests detecting parasite antigens and host antibodies are available for several important protozoan parasites and serve particularly well in the field setting. (
  • Members of the phylum Microsporidia used to be classified as protozoa but are now, based on DNA studies, thought to be fungi or closely related to them. (
  • Comparison of microsatellite and antigen-coding loci for differentiating recrudescing Plasmodium falciparum infections from reinfections in Kenya. (
  • We have compared the ability of five Plasmodium falciparum microsatellites and three antigen-coding loci to differentiate recrudescence from reinfection. (
  • Clinical immunity to malaria is associated with the acquisition of IgG specific for members of the Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family of clonally variant antigens on the surface of infected erythrocytes (IEs). (
  • Pan Plasmodium pLDH detection was assessed by an ELISA-malaria antigen test. (
  • Antibodies travel through the body's fluids and attach to antigens, targeting them for destruction by nonspecific defenses. (
  • Response: Involves production of antibodies and generation of specialized lymphocytes against specific antigens. (
  • Serum containing antibodies to a specific antigen(s). (
  • The study of reactions between antibodies and antigens. (
  • Now Offering Over 102,157 Antibodies & 44,722 Antigens! (
  • Antibodies bind specifically to one or a few closely related antigens. (
  • Antigen binding by antibodies is the primary function of antibodies and can result in protection of the host. (
  • Antigens can also react with formed antibodies. (
  • Microbial antigens prepared to induce protective antibodies are termed vaccines. (
  • When animals (mice, rats and cattle) were pretreated with Toxoplasma lysate antigens(TLA), lymphokines such as IFN,MAF,MIF,TOXO-GIF appeared in their blood and they showed a strong non-specific resistance. (
  • Toxoplasma gondii is a protozoan parasite capable of infecting humans and animals. (
  • Toxoplasma gondii ( T. gondii ) is a species of parasitic protozoa in the genus Toxoplasma that can be carried by many warm-blooded animals including humans [ 1 ]. (
  • Infection with the intracellular protozoan parasite Toxoplasma gondii causes serious public health problems and is of great economic importance worldwide. (
  • 2011. A general method for synthesis of GPI anchors illustrated by the total synthesis of the low-molecular-weight antigen from toxoplasma gondii . (
  • Current development efforts of subunit vaccines against Toxoplasma gondii , the etiological agent of toxoplasmosis, have been focused mainly on tachyzoite surface antigen 1 (SAG1). (
  • Toxoplasma gondii , the etiological agent of toxoplasmosis, is an intracellular protozoan parasite. (
  • Clinical malaria attacks and the associated clinical and parasitological parameters will be related to immunological profiles determined utilizing a protein microarray as a capture substratum to profile the humoral immune response against a vast number of parasite antigens. (
  • The T. gondii surface antigen protein SAG1 is a significant candidate vaccine against toxoplasmosis. (
  • Duffy antigen/chemokine receptor ( DARC ), also known as Fy glycoprotein ( FY ) or CD234 ( C luster of D ifferentiation 234), is a protein that in humans is encoded by the ACKR1 gene . (
  • The protein concentration of E/S antigens of C. cotylophorum and G. crumenifer ranged from 0.4 to 7.1 mg/ml and 3.3 to 5.9 mg/ml, respectively. (
  • stool testing for parasite antigens or DNA and microscopic examination of stool for cysts or organisms are necessary. (
  • Authors present what we have learnt from experiments performed in mice defective in one or multiple TLRs or key signaling molecules to gain insight into their role on immunity triggered by protozoan PAMPs, with emphasis on T. cruzi and Leishmania infections. (
  • Antigen: Antigen: Molecules from a pathogen or foreign organism that provoke a specific immune response. (
  • Both macrophages and DCs are able to present microbial antigens on major histocompatibility class I and class II molecules, which stimulate antigen-specific T-cell response. (
  • Antigens are usually known to be complex and huge molecules that are external to the body. (
  • Not all molecules can be considered as antigens because there are certain factors that affect its ability to become potential threats to the body's defenses. (
  • As what have been stated, there are actually receptors which are considered to be molecules that only detect certain patterns and this can only be compatible to the determinants on an antigen. (
  • Cell Mediated Immunity Involves specialized set of lymphocytes called T cells that recognize foreign antigens on the surface of cells. (
  • PCR, real-time PCR, and TechLab E. histolytica II antigen detection enzyme-linked immunosorbent assay [ELISA]) had high sensitivity ( 4 , 11 , 18 ). (
  • Immunity to re-infection is based on recognition of the antigens carried by the pathogen, which are "remembered" by the acquired immune response . (
  • If the pathogen's dominant antigen can be altered, the pathogen can then evade the host's acquired immune system. (
