HemocyaninAntigens: Substances that are recognized by the immune system and induce an immune reaction.Arthropods: Members of the phylum Arthropoda, composed of organisms having a hard, jointed exoskeleton and paired jointed legs. It includes the class INSECTS and the subclass ARACHNIDA, many species of which are important medically as parasites or as vectors of organisms capable of causing disease in man.Antigens, Bacterial: Substances elaborated by bacteria that have antigenic activity.Octopodiformes: A superorder in the class CEPHALOPODA, consisting of the orders Octopoda (octopus) with over 200 species and Vampyromorpha with a single species. The latter is a phylogenetic relic but holds the key to the origins of Octopoda.Antigens, Neoplasm: 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, Surface: 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.Antigens, Viral: Substances elaborated by viruses that have antigenic activity.Nephropidae: Family of large marine CRUSTACEA, in the order DECAPODA. These are called clawed lobsters because they bear pincers on the first three pairs of legs. The American lobster and Cape lobster in the genus Homarus are commonly used for food.Mollusca: A phylum of the kingdom Metazoa. Mollusca have soft, unsegmented bodies with an anterior head, a dorsal visceral mass, and a ventral foot. Most are encased in a protective calcareous shell. It includes the classes GASTROPODA; BIVALVIA; CEPHALOPODA; Aplacophora; Scaphopoda; Polyplacophora; and Monoplacophora.Spiders: Arthropods of the class ARACHNIDA, order Araneae. Except for mites and ticks, spiders constitute the largest order of arachnids, with approximately 37,000 species having been described. The majority of spiders are harmless, although some species can be regarded as moderately harmful since their bites can lead to quite severe local symptoms. (From Barnes, Invertebrate Zoology, 5th ed, p508; Smith, Insects and Other Arthropods of Medical Importance, 1973, pp424-430)Horseshoe Crabs: An arthropod subclass (Xiphosura) comprising the North American (Limulus) and Asiatic (Tachypleus) genera of horseshoe crabs.Brachyura: An infraorder of chiefly marine, largely carnivorous CRUSTACEA, in the order DECAPODA, including the genera Cancer, Uca, and Callinectes.Hemolymph: The blood/lymphlike nutrient fluid of some invertebrates.Antibody Formation: The production of ANTIBODIES by proliferating and differentiated B-LYMPHOCYTES under stimulation by ANTIGENS.Antigens, Protozoan: Any part or derivative of any protozoan that elicits immunity; malaria (Plasmodium) and trypanosome antigens are presently the most frequently encountered.Scorpions: Arthropods of the order Scorpiones, of which 1500 to 2000 species have been described. The most common live in tropical or subtropical areas. They are nocturnal and feed principally on insects and other arthropods. They are large arachnids but do not attack man spontaneously. They have a venomous sting. Their medical significance varies considerably and is dependent on their habits and venom potency rather than on their size. At most, the sting is equivalent to that of a hornet but certain species possess a highly toxic venom potentially fatal to humans. (From Dorland, 27th ed; Smith, Insects and Other Arthropods of Medical Importance, 1973, p417; Barnes, Invertebrate Zoology, 5th ed, p503)Antigens, Polyomavirus Transforming: 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.HLA Antigens: 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.Helix (Snails): A genus of chiefly Eurasian and African land snails including the principal edible snails as well as several pests of cultivated plants.Antigens, Fungal: Substances of fungal origin that have antigenic activity.Immunoglobulin G: The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.Epitopes: Sites on an antigen that interact with specific antibodies.Antigens, CD: 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.Antigens, Helminth: Any part or derivative of a helminth that elicits an immune reaction. The most commonly seen helminth antigens are those of the schistosomes.Crustacea: A large subphylum of mostly marine ARTHROPODS containing over 42,000 species. They include familiar arthropods such as lobsters (NEPHROPIDAE), crabs (BRACHYURA), shrimp (PENAEIDAE), and barnacles (THORACICA).Immunization: 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).H-2 Antigens: The major group of transplantation antigens in the mouse.