重组hIFN-α-2b-BCG对小鼠原位膀胱肿瘤免疫效应的研究

目的 探讨重组hIFN-α-2b-BCG对原位膀胱肿瘤小鼠体内抗肿瘤免疫反应及其作用机制.方法 构建C57BL/6原位膀胱肿瘤小鼠模型,采用流式细胞仪对小鼠膀胱灌注治疗后的淋巴细胞亚群进行分析,并测定小鼠血清中mTNF-α和mIL-12的水平,了解小鼠全身免疫状况.肿瘤组织冰冻切片进行T细胞亚群的免疫组织化学分析,免疫组化检测肿瘤Fas表达,了解膀胱局部免疫反应. 结果 重组BCG灌注治疗后小鼠外周血CD4+ T细胞比例明显增高,CD8+ T细胞比例无明显变化,CD4+ /CD8+比例为2.63,与野生BCG组(2.10)比较差异有统计学意义(P＜0.05).荷瘤小鼠外周血中Th1型细胞因子mTNF-α和mIL-12灌注治疗后比PBS对照组大幅提高,重组BCG组mTNF-α为806 pg/ml,mIL-12为860 pg/ml,与野生BCG组及野生BCG联合IFN组比较差异无统计学意义(P＞0.05).重组BCG组瘤组织内CD3、CD4和CD5检测强阳性,显著高于PBS对照组(P＜0.05),重组BCG组和野生BCG加IFN组瘤组织CD4+、重组BCG组CD8+检测值显著高于野生BCG组(P＜0.05).BCG灌注后荷瘤小鼠膀胱肿瘤表达Fas明显高于PBS对照组(P＜0.05). 结论 重组hIFN-α-2b-BCG具有在小鼠体内调节系统及局部免疫能力的作用,纠正荷瘤小鼠淋巴细胞亚群的比例失调,增强局部淋巴细胞浸润,具有增强Th1型细胞因子产生作用,上调荷瘤小鼠Fas的表达,诱导对膀胱肿瘤细胞的免疫攻击.

Abstract：

Objective To study local and systemic immune response in an animal model treated with recombinant hIFN-α-2b-BCG instillation. Methods The MB49 orthotopic bladder cancer model in C57BL/6 mice was established and treated separately with rBCG, wild BCG, wild BCG combined with IFN-α-2b and PBS as the control. The changes of lymphocyte subgroups in peripheral blood were analyzed with FCM, and mTNF-α and mIL-12 in peripheral blood of mice were detected with ELISA.Immunohistochemistry was carried out to detect the local immune reaction, T cell subsets and FAS, in bladder cancer after being treated with rBCG or wBCG. Results The content of CD4+ T lymphocyte was up-regulated in the rBCG group. The CD4+/CD8+ ratio of 2. 63 was up-regulated than pretreatment, significantly different than that of wBCG group(P＜0.05). ELISA assay showed that BCG significantly up-regulated the level of mTNF-α and mIL-12 in serum of orthotopie murine bladder cancer mice. The mTNF-α 806 pg/ml, mIL-12 860 pg/ml in rBCG group, was not significantly higher than those in wBCG group and combination group. The immunocompetent cell numbers with CD3, CD4,CD8 phenotype increased significantly in the tumor tissue of BCG treated group than the control(P＜0.05). The results of CD4+ in rBCG group and the combination group, and CD8+ in rBCG group were significantly higher than that of the wBCG(P＜0.05). The expression of Fas in tumor tissues treated with intravesical BCG was increased(P＜0. 05). Conclusions The recombinant IFN-α-2b-BCG can retrieve the disproportion of systemic lymphocyte subgroups, and increases Th1-type factors and local Fas expression in orthotopic murine bladder cancer. The recombinant IFN-α-2b-BCG is effective in regulating local and systemic immune reaction in orthotopic murine bladder cancer model.