Multi-subunit proteins which function in IMMUNITY. They are produced by B LYMPHOCYTES from the IMMUNOGLOBULIN GENES. They are comprised of two heavy (IMMUNOGLOBULIN HEAVY CHAINS) and two light chains (IMMUNOGLOBULIN LIGHT CHAINS) with additional ancillary polypeptide chains depending on their isoforms. The variety of isoforms include monomeric or polymeric forms, and transmembrane forms (B-CELL ANTIGEN RECEPTORS) or secreted forms (ANTIBODIES). They are divided by the amino acid sequence of their heavy chains into five classes (IMMUNOGLOBULIN A; IMMUNOGLOBULIN D; IMMUNOGLOBULIN E; IMMUNOGLOBULIN G; IMMUNOGLOBULIN M) and various subclasses.
Immunoglobulin Heavy Chains
The largest of polypeptide chains comprising immunoglobulins. They contain 450 to 600 amino acid residues per chain, and have molecular weights of 51-72 kDa.
Genes encoding the different subunits of the IMMUNOGLOBULINS, for example the IMMUNOGLOBULIN LIGHT CHAIN GENES and the IMMUNOGLOBULIN HEAVY CHAIN GENES. The heavy and light immunoglobulin genes are present as gene segments in the germline cells. The completed genes are created when the segments are shuffled and assembled (B-LYMPHOCYTE GENE REARRANGEMENT) during B-LYMPHOCYTE maturation. The gene segments of the human light and heavy chain germline genes are symbolized V (variable), J (joining) and C (constant). The heavy chain germline genes have an additional segment D (diversity).
Immunoglobulin preparations used in intravenous infusion, containing primarily IMMUNOGLOBULIN G. They are used to treat a variety of diseases associated with decreased or abnormal immunoglobulin levels including pediatric AIDS; primary HYPERGAMMAGLOBULINEMIA; SCID; CYTOMEGALOVIRUS infections in transplant recipients, LYMPHOCYTIC LEUKEMIA, CHRONIC; Kawasaki syndrome, infection in neonates, and IDIOPATHIC THROMBOCYTOPENIC PURPURA.
Immunoglobulin Light Chains
Immunoglobulins produced in response to VIRAL ANTIGENS.
Immunoglobulins produced in a response to BACTERIAL ANTIGENS.
Enzyme-Linked Immunosorbent Assay
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.
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.
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.
Immunoglobulin Variable Region
That region of the immunoglobulin molecule that varies in its amino acid sequence and composition, and comprises the binding site for a specific antigen. It is located at the N-terminus of the Fab fragment of the immunoglobulin. It includes hypervariable regions (COMPLEMENTARITY DETERMINING REGIONS) and framework regions.
Immunoglobulin A, Secretory
The classes of immunoglobulins found in any species of animal. In man there are nine classes that migrate in five different groups in electrophoresis; they each consist of two light and two heavy protein chains, and each group has distinguishing structural and functional properties.
A 15 kD "joining" peptide that forms one of the linkages between monomers of IMMUNOGLOBULIN A or IMMUNOGLOBULIN M in the formation of polymeric immunoglobulins. There is one J chain per one IgA dimer or one IgM pentamer. It is also involved in binding the polymeric immunoglobulins to POLYMERIC IMMUNOGLOBULIN RECEPTOR which is necessary for their transcytosis to the lumen. It is distinguished from the IMMUNOGLOBULIN JOINING REGION which is part of the IMMUNOGLOBULIN VARIABLE REGION of the immunoglobulin light and heavy chains.
An immunoglobulin which accounts for less than 1% of plasma immunoglobulin. It is found on the membrane of many circulating B LYMPHOCYTES.
A lymphoproliferative disorder characterized by pleomorphic B-LYMPHOCYTES including PLASMA CELLS, with increased levels of monoclonal serum IMMUNOGLOBULIN M. There is lymphoplasmacytic cells infiltration into bone marrow and often other tissues, also known as lymphoplasmacytic lymphoma. Clinical features include ANEMIA; HEMORRHAGES; and hyperviscosity.
Immunoglobulin Fc Fragments
Crystallizable fragments composed of the carboxy-terminal halves of both IMMUNOGLOBULIN HEAVY CHAINS linked to each other by disulfide bonds. Fc fragments contain the carboxy-terminal parts of the heavy chain constant regions that are responsible for the effector functions of an immunoglobulin (COMPLEMENT fixation, binding to the cell membrane via FC RECEPTORS, and placental transport). This fragment can be obtained by digestion of immunoglobulins with the proteolytic enzyme PAPAIN.
