Application of human IL-15 transgenic NCG mouse in preclinical evaluation of CAR-NK cell therapy for tumor treatment / 中国肿瘤生物治疗杂志

ABSTRACT

@#[Abstract] Objective: To explore the application value of human IL-15 transgenic NCG mice (NCG-hIL-15 mice) in preclinical evaluation of chimeric antigen receptor modified NK (CAR-NK) cell therapy for tumor treatment. Methods: qPCR and WB were performed to detect the expression of human IL-15 in the bone marrow and main organs (spleen, liver, lung, kidney and pancreas) of transgenic mice. After being transfused with human PBMC-derived NK (PB-NK) cells, the NCG-hIL-15 mice and control NCG mice were continuously monitored for the in vivo amplification of NK cells and the changes in body weight and survival time. Flow cytometry was used to detect the differential expressions of activated receptors and inhibitory receptors in amplified NK cells. WB was used to detect the expressions of perforin and granzyme-B. NCG-hIL-15 mice or NCG mice bearing MIAPaca-2 cell transplanted tumor were treated with anti-MUC1-CAR-NK cell reinfusion; then, the CAR-NK cell survival in different groups of mice was detected by Flow cytometry, and the survival time of tumor bearing mice was recorded and tumor growth was detected by in vivo imaging. Results: The results indicated that PB-NK cells could proliferate stably within 10 weeks in NCG-hIL-15 mice without obvious graft versus host diseases (GVHD) during the observation period. The in vivo-expanded human NK cells maintained the original expression patterns of various surface molecules, including KARs and KIRs. Compared with the NK cells in NCG mice, the NK cells in NCG-hIL-15 mice contained significantly higher amounts of granzyme-B and perforin (all P<0.05). CAR-NK cells showed significantly increased survival rate and stronger tumor-inhibitory effect in NCG-hIL-15 mice as compared with those in control NCG mice, resulting in significantly prolonged survival in NCG-hIL-15 mice (all P<0.01). Conclusion: NCG-hIL-15 mouse model has potential application value in preclinical trial and biological evaluation of NK cell-based immunotherapy.