Anti- Human HLA-B7 (BB7.1)

The monoclonal antibody BB7.1 is directed against the HLA-B7 antigen, a polymorphic surface protein of the human MHC class I family. HLA-B7 is expressed on all nucleated cells and forms a heterodimer composed of a specific transmembrane HLA-B heavy chain and a non-covalently associated beta-2 microglobulin light chain 1.

MHC class I molecules, including HLA-B7, play a central role in adaptive immunity by presenting intracellularly derived peptides to CD8⁺ T cells. These peptides may originate from endogenous proteins or, through cross-presentation, from extracellular sources. The primary ligands for MHC class I molecules are the T cell receptor (TCR) and the co-receptor CD8, which together mediate antigen-specific immune responses 1.

HLA-B7 is one of the most studied alleles within the HLA-B locus, and hundreds of polymorphic variants have been identified. Typing for these alleles is routinely performed in the context of organ and hematopoietic stem cell transplantation to ensure compatibility and reduce the risk of graft rejection 1.
In addition to its role in transplantation and immune surveillance, HLA-B7 is increasingly relevant in the field of immunopeptidomics. Antibodies targeting MHC class I molecules, such as BB7.1, are used to isolate peptide-MHC complexes for analysis by high-performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). This approach enables the identification of tumor-specific neoantigens and viral epitopes, contributing to the development of personalized immunotherapies 2.