Toll样受体5激动剂CBLB502蛋白的辐射防护作用

目的研究CBLB502蛋白辐射防护作用。方法 HCT116细胞经CBLB502刺激后,Western印迹法检测NF-κB入核,碱性磷酸酶报告基因法检测CBLB502对NF-κB报告基因的激活。150只C57BL/6J小鼠接受8.0 Gy60Coγ射线照射前随机分为PBS,WR2721,CBLB502 0.02、0.05和0.2 mg/kg共5组,观察小鼠受照后30 d存活率和平均生存时间。另外40只小鼠接受6.5 Gy60Coγ射线照射前随机分为PBS、WR2721、CBLB502 0.2 mg/kg组和正常对照组,照射前1 d和照后30 d内检测外周血细胞。结果 CBLB502可明显促进HCT116细胞NF-κB入核(P<0.01)并呈剂量依赖性激活NF-κB报告基因(r=0.998 3)。CBLB502显著提高8.0 Gy60Coγ射线照射后小鼠的存活率,PBS,WR2721,CBLB502 0.02、0.05和0.2 mg/kg组小鼠照后30 d存活率分别为0、83.3%、13.3%、66.7%和100%;照射后小鼠平均存活时间除0.02 mg/kg给药组与PBS对照相比无差异外,其余各给药组较PBS对照组有显著提高。6.5 Gy60Coγ射线照射后小鼠外周血白细胞、红细胞、血红蛋白和血小板急剧下降,CBLB502 0.2 mg/kg组上述指标降低持续时间较照射对照组明显缩短,开始恢复时间提前,各指标最低值亦明显高于照射对照组。结论 CBLB502蛋白具有体外生物学活性并对急性放射病小鼠有明显的辐射防护作用。

Radioprotection activity of Toll-like receptor 5 agonist CBLB502 protein

Objective To detect the radioprotection activity of CBLB502 protein.Methods The nuclear translocation of NF-κB subunit p65 was detected by western blotting in HCT116 cells treated with CBLB502 protein.The activation of NF-κB reporter gene was performed with secreted alkaline phosphatase(SEAP) reporter assay.Totaly 150 C57BL/6J mice were randomly assigned to PBS,WR2721 and CBLB502 0.02,0.05 and 0.2 mg/kg group before 8.0 Gy 60Co γ-ray total body irradiation(TBI).The 30 day survival and average survival time was calculated.Another 40 mice were assigned to PBS,WR2721,CBLB502 0.2 mg/kg and normal group at random before 6.5 Gy 60Co γ irradiation,the peripheral blood was obtained to assay hemogram pre and post irradiation.Results CBLB502 promotes NF-κB subunit p65 nuclear translocation significantly(P<0.01) and activated NF-κB reporter gene in dose-dependent manner(r=0.998 3).It significantly enhanced the 30-day survival of mice treated with 8.0 Gy 60Co γ-ray TBI,the survival of PBS group,WR2721 group and CBLB502 0.02,0.05 and 0.2 mg/kg group were 0,83.3%,13.3%,66.7% and 100% respectively;significant difference in average survival time was observed among CBLB502 0.05,0.2 mg/kg group and PBS group,except for the CBLB502 0.02 mg/kg group.The quantity of leukocytes,erythrocytes,hemoglobin and platelet of the peripheral blood decreased rapidly after irradiation.In CBLB502 0.2 mg/kg group,the leukocytopenia,erythropenia,decreased hemoglobin and thrombocytopenia were shortened and recovered in advance and the nadir was much higher.Conclusion CBLB502 has biological activity in vitro and obvious radioprotection effects on mice with acute radiation syndrome.