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.Antibodies, Monoclonal: Antibodies produced by a single clone of cells.Monophenol Monooxygenase: An enzyme of the oxidoreductase class that catalyzes the reaction between L-tyrosine, L-dopa, and oxygen to yield L-dopa, dopaquinone, and water. It is a copper protein that acts also on catechols, catalyzing some of the same reactions as CATECHOL OXIDASE. EC 1.14.18.1.T-Lymphocytes: 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.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.Amino Acid Sequence: 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.Carcinoembryonic Antigen: 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.Antibody Specificity: 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.Antigens, Viral, Tumor: 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.Mice, Inbred BALB CAntigens, Tumor-Associated, Carbohydrate: 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.Arachnida: A class of Arthropoda that includes SPIDERS; TICKS; MITES; and SCORPIONS.Immunoglobulin M: 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.HLA-DR Antigens: 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.Receptors, Antigen, T-Cell: 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.Haptens: Small antigenic determinants capable of eliciting an immune response only when coupled to a carrier. Haptens bind to antibodies but by themselves cannot elicit an antibody response.Histocompatibility Antigens Class II: 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.Cross Reactions: Serological reactions in which an antiserum against one antigen reacts with a non-identical but closely related antigen.Histocompatibility Antigens: 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.Proliferating Cell Nuclear Antigen: 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.Immune Sera: 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.Antibodies: 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).Adjuvants, Immunologic: Substances that augment, stimulate, activate, potentiate, or modulate the immune response at either the cellular or humoral level. The classical agents (Freund's adjuvant, BCG, Corynebacterium parvum, et al.) contain bacterial antigens. Some are endogenous (e.g., histamine, interferon, transfer factor, tuftsin, interleukin-1). Their mode of action is either non-specific, resulting in increased immune responsiveness to a wide variety of antigens, or antigen-specific, i.e., affecting a restricted type of immune response to a narrow group of antigens. The therapeutic efficacy of many biological response modifiers is related to their antigen-specific immunoadjuvanticity.B-Lymphocytes: 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.Prostate-Specific 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.O Antigens: 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)Receptors, Antigen, B-Cell: 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.Antigen-Antibody Reactions: The processes triggered by interactions of ANTIBODIES with their ANTIGENS.Lymphocyte Activation: 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.Spleen: An encapsulated lymphatic organ through which venous blood filters.Catechol Oxidase: An enzyme of the oxidoreductase class that catalyzes the reaction between catechol and oxygen to yield benzoquinone and water. It is a complex of copper-containing proteins that acts also on a variety of substituted catechols. EC 1.10.3.1.Antigens, CD15: 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.Trinitrobenzenes: Benzene derivatives which are substituted with three nitro groups in any position.Snails: Marine, freshwater, or terrestrial mollusks of the class Gastropoda. Most have an enclosing spiral shell, and several genera harbor parasites pathogenic to man.Molting: Periodic casting off FEATHERS; HAIR; or cuticle. Molting is a process of sloughing or desquamation, especially the shedding of an outer covering and the development of a new one. This phenomenon permits growth in ARTHROPODS, skin renewal in AMPHIBIANS and REPTILES, and the shedding of winter coats in BIRDS and MAMMALS.HLA-A2 Antigen: A specific HLA-A surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-A*02 allele family.Antigens, CD8: 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.Cancer Vaccines: Vaccines or candidate vaccines designed to prevent or treat cancer. Vaccines are produced using the patient's own whole tumor cells as the source of antigens, or using tumor-specific antigens, often recombinantly produced.Copper: A heavy metal trace element with the atomic symbol Cu, atomic number 29, and atomic weight 63.55.Hypersensitivity, Delayed: An increased reactivity to specific antigens