大鼠感染泡球蚴后外周血及脾脏中滤泡辅助T淋巴细胞的变化

Change in follicular helper T cells in the peripheral blood and spleen of rats after Echinococcus multilocularis infection

目的分析泡球蚴感染宿主后外周血和脾脏中滤泡辅助T淋巴细胞(Tfh)水平与包虫病进展的关系。方法20只SD大鼠随机分为正常对照组和模型组,每组10只,模型组开腹直视下在右肝接种约2000个原头节,对照组不做任何处理,3个月后麻醉处死SD大鼠,取外周血和脾脏细胞,以CD4^(+)CXCR5^(+)PD1^(+)为Tfh细胞的标记,使用流式细胞术检测外周血和脾脏中Tfh细胞的水平。使用t检验比较两组之间Tfh细胞的差异。结果大鼠感染泡球蚴3个月后,肝脏可见明显病灶,HE染色显示病灶中可见原头节。泡球蚴感染模型组外周血中CD4^(+)CXCR5^(+)PD1^(+)Tfh细胞在CD4+细胞中的平均占比为25.63%±3.47%,正常对照组为11.12%±2.94%,2组比较差异有统计学意义(t=10.230,P<0.001),模型组CD4^(+)CXCR5^(+)PD1^(+)Tfh细胞在所有细胞中所占的比例较正常对照组下降显著(0.08%±0.02%vs 0.18%±0.05%,t=5.520,P<0.001);在所有细胞中,模型组脾脏中CD4^(+)CXCR5^(+)PD1^(+)Tfh细胞所占的比例(3.00%±0.42%)显著低于正常对照组(5.30%±1.40%)(t=4.769,P<0.001)。结论外周血中Tfh细胞与包虫病进展密切相关,有望成为反应泡球蚴感染的指标。

Objective To investigate the level of follicular helper T(Tfh)cells in the peripheral blood and spleen of the host after Echinococcus multilocularis infection and its association with the progression of echinococcosis.Methods A total of 20 Sprague-Dawley rats were randomly divided into normal control group and model group,with 10 rats in each group.The rats in the model group were inoculated with about 2000 protoscoleces in the right liver under direct-view laparotomy,and those in the control group were not given any treatment.The rats were anesthetized and sacrificed after 3 months to collect peripheral blood and spleen cells,and with CD4^(+)CXCR5^(+)PD1^(+)as the marker of Tfh cells,flow cytometry was used to measure the level of Tfh cells in peripheral blood and spleen.The t-test was used for comparison of Tfh cells between the two groups.Results After 3 months of Echinococcus multilocularis infection,marked lesions were observed in the liver,and HE staining showed the presence of protoscoleces in the lesions.The proportion of CD4^(+)CXCR5^(+)PD1^(+)Tfh cells in CD4+cells in peripheral blood was 25.63%±3.47%in the model group and 11.12%±2.94%in the normal control group(t=10.230,P<0.001),and the model group had a significantly lower proportion of CD4^(+)CXCR5^(+)PD1^(+)Tfh cells in all cells than the normal control group(0.08%±0.02%vs 0.18%±0.05%,t=5.520,P<0.001).For the model group,the proportion of CD4^(+)CXCR5^(+)PD1^(+)Tfh cells in all cells in the spleen decreased to 3.00%±0.42%,which was significantly lower than the proportion of 5.30%±1.40%in the normal control group(t=4.769,P<0.001).Conclusion Tfh cells in peripheral blood are closely associated with the progression of echinococcosis and are expected to become an indicator of Echinococcus multilocularis infection.