TCR-independent Activation in Presence of a Src-family Kinase Inhibitor Improves CAR-T Cell Product Attributes.

Abstract

Chimeric antigen receptor expressing T cells (CAR-T cells) have shown remarkable efficacy against some blood cancers and have potential to treat many other human diseases. During CAR-T cell manufacturing, T cells are activated via engagement of the T-cell receptor (TCR); however, persistent TCR engagement can induce unchecked activation, differentiation, and exhaustion, which can negatively affect CAR-T cell product quality and in vivo potency. In addition, T cells may not uniformly respond to TCR-dependent activation (TCRD) contributing to lot-to-lot variability, poor expansion, and manufacturing failures. TCRD also presents challenges during manufacturing of allogeneic CAR-T cells when endogenous TCR is deleted to prevent graft-versus-host disease. Thus, novel strategies to activate T cells may help improve CAR-T cell product attributes and reduce manufacturing failures. In this study, we compared the effect of TCRD and TCR-independent activation (TCRI) on CAR-T cell product attributes. We found that TCRI in presence of a Src-kinase inhibitor significantly improved CAR-T cell expansion and yield without affecting viability and CD4/CD8 ratio. Markers of T-cell activation, exhaustion and differentiation were also reduced in these CAR-T cells compared with CAR-T cells manufactured by TCRD. TCRI did not affect CAR-T cell in vitro potency; however, following co-culture with target cells, CAR-T cells manufactured by TCRI released significantly less inflammatory cytokines compared with CAR-T cells manufactured by TCRD. Together, these data suggest that manufacturing CAR-T cells by TCRI activation in the presence of a Src-kinase inhibitor improves product quality attributes and may help reduce manufacturing failures and improve CAR-T cell safety and efficacy in vivo.

• Authors: Gauri Lamture, Alan Baer, Joseph W Fischer, Winston Colon-Moran, Nirjal Bhattarai
• Journal: Journal of immunotherapy (Hagerstown, Md. : 1997) (J Immunother) Vol. 45 Issue 3 Pg. 139-149 (04 01 2022) ISSN: 1537-4513 [Electronic] United States
• PMID: 34802014 (Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Receptors, Antigen, T-Cell
• src-Family Kinases

Topics

• Humans
• Immunotherapy, Adoptive
• Lymphocyte Activation
• Receptors, Antigen, T-Cell (genetics)
• T-Lymphocytes
• src-Family Kinases