Donor Variability and PD-1 Expression Limit BK Polyomavirus-specific T-cell Function and Therapy

Upregulated PD-1 expression of ex vivo expanded T cells contributes to third-party donor variability and potentially impairs the efficacy of adoptive T-cell therapy. Because BKPyV-infected RPTECs increase PD-L1 under inflammatory conditions, adding immune checkpoint inhibitors ex vivo before infusion could be evaluated for enhanced clinical efficacy when attempting treatment of BKPyV-associated pathologies without jeopardizing transplantation outcomes.