Interleukin-7 in Patients With Chronic Hepatitis B May Have Effect on T Follicular Helper Cells and Specific Cellular Immunity

Extended analysis on peripheral blood cytokines correlated with hepatitis B virus viral load in chronically infected patients - a systematic review and meta-analysis

Background

Hepatitis B Virus (HBV) can affect life quality. Monitoring and understanding the fluctuations of the HBV level of viremia related to the intricate immune activity of the host helps in the development of new treatment strategies and evaluation patterns. This meta-analysis presents the correlations between cytokines and the level of viremia in chronic HBV patients for a better comprehension of the immune mechanisms behind this infection.

Methods

We used PRISMA guidelines for this meta-analysis. The databases assessed were PUBMED, WEB OF SCIENCE, SCOPUS, and Cochrane Library. ZOTERO and PlotDigitizer helped the systematic research process. We extracted information related to the correlations between cytokines and the HBV-DNA level. Effect measures included comparisons between standardized mean differences and correlation coefficients. We evaluated retrieved articles with the Newcastle-Ottawa Quality Assessment Scale (NOS). The R 4.2.2 software displayed the statistical calculation and graphical representations.

Results

From 58,169 records, we extracted 16 articles with 32 different cytokine determinations. The main interleukins included in detection panels were IL-10 and IL-21. The meta-correlation analysis comprised 1,199 chronic HBV patients. The standardized mean difference between cytokine levels in HBV patients and healthy controls was 0.82 (95% CI = [-0.19, 1.84], p = 0.11). We observed a significant, fair, pooled correlation coefficient between IL-10, IL-9, and the viral load (r = 0.52, 95% CI = [0.19, 0.85]).

Conclusion

This meta-analysis brings novelty because it gives a first rigorous systematic look at multiple studies with many cytokines. Our research approaches a debatable issue and gives a possible solution for settling controversies. Future studies can arise towards understanding the immune disruption in HBV and the development of new, improved assays for prognosis.

Serum cytokine profiles predict outcomes of chronic hepatitis B patients discontinuing entecavir or tenofovir therapy

BACKGROUND/PURPOSE

Distinct hepatitis relapse has been observed after discontinuing entecavir (ETV) or tenofovir disoproxil fumarate (TDF) therapy in chronic hepatitis B (CHB) patients. End-of-therapy (EOT) serum cytokines were compared and used for outcome prediction.

METHODS

A total of 80 non-cirrhotic CHB patients in a tertiary medical center in Taiwan who discontinued ETV (n = 51) or TDF (n = 29) therapy after fulfilling the APASL guidelines were prospectively enrolled. Serum cytokines were measured at EOT and 3rd month afterwards. Multivariable analysis was performed to predict virological relapse (VR, HBV DNA >2000 IU/mL), clinical relapse (CR, VR and alanine aminotransferase > 2-fold upper limit of normal) and hepatitis B surface antigen (HBsAg) seroclearance.

RESULTS

Compared with TDF group, ETV stoppers had greater interleukin 5 (IL-5), IL-12 p70, IL-13, IL-17 A and tumor necrosis factor alpha (TNF-alpha) (all P < 0.05) at EOT. Older age, TDF use, higher EOT HBsAg and IL-18 (Hazard ratio [HR], 1.01; 95% CI, 1.00-1.02) levels at EOT predicted VR, while older age, higher EOT HBsAg and IL-7 (HR, 1.25; 95% CI, 1.00-1.56) levels predicted CR. In TDF stoppers, higher IL-7 (HR, 1.29; 95% CI, 1.05-1.60) and IL-18 (HR, 1.02; 95% CI, 1.00-1.04) levels predicted VR, while IL-7 (HR, 1.34; 95% CI, 1.08-1.65) and interferon-gamma (IFN-gamma) (HR, 1.08; 95% CI, 1.02-1.14) levels predicted CR. A lower EOT HBsAg level was associated with HBsAg seroclearance.

CONCLUSION

Distinct cytokine profiles were observed after stopping ETV or TDF. Higher EOT IL-7, IL-18, and IFN-gamma could be probable predictors for VR and CR in patients discontinuing NA therapies.

