BK virus peptide–HLA class I complex (BKV-peptide-HLA-I)

The BK virus peptide–HLA class I complex is a molecular assembly consisting of a short antigenic peptide derived from the BK polyomavirus (BKV) proteins, such as the Large T-antigen or VP1 capsid protein, non-covalently bound to a Human Leukocyte Antigen (HLA) class I molecule on the surface of infected cells. This complex serves as the primary ligand for the T-cell receptors (TCRs) of CD8+ cytotoxic T lymphocytes, which are essential for controlling BKV replication in immunocompromised individuals. In patients undergoing kidney or hematopoietic stem cell transplantation, reactivation of BKV can lead to severe complications like BK virus-associated nephropathy (BKVAN) or hemorrhagic cystitis due to the lack of an effective T-cell response. Therapeutic strategies targeting these complexes include the adoptive transfer of donor-derived or 'off-the-shelf' virus-specific T cells (VSTs) and the development of TCR-based biologics designed to recognize these specific pMHC signatures. By specifically targeting the BKV-peptide-HLA-I complex, these therapies aim to restore antiviral immunity and clear the infection without causing generalized immunosuppression or significant damage to the graft.

Other names

BK polyomavirus peptide-MHC class I complexBKV-pMHC complexBKV-HLA-I complexBK virus antigen-HLA complex

Recognition by T-cell receptors (TCRs) on CD8+ cytotoxic T lymphocytes leading to targeted lysis of infected cells.