Mini Review - Research and Reports in Immunology (2022) Volume 5, Issue 1
The function of anti-mesothelin CAR T cells is improved by hairpin RNAs.
Hematologic malignancies have demonstrated good results with chimeric antigen receptor (CAR) T cell treatment. CAR T cells' antitumor activity, on the other hand, needs to be improved in order to improve therapeutic efficacy in hematologic and solid malignancies. On-target, off-tumor toxicity, antigen escape, short CAR T cell persistence, limited growth, trafficking to the tumour, and T cell activity suppression by an inhibitory tumour microenvironment are all challenges to overcome. Here, we'll look at how genetic engineering can be used to improve the antitumor efficacy of CAR T cell therapy in preclinical animals by refining the design of CAR T cells. The goal of this work was to see how targeted Tim3 knockdown affected the antitumor function of anti-mesothelin (MSLN)-CAR T cells. Three distinct shRNA sequences specific to different regions of the human Tim3 gene were developed and co-inserted into lentiviral vectors with an anti-MSLN-CAR transgene to knock down Tim3 expression. Tim3 expression was measured before and after antigen stimulation to determine the efficiency of Tim3 targeting in T cells. MSLN-CAR T cells and Tim3-targeted MSLN-CAR T cells were then examined for cytotoxic effects, proliferative response, and cytokine production. Tim3 was up-regulated when T cells and MSLN-CAR T cells were activated, according to our findings. In distinct groups of MSLN-CAR T cells, knocking down Tim3 resulted in a considerable reduction in its expression. Tim3 knockdown increased MSLN-CAR T cells' cytotoxic efficacy, cytokine generation, and proliferative ability. Tim3 knockdown increased MSLN-CAR T cells' cytotoxic efficacy, cytokine generation, and proliferative ability. Our findings suggest that inhibiting Tim3 signalling allows tumor-infiltrating CAR T cells that would otherwise be inactivated to continue to grow and perform effector activities, thereby changing the tumour microenvironment from immunosuppressive to immunosupportive.Author(s): Stephanie Ryan