Viral peptide–HLA complexes derived from BK polyomavirus large T antigen (BKV LTA-HLA complex)

Viral peptide–HLA complexes derived from BK polyomavirus (BKV) large T antigen (LTA) are essential targets for the cellular immune response in controlling BKV infection (NIH, 2011). BKV is a double-stranded DNA virus that establishes lifelong latency in the renal tubular cells of most healthy adults but can reactivate under immunosuppression, leading to BKV-associated nephropathy (BKVAN) or hemorrhagic cystitis (PLOS, 2024). The LTA is a key regulatory protein produced early in the viral life cycle, providing immunogenic epitopes that are presented by HLA class I and II molecules to CD8+ and CD4+ T cells, respectively (ASM, 2011). These complexes are the primary focus of virus-specific T-cell (VST) therapies, such as posoleucel, which are designed to restore immune control in transplant recipients (NIH, 2025). Recognition of these complexes by T-cell receptors (TCRs) triggers cytotoxic activity and cytokine production to eliminate infected cells (NIH, 2008). However, therapeutic efficacy can be limited by HLA restriction and the emergence of viral variants with mutations in LTA epitopes that allow for immune escape (NIH, 2021).

Other names

BK polyomavirus large T antigen peptide-HLA complexBKV LTA-MHC complexBKV-LTA-HLABKPyV LTag-HLA complex

Recognition by T-cell receptors (TCRs) on CD8+ or CD4+ T cells to induce cytotoxic killing or immune response against BKV-infected cells.