BK polyomavirus Large T antigen peptide–Major Histocompatibility Complex (BKV LTAg pMHC)

The BK polyomavirus (BKV) Large T antigen (LTAg) peptide–Major Histocompatibility Complex (pMHC) is a specialized molecular target found on the surface of cells infected with BKV. The Large T antigen is a non-structural viral protein (UniProt P03071) that plays a pivotal role in viral genome replication and the subversion of host cell cycle controls. In the context of infection, fragments of this protein are processed and presented by the host's Major Histocompatibility Complex (MHC) molecules, signaling the presence of the virus to the immune system (PMID: 24652798). This target is particularly significant in transplant medicine, where BKV reactivation can lead to severe complications like BKV-associated nephropathy (BKVAN) or hemorrhagic cystitis due to immunosuppression (PMID: 33166345). Therapeutic interventions, such as adoptive T-cell therapy (e.g., posoleucel/ALVR106), utilize T cells engineered or selected to recognize these specific pMHC complexes to selectively eliminate infected cells. By targeting the pMHC, these therapies aim to provide a precise immune-mediated clearance of the virus while minimizing damage to healthy tissues. Monitoring viral load and HLA compatibility is essential for the efficacy of these targeted interventions.

Other names

BK virus Large T antigen pMHCBKV LTAg-HLA complexBK polyomavirus LTAg peptide-MHCBKV Large T-antigen-derived peptide-MHC

Recognition of viral peptide-MHC complexes by T-cell receptors (TCRs) on cytotoxic T lymphocytes, leading to the targeted lysis of BK virus-infected cells.