HBV感染对人T细胞免疫及细胞因子TNF-α、GF-β_2的影响

Effects of HBV infection on T cell immunity and hepatic expression of TNF-α and TGF-β_2

目的:检测HBV感染后外周血及感染肝组织内CD4+T 和CD8+T细胞的数量及功能,以及肝组织内TNF-α及TGF-β2表达,探讨HBV对人体T细胞免疫的影响及其可能机制. 方法:用流式细胞仪检测HBV感染者36例和正常人20 例外周血中T细胞亚群的数量.用免疫组化法HBV感染肝组织50例中CD4,CD8,CD25和TNF-α,TGF-β2 的表达,并作相应比较. 结果:HBV感染组外周血,CD4+和CD4+/CD8+比值明显低于对照组(P<0.05);CD8+细胞升高,明显高于对照组(P<0.05).肝组织内浸润的淋巴细胞主要聚集在汇管区和小叶坏死区,免疫组化结果显示HBV感染组肝组织内的CD8+和CD4+细胞数量多于非HBV感染组(P<0.01).HBV感染组肝组织内CD25+细胞数量减少,但统计学上无显著意义.HBV感染组肝组织TNF-α表达明显增强,与非HBV感染组相比有显著差异(P<0.05);而TGF-β2在HBV感染组肝组织的表达与非HBV感染组相比无显著差异.TGF-β2及TNF-α在肝硬化、癌旁肝硬化、肝细胞癌中均较强表达,且与慢性乙肝组和正常对照组比较有非常显著差异(P<0.01). 结论:HBV感染者外周血和肝内的T细胞亚群紊乱, 活性下降,功能受损.TNF-α表达与HBV感染和免疫损伤密切相关,而HBV对TGF-β2的影响微弱.

AIM: To study the influence of hepatitis B virus(HBV) infection on cellular immunity via examining the T cell subsets in peripheral blood and the hepatic tissues and the expression of cytokines in the liver. METHODS: CD4+T cells and CD8+ T cells in peripheral blood was enumerated by flow cytometry (FCM) in 36 patients with hepatitis B and 20 healthy controls. The expression of CD4, CD8, CD25, TNF-α and TGF-β2 were determined by streptavidin-peroxidase(SP) immunohis-tochemistry in 50 cases HBV-infected liver tissues. RESULTS: The quantity of CD4+ T cells and the ratio of CD4+/CD8+ in peripheral blood of patients were significantly lower than controls (P<0.05). The quantity of CD8+T cells was considerably higher than controls (P<0.05). T cells mostly accumulated in the lobule and the portal tract. More CD8+ cells than CD4+ cells were observed. The quantities of CD4+ and CD8+ cells in the liver tissues of HBV positive group were significantly different from the negative group (P<0.05). CD25+cells were reduced in the infected livers, but without significant difference. The expression of TNF-α in the liver tissues of HBV positive group were significantly different from the liver tissues of HBV negative group (P<0.05). In contrast, the expression of TGF-β2 was not significantly different between the two groups. TGF-β2 and TNF-α expression in liver cirrhosis, hepatocellular carcinoma and paratumor cirrhosis were significantly different from that in control group(P<0.01). CONCLUSION: Aberrant T cell subsets and reduced T cell activity exist in patients with HBV infection. TNF-α, but not TGF-β2. may be related to HBV infection and liver injury.