Gehring Adam J, Sun Dianxing, Kennedy Patrick T F, Nolte-'t Hoen Esther, Lim Seng Gee, Wasser Shanthi, Selden Clare, Maini Mala K, Davis Dan M, Nassal Michael, Bertoletti Antonio
UCL Institute of Hepatology, Royal Free and University College Medical School, London, UK.
J Virol. 2007 Mar;81(6):2940-9. doi: 10.1128/JVI.02415-06. Epub 2007 Jan 3.
CD8 T cells exert their antiviral function through cytokines and lysis of infected cells. Because hepatocytes are susceptible to noncytolytic mechanisms of viral clearance, CD8 T-cell antiviral efficiency against hepatotropic viruses has been linked to their capacity to produce gamma interferon (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha). On the other hand, intrahepatic cytokine production triggers the recruitment of mononuclear cells, which sustain acute and chronic liver damage. Using virus-specific CD8 T cells and human hepatocytes, we analyzed the modulation of virus-specific CD8 T-cell function after recognition peptide-pulsed or virally infected hepatocytes. We observed that hepatocyte antigen presentation was generally inefficient, and the quantity of viral antigen strongly influenced CD8 T-cell antiviral function. High levels of hepatitis B virus production induced robust IFN-gamma and TNF-alpha production in virus-specific CD8 T cells, while limiting amounts of viral antigen, both in hepatocyte-like cells and naturally infected human hepatocytes, preferentially stimulated CD8 T-cell degranulation. Our data document a mechanism where virus-specific CD8 T-cell function is influenced by the quantity of virus produced within hepatocytes.
CD8 T细胞通过细胞因子和对被感染细胞的裂解发挥其抗病毒功能。由于肝细胞易受病毒清除的非细胞溶解机制影响,CD8 T细胞对嗜肝病毒的抗病毒效率与其产生γ干扰素(IFN-γ)和肿瘤坏死因子α(TNF-α)的能力有关。另一方面,肝内细胞因子的产生会引发单核细胞的募集,从而维持急性和慢性肝损伤。我们使用病毒特异性CD8 T细胞和人肝细胞,分析了识别肽脉冲或病毒感染的肝细胞后病毒特异性CD8 T细胞功能的调节情况。我们观察到肝细胞抗原呈递通常效率低下,病毒抗原的量强烈影响CD8 T细胞的抗病毒功能。高水平的乙型肝炎病毒产生可诱导病毒特异性CD8 T细胞产生强大的IFN-γ和TNF-α,而在肝细胞样细胞和自然感染的人肝细胞中,有限量的病毒抗原优先刺激CD8 T细胞脱颗粒。我们的数据证明了一种机制,即病毒特异性CD8 T细胞功能受肝细胞内产生的病毒量的影响。