Antibody (redirected from Antibody repertoire)

antibody /an·ti·body/ (Ab) (an´ti-bod-e) an immunoglobulin molecule that reacts with a specific antigen that induced its synthesis and with similar molecules; classified according to mode of action as agglutinin, bacteriolysin, hemolysin, opsonin, or precipitin. Antibodies are synthesized by B lymphocytes that have been activated by the binding of an antigen to a cell-surface receptor. See immunoglobulin.

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anaphylactic antibody  IgE antibody causing anaphylaxis.

antimitochondrial antibodies  circulating antibodies directed against inner mitochondrial antigens seen in almost all patients with primary biliary cirrhosis.

antinuclear antibodies  (ANA) autoantibodies directed against components of the cell nucleus, e.g., DNA, RNA, and histones.

antireceptor antibodies  autoantibodies against cell-surface receptors, e.g., those directed against ß2-adrenergic receptors in some patients with allergic disorders.

antisperm antibody  (ASA) any of various surface-bound antibodies found on sperm after infection, trauma to the testes, or vasectomy; they interfere with the fertilization process or result in nonviable zygotes.

antithyroglobulin antibodies  those directed against thyroglobulin, demonstrable in about one-third of patients with thyroiditis, Graves' disease, and thyroid carcinoma.

blocking antibody 

1. one (usually IgG) that reacts preferentially with an antigen, preventing it from reacting with a cytotropic antibody (IgE), and producing a hypersensitivity reaction.

2. incomplete a.

complement-fixing antibody  one that activates complement when reacted with antigen: IgM and IgG fix complement by the classical pathway; IgA, by the alternative pathway.

complete antibody  one that reacts with the antigen in saline, producing an agglutination or precipitation reaction.

cytophilic antibody  cytotropic a.

cytotoxic antibody  any specific antibody directed against cellular antigens that, when bound to the antigen, activates the complement pathway or activates killer cells, resulting in cell lysis.

cytotropic antibody  any of a class of antibodies that attach to tissue cells through their Fc segments to induce the release of histamine and other vasoconstrictive amines important in immediate hypersensitivity reactions.

Donath-Landsteiner antibody  an IgG antibody directed against the P blood group antigen; it binds to red cells at low temperatures and induces complement-mediated lysis on warming, and is responsible for hemolysis in paroxysmal cold hemoglobinuria.

Forssman antibody  heterophile antibody directed against the Forssman antigen.

heteroclitic antibody  antibody produced in response to immunization with one antigen but having a higher affinity for a second antigen that was not present during immunization.

heterogenetic antibody , heterophil antibody, heterophile antibody antibody directed against heterophile antigens. Heterophile sheep erythrocyte agglutinins appear in the serum of patients with infectious mononucleosis.

immune antibody  one induced by immunization or by transfusion incompatibility, in contrast to natural antibodies.

incomplete antibody 

1. antibody that binds to erythrocytes or bacteria but does not produce agglutination.

2. a univalent antibody fragment, e.g., Fab fragment.

indium-111 antimyosin antibody  a monoclonal antibody against myosin, labeled with indium 111; it binds selectively to irreversibly damaged myocytes and is used in infarct avid scintigraphy.

monoclonal antibodies  chemically and immunologically homogeneous antibodies produced by hybridomas, used as laboratory reagents in radioimmunoassays, ELISA, and immunofluorescence assays.

natural antibodies  ones that react with antigens to which the individual has had no known exposure.

neutralizing antibody  one which, on mixture with the homologous infectious agent, reduces the infectious titer.

OKT3 monoclonal antibody  a mouse monoclonal antibody directed against T3 lymphocytes and used to prevent or treat organ rejection after transplantation.

panel-reactive antibody  (PRA)

1. the preexisting antibody against HLA antigens in the serum of a potential allograft recipient that reacts with a specific antigen in a panel of leukocytes, with a higher percentage indicating a higher risk of a positive crossmatch.

2. the percentage of such antibody in the recipient's blood.

P-K antibodies , Prausnitz-Küstner antibodies cytotropic antibodies of the immunoglobulin class IgE, responsible for cutaneous anaphylaxis.

protective antibody  one responsible for immunity to an infectious agent observed in passive immunity.

reaginic antibody  reagin.

saline antibody  complete a.

sensitizing antibody  anaphylactic a.

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an·ti·bod·y (nt-bd)

n.

1. Abbr. Ab A protein substance produced in the blood or tissues in response to a specific antigen, such as a bacterium or a toxin, that destroys or weakens bacteria and neutralizes organic poisons, thus forming the basis of immunity.

2. An immunoglobulin present in the blood serum or body fluids as a result of antigenic stimulus and interacting only with the antigen that induced it or with an antigen closely related to it.

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Antibody

A protein manufactured by a type of white blood cells called lymphocytes, in response to the presence of an antigen, or foreign protein, in the body. Because bacteria, viruses, and other organisms commonly contain many antigens, antibodies are formed against these foreign proteins to neutralize or destroy the invaders.

