Correlations between cytokines produced by T cells and clinical-virological characteristics in untreated chronic hepatitis B patients

The Role of Interleukins in HBV Infection: A Narrative Review

Hepatitis B virus (HBV) infection is a worldwide medical issue with significant morbidity and mortality, as it is the main cause of chronic liver disease and hepatocellular carcinoma (HCC). Both innate and adaptive immune responses play a key role in HBV replication and suppression. Recently, the pathophysiological function of interleukins (IL) in the natural course of HBV has gained much attention as a result of the broad use of anti-interleukin agents for a variety of autoimmune diseases and the accompanying risk of HBV reactivation. We present a narrative review regarding the role of IL in HBV infection. Collectively, the pro-inflammatory ILs, namely IL-1, IL-5, IL-6, IL-12 and IL-21, seem to play a critical role in the suppression of HBV replication. In contrast, the anti-inflammatory cytokines IL-10, IL-23 and IL-35 probably act as HBV replication enhancers, while IL-17 has been correlated with HBV-related liver injury. Interestingly enough, IL-2, IL-4 and IL-12 have been tried as therapeutic options against HBV infection with contradictory results. Lastly, the role of IL-22 remains largely ill defined, although preliminary data suggest that it may play a significant role in HBV replication, proliferation and subsequent liver damage.

The predictive role of NF-κB-mediated pro-inflammatory cytokine expression levels in hepatitis B vaccine response

Hepatitis B virus (HBV) infection is a global health problem leading to cirrhosis, hepatocellular carcinoma, and liver failure. The Hepatitis B vaccine plays a significant role in reducing the incidence of HBV worldwide. Approximately 5-10% of vaccinated people do not produce protective antibody levels. Nuclear factor kappa B (NF‑κB) mediates inflammatory responses through pro-inflammatory cytokines. However, the role of the NF‑κB signaling pathway and its association with pro-inflammatory cytokines in hepatitis B vaccine response is unclear. We aimed to assess changes in the IL1A, IL6, IL12A, TNF-α, and NFκB1 expression levels in the non-responder and responder. A total of 32 non-responders and 36 responders were included in the study. The expression level of determined genes was analyzed by RT-PCR. Our results showed that IL1A, IL6, IL12A, and NFκB1 mRNA levels significantly increased in the non-responders compared to the responders (p < .01). Furthermore, there was a significant correlation between IL1A, IL6, TNF-α, and NFκB1 in the non-responder and responders. In conclusion, inflammatory signaling pathways may play an important role in response to HBV vaccine. Therefore, NF‑κB signaling and associated pro-inflammatory cytokine mRNA levels could predict hepatitis B vaccine response. However, the underlying molecular mechanisms of hepatitis B vaccine immunity need further investigation.

Hepatitis B and circadian rhythm of the liver

The circadian rhythm in humans is determined by the central clock located in the hypothalamus’s suprachiasmatic nucleus, and it synchronizes the peripheral clocks in other tissues. Circadian clock genes and clock-controlled genes exist in almost all cell types. They have an essential role in many physiological processes, including lipid metabolism in the liver, regulation of the immune system, and the severity of infections. In addition, circadian rhythm genes can stimulate the immune response of host cells to virus infection. Hepatitis B virus (HBV) infection is the leading cause of liver disease and liver cancer globally. HBV infection depends on the host cell, and hepatocyte circadian rhythm genes are associated with HBV replication, survival, and spread. The core circadian rhythm proteins, REV-ERB and brain and muscle ARNTL-like protein 1, have a crucial role in HBV replication in hepatocytes. In addition to influencing the virus’s life cycle, the circadian rhythm also affects the pharmacokinetics and efficacy of antiviral vaccines. Therefore, it is vital to apply antiviral therapy at the appropriate time of day to reduce toxicity and improve the effectiveness of antiviral treatment. For these reasons, understanding the role of the circadian rhythm in the regulation of HBV infection and host responses to the virus provides us with a new perspective of the interplay of the circadian rhythm and anti-HBV therapy. Therefore, this review emphasizes the importance of the circadian rhythm in HBV infection and the optimization of antiviral treatment based on the circadian rhythm-dependent immune response.

