IL-21 Optimizes the CAR-T Cell Preparation Through Improving Lentivirus Mediated Transfection Efficiency of T Cells and Enhancing CAR-T Cell Cytotoxic Activities.

Li Du,Jingjing Huang,Yaru Nai,Da Pang,Aishun Jin,Tingting Li,Wang Wang,Xiaojian Han,Meiying Shen

doi:10.3389/fmolb.2021.675179

Abstract

Adoptive immunotherapy using CAR-T cells is a promising curative treatment strategy for hematological malignancies. Current manufacture of clinical-grade CAR-T cells based on lentiviral/retrovirus transfection of T cells followed by anti-CD3/CD28 activation supplemented with IL-2 has been associated with low transfection efficiency and usually based on the use of terminally differentiated effector T cells. Thus, improving the quality and the quantity of CAR-T cells are essential for optimizing the CAR-T cell preparation. In our study, we focus on the role of IL-21 in the γc cytokine conditions for CAR-T cell preparation. We found for the first time that the addition of IL-21 in the CAR-T preparation improved T cell transfection efficiency through the reduction of IFN-γ expression 24–48 h after T cell activation. We also confirmed that IL-21 enhanced the enrichment and expansion of less differentiated CAR-T cells. Finally, we validated that IL-21 improved the CAR-T cell cytotoxicity, which was related to increased secretion of effector cytokines. Together, these findings can be used to optimize the CAR-T cell preparation.

Highlights

CAR-T cell therapy has shown great promise in the advancement of individualized cancer immunotherapy (Maude et al, 2018; Park et al, 2018)
These results showed that the addition of IL21 in the cytokine conditions was beneficial for the transfection efficiency of T cells
We found that the addition of IL-21 in the commonly used cytokine cocktails enhanced lentiviral transfection efficiency of T cells, which was independent of the enrichment and expansion of less differentiated CAR-T cells by addition of IL-21

Summary

Introduction

CAR-T cell therapy has shown great promise in the advancement of individualized cancer immunotherapy (Maude et al, 2018; Park et al, 2018). It is of great importance to optimize the production methods to obtain CAR-T cells with advanced quality and potentials for antitumor immunotherapy. Lentivirus vectors are capable of stably infecting the dividing or non-dividing cells by integrating into the host genome (Bukrinsky et al, 1993; Schambach et al, 2013). These vectors are nontoxic to the human body since no viral genes are integrated into the vector genome which enables transduced T cells to obtain long term stable gene expression (Knight et al, 2012).

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Results

Conclusion