Mentioned in: AIDS, AIDS Tests, Alemtuzumab, Allergic Rhinitis, Allergies, Allergy Tests, Amebiasis, Anaphylaxis, Anthrax, Antimyocardial Antibody Test, Antinuclear Antibody Test, Aspergillosis, Ataxia-Telangiectasia, Blood Typing and Crossmatching, Brucellosis, Cholera, Coccidioidomycosis, Cold Agglutinins Test, Coombs' Tests, Cryptococcosis, Cytomegalovirus Antibody Screening Test, Delayed Hypersensitivity Skin Test, Detoxification, Discoid Lupus Erythematosus, Erythroblastosis Fetalis, Fifth Disease, Filariasis, Giardiasis, Goodpasture's Syndrome, Hemolytic Anemia, Hemorrhagic Fevers, Hepatitis A, Hepatitis B, Hepatitis C, Hepatitis D, Hepatitis E, Hepatitis G, Immune Complex Test, Immunoelectrophoresis, Immunoglobulin Deficiency Syndromes, Immunosuppressant Drugs, Infectious Mononucleosis, Japanese Encephalitis, Legionnaires' Disease, Maternal to Fetal Infections, Multiple Myeloma, Myasthenia Gravis, Noroviruses, Plasmapheresis, Polyglandular Deficiency Syndromes, Prostate-Specific Antigen Test, Rabies, Radiation Therapy, Respiratory Syncytial Virus Infection, Rubella Test, Serum Sickness, Shingles, Streptococcal Antibody Tests, Stress Reduction, Threadworm Infection, Tissue Typing, TORCH Test, Transfusion, Tuberculin Skin Test, Typhus, Vaginal Pain, Vasculitis, Waldenström's Macroglobulinemia, X-Linked Agammaglobulinemia

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antibody,

n any of a wide assortment of glycoproteins typically present in the bloodstream that attack antigens during an immune response.

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antibody (an´tibodē),

n 1. a specific substance that is produced by an animal as a reaction to the presence of an antigen and that reacts specifically with an antigen in some observable way.
n 2. an immunoglobulin (preferred term), essential to the immune system, produced by lymphoid tissue in response to bacteria, viruses, or other antigenic substances. Each type is identified by its action, agglutinins, bacteriolysins, opsonins, and precipitins. See also immunoglobulins.

antibody, antinuclear,

n an antibody having an affinity for the cell nuclei.

antibody formation,

n the response of the lymphatic system to the presence of foreign substances in the body such as bacteria, viruses, food substances, pollens, and other antigens.

antibody, monoclonal

n an antibody produced by a clone or genetically homogeneous population of hybrid cells.

antibody, specificity,

n the lymphatic system produces antibodies specific to each antigen. Viruses have the capacity to alter an antigen's genetic makeup, thereby creating a mutant antigen that requires new antibodies to combat it.

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antibody

specialized serum proteins produced by B lymphocytes in response to an immense number of different antigens (>10⁷) to which an animal may be exposed. Antibody produced by a particular antigen combines with that antigen only. The exquisite specificity of Ab for the antigen that stimulated its production is the basis for all antibody-antigen reactions both in vivo and in vitro. Antibodies are heterodimers composed of two light (L) and two heavy (H) chain polypeptide molecules. The amino termini of the L and H chains have a variable amino acid sequence V_L and V_H. The specificity of Ab for Ag is conferred by the V_L and V_H domains. There are five major classes of antibody, designated IgG, IgM, IgA, IgD and IgE. Abbreviated Ab or Ig. Called also immunoglubulin or gamma globulin. See also immunity.

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affinity purification of antibody

see immunofiltration.

anaphylactic antibody

antibody, usually IgE, formed after the first injection of certain allergens and responsible for the signs of anaphylaxis following subsequent exposures to the same allergen.

antibody-antigen reaction

the specific combination of antigen with homologous antibody resulting in the reversible formation of antibody-antigen complexes that differ in composition according to the antibody-antigen ratio. See also antigen.

antinuclear antibody (ANA)

autoantibodies directed against components of the cell nucleus, e.g. DNA, RNA and histones; they may be detected by immunofluorescence. A positive ANA test is characteristic of systemic lupus erythematosus, Sjögren's syndrome and rheumatoid arthritis.

anti-idiotype antibody

antibodies against the antibody variable region.

anti-immunoglobulin antibody

those produced against an immunoglobulin, often used as reagents to study immunoglobulin molecules.

antiplatelet antibody

see antiplatelet antibody.

antispermatozoal antibody

produced following entry of sperm into the bloodstream, e.g. following rupture of the epididymis as in Brucella ovis infections.

blocking antibody

circulating antibody (usually IgG) that reacts preferentially with an antigen, preventing it from reacting with a cell-bound antibody (IgE) and blocking the induction of anaphylaxis.

antibody classes

see immunoglobulin.

