BK virus antigen-peptide–Major Histocompatibility Complex (BKV-pMHC) (BKV-pMHC)

BK virus antigen-peptide–Major Histocompatibility Complex (pMHC) complexes are the primary molecular targets for the cellular immune response against BK polyomavirus (BKV) infection (Babel et al., 2011, PMID: 21564524). These complexes consist of short peptide fragments derived from BKV proteins—such as the Large T-Antigen (LTA) or VP1 capsid protein—bound within the groove of Major Histocompatibility Complex (MHC) molecules on the surface of infected urothelial or renal tubular epithelial cells (Leboeuf et al., 2017, PMID: 28112865). In healthy individuals, these pMHC complexes are recognized by the T-cell receptors (TCRs) of CD8+ and CD4+ T cells, which maintain viral latency and prevent disease (Ambalathingal et al., 2017, PMID: 28630091). However, in immunocompromised patients, such as kidney transplant recipients, BKV reactivates and replicates, leading to BK virus-associated nephropathy (BKVAN) or hemorrhagic cystitis (Hirsch and Randhawa, 2019, PMID: 31095471). Therapeutic strategies targeting these complexes include the adoptive transfer of virus-specific T cells (VSTs), such as Posoleucel, or the development of TCR-engineered T cells designed to specifically recognize and eliminate cells presenting BKV-pMHC (Tzannou et al., 2017, PMID: 28783452). These interventions aim to restore viral control and prevent graft loss without inducing graft-versus-host disease or systemic toxicity.

Other names

BKV-peptide-HLA complexBK polyomavirus antigen-MHC complexBKV-pMHC complexBK virus peptide-MHC complexBKV-specific peptide-MHC

T-cell receptor (TCR) mediated recognition of viral peptides presented by MHC molecules, leading to targeted cytotoxic lysis of infected cells and the release of antiviral cytokines.