mediated not by antibodies but by cells.Blood Group Antigens: Sets of cell surface antigens located on BLOOD CELLS. They are usually membrane GLYCOPROTEINS or GLYCOLIPIDS that are antigenically distinguished by their carbohydrate moieties.Oxygen: An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.Hepatitis B Surface Antigens: 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.Immunoelectrophoresis: 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.Antigens, CD3: 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).HLA-A Antigens: 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.Antibodies, Bacterial: Immunoglobulins produced in a response to BACTERIAL ANTIGENS.Immunoglobulin Idiotypes: 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.Dinitrobenzenes: Benzene derivatives which are substituted with two nitro groups in the ortho, meta or para positions.Histocompatibility Antigens Class I: 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.Mice, Inbred C57BLMolecular Weight: The sum of the weight of all the atoms in a molecule.Gastropoda: A class in the phylum MOLLUSCA comprised of SNAILS and slugs. The former have coiled external shells and the latter usually lack shells.Bromthymol Blue: A pH sensitive dye that has been used as an indicator in many laboratory reactions.Arthropod Proteins: Proteins synthesized by organisms belonging to the phylum ARTHROPODA. Included in this heading are proteins from the subdivisions ARACHNIDA; CRUSTACEA; and HORSESHOE CRABS. Note that a separate heading for INSECT PROTEINS is listed under this heading.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Rabbits: 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.Antibody-Producing Cells: Cells of the lymphoid series that can react with antigen to produce specific cell products called antibodies. Various cell subpopulations, often B-lymphocytes, can be defined, based on the different classes of immunoglobulins that they synthesize.HLA-D Antigens: 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.Antibodies, Anti-Idiotypic: Antibodies which react with the individual structural determinants (idiotopes) on the variable region of other antibodies.Receptors, Antigen: Molecules on the surface of B- and T-lymphocytes that recognize and combine with specific antigens.Antigens, CD45: 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.Immunity, Cellular: 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.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Hepatitis B Antigens: 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.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Antigens, CD4: 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.Dendritic Cells: 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).Peptide Fragments: Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.Lymnaea: A genus of dextrally coiled freshwater snails that includes some species of importance as intermediate hosts of parasitic flukes.Antigens, CD1: 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.Ovalbumin: An albumin obtained from the white of eggs. It is a member of the serpin superfamily.Dose-Response Relationship, Immunologic: A specific immune response elicited by a specific dose of an immunologically active substance or cell in an organism, tissue, or cell.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.Antigens, T-Independent: Antigens which may directly stimulate B lymphocytes without the cooperation of T lymphocytes.Hybridomas: Cells artificially created by fusion of activated lymphocytes with neoplastic cells. The resulting hybrid cells are cloned and produce pure MONOCLONAL ANTIBODIES or T-cell products, identical to those produced by the immunologically competent parent cell.Antigen-Antibody Complex: 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.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.HLA-B 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.Lymphocyte Cooperation: T-cell enhancement of the B-cell response to thymic-dependent antigens.Astacoidea: A superfamily of various freshwater CRUSTACEA, in the infraorder Astacidea, comprising the crayfish. Common genera include Astacus and Procambarus. Crayfish resemble lobsters, but are usually much smaller.Antigens, Differentiation: 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.Neutral Red: A vital dye used as an indicator and biological stain. Various adverse effects have been observed in biological systems.Cells, Cultured: 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.Lymphocytes: 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.