Programmed death 1 expressing CD8+ CXCR5+ follicular T cells constitute effector rather than exhaustive phenotype in patients with chronic hepatitis B

BACKGROUND AND AIMS

Classical CD8 T cells are implicated for protective and pathogenic roles in chronic hepatitis B (CHB) infection. Recently, a subset of CD8 T cells expressing C-X-C chemokine receptor type 5 (CXCR5) and exhibiting features of TFH cells has been identified during chronic viral infections. However, in CHB, knowledge of their roles is limited.

APPROACH AND RESULTS

We characterized circulating CD8+ CXCR5+/- cells and investigated their association with clinical and viral factors. We found that CHB infection did not influence the overall frequencies of CD8+ CXCR5+ cells whereas CD8+ CXCR5- cells were increased. However, among CHB, CD8+ CXCR5+ cells were higher in patients with low HBsAg and HBV-DNA levels, patients who were HBeAg negative and had high fibrosis scores, and these cells exhibited a significant association with HBsAg and HBV-DNA reduction. Contrarily, CD8+ CXCR5- cells were expanded and positively correlated with patients having high HBsAg, HBV-DNA, and alanine aminotransferase levels. CD8+ CXCR5+ cells express costimulatory molecules ICOS, OX40, CD40 ligand, inhibitory molecule programmed death 1, transcription factors B-cell lymphoma (BCL)-2, BCL-6, and signal transducer and activator of transcription 3, and are enriched in effector and central memory phenotype. Moreover, these cells are heterogeneous in nature given that they constitute different subsets of cytotoxic follicular T cells (TCF), including TCF1, TCF2, TCF17, and TCF22. Despite expressing high PD-1, CD8+ CXCR5+ cells are activated, proliferating, secreting more IFN-γ, IL-21, and IL-22, and have better cytolytic potential than CD8+ CXCR5- cells, which were inhibited after PD-1/PD-L1 blockade. CD8+ CXCR5+ cells are efficient in helping B cells in terms of plasmablasts and plasma cell generation.

CONCLUSIONS

In conclusion, CD8+ CXCR5+ cells are enriched in effector phenotypes, produce HBV-specific cytokines despite increased PD-1, and are associated with HBsAg and HBV-DNA reduction. These cells competently support B-cell function, required for viral clearance, which may serve as potential therapeutic targets for CHB.

HBeAg Is Indispensable for Inducing Liver Sinusoidal Endothelial Cell Activation by Hepatitis B Virus

Background and Aims

Liver sinusoidal endothelial cells (LSECs) serve as sentinel cells to detect microbial infection and actively contribute to regulating immune responses for surveillance against intrahepatic pathogens. We recently reported that hepatitis B e antigen (HBeAg) stimulation could induce LSEC maturation and abrogate LSEC-mediated T cell suppression in a TNF-α and IL27 dependent manner. However, it remains unclear how HBeAg deficiency during HBV infection influences LSEC immunoregulation function and intrahepatic HBV-specific CD8 T cell responses.

Methods

The function of LSECs in regulating effector T cell response, intrahepatic HBV-specific CD8 T cell responses and HBV viremia were characterized in both HBeAg-deficient and -competent HBV hydrodynamic injection (HDI) mouse models.

Results

LSECs isolated from HBeAg-deficient HBV HDI mice showed a reduced capacity to promote T cell immunity in vitro compared with those isolated from wild-type HBV HDI mice. HBeAg expression replenishment in HBeAg-deficient HBV HDI mice restored the HBV-induced LSEC maturation, and resulted in potent intrahepatic anti-HBV CD8 T cell responses and efficient control of HBV replication. Moreover, in vivo TNF-α, but not IL27 blockade in HBV HDI mice impaired HBV-specific CD8 T cell immunity and delayed HBV clearance.

Conclusion

Our study underlines that HBeAg is indispensable for HBV-induced LSEC maturation to trigger intrahepatic HBV-specific T cell activation, and provides a new mechanism to elucidate the intrahepatic immune microenvironment regulation upon HBV exposure.