Circulating cytokine profile and modulation of regulatory T cells in chronic hepatitis B patients with type 2 diabetes mellitus

The risk of hepatitis B virus (HBV) infection is higher in patients with diabetes mellitus, and diabetes mellitus is one of the metabolic complications of HBV infection. However, the cytokine profile of chronic hepatitis B (CHB) patients with type 2 diabetes mellitus (T2DM) is not fully understood. The aim of this study was to investigate the cytokine expression profile in CHB patients with T2DM, and to assess the regulatory function of cytokines to regulatory T cells (Tregs). Forty-four T2DM patients, 39 CHB patients, 17 patients with CHB and T2DM, and 21 control subjects were enrolled. Cytokine levels in the plasma were measured by Luminex multiplex assay. CD4+CD25+CD127dim/- Tregs were detected by flow cytometry. Tregs were purified and stimulated with recombinant human interleukin-15 (IL-15). The regulation of IL-15 on Tregs function was investigated by measuring cell number, IL-10/IL-35 secretion, and mRNA expression of immune checkpoint molecules in a Tregs+PBMC co-culture system. We found that levels of IL-1α, IL-6, and IL-33 were upregulated, while IFN-α, IL-2, IL-7, and IL-15 were downregulated in T2DM and CHB patients. CHB patients with T2DM had even lower plasma IL-7 and IL-15 levels. Tregs percentage was elevated in T2DM and CHB patients. CHB patients with T2DM had increased levels of Tregs, which correlated negatively with IL-15. Tregs showed stronger inhibitory activity in CHB patients with T2DM than in controls, T2DM, and CHB patients, which presented as reduction in cellular proliferation and induction of IL-10/IL-35 secretion. IL-15 suppressed Tregs function and inhibited the expression of immune checkpoint molecules in Tregs. The current data suggest that insufficient IL-15 levels and decreased responsiveness of Tregs to IL-15 signaling might contribute to strong immune dysfunction in CHB patients with T2DM.

Persistence of Hepatitis B Virus Infection: A Multi-Faceted Player for Hepatocarcinogenesis

Hepatitis B virus (HBV) infection has a multi-dimensional effect on the host, which not only alters the dynamics of immune response but also persists in the hepatocytes to predispose oncogenic factors. The virus exists in multiple forms of which the nuclear localized covalently closed circular DNA (cccDNA) is the most stable and the primary reason for viral persistence even after clearance of surface antigen and viral DNA. The second reason is the existence of pregenomic RNA (pgRNA) containing virion particles. On the other hand, the integration of the viral genome in the host chromosome also leads to persistent production of viral proteins along with the chromosomal instabilities. The interferon treatment or administration of nucleot(s)ide analogs leads to reduction in the viral DNA load, but the pgRNA and surface antigen clearance are a slow process and complete loss of serological HBsAg is rare. The prolonged exposure of immune cells to the viral antigens, particularly HBs antigen, in the blood circulation results in T-cell exhaustion, which disrupts immune clearance of the virus and virus-infected cells. In addition, it predisposes immune-tolerant microenvironment, which facilitates the tumor progression. Thus cccDNA, pgRNA, and HBsAg along with the viral DNA could be the therapeutic targets in the early disease stages that may improve the quality of life of chronic hepatitis B patients by impeding the progression of the disease toward hepatocellular carcinoma.

Serum IL-21 levels predict HBeAg decline during rescue therapy in patients with partial response to nucleos(t)ide analogues

To investigate whether IL-21 levels predict treatment outcomes of salvage therapy among patients with suboptimal response (SOR) to nucleos(t)ide analogues (NAs), serum IL-21 levels were measured in a prospective cohort of hepatitis B e antigen (HBeAg)-positive patients with SOR to antiviral therapy. The patients switched therapy to entecavir (ETV) with or without adefovir (ADV) for 104 weeks. IL-21 levels at treatment week 12 in patients who achieved HBeAg loss with undetectable levels of hepatitis B virus (HBV)-DNA at week 104 were the primary endpoint and the results were compared with those of corresponding patients without such an endpoint. Furthermore, IL-21 levels at treatment week 12 in patients who achieved an HBeAg-level decline at week 104 were assessed as the secondary endpoint. Among 24 enrolled patients with SOR to ADV (n=21), telbivudine (n=2) or ETV (n=1), the median (10-90th percentile) levels of HBeAg, HBV-DNA and ALT at baseline were 2.7 (0.2-3.1) log₁₀ S/CO, 5.2 (3.5-7.5) log₁₀ IU/ml and 0.9 (0.5-3.1) upper limit of normal, respectively. Comparison of the patients with and without HBeAg loss at week 104 indicated that their mean IL-21 levels did not significantly differ at week 12 (63.0±14.4 vs. 55.9±10.5 pg/ml; P=0.26). In the secondary endpoint analyses of patients with and without HBeAg level decline, the elevated levels of IL-21 at the first 12 weeks were significantly higher in the decline group (15.6±8.3 vs. 3.1±13.2 pg/ml; P=0.03). Following adjustment for confounding factors, the elevated levels of IL-21 from baseline to week 12 independently predicted an HBeAg level decline at week 104 (odds ratio=1.137, R²=0.23; P=0.047). In conclusion, the serum IL-21 levels at the first 12 weeks during the salvage therapy independently predicted HBeAg level decline at treatment week 104 in patients with SOR to NAs (ClinicalTrials.gov identifier: NCT01829685; date of registration, April 2013).

