Combined PD-L1 and TIM3 blockade improves expansion of fit human CD8+ antigen-specific T cells for adoptive immunotherapy

• Published in: Molecular therapy. Methods & clinical development Vol. 27; pp. 230 - 245
• Main Authors: Lak, Shirin, Janelle, Valérie, Djedid, Anissa, Boudreau, Gabrielle, Brasey, Ann, Lisi, Véronique, Smaani, Ali, Carli, Cédric, Busque, Lambert, Lavallée, Vincent-Philippe, Delisle, Jean-Sébastien
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 08.12.2022; American Society of Gene & Cell Therapy; Elsevier
• Subjects: adoptive immunotherapy; antigen-specific T cells; Epstein-Barr virus; immune checkpoint; Original; PD-1; single-cell RNA sequencing; T cell exhaustion; T cell manufacturing; TIM3; WT1; single-cell RNA sequencing; T cell manufacturing; WT1; immune checkpoint; T cell exhaustion; Epstein-Barr virus; TIM3; PD-1; antigen-specific T cells; adoptive immunotherapy
• ISSN: 2329-0501; 2329-0501
• DOI: 10.1016/j.omtm.2022.09.016

Antigen-specific T cell expansion ex vivo followed by adoptive transfer enables targeting of a multitude of microbial and cancer antigens. However, clinical-scale T cell expansion from rare precursors requires repeated stimulation, which may lead to T cell dysfunction and limited therapeutic potential. We used a clinically compliant protocol to expand Epstein-Barr virus (EBV) and Wilms tumor 1 (WT1) antigen-specific CD8+ T cells, and leveraged T cell exhaustion-associated inhibitory receptor blockade to improve T cell expansion. Several inhibitory receptors were expressed early by ex vivo-expanded antigen-specific CD8+ T cells, including PD-1 and TIM3, with co-expression matching evidence of T cell dysfunction as the cultures progressed. Introduction of anti-PD-L1 and anti-TIM3 blockade in combination (but not individually) to the culture led to markedly improved antigen-specific T cell expansion without inducing T cell dysfunction. Single-cell RNA sequencing (RNA-seq) and T cell receptor (TCR) repertoire profiling revealed that double blockade does not impart specific transcriptional programs in T cells or alterations in TCR repertoires. However, combined blockade may affect gene expression in a minority of clonotypes in a donor-specific fashion. We conclude that antigen-specific CD8+ T cell manufacturing can be improved by using TIM3 and PD-L1/PD-1 axis blockade in combination. This approach is readily applicable to several adoptive immunotherapy strategies. [Display omitted] Lak et al. reveal that combined blockade of the immune checkpoints TIM3 and PD-L1 can be leveraged to improve the yield of functional antigen-specific CD8+ T cells expanded ex vivo for adoptive immunotherapy. This approach represents a readily applicable strategy to improve manufacturing of antigen-specific T cell immunotherapies.