Technical Articles

MHC IIa molecules are a classic subtype of the major histocompatibility complex class II, primarily expressed on the surface of specialized antigen-presenting cells such as dendritic cells and B cells. Unlike MHC-I, which is primarily responsible for endogenous antigen presentation, MHC-IIa specifically presents exogenous antigen peptides to CD4 ⁺ T helper cells to initiate and regulate adaptive immune responses.