Question

How does the MHC aid the adaptive immune system recognizing antigen? TTT Arla 3 (12pt) TEE 2

Answer 1

Ans.

The major histocompatibility complex or MHC is a groups of genes that encodes cell surface proteins that control the adaptive immune system.The primary role of MHC is in the antigen presentation where it display peptide fragments for recognition by the appropriate T-cells,which is an important process in the adaptive immune response.The T-cells receptors can recognize only those antigen fragments that in complex with the MCH proteins.The detection of specific antigen and its response by the immune system is controlled by these MHC molecules.

When pathogen invades a cell,following its phagocytosis,the fragments of these pathogens are then complexed with MHC proteins and are displayed on the macrophage or dendritic cells surface of the innate immune system.If the cell is encountered by dangerous pathogen,a co-receptor called B7 is produced,which is an important step for the activation of adaptive immune response which will then develop a memory or pathogen threats.The helper T-cells with a receptor that recognizes the MHC complexed antigen fragment will be stimulated to proliferate and activated in case the co-receptor is also displayed.Once the helper T-cells are activated by an antigen presenting cells,it signals the B-cells and cytotoxic T cells to initiate an immune response.