Small nuclear ribonucleoprotein-associated proteins B and B' (58-72) peptide presented by HLA-DR15 (SmB/B'58-72/HLA-DR15)

The SmB/B' (58-72) peptide presented by HLA-DR15 is a peptide-major histocompatibility complex (pMHC) that serves as a primary autoantigenic target in Systemic Lupus Erythematosus (SLE). The SmB and SmB' proteins, encoded by the SNRPB gene, are essential components of the spliceosome, and the 58-72 residue segment (sequence: GTGNVGQQPPGIRRP) is recognized as a dominant epitope for CD4+ T cells in patients with the HLA-DR15 (specifically HLA-DRB1*15:01) haplotype (James et al., 1994, J Exp Med). Presentation of this specific peptide by HLA-DR15 molecules on antigen-presenting cells leads to the activation and expansion of autoreactive T-helper cells. These T cells subsequently drive the production of anti-Sm autoantibodies by B cells, which are highly specific for SLE and contribute to tissue damage through immune complex formation (Arbuckle et al., 2003, N Engl J Med). Because of its central role in the early stages of the autoimmune response, this pMHC complex is a high-priority target for antigen-specific immunotherapy. Therapeutic strategies under investigation aim to induce immune tolerance or selectively deplete the T-cell clones that recognize this complex, thereby treating the underlying cause of SLE while avoiding the side effects of global immunosuppression (Monneaux & Muller, 2002, Arthritis & Rheumatism). Current experimental approaches include the use of soluble pMHC monomers, tolerogenic nanoparticles, or peptide-based vaccines to modulate the immune response.

Other names

SmB/B' (58-72):HLA-DRB1*15:01 complexSmB/B' 58-72 peptide-MHC II complexSNRPB (58-72)/HLA-DR15SmB/B' autoantigenic epitope

Induction of antigen-specific immune tolerance or deletion of autoreactive CD4+ T cells.