BK virus peptide-major histocompatibility complex (BKV pMHC)

BK virus (BKV) peptide-major histocompatibility complex (pMHC) refers to the presentation of viral protein fragments, specifically from the major capsid protein VP1 and the regulatory Large T antigen, on the surface of infected cells via Human Leukocyte Antigen (HLA) molecules. These complexes serve as the primary recognition signal for the cellular immune system, allowing cytotoxic T lymphocytes (CTLs) to identify and eliminate BKV-infected cells. In immunocompromised patients, such as kidney or hematopoietic stem cell transplant recipients, the lack of an effective T-cell response leads to BKV reactivation, causing severe complications like polyomavirus-associated nephropathy (PVAN) and hemorrhagic cystitis. Therapeutic strategies targeting these pMHC complexes include the adoptive transfer of virus-specific T cells (VSTs), such as posoleucel, which are engineered or selected to recognize these specific viral epitopes. By restoring the immune system's ability to target BKV pMHC, these therapies aim to reduce viral load and prevent graft loss or organ damage. Monitoring BKV-specific T-cell frequency and viral load serves as a key biomarker for treatment efficacy and patient risk assessment.

Other names

BK virus peptide-HLA complexBKPyV pMHCVP1 and Large T antigen peptide-MHC complexBKV-specific MHC-peptide complexBK virus antigen-MHC complex