IL-6 Plays a Crucial Role in HBV Infection

Abstract

Interleukin-6 (IL-6), a cytokine mainly produced by activated monocytes, has broad pleiotropic actions that affect the functions of a variety of lymphoid cells. The roles of IL-6 in regulating immunity to infections are currently being defined. Remarkably, IL-6-mediated cellular and humoral immune responses play a crucial role in determining the outcome of viral infection. This article reviews the current knowledge on the critical role of IL-6 in hepatitis B virus (HBV) infection. As a competent intermediary, IL-6 derived from activated monocytes plays an important role in promoting lymphocytes responses that are essential for effective viral control. However, as a mediator of inflammation, IL-6 is also involved in the development of HBV-induced liver cirrhosis and exacerbating liver injury. Overall, the current data point to IL-6 as an immunoregulatory cytokine in HBV infection. Immunotherapeutic strategies aimed at optimizing the beneficial effects of IL-6 in HBV infection may prove to be an ordeal in the future, as they should foster the strengths of IL-6 while circumventing potential drawbacks.

The Role of Interleukin 6 During Viral Infections

“…However, certain scenarios create disparity of IL-6 production that may be detrimental to the cellular immune response during viral infections. Two different hypotheses may be considered to explain the change in IL-6 production during the immune response to viral infection: (i) the increased ability of some viral strains to overcome the immune response using a variety of evasion strategies (Beachboard and Horner, 2016), and consequently up-regulate the production of IL-6 as a result of increased viral loads, and (ii) polymorphisms in the IL-6 gene promoter stimulating overexpression of IL-6 during the immune response, a fact that has been shown to correlate with HBV progression (Lan et al, 2015). This last hypothesis might explain clinical reports correlating IL-6 overexpression with exacerbation of clinical outcomes in a sub-group of individuals during an outbreak caused by a single virus strain.…”

Potential circulating biomarkers of circulating chemokines CCL5, MIP-1β and HA as for early detection of cirrhosis related to chronic HBV (hepatitis B virus) infection

“…Since liver biopsy often leads to severe liver mechanical damage [5, 6], noninvasive evaluation of liver fibrosis has received increasing attention in clinical diagnosis [17–19]. The serum markers of fibrosis and inflammation are two types of indicators and considered for utilization as biomarkers to evaluate liver fibrosis [7, 20–22]. Although many previous studies have attempted to identify accurate or reliable noninvasive biomarkers in predicting liver fibrosis, so far, the results have not been satisfactory.…”

Circulating miR-122 and miR-200a as biomarkers for fatal liver disease in ART-treated, HIV-1-infected individuals

“…The correlations of miR-122 and miR-200a with IL-6 are interesting, as IL-6 is a marker of systemic inflammation, and it’s increase is associated with an increased risk of the development of SNAEs 16 , 17 . In the literature, IL-6 signalling has been shown to promote hepatocyte proliferation and survival 40 – 45 and IL-6 expression is increased in a number of liver specific diseases including HBV and HCV infection 40 , 46 . Therefore, it may be that one of the mechanisms in which IL-6 promotes hepatocyte proliferation and survival is by jettisoning, in EVs, these two potentially apoptotic miRNAs.…”