hIL-7-hyFc, A Long-Acting IL-7, Increased Absolute Lymphocyte Count in Healthy Subjects

A low lymphocyte count puts immune-compromised patients at risk of mortality. hIL-7-hyFc is a homodimeric interleukin-7 (IL-7), a potent T-cell amplifier, fused to the hybridizing IgD/IgG4 immunoglobulin domain. We performed a randomized, double-blind, placebo-controlled, dose-escalation, phase I study to assess the pharmacokinetic, pharmacodynamic, safety, tolerability, and immunogenicity profiles of hIL-7-hyFc administered s.c. and i.m. to healthy volunteers. Thirty subjects randomly received hIL-7-hyFc or its matching placebo in an 8:2 ratio at 20, 60 μg/kg s.c., or 60 μg/kg i.m. The hIL-7-hyFc was slowly absorbed and its terminal half-life was 63.26 hours after i.m. administration. The hIL-7-hyFc increased absolute lymphocyte count, mostly in T-cells, which peaked 3 weeks after administration and then lasted for several additional weeks. The hIL-7-hyFc was well-tolerated after a single s.c. and i.m. administration. Injection site reaction was the most common treatment-emergent adverse event, which resolved spontaneously without treatment. The hIL-7-hyFc can be developed into a beneficial treatment option for patients with compromised T-cell immunity. This trial was registered at www.clinicaltrials.gov as #NCT02860715.

Differential expression of pro-inflammatory and anti-inflammatory genes of layer chicken bursa after experimental infection with infectious bursal disease virus

Infectious bursal disease (IBD) is one of the most prevalent infectious diseases caused by IBD virus (IBDV), which results in bursal necrosis and immunosuppression that cause severe damage to the immune system in chickens. Cytokines are important mediators and regulators of both types of host responses. In the present study, layer chickens were artificially challenged with IBDV, and the differential expression of inflammatory genes was explored by using quantitative real-time PCR, which offered basic data for further study of IBDV pathogenesis. Data showed that after IBDV infection, the virus load in the bursa of Fabricius (BF) peaked at 96 h and then gradually decreased. Compared with those of the negative-infected group, the mRNA expression levels of pro-inflammatory cytokines (interleukin [IL]-1β, IL-6, IL-7, IL-8, tumor necrosis factor [TNF]-α, transforming growth factor [TGF]-β) and anti-inflammatory cytokine IL-10 in the infected group increased to varying degrees at 12 to 192 h, respectively. Furthermore, the IL-1β mRNA expression peaked at 48 h; the mRNA transcript levels of IL-6, IL-8, and IL-10 were the highest at 96 h; TNF-α mRNA expression peaked at 120 h; the IL-7 mRNA expression peaked at 144 h; and the TGF-β mRNA transcript level was the highest at 192 h. Taken together, these observations indicated that along with the change pattern of IBDV proliferation in BF, the mRNA expression of cytokines (IL-1β, IL-6, IL-7, IL-8, IL-10, TNF-α, TGF-β) obviously increased, and the kinetics of each of these cytokines was different. The kinetics of IL-6/IL-10 mRNA expression ratio was significantly positively correlated with that of the virus load. These results suggest that IBDV infection seriously interferes with the natural immune response mediated by inflammatory cytokines in chickens.

