a group of genes. They produce proteins which help to control signalling between antigen presenting cells and lymphocytes.

A large cluster of highly polymorphic genes that encode a family of cell-surface glycoproteins (MHC molecules) which bind intracellularly processed peptides and display them for recognition by T-cell antigen receptors. As well as controlling antigen recognition and the ability to mount an immune response to a given antigen, this region is responsible for tissue incompatibility.

see MHC

A set of genes found in all mammals whose products are primarily responsible for the rapid rejection of grafts between individuals, and funcion in signalling between lymphocytes and cells presenting antigen.

Part of the genome involved in the immune system's ability to target invading cells and leave one's own cells alone.

Cell-membrane receptors that bind to antigens and thus help initiate immune reactions.

set of genes producing proteins which mediate immunity

(also called human leukocyte antigens, HLAs) is the mechanism by which the immune system is able to differentiate between self and nonself cells.

is important in regulating the activity of all immune responses involving T-lymphocytes, as the T-lymphocyte receptor requires the presentation of foreign antigen with a class of MHC molecule. All cells express MHC class I but only a few specialised cells express MHC class II. These latter cells are termed antigen presenting cells and are important in controlling the extent to which an immunological reaction can be mounted. In the CNS, MHC class II expression is low and probably restricted to microglial cells

A group of genes in mammals that function especially in determining the histocompatibility antigens found on cell surfaces.

(MHC) - A group of genes that code for cell surface proteins that play a major role in histocompatibility (tissue compatibility; Latin: histo = tissue) in transplantation. Differences between the MHC proteins of a transplant donor and recipient are the major cause of transplant tissue rejection.

A group of genes that control several aspects of the immune response. They code for markers which go on the surface of all body cells and are recognised by the body as 'self', belonging to the body. These genes define a person's tissue type and are used to determine whether a transplant would be compatible or not.

Group of genes that code for proteins involved in transplantation rejection and the regulation of the immune response. In man they are located on chromosome 6.

A large set of cell surface antigens encoded by a family of genes. Foreign MHC markers trigger T-cell responses that may lead to the rejection of transplanted tissues and organs. Malpighian tubule(mal- pig-ee-un) A unique excretory organ of insects that empties into the digestive tract, removes nitrogenous wastes from the blood, and functions in osmoregulation.

The genetic loci that encode the histocompatibility antigens, cell-surface proteins that bind peptide fragments of foreign proteins, present them to T-lymphocytes, and induce an immune response.

Proteins recognised by T-cells in the immune response. Class I MHC molecules are involved in T-cell interactions and graft or organ transplant rejections.

two classes of molecules on cell surfaces. MHC class I molecules exist on all cells and hold and present foreign ANTIGENS to CD8 CYTOTOXIC T LYMPHOCYTES if the cell is infected by a VIRUS or other MICROBE. MHC class II molecules are found on the IMMUNE SYSTEM's ANTIGEN PRESENTING CELLS and display antigen to activate CD4 CELLS.

proteins whose major function is to present to the T cells peptides resulting from the fragmentation, or processing, of antigenic proteins.

an important region on the 6th chromosome in man, which in general controls the transplant rejection responses, and also the intensity of the immune response in general.

Two classes of molecules on cell surfaces. MHC class I molecules exist on all cells, and hold and present foreign antigens to CD8 cytotoxic T lymphocytes if the cell is infected by a virus or other microbe. MHC class II molecules are the billboards of the immune system. Peptides derived from foreign proteins are inserted into MHC's binding groove and displayed on the surface of antigen-presenting cells. These peptides are then recognized by T lymphocytes so that the immune system is alerted to the presence of foreign material. See Histocompatibility Testing.

molecules that are found on cell surfaces and display antigen; the antigen-MHC molecules may then interact with a T cell receptor.

the set of molecules making up the tissue type (MHC-I and MHC-II)

A group of genes that controls several aspects of the Imo response. MHC genes code for self markers on all body cells.

A cluster of genes on chromosome 6 in humans, encoding cell surface molecules that are polymorphic and that code for antigens which lead to rapid graft rejection between members of a single species which differ at these loci. Several classes of protein such as MHC class I and II proteins are encoded in this region. These in humans, are known as 'Human leukocyte antigens' (HLA).

the area on chromosome 6 containing genes that determine the structure of human leukocyte antigen (HLA) molecules

Originally recognized as antigens responsible for graft rejection in incompatible hosts after transplantation. These are molecules that bind with processed antigens and are displayed on the surface of cells. MHC class I molecules are displayed on non-immune cells and MHC class II on antigen-presenting cells

A group of genes that control aspects of the immune response. The products of these genes, the histocompatibility antigens, are present on every cell of the body and serve as markers to distinguish self from nonself cells. See also Antigen; Histocompatibility Testing.

A genetic region of chromosomes responsible for the production of products that function in cell to cell communication.

The major histocompatibility complex (MHC) is a large genomic region or gene family found in most vertebrates. It is the most gene-dense region of the mammalian genome and plays an important role in the immune system, autoimmunity, and reproductive success. The proteins encoded by the MHC are expressed on the surface of cells in all jawed vertebrates, and display fragments of molecules from invading microbes or dysfunctional cells (e.g. tumor cells) to a particular type of white blood cell called a T cell that has the capacity to kill or co-ordinate the killing of the microbe, infected cell or malfunctioning cell.