Immunoglobulin Constant Regions
The domains of the immunoglobulin molecules that are invariable in their amino acid sequence within any class or subclass of immunoglobulin. They confer biological as well as structural functions to immunoglobulins. One each on both the light chains and the heavy chains comprises the C-terminus half of the IMMUNOGLOBULIN FAB FRAGMENT and two or three of them make up the rest of the heavy chains (all of the IMMUNOGLOBULIN FC FRAGMENT)
Immunoglobulin Class Switching
Gene rearrangement of the B-lymphocyte which results in a substitution in the type of heavy-chain constant region that is expressed. This allows the effector response to change while the antigen binding specificity (variable region) remains the same. The majority of class switching occurs by a DNA recombination event but it also can take place at the level of RNA processing.
Antibodies found in adult RHEUMATOID ARTHRITIS patients that are directed against GAMMA-CHAIN IMMUNOGLOBULINS.
The acquired form of infection by Toxoplasma gondii in animals and man.
Complement Fixation Tests
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.
Immunoglobulin Fab Fragments
Univalent antigen-binding fragments composed of one entire IMMUNOGLOBULIN LIGHT CHAIN and the amino terminal end of one of the IMMUNOGLOBULIN HEAVY CHAINS from the hinge region, linked to each other by disulfide bonds. Fab contains the IMMUNOGLOBULIN VARIABLE REGIONS, which are part of the antigen-binding site, and the first IMMUNOGLOBULIN CONSTANT REGIONS. This fragment can be obtained by digestion of immunoglobulins with the proteolytic enzyme PAPAIN.
Fluorescent Antibody Technique
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.
Antibodies which react with the individual structural determinants (idiotopes) on the variable region of other antibodies.
Receptors, Antigen, B-Cell
Any discrete, presumably solitary, mass of neoplastic PLASMA CELLS either in BONE MARROW or various extramedullary sites.
Evaluation Studies as Topic
Heavy chains of IMMUNOGLOBULIN G having a molecular weight of approximately 51 kDa. They contain about 450 amino acid residues arranged in four domains and an oligosaccharide component covalently bound to the Fc fragment constant region. The gamma heavy chain subclasses (for example, gamma 1, gamma 2a, and gamma 2b) of the IMMUNOGLOBULIN G isotype subclasses (IgG1, IgG2A, and IgG2B) resemble each other more closely than the heavy chains of the other IMMUNOGLOBULIN ISOTYPES.
Sensitivity and Specificity
An acute infectious disease caused by the RUBELLA VIRUS. The virus enters the respiratory tract via airborne droplet and spreads to the LYMPHATIC SYSTEM.
Hemagglutination Inhibition Tests
Receptors, Polymeric Immunoglobulin
Specialized Fc receptors (RECEPTORS, FC) for polymeric immunoglobulins, which mediate transcytosis of polymeric IMMUNOGLOBULIN A and IMMUNOGLOBULIN M into external secretions. They are found on the surfaces of epithelial cells and hepatocytes. After binding to IMMUNOGLOBULIN A, the receptor-ligand complex undergoes endocytosis, transport by vesicle, and secretion into the lumen by exocytosis. Before release, the part of the receptor (SECRETORY COMPONENT) that is bound to IMMUNOGLOBULIN A is proteolytically cleaved from its transmembrane tail. (From Rosen et al., The Dictionary of Immunology, 1989)
Immunoglobulins produced in a response to PROTOZOAN ANTIGENS.
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.
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.
Immunoglobulin Joining Region
A segment of the immunoglobulin heavy chains, encoded by the IMMUNOGLOBULIN HEAVY CHAIN GENES in the J segment where, during the maturation of B-LYMPHOCYTES; the gene segment for the variable region upstream is joined to a constant region gene segment downstream. The exact position of joining of the two gene segments is variable and contributes to ANTIBODY DIVERSITY. It is distinguished from the IMMUNOGLOBULIN J CHAINS; a separate polypeptide that serves as a linkage piece in polymeric IGA or IGM.
A technique using antibodies for identifying or quantifying a substance. Usually the substance being studied serves as antigen both in antibody production and in measurement of antibody by the test substance.
Prenatal protozoal infection with TOXOPLASMA gondii which is associated with injury to the developing fetal nervous system. The severity of this condition is related to the stage of pregnancy during which the infection occurs; first trimester infections are associated with a greater degree of neurologic dysfunction. Clinical features include HYDROCEPHALUS; MICROCEPHALY; deafness; cerebral calcifications; SEIZURES; and psychomotor retardation. Signs of a systemic infection may also be present at birth, including fever, rash, and hepatosplenomegaly. (From Adams et al., Principles of Neurology, 6th ed, p735)
Molecular Sequence Data
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.
