HLA class II DP beta 1*04 peptide–receptor complex (HLA-DPB1*04:01 complex)

The HLA class II DP beta 1*04 peptide–receptor complex is a cell-surface receptor composed of two subunits (DPα and DPβ, the latter encoded by the HLA-DPB1*04 allele), forming part of the major histocompatibility complex (MHC) class II pathway on human chromosome 6. This complex binds and displays extracellularly derived peptides on the surface of antigen-presenting cells such as dendritic cells, macrophages, and B cells for recognition by CD4+ T lymphocytes, initiating and regulating adaptive immune responses. HLA-DPB1*04:01 variants influence susceptibility to certain autoimmune diseases (notably granulomatosis with polyangiitis), can modulate responses to infections and cancer, and are important in transplantation medicine for matching donor and recipient compatibility. Novel structural studies reveal that this particular complex can bind peptides in both conventional and reverse orientations, broadening the repertoire of T cell responses.

Other names

HLA-DP (generic locus)HLA-DPB1*04-restricted peptide complexHLA-DPB1*04:01–peptide complexHuman leukocyte antigen DPB1*04MHC class II DPB1*04:01 complex

Presentation of extracellular peptide antigens to CD4+ T cells, triggering adaptive immune activation