BK polyomavirus small T, VP2, and VP3 protein-derived peptide antigens presented on MHC class I (BKV sT/VP2/VP3-MHC I)

BK polyomavirus (BKV) small T, VP2, and VP3 protein-derived peptide antigens presented on MHC class I are molecular complexes formed when viral proteins are processed by the host cell's proteasome and displayed on the cell surface (Source 1.3.4, 1.4.2). These antigens are derived from the early non-structural small T antigen, which regulates viral replication and host cell cycle, and the late minor capsid proteins VP2 and VP3, which are essential for viral entry and nuclear import (Source 1.3.1, 1.5.4, 1.5.5). In healthy individuals, these complexes are recognized by the endogenous immune system to maintain viral latency (Source 1.3.1). However, in immunocompromised patients, such as those undergoing kidney or bone marrow transplantation, the lack of an effective T-cell response allows BKV to reactivate, leading to diseases like BKV-associated nephropathy (BKVAN) and hemorrhagic cystitis (Source 1.1.2, 1.5.1). These peptide-MHC complexes serve as the primary targets for adoptive virus-specific T-cell (VST) therapies, such as posoleucel (ALVR105) (Source 1.1.1, 1.2.2). VSTs recognize these specific epitopes via their T-cell receptors (TCRs), triggering the release of cytotoxic granules and proinflammatory cytokines to selectively eliminate infected cells and reduce viral burden (Source 1.2.1, 1.3.3). The therapeutic use of these antigens involves expanding donor-derived T cells ex vivo using peptide pools and infusing them into patients to restore anti-viral immunity (Source 1.2.2, 1.4.2). This approach provides a targeted alternative to traditional antivirals, which are often limited by toxicity or lack of efficacy against BKV (Source 1.1.2, 1.2.4).

Other names

BKV-specific T cell antigensBKV peptide-HLA complexesBKV sT/VP2/VP3 epitopesBKPyV small T, VP2, and VP3 antigensBK polyomavirus sT, VP2, and VP3 MHC I presented peptides

Adoptive T-cell therapy involving T-cell receptor (TCR) mediated recognition of viral peptide-MHC complexes on infected cells, leading to targeted cytolysis and cytokine release.