Immunological terms

By Mrs. N Makandi Immunological terms Antigen • A substance which induces the formation of antibody. • A substance capable of reacting immune specifically with antibody

Antibody • A molecule produced by animals in response to antigen which has the particular property of combining specifically with the antigen which induced its formation.

Antigen presentation • This is the process by which certain cells in the body (Antigen presenting cells) express antigen on their surface in a form recognizable by a lymphocyte. Antigen presenting cell • This is a variety of cell type, which carry antigen in a form that can stimulate lymphocytes. Adjuvant • A substance that non specifically enhances the immune response to an antigen Bursa of fabricious • A lymphepithelial organ, found at the junction of the hind gut and the cloaca of birds, which is the site of B cell maturation. Baccile calmette guevin (BCG) it is an attenuated strain of mycobacterium tuberculosis used as a vaccine ,also used as an adjuvant or a biological response modifier in different circumstances. Chemotaxis • This is an increased directional migration of cells, particularly in response to concentration gradients of certain chemotactic factors.

Clone • This is a family of cells having a genetically identical constitution

Clonal selection • This is the fundamental basis of lymphocyte activation in which antigen selectively stimulates only those cells which express receptors for it to differentiate /divide. Cytokines • This is a genetic term for soluble molecules which mediate interaction between cells

Epitope • This is a single antigenic determinant. Functionally it is the portion of an antigen which combines with the antibody paratope.

Paratope • This is part of an antibody molecule which makes contact with the antigenic determinant (epitope)

Hapten • This is a small molecule which can act as an epitope but it is incapable by itself of eliciting an antibody response. Interleukins(IL1 – IL7) • This is a group of molecules involved in signaling between cells of the immune system

Idiotype • This is a single antigenic determinant on an antibody variable region

Isotype • This the genetic variation within a family of proteins or peptides such that every member of the species will have each isiotype of the representative family in its gene.

Monoclonal • Derived from a single clone e.g. monoclonal antibodies produced by a single clone and are homogeneous Polyclonal • This is a term describing the products of a number of different cell types.

Opsonization • This is a process by which phaghocytosis is facilitated by the deposition of opsonins e.g. antibody, C3b,

Opsonin • A molecule which when deposited on an antigen, enhances phaghocytosis •

Plasma cell • This is an antibody producing B cell which has reached the end of its differentiation pathway.