clonotypic antibody

clone specific antibody.

cold-reacting antibody

see cold agglutinin.

complement-fixing antibody

immunoglobulins of the IgG or IgM class which bind complement.

cross-reacting antibody

one that combines with an antigen other than, but structurally related to, the one that induced its production.

cytophilic antibody

cytotropic antibody (below).

cytotoxic antibody

that which binds antigens expressed on the cell surface, which may (a) activate the complement pathway or (b) activate killer cells, resulting in cell lysis.

cytotropic antibody

those that attach to tissue cells (such as IgE to mast cells and basophils) that have an Fc receptor.

antibody-dependent cell-mediated cytotoxicity (ADCC)

a cytotoxic reaction in which nonsensitized cells bearing Fc receptors recognize target cells that have antibody bound to antigen exposed in the cell membrane of the target cell.

fluorescent antibody

see fluorescence microscopy.

heteroclitic antibody

one with greater affinity for an antigen other than the one that stimulated its formation.

hormonal antibody

has been investigated mostly as a means of controlling fertility in animals. See also contraception.

humoral antibody

see humoral immunity.

immune antibody

one induced by immunization or by transfusion incompatibility, in contrast to natural antibodies.

incomplete antibody

an antibody which combines with antigen without producing an observable reaction such as agglutination; originally used to describe Rh antibodies.

maternal a's

those passively transferred from dam to fetus or neonate, transplacentally or via colostrum or yolk sac. See also passive immunity.

antibody-mediated cytotoxicity

damage to cells, especially erythrocytes, caused by the reaction of antibodies (IgG, IgM or IgA) with cell surface antigens.

antibody-mediated immunity

humoral immunity.

monoclonal antibody

see monoclonal antibodies.

natural a's

ones that react with antigens to which the individual has had no known exposure. The best examples are anti a and b antibodies present in serum of humans of blood group B and A, respectively.

neutralizing antibody

one that reduces, destroys or blocks infectivity of an infectious agent, particularly virus, by partial or complete destruction of the agent.

nonagglutinating antibody

see incomplete antibody (above).

polyclonal antibody

a collection of immunoglobulins that react against the same or different antigenic determinants of the one antigen molecule.

protective antibody

one responsible for immunity to an infectious agent.

reaginic antibody

see reagin and immunoglobulin E.

antibody repertoire

all the antibody specificities that can be produced by an individual.

saline antibody

complete antibody.

skin-sensitizing antibody

see reagin.

univalent antibody

see incomplete antibody (above).

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antibody Immunology An immunoglobulin produced by plasma cells, which has a specific amino acid sequence and specifically binds to the antigen(s)–eg, foreign proteins, microbes or toxins, that induced its synthesis; antibodies may bind to closely related antigens. See Acetylcholine receptor antibody, Anticardiolipin antibody, Anticentromere antibody, Anti-double-stranded DNA antibody, Anti-epidermal antibody, Anti-extractable nuclear antibody, Antigliadin antibody, Antihistone antibody, Anti-idiotype antibody, Anti-insulin antibody, Anti-islet cell antibody, Anti-Jo-1 antibody, Anti-LANA antibody, Antimicrosomal antibody, Antimitochondrial antibody, Antimyelin antibody, Antimyeloperoxidase antibody, Antineuronal-nuclear antibody, Antineutrophil cytoplasmic antibody, Antinuclear antibody, Antiparietal cell antibody, Anti-platelet antibody, Anti-PRP antibody, Anti-Purkinje cell antibody, Anti-receptor antibody, Anti-reticulin antibody, Anti-ribosomal antibody, Anti-Ro/SSA antibody, Anti-single-stranded DNA antibody, Anti-striated muscle antibody, Anti-thyroglobulin antibody, Antithyroid antibody, Antithyroid peroxidase antibody, Anti-tumor necrosis factor- α monoclonal antibody, Autoantibody, Bexxar radiolabeled monoclonal antibody, Secondary antibody, Binding antibody, Blocking antibody, Catabolic antibody, Catalytic antibody, Chimeric antibody, Core antibody, Cross-reactive antibody, Designer antibody, Enhancing antibody, Fluorescent treponemal antibody, Functional antibody, GAD antibody, Glutamic acid decarboxylase autoantibody, HAMA antibody, Heterophile antibody, HIV antibody, HTLA antibody, Humanized antibody, Immunoglobulin, Insulin receptor antibody, Intrinsic factor antibody, Islet antibody, Isotypic control antibody, Ku antibody, LW antibody, Miniantibody, MOC-31 antibody, Monoclonal antibody, Neutralizing antibody, Parietal cell antibody, Plantibody antibody, PM-1 antibody, Polyclonal antibody, Primary antibody, Purkinje cell antibody, RANA antibody, Scleroderma antibody, Sjögren antibody, Sm antibody, Smooth muscle antibody, Sperm antibody, Thyroid stimulating hormone receptor antibody, Trichinosis antibody, Warm antibody.