BK polyomavirus peptide-Human Leukocyte Antigen complex (BKV peptide-HLA complex)

BK polyomavirus (BKV) peptide-Human Leukocyte Antigen (HLA) complexes are molecular assemblies on the surface of infected cells that present viral antigens to the host immune system (nih.gov, asm.org). These complexes consist of short peptides derived from BKV proteins, such as the Large T-antigen (LTAg) or the major capsid protein VP1, bound within the groove of HLA Class I or Class II molecules (nih.gov). In healthy individuals, these complexes are recognized by endogenous T-cell receptors (TCRs), which maintain viral latency (nih.gov, frontiersin.org). However, in immunocompromised transplant recipients, the absence of effective T-cell surveillance allows BKV to reactivate, leading to severe complications like BKV-associated nephropathy (BKVAN) in kidney transplant patients and hemorrhagic cystitis in hematopoietic stem cell transplant recipients (nih.gov). These complexes serve as the primary therapeutic target for adoptive T-cell therapies, such as virus-specific T cells (VSTs) like posoleucel (firstwordpharma.com, nih.gov). These therapies utilize donor-derived or off-the-shelf T cells that specifically recognize BKV peptide-HLA complexes to selectively eliminate infected cells and restore viral control (hhv-6foundation.org, ashpublications.org).

Other names

BKPyV peptide-MHC complexBKV-specific HLA-peptide complexBK virus antigen-HLA complexBKV peptide-MHC

Recognition of the peptide-HLA complex by the T-cell receptor (TCR) of virus-specific T cells (VSTs), triggering cytotoxic activity and cytokine production to eliminate infected cells.