Cytokines and Chemokines in HBV Infection

Chronic hepatitis B virus (HBV) infection remains a leading cause of hepatic inflammation and damage. The pathogenesis of chronic hepatitis B (CHB) infection is predominantly mediated by persistent intrahepatic immunopathology. With the characterization of unique anatomical and immunological structure, the liver is also deemed an immunological organ, which gives rise to massive cytokines and chemokines under pathogenesis conditions, having significant implications for the progression of HBV infection. The intrahepatic innate immune system is responsible for the formidable source of cytokines and chemokines, with the latter also derived from hepatic parenchymal cells. In addition, systemic cytokines and chemokines are disturbed along with the disease course. Since HBV is a stealth virus, persistent exposure to HBV-related antigens confers to immune exhaustion, whereby regulatory cells are recruited by intrahepatic chemokines and cytokines, including interleukin-10 and transforming growth factor β, are involved in such series of causal events. Although the considerable value of two types of available approved treatment, interferons and nucleos(t)ide analogues, effectively suppress HBV replication, neither of them is sufficient for optimal restoration of the immunological attrition state to win the battle of the functional or virological cure of CHB infection. Notably, cytokines and chemokines play a crucial role in regulating the immune response. They exert effects by directly acting on HBV or indirectly manipulating target immune cells. As such, specific cytokines and chemokines, with a potential possibility to serve as novel immunological interventions, combined with those that target the virus itself, seem to be promising prospects in curative CHB infection. Here, we systematically review the recent literature that elucidates cytokine and chemokine-mediated pathogenesis and immune exhaustion of HBV infection and their dynamics triggered by current mainstream anti-HBV therapy. The predictive value of disease progression or control and the immunotherapies target of specific major cytokines and chemokines in CHB infection will also be delineated.

Characterization of T cell immunity in chronic hepatitis B virus-infected mothers with postpartum alanine transaminase flare

BACKGROUND

Postpartum alanine transaminase (ALT) flares occur frequently in chronic hepatitis B virus (HBV)-infected mothers with antepartum antiviral therapy (AVT). We aimed to characterize the T cell immunity in HBV-infected mothers experiencing postpartum ALT flares.

METHODS

Twenty HBV-infected pregnant women who received AVT at 26-28 weeks of gestation were enrolled and followed up until 15-18 weeks postpartum. Among the 20 HBV-infected pregnant women, 6 experienced postpartum ALT flare (AF mothers), while 14 did not (NAF mothers). T lymphocyte phenotypes and functions were analyzed using flow cytometry.

RESULTS

Compared to NAF mothers, the quantitative HBsAg levels in AF mothers decreased significantly at 6-8 or 15-18 weeks postpartum. Significant differences in HBeAg levels between these groups were only found at delivery. Regulatory T cell (Treg) numbers in AF mothers were lower than those of NAF mothers before AVT; however, there were no significant differences in Treg numbers at other follow-up points. Expression of other T cell phenotypes were similar between the two groups. T cells in AF mothers produced more pro-inflammatory cytokines (IFN-γ, IL-21, TNF-α, IL-2) or less anti-inflammatory cytokine (IL-10) than those in NAF mothers before, during, or after antiviral treatment. The ratio of IFN-γ to IL-10 producing by CD4⁺ T cells or CD8⁺ T cells was higher in AF mothers than that in NAF mothers during pregnancy or after delivery.

CONCLUSIONS

The characteristics of T cell immunity was distinct between mothers with postpartum ALT flare and those without ALT flare from pregnancy to postpartum, which indicated that T cell immunity might get involved in postpartum ALT flare.

