BK virus large T antigen-derived peptides presented on MHC (BKV LTAg-MHC)

The BK virus large T antigen (LTAg) is a multifunctional regulatory protein essential for the replication and life cycle of the BK polyomavirus (BKV) (UniProt P03071). In immunocompromised individuals, such as kidney or hematopoietic stem cell transplant recipients, BKV can reactivate, leading to severe complications like BKV-associated nephropathy or hemorrhagic cystitis (PubMed 30135633). Peptides derived from the LTAg are processed by infected cells and presented on the cell surface via Major Histocompatibility Complex (MHC) molecules (PubMed 28835477). These peptide-MHC complexes serve as the primary targets for the host's cytotoxic T lymphocytes (CTLs), which recognize and eliminate virus-infected cells (PubMed 31533975). Therapeutic strategies focusing on this target include the administration of ex vivo expanded virus-specific T cells (VSTs), such as Posoleucel, or the development of TCR-engineered T cells designed to specifically bind these LTAg-MHC complexes (ClinicalTrials.gov NCT04312997). By enhancing the immune system's ability to detect these specific viral signatures, these therapies aim to control viral replication and prevent organ rejection or damage.

Other names

BK polyomavirus large T antigenBKV LTAgBKV large T-antigenBKV LTAg-HLA complexBKV LTAg-MHC complex

Targeting of peptide-MHC complexes by virus-specific T cells (VSTs) or T-cell receptor (TCR) engineered cells to induce cytotoxic lysis of infected cells and reduce viral load.