| 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 i.e. 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. (12 Dec 1998) |
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| HIV antigens | Antigens associated with specific proteins of the human adult T-cell immunodeficiency virus (HIV); also called HTLV-III-associated and lymphadenopathy-associated virus (lav) antigens. (12 Dec 1998) |
| HLA-a antigens | <immunology> 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. (12 Dec 1998) |
| HLA antigens | <immunology> A complex family of genetically inherited proteins which are found on the surface of cells throughout the body. They determine the match between patient and potential donor in bone marrow transplantation. These factors are inherited from the mother and father and so the chance of having the same HLA antigens between siblings is 1 in 4. See: human lymphocyte antigens. (20 Jun 2000) |
| HLA-b antigens | <immunology> 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. (12 Dec 1998) |
| HLA-c antigens | <immunology> Class I human histocompatibility (HLA) antigens encoded by a small cluster of structural genes at the c locus on chromosome 6. They have significantly lower immunogenicity than the HLA-a and -b determinants and are therefore of minor importance in donor/recipient crossmatching. Their primary role is their high-risk association with certain disease manifestations (e.g., spondylarthritis, psoriasis, multiple myeloma). (12 Dec 1998) |
| HLA-d antigens | <immunology> 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 aetiology. (12 Dec 1998) |
| HLA-dp antigens | <immunology> A group of the d-related HLA antigens (human) found to differ from the dr antigens in genetic locus and therefore inheritance. These antigens are polymorphic glycoproteins comprising alpha and beta chains and are found on lymphoid and other cells, often associated with certain diseases. (12 Dec 1998) |
| HLA-dq antigens | <immunology> A group of the d-related HLA antigens found to differ from the dr antigens in genetic locus and therefore inheritance. These antigens are polymorphic glycoproteins comprising alpha and beta chains and are found on lymphoid and other cells, often associated with certain diseases. (12 Dec 1998) |
| HLA-dr antigens | <immunology> A group of d-related human leukocyte antigens that are polymorphic glycoproteins found on lymphoid cells. They consist of alpha and beta chains and their inheritance differs from that of the dq and dp antigens; their presence seems to be associated with certain skin diseases like pemphigus vulgaris, dermatitis herpetiformis, and type I diabetes. (12 Dec 1998) |
| HTLV-blv antigens | Antigens associated with the HTLV-blv viruses. Htlv-I antigens and HTLV-II antigens belong to this group. (12 Dec 1998) |
| HTLV-I antigens | Antigens associated with the HTLV-I virus. (12 Dec 1998) |
| HTLV-II antigens | Antigens associated with the HTLV-II virus. (12 Dec 1998) |
| Hu antigens | he antigens |
| human leukaemia-associated antigens | Antigen's on the surface of leukaemic cells which seem not to be present on the surfaces of the same type of normal cells; the myeloblast antigen of acute myelogenous leukaemia found in chronic myelogenous leukaemia is thought to be associated with a "blastic" transformation. (05 Mar 2000) |