Major Histocompatibility Complex Molecule Class II (MHC class II)

Major histocompatibility complex (MHC) class II molecules are cell surface glycoproteins that play a critical role in the adaptive immune response. They are primarily expressed on professional antigen-presenting cells (APCs) and function to present processed peptide antigens derived from exogenous proteins to CD4+ T lymphocytes, thereby initiating and regulating antigen-specific immune responses. MHC class II molecules are heterodimers composed of an α chain and a β chain, both encoded within the MHC locus. These molecules are highly polymorphic, contributing to the diversity of antigen presentation and influencing susceptibility to autoimmune diseases. Deficiencies or mutations affecting MHC class II expression or function can lead to severe immunodeficiencies.

Other names

MHC-IIClass II MHCMHC class 2

Modulation of antigen presentation to CD4+ T cells (e.g., blocking peptide binding, altering MHC-II expression).