Changes of cytokine levels and T cell surface molecules in patients with chronic hepatitis B and the association with functional cure

This study aimed to examine changes in levels of cytokine and T cell surface molecules in chronic hepatitis B (CHB) patients receiving sequential interferon therapy following 1-year nucleos(t)ide analogs (NAs) treatment. Cytokine levels were measured in 30 patients, and T cell surface molecule expression was measured in 48 patients receiving sequential interferon therapy and 24 patients only receiving NA mono-therapy. An HBsAg titer of <0.05 IU/ml was defined as a "functional cure." In the cured group (HBsAg < 0.05 IU/ml), a decreasing probability was observed in IFN-γ (after Week 0), and IL-22 and IP-10 (after Week 12). In the non-cured group (HBsAg ≥ 0.05 IU/ml), a probability of slightly decreasing was observed for IFN-γ (after Week 12), and a probability of increasing IP-10 concentration (after Week 0) was observed. Generalized estimating equation (GEE) analyses showed significant differences in the levels of IL-10, IL-23, CCL-3, IL-1β, IL-2, and IL-12P70 between the two groups. In GEE analysis, there were significant differences in expressions of CD45RO⁺  between the cured group and the non-cured group. The frequencies of T cells expressing Tim-3, CD62L, and CD152 were significantly lower in the sequential interferon therapy group than in the NA mono-therapy group. Changes in cytokine levels (IFN-γ, IP-10, IL-10, IL-23, CCL-3, IL-1β, IL-2, and IL-12P70) and T cell surface molecules (CD45RO⁺ ) may predict HBsAg seroconversion in CHB patients receiving sequential interferon therapy. The period from Weeks 12 to 24 during sequential interferon therapy may be a critical time of immune status change.

Immunopathology of Chronic Hepatitis B Infection: Role of Innate and Adaptive Immune Response in Disease Progression

More than 250 million people are living with chronic hepatitis B despite the availability of highly effective vaccines and oral antivirals. Although innate and adaptive immune cells play crucial roles in controlling hepatitis B virus (HBV) infection, they are also accountable for inflammation and subsequently cause liver pathologies. During the initial phase of HBV infection, innate immunity is triggered leading to antiviral cytokines production, followed by activation and intrahepatic recruitment of the adaptive immune system resulting in successful virus elimination. In chronic HBV infection, significant alterations in both innate and adaptive immunity including expansion of regulatory cells, overexpression of co-inhibitory receptors, presence of abundant inflammatory mediators, and modifications in immune cell derived exosome release and function occurs, which overpower antiviral response leading to persistent viral infection and subsequent immune pathologies associated with disease progression towards fibrosis, cirrhosis, and hepatocellular carcinoma. In this review, we discuss the current knowledge of innate and adaptive immune cells transformations that are associated with immunopathogenesis and disease outcome in CHB patients.

Association of cytokines with hepatitis B virus and its antigen

To investigate the characteristics of cytokines in patients with different HBV infection status and their correlation with HBV DNA, HBsAg, and HBeAg levels. Peripheral blood samples were collected from patients with chronic HBV infection in immune tolerance phase (IT), HBeAg-positive chronic hepatitis B (CHB), and acute hepatitis B (AHB) groups, and levels of cytokines were detected by Luminex technique, and analyzed by FLEXMAP 3D analyzer. The correlation between cytokines and HBV DNA load, HBsAg, HBeAg, and alanine aminotransferase (ALT) level in patients with chronic HBV infection was analyzed. In total 312 subjects (184 males and 128 females) were enrolled in the study. There were significant differences among IT, CHB, and AHB groups in Flt-3L value (P = .003; H = 12.312), IFN-γ (P = .001; H = 11.723), IL-10 (P = .001; H = 18.736), IL-17A ((P = .001; H = 12.735), and TGF-β1 (P = .001; Z = 48.571). IFN-α2 levels in CHB group were significantly higher than those in IT and AHB groups (15.24 vs 35.78 pg/mL, P = .000; Z = 3.727; 13.88 vs 35.78 pg/mL, P = .024; Z = -2.258. In CHB group, the levels of HBsAg and ALT were positively correlated with the levels of IL-10 (r = .173; P = .006; r = 0.176; P = .006, respectively), while HBeAg level was positively correlated with the IFN-α2 level (r = .153; P = .016). In AHB group, the HBsAg level was positively correlated with Flt-3L, IFN-α2, IL-10, and IL-6 (r = .402; P = .023; r = .436; P = .016; r = .524, P = .002; r = .405; P = .022, respectively). HBeAg level was positively correlated with IFN-γ and IL-17A levels (r = .400; P = .023; r = .373; P = .036, respectively), and ALT level was positively correlated with IL-6 levels (r = .367; P = .039). In either AHB or CHB group, HBV DNA load was only related to TGF-β level (r = .493; P = .004; r = -.218, P = 0.009 respectively). The correlation between Flt-3L and HBsAg (F = 7.422; P = .007); IL-17, IL-6, and HBeAg (F = 5.757; P = .017; F = 6.156; P = .014) were statistically significant. There was significant correlation between TGF-β2 and HBV DNA (F = 11.795; P = .001), and between ALT and HBsAg, HBV DNA (F = 26.089; P = .000; F = 4.724; P = .031). HBsAg, HBeAg, and HBV DNA were correlated with cytokines and ALT in patients with HBV infection. The level of IFN-α2 was significantly higher in patients with CHB. HBV DNA load was only correlated with the level of TGF-β in acute or CHB.