  • Legionella pneumophila , the agent responsible for Legionnaire's disease, is a facultative intracellular pathogen that can replicate within protozoa and macrophages. (
  • Adaptive immunity is an immunity that occurs after exposure to an antigen either from a pathogen or a vaccination. (
  • When a pathogen is detected, these APCs will phagocytose the pathogen and digest it to form many different fragments of the antigen. (
  • negative lymphocytes were found to accumulate remarkably in the thymus and spleen and there was a remarkable increase in the immune response of the host to infection with protozoan organisms. (
  • Genetic immunization elicits antigen-specific protective immune responses and decreases disease severity in Trypanosoma cruzi infection. (
  • Overall, microsatellite loci revealed significantly higher expected heterozygosity and multiplicity of infection levels than antigen-coding loci. (
  • Both antigen-specific humoral and cell-mediated immune responses are induced during Legionella infection. (
  • Excretory/secretory antigen may be used for serodiagnosis of paramphistomosis infection in sheep. (
  • Awad WS, Ibrahim AK, Salib FA (2009) Using indirect ELISA to assess different antigens for the serodiagnosis of F. gigantica infection in cattle, sheep and donkeys. (
  • Occasionally, large foodborne and waterborne outbreaks of intestinal protozoan infection have occurred in the US (eg, the multi-state outbreak of Cyclospora cayetanensis infection attributed to contaminated fresh vegetable trays in 2018 and the massive waterborne Cryptosporidium outbreak in Milwaukee in 1993). (
  • An antigen-presenting cell (APC) is an immune cell that detects, engulfs, and informs the adaptive immune response about an infection. (
  • Current development efforts of subunit vaccines against the parasite have been focused mainly on the major immunodominant surface antigens of T. gondii tachyzoites[ 7 ], the rapidly multiplying stage during the acute phase infection. (
  • Numerous protozoa inhabit the gastro-intestinal tract of humans (see Box). (
  • Intestinal protozoa are transmitted by the fecal-oral route and tend to exhibit similar life cycles consisting of a cyst stage and a trophozoite stage (Figure). (
  • Factors which increase the likelyhood of ingesting material contaminated with fecal material play a role in the transmission of this intestinal protozoa (see Box). (
  • Coccidiosis is an invasion and destruction of intestinal tissues by any of several protozoa. (
  • van Lieshout L and Verweij JJ (2010) Newer diagnostic approaches to intestinal protozoa. (
  • Intestinal protozoa are spread by the fecal-oral route, so infections are widespread in areas with inadequate sanitation and water treatment. (
  • Types of Acquired Immunity I. Body generates an immune response to antigens. (
  • Naturally Acquired Active Immunity: Immunity: Antigens or pathogens enter body naturally. (
  • 1. Artificially Acquired Active Immunity: Immunity: Antigens are introduced in vaccines (immunization). (
  • Immunity to Protozoa and Worms 16. (
  • The protozoan parasite Trypanosoma cruzi, causative agent of Chagas disease, depends upon a cell surface-expressed trans -sialidase (ts) to avoid activation of complement-mediated lysis and to enhance intracellular invasion. (
  • The causative agent of both human and animal trypanosomiasis is Trypanosoma brucei, a protozoan parasite covered by a dense variant surface glycoprotein (VSG) coat. (
  • 2016) A Conserved DNA Repeat Promotes Selection of a Diverse Repertoire of Trypanosoma brucei Surface Antigens from the Genomic Archive. (
  • Of the around 100 protozoan species that can infect humans, some are of prime importance for human health, including the causative agents of malaria, amebiasis, leishmaniasis and sleeping sickness . (
  • Allergens are antigens that induce allergic states in humans or animals. (
  • Our data indicated that in addition to differences in mechanisms of uptake of L. pneumophila by macrophages and protozoa, there were also genetic loci required for L. pneumophila to parasitize mammalian but not protozoan cells. (
  • Uptake of L. pneumophila by macrophages and protozoa occurs by different mechanisms ( 5 , 29 ). (
  • In this investigation, we identified six MHC class-II-restricted epitope hotspots of Leishmania antigens that induce CD4+ Th1 and Th17 responses, which could be used to potentiate a human universal T-epitope vaccine against VL. (
  • Further research will be required to define target antigens involved in distinct biological activities of vector's saliva for novel vaccines against Leishmania spp . (
  • The size of protozoan pathogens varies from ∼2 μm (amastigote Leishmania spp. (
  • In vitro cultivation of parasitic protozoa that cause human disease is invaluable, as it provides not only information on the development of the parasite but also avenues for new approaches to the containment and/or eradication of the parasite. (
  • Furthermore, these antigens were also tested against human sera positive for other parasitic infections and showed no or very minimal cross-reaction. (
  • Parasitic GPIs are believed to regulate the immune response of the host by protozoa. (
