IMMUNOLOGY

Detailed explanation-1: -Human leukocyte antigens (HLA) are a group of identification molecules located on the surface of all cells in a combination that is almost unique for each person, thereby enabling the body to distinguish self from nonself. This group of identification molecules is also called the major histocompatibility complex.

Detailed explanation-2: -major histocompatibility complex (MHC), group of genes that code for proteins found on the surfaces of cells that help the immune system recognize foreign substances. MHC proteins are found in all higher vertebrates. In human beings the complex is also called the human leukocyte antigen (HLA) system.

Detailed explanation-3: -MHC class I or major histocompatibility complex type 1 is a diverse set of cell surface receptors expressed on all nucleated cells in the body, as well as platelets. In humans, MHC also has the name HLA (human leukocyte antigen), and these are three subtypes, HLA-A, HLA-B, and HLA-C.

Detailed explanation-4: -Cytotoxic T cells recognize foreign peptides in association with class I MHC proteins, whereas helper T cells recognize foreign peptides in association with class II MHC proteins.