新疆家蚕抗菌肽CecropinXJ对荷瘤小鼠免疫系统的影响

摘要

Objective:Antimicrobial peptides ( AMPs ) are peptides generated in the biological defense system against exogenous pathogens ,which is all important constituent of the non-specific immune system.The immune system can react and sometimes play an important role in tumor control both in animal models and in humans.In this study,CecropinXJ were used in the BALB/c Eca109 cells-bearing mice model.To investigate whether CecropinXJ exert anti-tumor efficiency through regulating immune response when treated with tumor-bearing mice.Methods:The expression of cytokines and DC surface molecules were detected by immunohisto-chemistry and Flow cytometry.Results:The experiment of mice showed that CecropinXJ could significantly inhibit the proliferation of transplanted tumors in dose-dependent manner.There were significant difference between control group and 10mg/kg CecropinXJ group on the volume and weight of tumor ( P<0.05 ).CecropinXJ inhibited Eca 109 cells infiltrating growth in tumor tissue without affecting viscera,and the expressions of VEGF and bFGF proteins were higher than those in the control group .The expression of cytokines and DC surface molecules,the results that,compared with the control group,CecropinXJ could not significantly promote the expression of CD4,IL-4 and IFN-γ,while not involving the expression of surface molecules on DCs in spleen (P>0.05).In CecropinXJ treatment group,TNF-αlevel in serum was significantly higher than the control group ( P<0.01 ).Conclusion: CecropinXJ could significantly inhibit tumor growth in Eca109 cells-bearing mice,and might not be affected anti-tumor efficiency through regulating immune response.%目的：抗菌肽是生物防御系统中产生的一类对抗外源性病原体的肽类物质，是生物体内固有的、非特异性免疫系统的重要组成部分。在动物模型及人体中，免疫系统在控制肿瘤方面具有重要作用。本文通过建立BALB／c荷瘤小鼠模型，探讨新疆家蚕抗菌肽CecropinXJ对人食管癌Eca109细胞荷瘤小鼠是否通过影响机体免疫应答发挥抗肿瘤作用。方法：通过免疫组化和流式细胞术等方法检测免疫应答相关细胞因子和DC表面分子的表达。结果：10 mg／kg CecropinXJ对Eca109细胞移植瘤具有显著的抑制作用。10 mg／kg CecropinXJ给药组肿瘤体积和肿瘤重量与生理盐水对照组相比，具有显著差异（ P＜0.05）。同时，CecropinXJ可抑制肿瘤组织癌细胞的浸润生长而对小鼠体内脏器无影响。在CecropinXJ抑制肿瘤生长过程中， VEGF和bFGF上调表达。与对照组相比，CecropinXJ对荷瘤小鼠的抑瘤作用不能够显著促进CD4、IL-4和IFN-γ的表达，同时也不涉及脾脏中DCs表面分子的表达（ P＞0.05），但对TNF-α的表达具有显著的促进作用（ P＜0.01）。结论：CecropinXJ 可以显著抑制荷瘤小鼠体内肿瘤的生长，在该过程中，可能并不通过影响机体免疫应答发挥抗肿瘤作用。