Semmo Nasser, Klenerman Paul
Nuffield Department of Clinical Medicine, University of Oxford, The Peter Medawar Building for Pathogen Research, South Parks Road, Oxford OX1 3SY, United Kingdom.
World J Gastroenterol. 2007 Sep 28;13(36):4831-8. doi: 10.3748/wjg.v13.i36.4831.
Hepatitis C virus (HCV) infection is a major cause of liver damage, with virus-induced end-stage disease such as liver cirrhosis and hepatocellular carcinoma resulting in a high rate of morbidity and mortality worldwide. Evidence that CD4+ T cell responses to HCV play an important role in the outcome of acute infection has been shown in several studies. However, the mechanisms behind viral persistence and the failure of CD4+ T cell responses to contain virus are poorly understood. During chronic HCV infection, HCV-specific CD4+ T cell responses are relatively weak or absent whereas in resolved infection these responses are vigorous and multispecific. Persons with a T-helper type I profile, which promotes cellular effector mechanisms are thought to be more likely to experience viral clearance, but the overall role of these cells in the immunopathogenesis of chronic liver disease is not known. To define this, much more data is required on the function and specificity of virus-specific CD4+ T cells, especially in the early phases of acute disease and in the liver during chronic infection. The role and possible mechanisms of action of CD4+ T cell responses in determining the outcome of acute and chronic HCV infection will be discussed in this review.
丙型肝炎病毒（HCV）感染是肝损伤的主要原因，由病毒引起的终末期疾病，如肝硬化和肝细胞癌，在全球范围内导致了很高的发病率和死亡率。多项研究表明，CD4 + T细胞对HCV的反应在急性感染的转归中起重要作用。然而，病毒持续存在以及CD4 + T细胞反应无法控制病毒背后的机制仍知之甚少。在慢性HCV感染期间，HCV特异性CD4 + T细胞反应相对较弱或不存在，而在感染清除时，这些反应则强烈且具有多特异性。具有促进细胞效应机制的I型辅助性T细胞特征的人被认为更有可能实现病毒清除，但这些细胞在慢性肝病免疫发病机制中的总体作用尚不清楚。为了明确这一点，需要更多关于病毒特异性CD4 + T细胞功能和特异性的数据，特别是在急性疾病的早期阶段以及慢性感染期间肝脏中的数据。本综述将讨论CD4 + T细胞反应在决定急性和慢性HCV感染转归中的作用及可能的作用机制。