  • The available antigen detection tests such as TechLab E. histolytica II ELISA, which detects E. histolytica lectin antigen, can be used for diagnosis of acute ALA patients who have not received treatment ( 23 ). (
  • Molecular diagnosis using polymerase chain reaction-based assays is available for many enteric protozoa. (
  • Giardia lamblia (also known as G. duodenalis , see comments on taxonomy ) is a protozoan parasite that colonizes the upper portions of the small intestine. (
  • ABSTRACT The aim of this study in Iraq was to determine the sensitivity and specificity of a commercial ELISA test for detection of Giardia lamblia antigen in stool. (
  • RÉSUMÉ L'objectif de cette étude réalisée en Iraq était de définir la sensibilité et la spécificité d'un test ELISA commercial pour la détection de l'antigène de Giardia lamblia dans les selles. (
  • The protozoan parasite Giardia lamblia is recognized as a major cause of diarrhoeal illness in human [1]. (
  • Therefore, it is not surprising that about 70% of the papers published here deal with early steps of immune responses to protozoan infections, including the role of parasite products, host receptors, molecular mechanisms, and effector cells of innate immune system. (
  • A considerable part of protozoan diagnostics still mainly relies on microscopy, however, in the past years molecular methods, particularly polymerase chain reaction (PCR)‐based techniques, have gained more and more importance. (
  • Although numerous protocols for molecular detection of protozoan pathogens have been established in the past years, consent on the most reliable technique is missing for most protozoan taxa, thus demonstration of the causative agent in native material or stained smears is still the gold standard for detection. (
  • In many protozoan taxa, morphology alone does not provide enough information for identification on or below the species level, this is today mainly based on molecular biological methods . (
  • If the immunogen causes the entire Immune System to react, there are also substances that can cause parts or specific segments of the said system to react aggressively and these are known as antigens. (
  • Antigens are substances that can stimulate one part of the Immune System which can in turn alert other segments eventually leading to the activation of the entire system or the creation of an immune response. (
  • A primary immune response happens the first time that the body encounters a specific antigen. (
  • In wild and laboratory mice, several protozoa have been documented to be disease causing, whereas others, such as Entamoeba muris and Tritrichomonas muris , are considered nonpathogenic members of the murine microbiome ( Baker, 2008 ). (
  • Western blots using excretory-secretory antigen (ESA) collected from axenically grown Entamoeba histolytica were probed with the above serum samples. (
  • Excretory/Secretory (E/S) antigens of G. crumenifer and C. cotylophorum were prepared by incubating in PBS at 28.3 °C overnight in a shaking incubator and centrifuged. (
  • Arunkumar S, Prakash Krupakaran R, Balamurugan TC Pandiyan DV (2014) Assessment of matrix metalloproteinase activity in excretory/secretory antigens of Gastrothylax crumenifer from buffalo by gelatinzymography. (
  • Latchumikanthan A, Soundararajan C, Dhinakarraj G, Abdul Basith S (2012) Purification and characterization of excretory/secretory antigens of Fasciola gigantica . (
  • Saifullah MK, Ahmad Gul, Abidi SMA (2011) Isolation and partial characterization of excretory/secretory antigens of Gastrothylax crumenifer . (
  • Initially, 37 epitopes derived from six stage-dependent, overexpressed antigens were predicted, which were presented by at least 26 diverse MHC class-II allele. (
  • Based on a population coverage analysis and human leukocyte antigen cross-presentation ability, six of the 37 epitopes were selected for further analysis. (
  • Ability of an organism to recognize and defend itself against specific pathogens or antigens. (
  • This technique provides a method to harvest, normalize and quantify intracellular growth of bacterial pathogens that are pre-cultivated in natural protozoan host cells prior to infections of mammalian cells. (
  • Many intracellular bacterial pathogens use freshwater protozoans as a natural reservoir for proliferation in the environment. (
  • The identification of protozoan pathogens is based upon direct detection of the respective causative agent in clinical specimens and/or upon detection of specific immune reactions of the host. (
  • There are such parts of the antigen known as the antigenic determinant that are considered to be immunogenic. (
  • The basic principle behind the practice of immunization is that the body's own immune system is stimulated to produce a humoral or cellular response against a specific disease-causing organism by exposing the system to an antigen of the causative agent without actually bringing on the full symptoms of the disease. (
  • In the environment, L. pneumophila is a parasite of at least 13 species of amoebae and ciliated protozoa ( 20 ). (
  • Dogs can be infected with species of Isospora , Hammondia , and Sarcocystis protozoa, with Isospora as the most common. (