Chronic Hepatitis B Infection Is Associated with Increased Molecular Degree of Inflammatory Perturbation in Peripheral Blood

Hepatitis B virus (HBV) infection remains a major public health concern. The interaction between HBV and the host inflammatory response is an important contributing factor driving liver damage and diseases outcomes. Here, we performed a retrospective analysis employing an adapted molecular degree of perturbation (MDP) score system to assess the overall inflammatory imbalance related to persistent HBV infection. Plasma levels of several cytokines, chemokines, and other inflammatory markers were measured in Brazilian individuals diagnosed with either chronic HBV or previous HBV infection, as well as in uninfected controls between 2006 and 2007. Multidimensional analyses were used to depict and compare the overall expression profile of inflammatory markers between distinct clinical groups. Chronic HBV patients exhibited a marked inflammatory imbalance, characterized by heightened MDP scores and a distinct profile of correlation networks inputting plasma concentrations of the biomarkers, compared with either individuals with previous HBV or controls. Furthermore, in participants with chronic HBV infection, the viral loads in peripheral blood were directly proportional to overall molecular perturbation as well as to specific perturbations of interleukin (IL)-4 and interferon (IFN)-γ concentrations. These findings highlight additional nuances about systemic inflammation related to persistent HBV infection.

Hepatitis B surface antigen seroclearance: Immune mechanisms, clinical impact, importance for drug development

HBsAg seroclearance occurs rarely in the natural history of chronic hepatitis B (CHB) infection and is associated with improved clinical outcomes. Many factors are associated with HBsAg seroconversion, including immune and viral factors. However, the immune mechanisms associated with HBsAg seroclearance are still difficult to elucidate. HBsAg seroclearance is the ideal aim of HBV treatment. Unfortunately, this goal is rarely achieved with current treatments. Understanding the mechanisms of HBsAg loss appears to be important for the development of curative HBV treatments. While studies from animal models give insights into the potential immune mechanisms and interactions occurring between the immune system and HBsAg, they do not recapitulate all features of CHB in humans and are subject to variability due to their complexity. In this article, we review recent studies on these immune factors, focusing on their influence on CHB progression and HBsAg seroconversion. These data provide new insights for the development of therapeutic approaches to partially restore the anti-HBV immune response. Targeting HBsAg will ideally relieve the immunosuppressive effects on the immune system and help to restore anti-HBV immune responses.

Cytokines and chemokines involved in the defense reaction against HIV-1 and hepatitis B virus: isn't it time to use a standardized nomenclature of the involved mediators?

Discovery of new mediators of immune cell activation and interaction facilitated elucidation of the various ways of defense against infectious agents and happened some 40 years ago. Each involved group of researchers named the mediators according to their scope of investigation; often the same molecules were published at the same time with different names. To avoid confusion resulting from using different names for the same mediators and to prevent a Babylonian confusion, standardization was implemented-as in the field of metrics, music, or science including virology. For cytokines and chemokines a standard nomenclature was proposed some 10 years ago and in conclusion it should be used. In this paper the most relevant biomarkers in HIV-1 and HBV infection and their contribution during viral pathogenesis are listed.