HLA-DMB


HLA class II histocompatibility antigen, DM beta chain is a protein that in humans is encoded by the HLA-DMB gene.

Function

HLA-DMB belongs to the HLA class II beta chain paralogues. This class II molecule is a heterodimer consisting of an alpha and a beta chain, both anchored in the membrane. It is located in intracellular vesicles. DM plays a central role in the peptide loading of MHC class II molecules by helping to release the CLIP molecule from the peptide binding site. Class II molecules are expressed in antigen presenting cells. The beta chain is approximately 26-28 kDa and its gene contains 6 exons. Exon one encodes the leader peptide, exons 2 and 3 encode the two extracellular domains, exon 4 encodes the transmembrane domain and exon 5 encodes the cytoplasmic tail.

Clinical significance

HLA-DMB is upregulated in tumor tissue of Caucasian but not African patients. Its role in tumor immunology is undefined but has been shown to positively correlated with increased T-cell infiltration and improved prognosis in ovarian cancer. Differential immune processes mediated by HLA-DMB may contribute to the disparity in cancer outcome.