Toll样受体4在乙型肝炎组织及细胞株HepG2/HepG2.2.15内的表达特征

Expression of TLR4 in Liver Tissue Infected HBV and HepG2/HepG2.2.15

【目的】探讨Toll样受体4(TLR4)在乙型肝炎组织及细胞株HepG2/HepG2.2.15内的表达特征。【方法】采用免疫组化染色法检测慢性乙型病毒性肝炎(CHB)63例、慢性重型肝炎(CSH)11例及健康对照组10例肝组织TLR4的表达,综合评分法判断结果。常规培养肝癌细胞株HepG2及HepG2.2.15,采用直接免疫荧光流式细胞术(FCM)检测TLR4在细胞上表达的平均荧光强度(MFI)及阳性细胞率。【结果】TLR4在慢性乙型病毒性肝炎及慢性重型肝炎患者肝组织上的表达明显高于健康对照组(P<0.01),主要表达于肝细胞胞浆及部分胞膜,在慢性乙型病毒性肝炎中,TLR4的表达强度与肝组织炎症活动度分级(G)呈显著正相关(r=0.632,P<0.001)。TLR4在肝癌细胞株HepG2.2.15上表达的平均荧光强度及阳性细胞率分别为18.24±8.18、(17.79±9.46)%,明显高于HepG2的2.33±0.41、(1.71±0.77)%(P<0.001)。【结论】TLR4的表达与乙型病毒性肝炎肝组织的炎症活动密切相关,而乙型肝炎病毒可直接上调细胞TLR4的表达,故TLR4参与了乙型病毒性肝炎发病过程中的免疫反应并极有可能与免疫损伤有关。

[ Objective ] To investigate the expression of Toll-like receptor （TLR4） in liver tissue with hepatitis B virus （HBV） and cell lines HepG2/HepG2.2.15. [Methods] The expression of TLR4 was determined by immunohistochemistry in human livers with chronic viral hepatitis B （CHB）, chronic severe hepatitis （CSH）, and health control. The results were evaluated by integrative index. Hepatocellular carcinoma HepG2 and HepG2.2.15 cells were cultured by routine method. Immunofluorescence flow cytometry was used to detect TLR4＋ cells and mean fluorescence intensity （MFI）. [Results] The intensity of TLR4 expression in liver tissue of CHB and CSH was significantly higher than that of health control P〈 0.01 ）. The positive staining was mainly located in cytoplasm and some on cell membrane. In chronic viral hepatitis B, the intensity of TLR4 expression was positively correlated with the grade of necroinflammatory activity （ r=0.632, P〈 0.001）. MFI of TLR4 （18.24 ± 8.18） and TLR4＋ cell percentage of HepG2.2.15 cells （17.79% ± 9.46%） were significantly higher than those of HepG2 （2.33 ± 0.41, 1.71% ± 0.77%, P〈 0.001）. [Conclusions] The expression of TLR4 had closely correlation with the grade of necroinflammatory activity of viral hepatitis B. Hepatitis B virus might directly up-regulate the expression of TLR4. Therefore TLR4 might participate in immunoreaction, especially in immune-mediated hepatic damage in course of viral hepatitis B.