Immunoglobulins produced in a response to FUNGAL ANTIGENS.
Reagent Kits, Diagnostic
Staphylococcal Protein A
A protein present in the cell wall of most Staphylococcus aureus strains. The protein selectively binds to the Fc region of human normal and myeloma-derived IMMUNOGLOBULIN G. It elicits antibody activity and may cause hypersensitivity reactions due to histamine release; has also been used as cell surface antigen marker and in the clinical assessment of B lymphocyte function.
Unique genetically-controlled determinants present on ANTIBODIES whose specificity is limited to a single group of proteins (e.g., another antibody molecule or an individual myeloma protein). The idiotype appears to represent the antigenicity of the antigen-binding site of the antibody and to be genetically codetermined with it. The idiotypic determinants have been precisely located to the IMMUNOGLOBULIN VARIABLE REGION of both immunoglobin polypeptide chains.
False Positive Reactions
Abnormal immunoglobulins characteristic of MULTIPLE MYELOMA.
Contagious infection with human B19 Parvovirus most commonly seen in school age children and characterized by fever, headache, and rashes of the face, trunk, and extremities. It is often confused with rubella.
Sites on an antigen that interact with specific antibodies.
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).
Genes, Immunoglobulin Heavy Chain
Genes and gene segments encoding the IMMUNOGLOBULIN HEAVY CHAINS. Gene segments of the heavy chain genes are symbolized V (variable), D (diversity), J (joining), and C (constant).
Somatic Hypermutation, Immunoglobulin
Encephalitis, St. Louis
A viral encephalitis caused by the St. Louis encephalitis virus (ENCEPHALITIS VIRUS, ST. LOUIS), a FLAVIVIRUS. It is transmitted to humans and other vertebrates primarily by mosquitoes of the genus CULEX. The primary animal vectors are wild birds and the disorder is endemic to the midwestern and southeastern United States. Infections may be limited to an influenza-like illness or present as an ASEPTIC MENINGITIS or ENCEPHALITIS. Clinical manifestations of the encephalitic presentation may include SEIZURES, lethargy, MYOCLONUS, focal neurologic signs, COMA, and DEATH. (From Adams et al., Principles of Neurology, 6th ed, p750)
Binding Sites, Antibody
A genus of PICORNAVIRIDAE causing infectious hepatitis naturally in humans and experimentally in other primates. It is transmitted through fecal contamination of food or water. HEPATITIS A VIRUS is the type species.
Amino Acid Sequence
Immunoglobulin Switch Region
A site located in the INTRONS at the 5' end of each constant region segment of a immunoglobulin heavy-chain gene where recombination (or rearrangement) occur during IMMUNOGLOBULIN CLASS SWITCHING. Ig switch regions are found on genes encoding all five classes (IMMUNOGLOBULIN ISOTYPES) of IMMUNOGLOBULIN HEAVY CHAINS.
Complement System Proteins
Serum glycoproteins participating in the host defense mechanism of COMPLEMENT ACTIVATION that creates the COMPLEMENT MEMBRANE ATTACK COMPLEX. Included are glycoproteins in the various pathways of complement activation (CLASSICAL COMPLEMENT PATHWAY; ALTERNATIVE COMPLEMENT PATHWAY; and LECTIN COMPLEMENT PATHWAY).
A measure of the binding strength between antibody and a simple hapten or antigen determinant. It depends on the closeness of stereochemical fit between antibody combining sites and antigen determinants, on the size of the area of contact between them, and on the distribution of charged and hydrophobic groups. It includes the concept of "avidity," which refers to the strength of the antigen-antibody bond after formation of reversible complexes.
The measurement of infection-blocking titer of ANTISERA by testing a series of dilutions for a given virus-antiserum interaction end-point, which is generally the dilution at which tissue cultures inoculated with the serum-virus mixtures demonstrate cytopathology (CPE) or the dilution at which 50% of test animals injected with serum-virus mixtures show infectivity (ID50) or die (LD50).
Parvovirus B19, Human
The type species of ERYTHROVIRUS and the etiological agent of ERYTHEMA INFECTIOSUM, a disease most commonly seen in school-age children.