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Immune Tolerance: 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.Ficoll: A sucrose polymer of high molecular weight.Cloning, Molecular: 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.Binding Sites, Antibody: Local surface sites on antibodies which react with antigen determinant sites on antigens (EPITOPES.) They are formed from parts of the variable regions of FAB FRAGMENTS.Hemolytic Plaque Technique: A method to identify and enumerate cells that are synthesizing ANTIBODIES against ANTIGENS or HAPTENS conjugated to sheep RED BLOOD CELLS. The sheep red blood cells surrounding cells secreting antibody are lysed by added COMPLEMENT producing a clear zone of HEMOLYSIS. (From Illustrated Dictionary of Immunology, 3rd ed)Flow Cytometry: 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.Protein Conformation: The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).Immunoglobulins: 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.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.MART-1 Antigen: 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.Immunity, Humoral: Antibody-mediated immune response. Humoral immunity is brought about by ANTIBODY FORMATION, resulting from TH2 CELLS activating B-LYMPHOCYTES, followed by COMPLEMENT ACTIVATION.Vaccination: Administration of vaccines to stimulate the host's immune response. This includes any preparation intended for active immunological prophylaxis.Vaccines: Suspensions of killed or attenuated microorganisms (bacteria, viruses, fungi, protozoa), antigenic proteins, synthetic constructs, or other bio-molecular derivatives, administered for the prevention, amelioration, or treatment of infectious and other diseases.Species Specificity: 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.Peptides: 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.Allosteric Regulation: The modification of the reactivity of ENZYMES by the binding of effectors to sites (ALLOSTERIC SITES) on the enzymes other than the substrate BINDING SITES.Immunization, Passive: Transfer of immunity from immunized to non-immune host by administration of serum antibodies, or transplantation of lymphocytes (ADOPTIVE TRANSFER).
  • Further analyses show that the early stress-induced increase in T cell memory may stimulate the robust increase in infiltrating lymphocyte and macrophage numbers observed months later at a novel site of antigen reexposure. (physiology.org)
  • a ) therapeutic function, ( b ) immunogenicity, ( c ) role of the antigen in oncogenicity, ( d ) specificity, ( e ) expression level and percent of antigen-positive cells, ( f ) stem cell expression, ( g ) number of patients with antigen-positive cancers, ( h ) number of antigenic epitopes, and ( i ) cellular location of antigen expression. (aacrjournals.org)
  • The purpose of the National Cancer Institute pilot project to prioritize cancer antigens was to develop a well-vetted, priority-ranked list of cancer vaccine target antigens based on predefined and preweighted objective criteria. (aacrjournals.org)
  • We report on the development of a prioritized list of cancer vaccine target antigens using well-vetted criteria generated by expert panels. (aacrjournals.org)
  • The approach is called the multiple antigen peptide system (MAP) and it utilizes a simple scaffolding of a low number of sequential levels (n) of a trifunctional amino acid as the core matrix and 2n peptide antigens to form a macromolecule with a high density of peptide antigens of final Mr 10,000. (pnas.org)
  • The MAP model chosen for study was an octa-branching MAP consisting of a core matrix made up of three levels of lysine and eight amino terminals for anchoring peptide antigens. (pnas.org)
  • However, while vaccines have proven to be effective in combating pathogenic microorganisms, based on the immune recognition of these foreign antigens, vaccines aimed at inducing effective antitumor activity are still unsatisfactory. (asm.org)
  • The hallmark of immune response in the intestine is one of tolerance or active suppression of immunity against non-pathogens (commensal flora, dietary antigens). (immunetolerance.org)
  • The unique nature of the mucosal immune response may be the consequence of an enormous antigenic burden of dietary antigens and commensal bacteria that are in constant contact with the intestinal epithelium. (lww.com)
  • The antigen specificity of the n -butyrate-induced T cell tolerance makes butyrate a good candidate for an immunotherapeutic agent. (aspetjournals.org)
