What is the function of histocompatibility complex?
1 Answer
The phenomenon of the rejection of foreign tissue is the outcome of an immune response to cell-surface molecules, called as Major histocompatibility antigens,It is a part of adaptive immunity which is very specific to pathogens.
Explanation:
Major histocompatibility complexes are cell surface proteins also known as human leucocyte antigens(HLA).The MHC is referred to as the HLA complex in humans and as the H-2 complex in mice.Naive T cells are activated to stimulate effector T cells for the first time they encounter their specific antigen in the form of a peptide:MHC complex on the surface of an activated antigen-presenting cell (APCs).MHC are highly polymorphic means alternative forms of the gene, or alleles, exist at each locus among the population.
There are three classes of MHC:
Class 1 MHC:These are glycoproteins expressed on
the surface of nearly all nucleated cells and the main function is the presentation of peptide antigens to Tc (cytotoxic cells)cells.It is CD8+ means thymocytes express CD8+ forms Tc cells.
Class 2 MHC:These are glycoproteins expressed
mainly on antigen-presenting cells (macrophages,
dendritic cells, and B cells), and present processed
antigenic peptides to TH(helper cells).It is CD4+,means thymocytes express CD4+ forms T helper cells.
Class 3 MHC genes:These include components of the complement
system and molecules involved in inflammation.
