monoclonal antibody

monoclonal antibody

n.

Any of a class of highly specific antibodies produced by the clones of a single hybrid cell formed in the laboratory by the fusion of a B cell with a tumor cell and widely used in medical and biological research.

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Monoclonal antibody

A protein substance which is produced in the laboratory by a single population of cells. They are being tested as a possible form of cancer treatment.

Mentioned in: Cutaneous T-Cell Lymphoma, Neuroblastoma

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monoclonal antibody (MAB)

Etymology: Gk, monos, single, klon, twig; Gk, anti + AS, bodig, body

an antibody produced in a laboratory from a single clone of B lymphocytes. All MABs produced from the same clone are identical and have the same antigenic specificity.

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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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monoclonal antibody

MAb, MoAb Diagnostics MAbs are used in diagnostics by radioactively-labelling MAbs to target malignant cells, detect metastases, and screen body fluids for microorganisms or measure levels of circulating hormones. MAbs are used in pathology to differentiate tumor subtypes with batteries of MAbs against intermediate filaments or membrane antigens. See Hybridoma Immunology A highly specific antibody formed by a clone of B lymphocytes, either naturally–eg, in cold hemagglutinin disease, plasma cell dyscrasia, or produced synthetically by fusing an immortal cell–mouse myeloma to a cell producing an antibody against a desired antigen. See Monoclonal immunoglobulin Oncology MAbs are viewed as a therapy for CA, as they directly inhibit the growth of certain tumors, can be chemically bound to toxins that are lethal to malignant cells, stimulate the complement system–a nonspecific arm of the immune system, which may destroy malignant cells, can be used to purge the BM of malignant cells, form the basis for CA vaccines, and for drug delivery systems Adverse effects Allergic reactions, fevers, chills, hypotension, liver and kidney problems. See Biological response modifier, Clone bank, HAMA. Cf Humanized antibody.