  • This consistency was not caused by selectivity of HLA class II molecules because the donors expressed a diversity of HLA antigens, but was largely a result of the substrate-specificity of the endosomal proteases Cathepsin D and E. There was a significant correlation between high susceptibility to Cathepsin D digestion and the capacity to stimulate primary T cell responses ( P = 0.00006). (asnjournals.org)
  • The elucidation and weighting of criteria to assess cancer antigens will assist investigators in the immunotherapy field in determining the characteristics and the experimental data required to select the most promising antigens for further development and testing in clinical trials. (aacrjournals.org)
  • Nevertheless, there is consensus that optimally designed cancer vaccine trials combining the best antigens with the most effective immunotherapy agents might yield positive clinical results. (aacrjournals.org)
  • The clonotypic surface Ig receptor expressed by malignant B cells, idiotype, is a tumor-specific antigen and an attractive target for active immunotherapy. (jci.org)
  • Such antigenic epitopes may serve as candidates for novel peptide-vaccine strategies, and as tools to selectively expand tumor antigen-specific T cells for adoptive immunotherapy and for monitoring T cell immunity in vaccinated patients. (jci.org)
  • Active immunotherapy is aimed either at eliciting a specific de novo host immune response against selected tumor antigens (Ags) by employing cancer vaccines or at amplifying the existing antitumor immune response by administering nonspecific proinflammatory molecules or adjuvants. (asm.org)
  • Two of the proteins in this family are exclusively or predominantly expressed in the prostate, as well as in prostate cancer, and thus members of this family have been termed "STEAP" (Six Transmembrane Epithelial Antigen of the Prostate). (freepatentsonline.com)
  • Subsequently, it was further documented that RP215 not only reacts with the epitope of immunoglobulin heavy chains, but also many other immunoglobulin superfamily (IgSF) proteins including antigen receptors, such as immunoglobulins and T-cell receptors, as well as cell adhesion molecules [ 3 , 4 ]. (omicsonline.org)
  • Subsequently, numerous studies have found that animals that were fed proteins such as ovalbumin or sheep erythrocytes do not respond as well to these antigens when subsequently immunized but do respond normally to other antigens. (immunetolerance.org)
  • Immune response to the hepatitis B antigen in the RTS,S/AS01 malaria vaccine, and co-administration with pneumococcal conjugate and rotavirus vaccines in African children: a randomized controlled trial. (bioportfolio.com)
  • Thus, the MAP provided a general, but chemically unambiguous, approach for the preparation of carrier-bound antigens of predetermined and reproducible structure and might be suitable for generating vaccines. (pnas.org)
  • This review aims to describe the vast spectrum of tumor antigens and strategies to develop cancer vaccines. (asm.org)
  • In this context, considering the disappointing results up to now, the quest for specific and selective tumor antigens for developing tumor-specific cancer vaccines, optimal delivery systems (i.e., dendritic cell [DC]-based vaccines), adjuvants, and strategies to overcome immune tolerance and regulatory T (Treg) cell responses is the main goal for several research groups and leading health care companies. (asm.org)
  • Compounds with the capacity to induce antigen-specific unresponsiveness in CD4 + T cells can in some clinical situations be more beneficial than general immune suppressants. (aspetjournals.org)
  • Newly synthesized ester, ester/amide, and amide derivatives of butyrate with the capacity to induce antigen-specific T cell unresponsiveness in vivo and in vitro were tested here. (aspetjournals.org)
  • In addition to its effects on tumor cells, n -butyrate has been shown to induce antigen-specific unresponsiveness in CD4 + T cells in vivo ( Gilbert and Weigle, 1993 ). (aspetjournals.org)
  • 7 ) introduced the concept of low and high dose oral tolerance (analogous to systemic tolerance) where low dose feeding regimenns induced the activation of regulatory cells whereas higher doses resulted in deletion or induction of anergy in antigen reactive cells ( 8 ). (lww.com)
  • In low dose oral tolerance, antigen reactive CD4+ T cells were shown to secrete regulatory cytokines such as TGFβ, IL10 and IL4. (lww.com)
  • Random peptide microarrays of even limited diversity may serve as a useful tool to prioritize candidates for epitope mapping or antigen identification. (mcponline.org)
