Cleveland VA Medical Center, Cleveland, OH 44106, USA.
Pathology Department, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
Cells. 2023 Aug 10;12(16):2034. doi: 10.3390/cells12162034.
Both acute and chronic hepatitis C virus (HCV) infections are characterized by inflammation. HCV and reduced liver blood filtration contribute to inflammation; however, the mechanisms of systemic immune activation and dysfunction as a result of HCV infection are not clear. We measured circulating inflammatory mediators (IL-6, IP10, sCD163, sCD14), indices of endotoxemia (EndoCab, LBP, FABP), and T cell markers of exhaustion and senescence (PD-1, TIGIT, CD57, KLRG-1) in HCV-infected participants, and followed a small cohort after direct-acting anti-viral therapy. IL-6, IP10, Endocab, LBP, and FABP were elevated in HCV participants, as were T cell co-expression of exhaustion and senescence markers. We found positive associations between IL-6, IP10, EndoCab, LBP, and co-expression of T cell markers of exhaustion and senescence. We also found numerous associations between reduced liver function, as measured by plasma albumin levels, and T cell exhaustion/senescence, inflammation, and endotoxemia. We found positive associations between liver stiffness (TE score) and plasma levels of IL-6, IP10, and LBP. Lastly, plasma IP10 and the proportion of CD8 T cells co-expressing PD-1 and CD57 decreased after initiation of direct-acting anti-viral therapy. Although associations do not prove causality, our results support the model that translocation of microbial products, resulting from decreased liver blood filtration, during HCV infection drives chronic inflammation that results in T cell exhaustion/senescence and contributes to systemic immune dysfunction.
无论是急性还是慢性丙型肝炎病毒 (HCV) 感染都以炎症为特征。HCV 和肝脏血液滤过减少导致炎症;然而,HCV 感染导致全身免疫激活和功能障碍的机制尚不清楚。我们测量了 HCV 感染参与者的循环炎症介质(IL-6、IP10、sCD163、sCD14)、内毒素血症指标(EndoCab、LBP、FABP)以及 T 细胞衰竭和衰老标志物(PD-1、TIGIT、CD57、KLRG-1),并在直接作用抗病毒治疗后对一小部分患者进行了随访。HCV 参与者的 IL-6、IP10、Endocab、LBP 和 T 细胞衰竭和衰老标志物的共表达均升高。我们发现 IL-6、IP10、EndoCab、LBP 与 T 细胞衰竭和衰老标志物的共表达之间存在正相关。我们还发现,肝功能下降(血浆白蛋白水平)与 T 细胞衰竭/衰老、炎症和内毒素血症之间存在许多关联。我们发现肝硬度 (TE 评分) 与 IL-6、IP10 和 LBP 的血浆水平之间存在正相关。最后,直接作用抗病毒治疗开始后,血浆 IP10 和共表达 PD-1 和 CD57 的 CD8 T 细胞比例降低。虽然关联并不能证明因果关系,但我们的结果支持这样一种模型,即 HCV 感染期间肝脏血液滤过减少导致微生物产物易位,从而驱动慢性炎症,导致 T 细胞衰竭/衰老,并导致全身免疫功能障碍。