Immunopathological Study for Pathogenesis of Chronic Hepatitis, Type C

为了阐明慢性丙型肝炎肝损伤的机制，我们研究了肝活检标本中丙型肝炎病毒（HCV）的免疫病理学表现和细胞免疫反应。应用抗HCV核心抗原（抗HCc：抗CP-9）免疫组化和T-T二聚体寡核苷酸探针原位杂交技术。采用间接免疫过氧化物酶法检测肝组织中淋巴细胞亚群和T细胞亚群的CD 8、CD 11b、CD 4、CD 22和CD 57抗体。抗-ABC、抗-DR、抗-DP和抗-DQ用于HLA抗原的研究。采用抗ICAM-1、抗VCAM-1、抗LFA-1抗体检测粘附分子。用B细胞杂交瘤（ZB 4和UB 2）分泌的鼠源性单克隆抗体，用免疫过氧化物酶法检测了肝细胞Fas抗原的表达，结果表明，大多数患者肝细胞中HCcAg和/或HCV-RNA呈小颗粒和散在分布，但也有部分患者肝细胞呈小叶分布。慢性活动性肝炎患者肝组织中存在大量的T淋巴细胞，尤其是在片状坏死和局灶性坏死区有大量的OKT 8（+）、IIb（-1）和LFA-1（+）CTL浸润。在这些区域的肝细胞表面，HLA-1和ICAM-1抗原呈膜性表达。在大多数慢性活动性肝炎患者的肝细胞小叶上也观察到弥漫性FasAg。这些发现表明慢性丙型肝炎的肝细胞损伤可能是由识别HCV和HLA-1的CD 8 +CTL引起的。

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.