  • Some gastrointestinal protozoa are spread sexually, especially with practices involving oral-anal contact, and several protozoan species cause severe opportunistic infections in patients with AIDS. (
  • Protozoa are single-celled organisms that can sometimes cause disease. (
  • This is why the immune system can recognize millions of antigens with specificity. (
  • Host immune system does not respond to antigens. (
  • You may also hear about determinants which are actually parts of the antigen that are the ones recognized by the agents of the Immune System. (
  • An antigen is a foreign or "non-self" macromolecule that reacts with cells of the immune system. (
  • The innate immune system contains cells that detect potentially harmful antigens, and then inform the adaptive immune response about the presence of these antigens. (
  • Detection of the pLDH antigen seems to be an adequate screening tool in endemic areas, for this antigen indicates parasite presence. (
  • If indicated, aspiration of the sample is performed for culture, DNA detection, and/or antigen detection. (
  • Many reports showed that DNA and antigen detection-based methods performed on the abscess sample (e.g. (
  • Segments of the silent cassettes recombine with the vlsE gene, generating variants of the surface lipoprotein antigen. (
  • In the present research, the surface antigen gene of E. maxima (EmSAG) was cloned, and the ability of EmSAG to stimulate protection against E. maxima was evaluated. (
  • was expressed in E. coli BL21 (DE3) as described previ- Surface antigens have been proven to confer protec- ously [21]. (
  • The APC then breaks the invader apart into its antigens and moves these antigens to its cell surface. (
  • Members of the genus Paramecium (from the classical Greek, παραμηκησ, oblong or oval‐shaped) are ciliated protozoa with an elongated shape (length approximately three to four times the width), a uniform distribution of cilia over the cell surface and a ciliated oral groove leading from the anterior of the cell to a midventral deep oral cavity. (
  • The Duffy antigen is located on the surface of red blood cells , and is named after the patient in whom it was discovered. (
  • Antigen fragments will then be transported to the surface of the APC, where they will serve as an indicator to other immune cells. (
  • The highly antigenic VSG is so densely packed on the parasite cell surface that it effectively obscures all other antigens from immune recognition. (
  • Saifullah MK, Ahmad Gul, Nizami WA, Abidi SMA (2000) Partial purification and characterization of Gastrothylax crumenifer somatic antigens. (
  • Arora R, Singh NK, Hassan SS, Juyal PD (2007) Identification of immunodominant antigens of Paramphistomum epiclitum . (
  • Identification of antigens and determination of vesicular trafficking mechanisms involved in processing and presentation remain to be understood in greater detail. (
  • Like T H cells, each T C cell and B cell has receptors that match one antigen. (
  • These receptors actually have one recognition site which is the area where the determinant of an antigen binds. (
  • However, when it comes to the antigen, it is entirely different because yes, the receptors for the antigen can be a part of the body or is considered as self but then the antigen itself is known by the body as non self. (
  • These antigens have been shown to protect bradyzoites against immune responses during chronic infections. (
  • The survival and transmission of pathogenic protozoa depends on their ability to evade or subvert host's innate and adaptive immune responses. (
  • Although all immune responses are similar, each time the body is invaded by a different antigen, the exact response is specific to that antigen. (
  • Macrophage migration inhibitory factor (MIF, " Macrophage migration inhibitory factor in protozoan infections ") is a host inflammatory cytokine with protective or pathogenic actions in distinct protozoan infections. (
  • The Fy4 antigen, originally described on Fy (a-b-) RBCs, is now thought to be a distinct, unrelated antigen and is no longer included in the FY system. (
  • Amoebiasis is caused by the enteric protozoan Entamoeba histolytica , which affects 50 million people worldwide and leads to 100,000 fatal cases annually ( 19 , 21 ). (
  • It has a worldwide distribution and is the most common protozoan isolated from human stools. (
  • Trypanosomes are blood-borne protozoa that cause human sleeping sickness and the livestock disease, nagana. (
  • We have recently shown that many mutants of Legionella pneumophila exhibit similar defective phenotypes within both U937 human-derived macrophages and the protozoan host Acanthamoeba (L.-Y. Gao, O. S. Harb, and Y. Abu Kwaik, Infect. (
  • We identified 32 mutants with various degrees of defects in cytopathogenicity, intracellular survival, and replication within human macrophages, and most of the mutants exhibited wild-type phenotypes within protozoa. (
  • Alternatively, ecological coevolution with protozoa has allowed L. pneumophila to possess multiple redundant mechanisms to parasitize protozoa and that some of these mechanisms do not function within macrophages. (
  • After an antigen is cleared from the body, immunological memory allows an antigen to be recognized and removed more quickly if encountered again. (