Immunopathological Study for Pathogenesis of Chronic Hepatitis, Type C

为探讨慢性丙型肝炎的肝损伤机制，我们对慢性丙型肝炎患者肝组织中丙型肝炎病毒的免疫病理改变和肝活检组织中的细胞免疫反应进行了研究。采用抗丙型肝炎病毒核心抗原(抗肝细胞癌：抗CP-9)免疫组织化学方法和T-T二聚化寡核苷酸探针原位杂交技术。用抗CD8、抗CD11b、抗CD4、抗CD22、抗CD57的间接免疫过氧化物酶标记淋巴细胞亚群和T细胞亚群，观察肝组织的细胞免疫反应。以抗ABC、抗DR、抗DP、抗DQ为研究对象。用抗ICAM-1、抗VCAM-1和抗LFA-1检测黏附分子。用B细胞杂交瘤(ZB4和UB2)分泌的小鼠单抗，用免疫过氧化物酶方法研究了肝细胞FasAg的表达。在大多数患者中，带有HCcAg和/或丙型肝炎病毒核糖核酸的肝细胞散在分布，但也有部分患者肝细胞呈小叶状分布。免疫组织化学显示慢性活动性肝炎患者肝脏内存在大量T淋巴细胞，尤其是大量OKT8(+)、LLB1(-1)和LFA-1(+)CTL在小片坏死区和局灶性坏死区均有分布。在这些区域的肝细胞表面，有HLA1和ICAM 1抗原的膜性表达。大多数慢性活动性肝炎患者肝细胞内也可见FasAg弥漫分布于肝小叶。提示慢性丙型肝炎患者肝细胞损伤可能与CD8+CTL识别丙型肝炎病毒和人类白细胞抗原1类有关。

In order to clarify the mechanism of liver injuries in chronic hepatitis, type C,we investigated immunopathological findings of hepatitis C virus (HCV) and cellular immune responses in liver biopsy specimens. An immunohistochemical method using anti-HCV core antigen (anti-HCc : anti-CP-9) and in situ hybridization technique using T-T dimerized oligo cDNA probes were applied. Cellular immune responses in liver tissues were observed by indirect immunoperoxidase method using anti-CD8, anti-CDllb, anti-CD4, anti-CD22 and anti-CD57 for the subpopulation of lymphocytes and T cell subsets. Anti-ABC,anti-DR,anti-DP,and anti-DQ were studies for HLA antigens. Anti-ICAM-1, anti-VCAM-1 and anti-LFA-1 were used for detection of adhesion molecules. Expression of FasAg on hepatocytes was also studied by immunoperoxidase method usingmouse monoclonal antibodies secreted by B cell hybridomas (clone ZB4 and UB2).In most patients, liver cells with HCcAg and /or HCV-RNA were present in small mumbers and sporadically, but lobular distribution of HCV-positive hepatocytes was observed in some patients. Numerous Tlymphocytes were present immunohistochemically in the liver of patients with chronic active hepatitis, and particularly, numerous OKT8 (+), llb (-1) and LFA-1 (+) CTL infiltrated in areas of piecemeal necrosis and focal necrosis. On surface of hepatocytes in these areas, HLA-class 1 and ICAM-1 antigens were membranously expressed. FasAg was also observed diffusely on hepatocytes throughout lobules in most patients with chronic active hepatitis. These findings suggest liver cell injuries in chronic hepatitis C,may be caused by CD8+CTL recognizing HCV and HLA-class 1.