A mosquito-borne encephalitis caused by the Japanese B encephalitis virus (ENCEPHALITIS VIRUS, JAPANESE) occurring throughout Eastern Asia and Australia. The majority of infections occur in children and are subclinical or have features limited to transient fever and gastrointestinal symptoms. Inflammation of the brain, spinal cord, and meninges may occur and lead to transient or permanent neurologic deficits (including a POLIOMYELITIS-like presentation); SEIZURES; COMA; and death. (From Adams et al., Principles of Neurology, 6th ed, p751; Lancet 1998 Apr 11;351(9109):1094-7)
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.
Serum globulins that migrate to the gamma region (most positively charged) upon ELECTROPHORESIS. At one time, gamma-globulins came to be used as a synonym for immunoglobulins since most immunoglobulins are gamma globulins and conversely most gamma globulins are immunoglobulins. But since some immunoglobulins exhibit an alpha or beta electrophoretic mobility, that usage is in decline.
Borrelia burgdorferi Group
Gram-negative helical bacteria, in the genus BORRELIA, that are the etiologic agents of LYME DISEASE. The group comprises many specific species including Borrelia afzelii, Borellia garinii, and BORRELIA BURGDORFERI proper. These spirochetes are generally transmitted by several species of ixodid ticks.
Specialized forms of antibody-producing B-LYMPHOCYTES. They synthesize and secrete immunoglobulin. They are found only in lymphoid organs and at sites of immune responses and normally do not circulate in the blood or lymph. (Rosen et al., Dictionary of Immunology, 1989, p169 & Abbas et al., Cellular and Molecular Immunology, 2d ed, p20)
The type species of MORBILLIVIRUS and the cause of the highly infectious human disease MEASLES, which affects mostly children.
Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.
A viral infection of the brain caused by serotypes of California encephalitis virus (ENCEPHALITIS VIRUS, CALIFORNIA) transmitted to humans by the mosquito AEDES triseriatus. The majority of cases are caused by the LA CROSSE VIRUS. This condition is endemic to the midwestern United States and primarily affects children between 5-10 years of age. Clinical manifestations include FEVER; VOMITING; HEADACHE; and abdominal pain followed by SEIZURES, altered mentation, and focal neurologic deficits. (From Joynt, Clinical Neurology, 1996, Ch26, p13)
The extracellular moiety of the POLYMERIC IMMUNOGLOBULIN RECEPTOR found alone or complexed with IGA or IGM, in a variety of external secretions (tears, bile, colostrum.) Secretory component is derived by proteolytic cleavage of the receptor during transcytosis. When immunoglobulins IgA and IgM are bound to the receptor, during their transcytosis secretory component becomes covalently attached to them generating SECRETORY IMMUNOGLOBULIN A or secretory IMMUNOGLOBULIN M.
West Nile Fever
A mosquito-borne viral illness caused by the WEST NILE VIRUS, a FLAVIVIRUS and endemic to regions of Africa, Asia, and Europe. Common clinical features include HEADACHE; FEVER; maculopapular rash; gastrointestinal symptoms; and lymphadenopathy. MENINGITIS; ENCEPHALITIS; and MYELITIS may also occur. The disease may occasionally be fatal or leave survivors with residual neurologic deficits. (From Joynt, Clinical Neurology, 1996, Ch26, p13; Lancet 1998 Sep 5;352(9130):767-71)
West Nile virus
A species of FLAVIVIRUS, one of the Japanese encephalitis virus group (ENCEPHALITIS VIRUSES, JAPANESE). It can infect birds and mammals. In humans, it is seen most frequently in Africa, Asia, and Europe presenting as a silent infection or undifferentiated fever (WEST NILE FEVER). The virus appeared in North America for the first time in 1999. It is transmitted mainly by CULEX spp mosquitoes which feed primarily on birds, but it can also be carried by the Asian Tiger mosquito, AEDES albopictus, which feeds mainly on mammals.
A glycoprotein that is central in both the classical and the alternative pathway of COMPLEMENT ACTIVATION. C3 can be cleaved into COMPLEMENT C3A and COMPLEMENT C3B, spontaneously at low level or by C3 CONVERTASE at high level. The smaller fragment C3a is an ANAPHYLATOXIN and mediator of local inflammatory process. The larger fragment C3b binds with C3 convertase to form C5 convertase.
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.
Encephalitis Virus, Japanese
A species of FLAVIVIRUS, one of the Japanese encephalitis virus group (ENCEPHALITIS VIRUSES, JAPANESE), which is the etiological agent of Japanese encephalitis found in Asia, southeast Asia, and the Indian subcontinent.
