Construction and function of Glypican-3-targeted fourth-generation chimeric antigen receptor T cells (secreting IL-7 and CCL19) / 生物工程学报

Adoptive immunotherapy based on chimeric antigen receptor-modified T cells (CAR-T) is one of the most promising strategies to treat malignant tumors, but its application in solid tumors is still limited. Glypican-3 (GPC3) is a meaningful diagnostic, therapeutic, and prognostic biomarker for hepatocellular carcinoma (HCC). The second/third generation GPC3-targeted CAR-T cells are generated to treat HCC. In order to improve the therapeutic effect, we constructed a fourth-generation lentiviral vector to express GPC3 CAR, human interleukin-7 (IL-7) and CCL19. Then the lentiviral vector and packaging plasmids were co-transfected into HEK293T cells to generate CAR lentiviral particles. Human T lymphocyte cells were transduced with CAR lentiviral to develop the fourth-generation GPC3-targeted CAR-T cells (GPC3-BBZ-7×19). In vitro, we used cell counting, transwell assay, luciferase bioluminescence assay and flow cytometry to compare the proliferation, chemotaxis, cytotoxicity and subtype distribution between GPC3-BBZ-7×19 CAR-T cells and the second generation GPC3-targeted CAR-T cells (GPC3-BBZ). In vivo, we established GPC3-positive HCC xenograft model in immunodeficient mice, then untransduced T cells (non-CAR-T) or GPC3-BBZ-7×19 CAR-T cells were injected. Tumor growth in mice was observed by bioluminescence imaging. Results showed that compared with GPC3-BBZ CAR-T, GPC3-BBZ-7×19 CAR-T cells had stronger proliferation, chemotactic ability, and higher composition of memory stem T cells (Tscm) (P values<0.05). However, there were no significant difference in cytotoxicity and cytokine secretion between them. In addition, GPC3-BBZ-7×19 CAR-T cells could significantly eliminate GPC3-positive HCC xenografts established in immunodeficient mice. Therefore, the fourth-generation GPC3-targeted CAR-T cells (secreting IL-7 and CCL19) are expected to be more durable and effective against HCC and produce tumor-specific memory, to provide a preclinical research basis for future clinical trials.

Effect of GDF11 on expansion of CD8 +memory stem T cells / 中国病理生理杂志

AIM:To investigate the effect of growth differentiation factor 11 ( GDF11 ) on the expansion of CD8 +memory stem T cells ( Tscm) and to further improve the effect of adoptive immunotherapy.METHODS:Healthy human peripheral blood mononuclear cells ( PBMCs) were isolated by density gradient centrifugation at first.Among the i-solated PBMCs, CD8 +T cells were further purified with MACS microbeads.The CD8 +T cells were then randomly divided into experimental groups and control group.The same volume of different concentrations of GDF11 were added into the ex-perimental groups, and the same volume of PBS solution was added into the control group.Finally, the expansion of Tscm in experimental groups and control group was measured by flow cytometry at several time points.RESULTS:GDF11 sig-nificantly increased the number of Tscm in CD8 +T cells in vitro expansion and also dramatically increased the ratio of Tscm in CD8 +T cells.Furthermore, 400 μg/L GDF11 treatment for 3 weeks was the optimal condition to induce CD8 +Tscm. CONCLUSION:GDF11 effectively increases the number and ratio of Tscm in the CD8 +T cells in cell culture growth, thereby creating a new strategy to further improve the efficiency of adoptive immunotherapy.