Klöss Volker, Grünvogel Oliver, Wabnitz Guido, Eigenbrod Tatjana, Ehrhardt Stefanie, Lasitschka Felix, Lohmann Volker, Dalpke Alexander H
Department of Infectious Diseases, Medical Microbiology and Hygiene, University Hospital Heidelberg, Heidelberg, Germany.
Department of Infectious Diseases, Molecular Virology, University of Heidelberg, Heidelberg, Germany.
Front Immunol. 2017 Sep 29;8:1238. doi: 10.3389/fimmu.2017.01238. eCollection 2017.
Innate immune cells can sense hepatitis C virus (HCV)-infected cells and respond with anti-viral actions including secretion of interferons (IFNs). In previous studies, the response of individual innate immune cells against HCV was analyzed in detail. We hypothesized that interaction of multiple innate immune cells increases the magnitude of the immune response and eventually leads to clearance of HCV-infected cells. To investigate this, we co-cultured Huh-7 HCV subgenomic replicon (SGR) cells with peripheral blood mononuclear cells (PBMCs). We confirm secretion of IFNα by plasmacytoid dendritic cells (pDCs) and IFNγ by natural killer (NK) cells in the co-culture setup. Moreover, we observed that also monocytes contribute to the anti-viral response. Flow cytometry and ImageStream analysis demonstrated that monocytes take up material from HCV SGR cells in co-culture with PBMCs. Preceding the uptake, PBMCs caused apoptosis of HCV SGR cells by tumor necrosis factor-related apoptosis inducing ligand (TRAIL) expression on NK cells. We observed that only the interplay of monocytes, pDCs, and NK cells resulted in efficient clearance of HCV SGR cells, while these cell populations alone did not kill HCV SGR cells. Despite similar TRAIL receptor expression on Huh-7 control cells and HCV SGR cells, HCV activated PBMCs specifically killed HCV SGR cells and did not target Huh-7 control cells. Finally, we showed that HCV replicating cells are sensitive toward TRAIL-induced apoptosis. Our results highlight the importance of the interplay of different innate immune cells to initiate an efficient, rapid, and specific response against HCV-infected cells.
天然免疫细胞能够识别丙型肝炎病毒（HCV）感染的细胞，并通过包括分泌干扰素（IFN）在内的抗病毒作用做出反应。在先前的研究中，已详细分析了单个天然免疫细胞对HCV的反应。我们推测，多种天然免疫细胞的相互作用会增强免疫反应的强度，并最终导致HCV感染细胞的清除。为了对此进行研究，我们将Huh-7 HCV亚基因组复制子（SGR）细胞与外周血单核细胞（PBMC）进行了共培养。我们证实在共培养体系中浆细胞样树突状细胞（pDC）分泌IFNα，自然杀伤（NK）细胞分泌IFNγ。此外，我们观察到单核细胞也有助于抗病毒反应。流式细胞术和ImageStream分析表明，在与PBMC共培养时，单核细胞摄取了来自HCV SGR细胞的物质。在摄取之前，PBMC通过NK细胞上肿瘤坏死因子相关凋亡诱导配体（TRAIL）的表达导致HCV SGR细胞凋亡。我们观察到，只有单核细胞、pDC和NK细胞的相互作用才能有效清除HCV SGR细胞，而这些细胞群体单独作用时并不能杀死HCV SGR细胞。尽管Huh-7对照细胞和HCV SGR细胞上的TRAIL受体表达相似，但HCV激活的PBMC特异性杀死HCV SGR细胞，而不靶向Huh-7对照细胞。最后，我们表明HCV复制细胞对TRAIL诱导的凋亡敏感。我们的结果突出了不同天然免疫细胞相互作用对于启动针对HCV感染细胞的有效、快速和特异性反应的重要性。