A genus of the family HERPESVIRIDAE, subfamily BETAHERPESVIRINAE, infecting the salivary glands, liver, spleen, lungs, eyes, and other organs, in which they produce characteristically enlarged cells with intranuclear inclusions. Infection with Cytomegalovirus is also seen as an opportunistic infection in AIDS.
Infections with bacteria of the genus LEPTOSPIRA.
Encephalitis Virus, St. Louis
A species of FLAVIVIRUS, one of the Japanese encephalitis virus group (ENCEPHALITIS VIRUSES, JAPANESE), which is the etiologic agent of ST. LOUIS ENCEPHALITIS in the United States, the Caribbean, and Central and South America.
Immunoglobulin Gm Allotypes
Allelic variants of the gamma-immunoglobulin heavy chain (IMMUNOGLOBULIN GAMMA-CHAINS) encoded by ALLELES of IMMUNOGLOBULIN HEAVY CHAIN GENES.
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.
The thin, yellow, serous fluid secreted by the mammary glands during pregnancy and immediately postpartum before lactation begins. It consists of immunologically active substances, white blood cells, water, protein, fat, and carbohydrates.
Infection with CYTOMEGALOVIRUS, characterized by enlarged cells bearing intranuclear inclusions. Infection may be in almost any organ, but the salivary glands are the most common site in children, as are the lungs in adults.
An infectious disease caused by a spirochete, BORRELIA BURGDORFERI, which is transmitted chiefly by Ixodes dammini (see IXODES) and pacificus ticks in the United States and Ixodes ricinis (see IXODES) in Europe. It is a disease with early and late cutaneous manifestations plus involvement of the nervous system, heart, eye, and joints in variable combinations. The disease was formerly known as Lyme arthritis and first discovered at Old Lyme, Connecticut.
Monoclonal Gammopathy of Undetermined Significance
Gene Rearrangement, B-Lymphocyte, Heavy Chain
Gene Rearrangement, B-Lymphocyte
Ordered rearrangement of B-lymphocyte variable gene regions coding for the IMMUNOGLOBULIN CHAINS, thereby contributing to antibody diversity. It occurs during the differentiation of the IMMATURE B-LYMPHOCYTES.
Dose-Response Relationship, Immunologic
Blood Bactericidal Activity
The natural bactericidal property of BLOOD due to normally occurring antibacterial substances such as beta lysin, leukin, etc. This activity needs to be distinguished from the bactericidal activity contained in a patient's serum as a result of antimicrobial therapy, which is measured by a SERUM BACTERICIDAL TEST.
Encephalitis Virus, Western Equine
Atypical gamma immunoglobulins characterized by their irreversible heat denaturation at 56-degrees C. Pyroprecipitation is inhibited at pH below 3 and above 9. The presence of pyroglobulins in the serum is the cause of pyroglobulinemia. They are frequently present in multiple myeloma and the pyroglobulin precipitate binds complement, reacts with rheumatoid factor, produces passive cutaneous anaphylaxis, generalized passive anaphylaxis and passive Arthus-type phenomena.
Lipid-containing polysaccharides which are endotoxins and important group-specific antigens. They are often derived from the cell wall of gram-negative bacteria and induce immunoglobulin secretion. The lipopolysaccharide molecule consists of three parts: LIPID A, core polysaccharide, and O-specific chains (O ANTIGENS). When derived from Escherichia coli, lipopolysaccharides serve as polyclonal B-cell mitogens commonly used in laboratory immunology. (From Dorland, 28th ed)
Infections of the brain caused by arthropod-borne viruses (i.e., arboviruses) primarily from the families TOGAVIRIDAE; FLAVIVIRIDAE; BUNYAVIRIDAE; REOVIRIDAE; and RHABDOVIRIDAE. Life cycles of these viruses are characterized by ZOONOSES, with birds and lower mammals serving as intermediate hosts. The virus is transmitted to humans by the bite of mosquitoes (CULICIDAE) or TICKS. Clinical manifestations include fever, headache, alterations of mentation, focal neurologic deficits, and COMA. (From Clin Microbiol Rev 1994 Jan;7(1):89-116; Walton, Brain's Diseases of the Nervous System, 10th ed, p321)
A group of ALPHAVIRUS INFECTIONS which affect horses and man, transmitted via the bites of mosquitoes. Disorders in this category are endemic to regions of South America and North America. In humans, clinical manifestations vary with the type of infection, and range from a mild influenza-like syndrome to a fulminant encephalitis. (From Joynt, Clinical Neurology, 1996, Ch26, pp8-10)
Polymerase Chain Reaction
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.
