动物造模 z-bio 2022-08-04 454

　　Objective To construct and evaluate a humanized mouse model of pancreatic cancer immune system, in order to provide an ideal preclinical model for the immunotherapy of pancreatic cancer.

　　Methods Fresh peripheral blood mononuclear cells (PBMC) were isolated from the peripheral blood of healthy people by Ficoll density gradient centrifugation and implanted into NCG of severe combined immunodeficiency mice by tail vein injection to construct human immune system. After PBMC implantation, the human pancreatic cancer cell line Aspc1 was subcutaneously implanted in mice, and tumor growth was monitored regularly. At the 3rd week after PBMC implantation, the peripheral blood of mice was collected by tail docking method for flow cytometry analysis. The level of human CD45+ cells was detected. When the tumor grew to 100-200 mm3, anti-PD-1 monoclonal antibody treatment was started. After 3 weeks of continuous treatment, the mice were euthanized and the materials were collected. Flow cytometry, immunohistochemistry and other methods were used. The infiltration and activation of human immune cells in peripheral blood, spleen, bone marrow and tumor tissues of humanized mice with pancreatic cancer immune system were analyzed.

　　Results After 3 weeks of implantation of human PBMCs, high levels of human CD45+ cells could be detected in the peripheral blood, spleen and bone marrow of mice; the reconstituted human immune system could significantly inhibit the growth of human pancreatic cancer tumors (P < 0.01 , P<0.001), and was activated by human anti-PD-1 mAb to promote cytotoxic CD8+ T cell infiltration and PD-L1 expression in tumor tissues.

　　Conclusion The humanized mouse model of pancreatic cancer immune system was successfully constructed. Its immune system can respond to human anti-PD-1 monoclonal antibody and inhibit tumor growth. It can be used as an ideal preclinical animal model for pancreatic cancer immunotherapy research.