  • They are a mixture of immunoglobulin molecules secreted against a specific antigen , each recognising a different epitope . (bionity.com)
  • Autoreactive T cells in patients with Goodpasture's disease are specific for epitopes in the Goodpasture antigen (the NC1 domain of the α3 chain of type IV collagen) that are rapidly destroyed during antigen processing to a degree that diminishes their presentation to T cells. (asnjournals.org)
  • We hypothesized that patients' autoreactive T cells exist because antigen processing prevents presentation of the self-epitopes they recognize, circumventing specific tolerance mechanisms. (asnjournals.org)
  • 1 Peripheral controls are thought to be evoked when autoreactive T cells recognize self-epitopes presented by antigen-presenting cells (APC) in benign environments and can lead to autoreactive T cells being deleted, rendered unresponsive (anergic), or directed to develop one of probably several anti-inflammatory phenotypes (regulatory T cells). (asnjournals.org)
  • In B cell malignancies, the clonotypic surface Ig expressed by malignant B cells, idiotype (Id), is a tumor-specific antigen ( 4 - 6 ) and, therefore, provides a unique opportunity to target the antitumor immune responses. (jci.org)
  • With a variable antigen-binding region that acts as a surrogate antigen for CA-125, abagovomab may stimulate the host immune system to elicit humoral and cellular immune responses against CA-125-positive tumor cells, resulting in inhibition of tumor cell proliferation. (cancer.gov)
  • 3 subcutaneous injections of ex vivo-generated autologous dendritic cell vaccine: 1) autologous dendritic cell vaccine (DC/PC3): ex vivo generated autologous dendritic cells pulsed with apoptotic PC3 cells and 2) pulsed with apoptotic PC3-M1 cells (control apoptotic cells) and 3) pulsed with KLH (control antigen). (clinicaltrials.gov)
  • Dendritic cells (DCs) and Foxp3-expressing CD4 + regulatory T (Treg) cells play non-redundant roles in the maintenance of peripheral tolerance to self-antigens, thereby preventing fatal autoimmunity. (soc-bdr.org)
  • Previous studies have shown that whereas chronic stress is immunosuppresive, acute stress experienced at the time of secondary antigen exposure has potent immunoenhancing effects with respect to skin immune function ( 14 ). (physiology.org)
  • The invention further includes a composition comprising the multivalent anti-serum and a plurality of labeled antigens and non-labeled antigens. (freepatentsonline.com)
  • 8. In a method for the simultaneous multiple immunoassay of a plurality of antigens in a biological tissue or fluid, wherein a multi-valent anti-serum is combined with said biological tissue or fluid to form complexes with said plurality of antigens, said complexes being capable of detection in an assay, the improvement comprising employing the anti-sera of claim 6 to form said complexes. (freepatentsonline.com)
  • For both cell lines, RP215 and anti-antigen receptors were found to regulate similarly and consistently a number of genes including NFκB-1, IgG, P21, Cyclin D1, ribosomal P1 and c-fos with only exceptions for EGFR and ribosomal P0. (omicsonline.org)
  • Based on these preliminary observations, it can be proposed that apoptosis of the two cancer cell lines was induced similarly by RP215 and anti-antigen receptors through consistent regulations of the same groups of genes. (omicsonline.org)
  • Many of the ranked immunotherapeutic agents are effective as components of cancer vaccine regimens in preclinical models, but this abundance of promising opportunities raises immediate questions as to which antigen or sets of antigens are most appropriate for codevelopment. (aacrjournals.org)
  • Our current effort to prioritize cancer antigens represents the logical next step in attempting to focus translational efforts on cancer vaccine regimens with the highest potential for success. (aacrjournals.org)
  • 2. A method of producing an anti-sera suitable for use in a simultaneous multiple immunoassay of a plurality of antigens in a biological tissue or fluid comprising immunizing an animal by injection with a plurality of antigens and eliciting a multivalent anti-sera from said animal capable of complexing a plurality of antigens. (freepatentsonline.com)
  • 10. A composition suitable for use in a simultaneous multiple immunoassay of a plurality of antigens in a biological tissue or fluid comprising the anti-sera of claim 6 and a plurality of labeled antigens corresponding to the antigens to be detected. (freepatentsonline.com)