Koziel M J
Infectious Disease Division, Beth Israel-Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
J Viral Hepat. 1997;4 Suppl 2:31-41. doi: 10.1111/j.1365-2893.1997.tb00178.x.
Hepatitis C virus (HCV) is notable for the high rate of chronic infection, which occurs in nearly all individuals who become infected. Liver biopsies from individuals with chronic HCV infection are notable for the presence of numerous mononuclear cells, at least some of which are CD4+ and CD8+ T lymphocytes. The immune response to HCV is polyclonal and multispecific, both in terms of antibody and cellular immune responses. Individuals who recover from acute HCV infection appear to have quantitatively more vigorous CD4+ proliferative responses against one or more HCV proteins compared with those individuals who develop chronic disease. CD8+ responses are less well characterized, in part because of the technical difficulties involved in isolating and characterizing these cells. HCV-specific CTL can be readily isolated from the liver and PBMC of chronically infected individuals, and recognize multiple epitopes. Even individuals with the same HLA type do not consistently recognize the same epitope. Thus, there does not appear to be an immunodominant response on the CD8+ level in this infection. CD8+ cells do appear to play some role in limiting viral replication. These responses are insufficient to eradicate virus completely, however, and may cause liver injury once chronic infection is established. Cytokines produced by both CD4+ and CD8+ cells may play an important role in both inhibiting viral replication and causing liver injury. A better understanding of the role of cellular immunity in the pathogenesis of HCV infection may aid in the development of vaccines and immunotherapeutic intervention strategies.
丙型肝炎病毒（HCV）以其高慢性感染率而著称，几乎所有感染该病毒的个体都会发生慢性感染。慢性HCV感染个体的肝活检显示存在大量单核细胞，其中至少一些是CD4 +和CD8 + T淋巴细胞。对HCV的免疫反应在抗体和细胞免疫反应方面都是多克隆和多特异性的。与那些发展为慢性疾病的个体相比，从急性HCV感染中康复的个体似乎对一种或多种HCV蛋白具有数量上更强烈的CD4 +增殖反应。CD8 +反应的特征尚不明确，部分原因是分离和鉴定这些细胞存在技术困难。HCV特异性CTL可以很容易地从慢性感染个体的肝脏和外周血单核细胞中分离出来，并识别多个表位。即使是具有相同HLA类型的个体也并非始终识别相同的表位。因此，在这种感染中，CD8 +水平上似乎不存在免疫优势反应。CD8 +细胞似乎确实在限制病毒复制中发挥了一定作用。然而，这些反应不足以完全根除病毒，并且一旦建立慢性感染，可能会导致肝损伤。CD4 +和CD8 +细胞产生 的细胞因子可能在抑制病毒复制和导致肝损伤方面都发挥重要作用。更好地了解细胞免疫在HCV感染发病机制中的作用可能有助于开发疫苗和免疫治疗干预策略。
