T cell receptor gene‐modified allogeneic T cells with siRNA for endogenous T cell receptor induce efficient tumor regression without graft‐versus‐host disease
Satomi Okada, Daisuke Muraoka, Kiyoshi Yasui, Isao Tawara, Ayumi Kawamura, Sachiko Okamoto, Junichi Mineno, Naohiro Seo, Hiroshi Shiku, Susumu Eguchi, Hiroaki Ikeda
Abstract
Abstract Adoptive immunotherapy using genetically engineered patient‐derived lymphocytes to express tumor‐reactive receptors is a promising treatment for malignancy. However, utilization of autologous T cells in this therapy limits the quality of gene‐engineered T cells, thereby inhibiting the timely infusion of the cells into patients. In this study, we evaluated the anti‐tumor efficacy and the potential to induce graft‐versus‐host disease (GVHD) in T cell receptor (TCR) gene‐engineered allogeneic T cells that downregulate the endogenous TCR and HLA class I molecules with the aim of developing an “off‐the‐shelf” cell product with expanded application of genetically engineered T cells. We transduced human lymphocytes with a high‐affinity TCR specific to the cancer/testis antigen NY‐ESO‐1 using a novel retrovirus vector with siRNAs specific to the endogenous TCR (siTCR vector). These T cells showed reduced expression of endogenous TCR and minimized reactivity to allogeneic cells in vitro. In non‐obese diabetic/SCID/γc null mice, TCR gene‐transduced T cells induced tumor regression without development of GVHD. A lentivirus‐based CRISPR/Cas9 system targeting β‐2 microglobulin in TCR gene‐modified T cells silenced the HLA class I expression and prevented allogeneic CD8 + T cell stimulation without disrupting their anti‐tumor capacity. This report is the first demonstration that siTCR technology is effective in preventing GVHD. Adoptive cell therapy with allogeneic T cells engineered with siTCR vector may be useful in developing an “off‐the‐shelf” therapy for patients with malignancy.