The In Vitro Anti-tumor Study Of CAR-T Cells From Pluripotent Stem Cells

Surgery,chemotherapy,and radiotherapy are the typical methods for cancer treatment in clinic,but these methods inevitably cause damages to normal organs and tissues due to their principles of lacking tumor-specificity.Forthermore,tumor relapse is a common phenomenon after these treatments.Recently,CAR-T cells therapy is a great innovation in the treatment of refractory cancers.Besides the autologous peripheral blood T cells,however,T cell source of CAR-T cells is still a major problem to be solved.T cells from patients are often functionally exhausted and in certain cases show extremely low activity in vitro and in vivo.Pluripotent stem cells(PSCs)with unlimted culture potential are ideal for generating T cells.Up to now,the conventional PSCs-derived T cells showed much lower activity than natural counterparts in vivo.Our group has recently developed a de novo approach to generate functional iT cells from mouse embryonic stem cells(mESCs)driven by the inducible expression of Runxl and Hoxa9.Following our previous method of generating iT cells,we successfully obtained inducible hematopoietic endothelial cells(iHECs)from iRunx1-p2a-Hoxa9-ESCs.Next,the iHECs were sorted and co-cultured with OP9-DL1 cells for induced hematopoietic progenitor cells(iHPCs)maturation.Finally,we transplanted iHPCs into sublethal-irradiated B-NDG mice for T lymphoid reconstition in vivo.Five weeks post translation,a large number of donor-derived inducible T(iT)cells were detected in the peripheral blood,lymph nodes and spleen of the recipient mice.We subsequently enriched iT cells from the spleens of recipient mice and engineered these cells with CD 19-CAR to further assess their anti-tumor.When CD 19-CAR iT cells were co-cultured with B cells lymphoma(Ka539)cells in vitro,the percentage of ka539 tumor cells was sharply decreased,which demonstrated that CAR-iT cells from PSCs exhibited strong ability of killing tumor cells in vitro.Therefore,our research might provide insights into translational application of CAR-iT cells for cancer immunotherapy.