HLA A antigens, also known as human leukocyte antigen A antigens, are a group of proteins that are present on the surface of almost all cells in the human body. They play a crucial role in the immune system and are involved in the identification and elimination of foreign substances, such as bacteria, viruses, or other pathogens.
HLA A antigens are part of a larger family of proteins called human leukocyte antigens, or HLAs, which are encoded by a group of genes known as major histocompatibility complex (MHC) genes. These genes are located on chromosome 6 in humans.
Specifically, HLA A antigens are classified into different subtypes, or alleles, which are determined by small genetic variations within the HLA A gene. These alleles are inherited in a Mendelian fashion, with each individual inheriting one allele from their mother and one from their father.
HLA A antigens play a critical role in allorecognition, which is the process by which the immune system recognizes and discriminates between self and non-self cells. They act as markers on the surface of cells, allowing immune cells called T lymphocytes to distinguish between self-cells (those that belong to the individual) and foreign cells (those that do not belong).
These antigens are also important in the field of organ transplantation, as matching the HLA A antigens between a donor and recipient can reduce the risk of rejection. Additionally, HLA A antigens have been linked to various diseases, including autoimmune disorders, cancers, and infectious diseases, making them an area of interest for medical research.