A subcomponent of complement C1, composed of six copies of three polypeptide chains (A, B, and C), each encoded by a separate gene (C1QA; C1QB; C1QC). This complex is arranged in nine subunits (six disulfide-linked dimers of A and B, and three disulfide-linked homodimers of C). C1q has binding sites for antibodies (the heavy chain of IMMUNOGLOBULIN G or IMMUNOGLOBULIN M). The interaction of C1q and immunoglobulin activates the two proenzymes COMPLEMENT C1R and COMPLEMENT C1S, thus initiating the cascade of COMPLEMENT ACTIVATION via the CLASSICAL COMPLEMENT PATHWAY.
Immunoglobulins raised by any form of viral hepatitis; some of these antibodies are used to diagnose the specific kind of hepatitis.
Resistance to a disease-causing agent induced by the introduction of maternal immunity into the fetus by transplacental transfer or into the neonate through colostrum and milk.
Abnormal immunoglobulins, especially IGG or IGM, that precipitate spontaneously when SERUM is cooled below 37 degrees Celsius. It is characteristic of CRYOGLOBULINEMIA.
Electrophoresis, Polyacrylamide Gel
Herpesvirus 4, Human
Any part or derivative of any protozoan that elicits immunity; malaria (Plasmodium) and trypanosome antigens are presently the most frequently encountered.
Immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies.
Hepatitis E virus
A positive-stranded RNA virus species in the genus HEPEVIRUS, causing enterically-transmitted non-A, non-B hepatitis (HEPATITIS E).
Encephalitis Virus, Eastern Equine
A species of ALPHAVIRUS causing encephalomyelitis in Equidae and humans. The virus ranges along the Atlantic seaboard of the United States and Canada and as far south as the Caribbean, Mexico, and parts of Central and South America. Infections in horses show a mortality of up to 90 percent and in humans as high as 80 percent in epidemics.
Genes, Immunoglobulin Light Chain
Genes and gene segments encoding the IMMUNOGLOBULIN LIGHT CHAINS. Gene segments of the light chain genes are designated as V (variable), J (joining), and C (constant).
The class of heavy chains found in IMMUNOGLOBULIN E. They have a molecular weight of approximately 72 kDa and they contain about 550 amino acid residues arranged in five domains and about three times more carbohydrate than the heavy chains of IMMUNOGLOBULIN A; IMMUNOGLOBULIN D; and IMMUNOGLOBULIN G.
A gram-negative, rod-shaped to coccoid bacterium. It is the etiologic agent of SCRUB TYPHUS in humans and is transmitted by mites from rodent reservoirs.
Erythema Chronicum Migrans
A deep type of gyrate erythema that follows a bite by an ixodid tick; it is a stage-1 manifestation of LYME DISEASE. The site of the bite is characterized by a red papule that expands peripherally as a nonscaling, palpable band that clears centrally. This condition is often associated with systemic symptoms such as chills, fever, headache, malaise, nausea, vomiting, fatigue, backache, and stiff neck.
Hepatitis A virus
Hepatitis B Core Antigens
Hepatitis A Antibodies
Pregnancy Complications, Infectious
The co-occurrence of pregnancy and an INFECTION. The infection may precede or follow FERTILIZATION.
Gene Rearrangement, B-Lymphocyte, Light Chain
An acute infectious disease caused by ORIENTIA TSUTSUGAMUSHI. It is limited to eastern and southeastern Asia, India, northern Australia, and the adjacent islands. Characteristics include the formation of a primary cutaneous lesion at the site of the bite of an infected mite, fever lasting about two weeks, and a maculopapular rash.
Mice, Inbred Strains
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.
Immunologic Deficiency Syndromes
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 dysgammaglobulinemia characterized by a deficiency of IMMUNOGLOBULIN A.
Complement Pathway, Classical
Complement activation initiated by the binding of COMPLEMENT C1 to ANTIGEN-ANTIBODY COMPLEXES at the COMPLEMENT C1Q subunit. This leads to the sequential activation of COMPLEMENT C1R and COMPLEMENT C1S subunits. Activated C1s cleaves COMPLEMENT C4 and COMPLEMENT C2 forming the membrane-bound classical C3 CONVERTASE (C4B2A) and the subsequent C5 CONVERTASE (C4B2A3B) leading to cleavage of COMPLEMENT C5 and the assembly of COMPLEMENT MEMBRANE ATTACK COMPLEX.