Increased CCR7loPD-1hiCXCR5+CD4+ T Cells in Peripheral Blood Mononuclear Cells Are Correlated with Immune Activation in Patients with Chronic HBV Infection

T follicular helper cells (Tfh cells) affect essential immune pathogenesis in chronic hepatitis B virus (HBV) infection. The CCR7^loPD-1^hi Tfh subset has a partial Tfh effector phenotype and is associated with active Tfh differentiation, whereas the CCR7^hiPD-1^lo Tfh subset is a resting phenotype. We recruited 20 healthy volunteers and 77 patients with chronic HBV infection, including those in the immune tolerant (IT) phase (n=19), immune clearance (IC) phase (n=20), low replicative (LR) phase (n=18), and reactivation (RA) phase (n=20). The expression of CD4, CXCR5, PD-1, and CCR7 was detected in T cells from peripheral blood by flow cytometry. The frequency of the CCR7^loPD-1^hi T subset was significantly higher in the patients than in the healthy controls (14.92±4.87% vs 12.23±2.95%, p=0.018). The frequency of this Tfh subset in the IC group (18.42%±3.08) was increased compared with the IT group (11.94±2.87%, p=0.001) and LR group (13.65±4.93%, p=0.031) and was higher in the RA group than in the IT group (16.03±5.37% vs 11.94±2.87%, p=0.030). We observed a weak positive correlation between the CCR7^loPD-1^hi Tfh subset population and the alanine transaminase (ALT) level (r=0.370, p=0.001). The CCR7^loPD-1^h Tfh subset in the chronic HBV-infected patients was elevated to various degrees among the different immune phases. CCR7^loPD-1^hiCXCR5⁺CD4⁺ T cells are correlated with the immune status of chronic HBV infection patients and may be developed as a potential indicator for antiviral treatment.

Interleukin-7 Regulates T Follicular Helper Cell Function in Patients with Chronic Hepatitis C

Signaling through interleukin (IL)-7 is essential and required for development, differentiation, proliferation, and homeostasis of T cells. However, the role of IL-7 in regulation of CD4⁺ T cells in chronic viral infections was not fully elucidated. Thus, the aim of the current study was to investigate the immunomodulatory activity of IL-7 to T follicular helper (Tfh) cells and its contribution to pathogenesis of chronic HCV, hepatitis C virus (HCV) infection. A total of 47 patients with chronic hepatitis C and 19 normal controls were enrolled. Serum IL-7 and proportion of Tfh cells was measured. The regulatory function of IL-7 to Tfh cells was also investigated in CD4⁺ T cells and CD4⁺ T/HCVcc-infected Huh7.5 cell cocultured system. Serum IL-7 concentration was significantly downregulated in patients with chronic hepatitis C, and was negatively correlated with HCV RNA level. Tfh frequency and Tfh-associated cytokines (IL-21 and IL-6) were also reduced in chronic HCV-infected patients. Moreover, recombinant IL-7 stimulation elevated proportion of Tfh cells and IL-21/IL-6 secretion in both HCV-specific and nonspecific manners. Furthermore, IL-7-treated CD4⁺ T cells exhibited elevated antiviral activities without killing infected hepatocytes, which presented as inhibition of HCV RNA, induction of antiviral proteins, and promotion of cytokine production (especially IL-21) in cocultured system. This process might be dependent on IL-6 secretion. The current data revealed that IL-7 regulated HCV-specific and nonspecific activated Tfh cells, which might contribute to viral clearance. IL-7 could be a potential therapeutic agent for the treatment of chronic hepatitis C.

Interleukin-7 augments CD8+ T cells function and promotes viral clearance in chronic hepatitis C virus infection

Interleukin (IL)-7 is a potent proliferation, activation, and survival cytokine for CD8⁺ T cells to improve viral and tumor specific CD8⁺ T cell responses. However, the role of IL-7 in regulation of dysfunctional hepatitis C virus (HCV)-specific CD8⁺ T cells was not fully elucidated. Thus, a total of 53 patients with chronic hepatitis C and 24 healthy individuals were enrolled in the current study. Serum IL-7 and its receptor α chain CD127 expression was measured. The modulatory function of IL-7 to CD8⁺ T cells was investigated in both direct and indirect contact co-culture with HCVcc-infected Huh7.5 cells. Both serum IL-7 and CD127 expression on CD8⁺ T cells was significantly reduced in chronic HCV-infected patients, which was negatively correlated with HCV RNA. Stimulation of IL-7 promoted both cytotoxicity and cytokines (interferon-γ, tumor necrosis factor-α, and IL-2) production of CD8⁺ T cells from patients with chronic hepatitis C. Moreover, IL-7 increased proliferation of CD8⁺ T cells, while downregulated a critical repressor of cytokine signaling, suppressor of cytokine signaling 3 (SOCS3). The IL-7-mediated enhancement effects to CD8⁺ T cells were dependent on IL-6 production. The current data suggested that IL-7 induced both cytolytic and noncytolytic functions of CD8⁺ T cells probably via repression of SOCS3. IL-7 might be considered as one of the therapeutic candidates for treatment of chronic HCV infection.