人源性荷三阴乳腺癌NOD/SCID小鼠模型建立及其免疫应答

摘要

目的：建立具有人免疫学特征的NOD/SCID小鼠模型，并观察其对三阴乳腺癌的免疫应答。方法筛选无免疫渗漏NOD/SCID小鼠24只，分成4组，免疫重建组提前3 d腹腔注射250 mg/kg环磷酰胺（CTX），后经腹腔注射健康人外周血单个核细胞（PBMC）同时背部皮下接种人三阴乳腺癌细胞MDA-MB-231；单纯免疫组只注射CTX及PBMC；单纯荷瘤组只接种MDA-MB-231；空白对照组不作任何处理。定期观察各组小鼠生物学及免疫学特征。结果免疫荷瘤组成瘤潜伏期（10~12 d）较单纯荷瘤组（8~10 d）延长，肿瘤生长速度减缓，第5周末肿瘤体积分别为1244.82±792.82 mm3和4308.77 mm3（P<0.01），生存率提高（P<0.01）。接受免疫重建的小鼠外周血人IgG于第2周即可测到，并逐渐上升，较未接受免疫重建小鼠差异有统计学意义（P<0.01）。外周血中CD3+细胞比例于第2周逐渐下降，但于第9周仍可测到。第9周小鼠脾脏细胞中CD3+T细胞比例高达55.3%（免疫荷瘤组）及52.7%（单纯荷瘤组）。免疫荷瘤组小鼠脾指数9.64 mg/g明显高于单纯免疫组3.82±0.31 mg/g及空白对照组1.51±0.14 mg/g。结论成功构建稳定的具有人免疫学特征的NOD/SCID小鼠模型，并观察到其对三阴乳腺癌产生免疫应答，可为三阴乳腺癌免疫治疗研究提供较为理想的动物模型。%Objective To establish a NOD/SCID mouse model with human immune reconstitution and observe its immune response to human triple-negative breast cancer xenograft. Methods Twenty-four NOD/SCID mice without immune leakage were subjected to cyclophosphamide (CTX) treatment 3 days prior to immune reconstitution with human peripheral blood mononuclear cell (PBMC) injection and subcutaneous transplantation of human triple-negative breast cancer MDA-MB-231 cells, CTX treatment and PBMC injection without tumor cell transplantation, MDA-MB-231 cell transplantation only, or no treatments. The tumor growth and immune responses of the mice were observed at regular intervals. Results Compared with the tumor-bearing mice, the tumor-bearing mice with immune reconstitution showed prolonged incubation period of tumor formation, slower tumor growth rate and increased survival rate. Human IgG and CD3+T cells were detected in the peripheral blood of the mice 1 week after human PBMC injection. The percentage of CD3+T cells in the spleen cells was 55.3%at 9 weeks in tumor-bearing mice with immune reconstitution and 52.7% in tumor-bearing mice without immune reconstitution. The spleen index of the tumor-bearing mice with immune reconstitution was much higher than that in mice with only immune reconstitution and the control mice (9.64 vs 3.82±0.31 and 1.51±0.14 mg/g). Conclusion A stable NOD/SCID mouse model with immune reconstitution has been established successfully, which shows immune responses to triple-negative breast cancer xenografts and allows studies of immunological therapy study of triple-negative breast cancer.