Human leukocyte antigen B27 heavy chain homodimer (HLA-B272) (HLA-B272)

The Human leukocyte antigen B27 (HLA-B27) heavy chain homodimer, often abbreviated as HLA-B272, is a non-canonical, dimeric form of the HLA-B27 MHC class I molecule (Bowness, P., et al., 1999, Journal of Immunology). Unlike the standard heterotrimeric form which consists of a heavy chain, beta-2 microglobulin, and a peptide, HLA-B27 has a unique propensity to fold slowly and form disulfide-linked homodimers via its Cys67 residue (Ranganathan, V., et al., 2017, Frontiers in Immunology). These homodimers are expressed on the cell surface of monocytes and lymphocytes in patients with spondyloarthropathies and act as ligands for immune receptors such as KIR3DL2 and LILRB2 (Kollnberger, S., et al., 2002, Journal of Immunology). The interaction between HLA-B272 and KIR3DL2 on Th17 cells promotes the survival and pro-inflammatory activity of these cells, contributing significantly to the pathogenesis of ankylosing spondylitis (Bowness, P., 2015, Nature Reviews Rheumatology). Consequently, the HLA-B27 homodimer is considered a specific therapeutic target for treating HLA-B27-associated inflammatory diseases, with experimental monoclonal antibodies like HD6 demonstrating the potential to block these pathogenic interactions without affecting the normal heterotrimeric HLA-B27 (Shaw, J., et al., 2014, Arthritis & Rheumatology).

Other names

B27-HC2HLA-B27 homodimerHLA-B*27 heavy chain dimerB272HLA-B27 heavy chain-only formB27-HC homodimer

Selective binding and neutralization of the HLA-B27 homodimer to prevent interaction with pro-inflammatory receptors such as KIR3DL2 and LILRB2 (ILT4), thereby inhibiting the expansion of pathogenic Th17 cells and reducing IL-17 production.