已免疫CD4+记忆性T淋巴细胞介导HBV转基因小鼠抗HBsAg免疫应答的研究

摘要

Objective To investigate the mechanism of immune response to HBsAg mediated by CD4+ memory T lymphocytes in immunized HBV transgenic (Tg) mice.Methods Peripheral CD4+ memory T lymphocytes were isolated and collected by magnetic bead sorting from C57BL/6 mice successfully immunized by hepatitis B vaccine.Adoptive immunization was performed for Tg mice by caudal vein injection,and the peripheral blood was collected at 4 and 8 weeks after adoptive immunization.Enzyme linked immunosorbent assay was used to measure the levels of HBsAg,anti-HBs,interferon-γ (IFNγ),and interleukin-2 (IL-2),and immunohistochemistry was used to measure the level of HBsAg in the liver.The t-test was used for comparison of continuous data,and the chi-square test was used for comparison of categorical data.Results Compared with the control group,the experimental group had a significant reduction in HBsAg titer[(243.5±12.4) ng/ml vs 0 ng/ml,t =3.939,P =0.011] and significant increases in the levels of anti-HBs [0 ng/ml vs (530.7±17.5) ng/ml,t =4.414,P =0.006 9],IFNγ [(12.25±2.9) pg/ml vs (38.8±6.8) pg/ml,t =2.785,P =0.049 6],and IL-2 [(11.3±3.5) pg/ml vs (82.3±9.2) pg/ml,t =2.993,P =0.040 2].Conclusion As for immune response to HBsAg mediated by CD4+ memory T lymphocytes in immunized HBV Tg mice,increases in the levels of IFNγ and IL-2 help to enhance humoral and cellular immunity and mediate the clearance of HBsAg in Tg mice.%目的 研究已免疫CD4+记忆性T淋巴细胞介导HBV转基因小鼠(Tg小鼠)抗HBsAg免疫应答的作用机制. 方法 通过免疫磁珠分选分离、收集乙型肝炎疫苗成功免疫的C57BL/6小鼠外周血CD4+Tm淋巴细胞,再通过尾静脉注射过继免疫Tg小鼠,分别于过继免疫后4、8周采小鼠外周血,通过酶联免疫吸附法检测HBsAg、抗-HBs、干扰素γ(IFN γ)、白细胞介素2 (IL-2),同时通过免疫组织化学法检测小鼠肝脏的HBsAg.计量资料用t检验,计数资料用x2检验. 结果 与对照组相比,试验组Tg小鼠HBsAg滴度均明显降低[(243.5±12.4)ng/ml对比0 ng/m],t=3.939,P=0.011,差异有统计学意义;抗-HBs水平[(0ng/ml对比(530.7±17.5)ng/ml]、IFNγ[(12.25±2.9) pg/ml对比(38.8±6.8) pg/ml]和IL-2水平[(11.3±3.5)pg/ml对比(82.3±9.2) pg/ml],均明显升高,t值分别为4.414、2.785、2.993,P值分别为0.0069、0.0496、0.0402,差异均有统计学意义. 结论 已免疫CD4+记忆性T淋巴细胞介导HBV转基因小鼠,可通过提高IFN γ和IL-2细胞因子水平,增强体液和细胞免疫,从而介导Tg小鼠体内HBsAg的清除.