What is MHC restrictions?

MHC restriction refers to the requirement that T cells recognize antigens only when they are presented by Major Histocompatibility Complex (MHC) molecules. T cells, particularly CD4+ helper and CD8+ cytotoxic T cells, can only bind to specific peptides displayed on the surface of antigen-presenting cells in conjunction with their corresponding MHC class (Class I for CD8+ and Class II for CD4+). This mechanism ensures that T cells can identify and respond to infected or abnormal cells while maintaining self-tolerance. MHC restriction is crucial for the adaptive immune response and plays a significant role in organ transplantation and autoimmune diseases.