Association Between Adherence to EAT-Lancet Diet and Risk of Hypertension: An 18-Year National Cohort Study in China.

OBJECTIVE: The EAT-Lancet Commission has proposed an EAT-Lancet diet (ELD), also known as a planetary health diet (PHD), which is environmentally sustainable and promotes human health. However, the association between this diet and the risk of hypertension remains unclear. This study aimed to determine whether adherence to ELD was associated with a lower risk of hypertension. METHODS: 11,402 adults without hypertension at baseline from the China Health and Nutrition Survey were included. The PHD score was used to evaluate ELD adherence, with higher scores reflecting better compliance. Cox proportional hazards regression analysis was utilized to estimate the hazard ratio (HR) with a 95% confidence interval (CI). Additionally, a subgroup analysis was performed to identify the possible effect modifiers, and a mediation analysis was conducted to explore the mediation effects of anthropometric measurements on the association between ELD and hypertension. RESULTS: A total of 3993 participants (35%) developed hypertension during 93,058 person-years of follow-up. In the covariate-adjusted model, hypertension risk was reduced in the highest quartile participants compared to the lowest quartile of the PHD score (adjusted HR: 0.79, 95%CI: 0.71-0.87; P-trend < 0.001), which remained significant after sensitivity analysis. Notably, the association was also observed in isolated systolic hypertension, isolated diastolic hypertension, and systolic-diastolic hypertension. Subgroup analysis revealed that the inverse association between the PHD score and hypertension risk was more pronounced in nonsmokers and high-sodium intake consumers than in smokers and low-sodium consumers (P-interaction < 0.05). Additionally, mediation analysis revealed that 23.3% of the association between the PHD score and hypertension risk was mediated by the waist-to-height ratio. CONCLUSION: Our findings suggest that a higher adherence to ELD is associated with a lower risk of hypertension. These results emphasize that ELD may serve as a potential strategy to prevent hypertension.

Integrated Network Analysis of Symptom Clusters Across Monkeypox Epidemics From 1970 to 2023: Systematic Review and Meta-Analysis.

BACKGROUND: The worldwide spread of monkeypox (mpox) has witnessed a significant increase, particularly in nonendemic countries. OBJECTIVE: We aimed to investigate the changing clinical symptoms associated with mpox from 1970 to 2023 and explore their interrelations. METHODS: In this systematic review and meta-analysis, 3 electronic databases were searched for English peer-reviewed studies conducted from January 1970 to April 2023 that reported any symptoms among confirmed mpox cases. We categorized the mpox epidemics into 3 periods: 1970-2002 (period 1, within the African region), 2003-2021(period 2, epidemics outside Africa), and 2022-2023 (period 3, worldwide outbreak). Following PRISMA guidelines, a meta-analysis was performed to estimate the pooled prevalence for each symptom. The correlation among symptoms was analyzed and visualized using network analysis. RESULTS: The meta-analysis included 61 studies that reported 21 symptoms in 720 patients from period 1, 39 symptoms in 1756 patients from period 2, and 37 symptoms in 12,277 patients from period 3. The most common symptom among patients from all 3 periods was rash (period 1: 92.6%, 95% CI 78.2%-100%; period 2: 100%, 95% CI 99.9%-100%; and period 3: 94.8%, 95% CI 90.9%-98.8%), followed by lymphadenopathy (period 1: 59.8%, 95% CI 50.3%-69.2%; period 2: 74.1%, 95% CI 64.2%-84.1%; and period 3: 61.1%, 95% CI 54.2%-68.1%). Fever (99%, 95% CI 97%-100%), enlarged lymph nodes (80.5%, 95% CI 75.4%-85.0%), and headache (69.1%, 95% CI 4%-100%) were the main symptoms in period 1, with a significant decrease in period 3: 37.9%, 31.2%, and 28.7%, respectively. Chills/rigors (73.3%, 95% CI 60.9%-85.7%), fatigue (68.2%, 95% CI 51.6%-84.8%), and dysphagia/swallowing difficulty (61.2%, 95% CI 10.5%-100%) emerged as primary new symptoms in period 2 and decreased significantly in period 3. Most other symptoms remained unchanged or decreased in period 3 compared to the former 2 periods. Nausea/vomiting had the highest degree of correlation (with 13 symptoms) and was highly positively correlated with lymphadenopathy (r=0.908) and conjunctivitis (r=0.900) in period 2. In contrast, rash and headache were 2 symptoms with the highest degree of correlation (with 21 and 21 symptoms, respectively) in period 3 and were highly positively correlated with fever (r=0.918 and 0.789, respectively). CONCLUSIONS: The manifestation of symptoms in patients with mpox has become more diverse, leading to an increase in their correlation. Although the prevalence of rash remains steady, other symptoms have decreased. It is necessary to surveil the evolving nature of mpox and the consequential changes in clinical characteristics. Epidemic countries may shift their focus on the potential association among symptoms and the high synergy risk. TRIAL REGISTRATION: PROSPERO Registration: CRD42023403282; http://tinyurl.com/yruuas5n.

Impaired antibody responses were observed in patients with type 2 diabetes mellitus after receiving the inactivated COVID-19 vaccines.

BACKGROUND: Patients with type 2 diabetes mellitus (T2DM) have been reported to be more susceptible to 2019 novel coronavirus (2019-nCoV) and more likely to develop severe pneumonia. However, the safety and immunological responses of T2DM patients after receiving the inactivated vaccines are not quite definite. Therefore, we aimed to explore the safety, antibody responses, and B-cell immunity of T2DM patients who were vaccinated with inactivated coronavirus disease 2019 (COVID-19) vaccines. METHODS: Eighty-nine patients with T2DM and 100 healthy controls (HCs) were enrolled, all of whom had received two doses of full-course inactivated vaccines. At 21-105 days after full-course vaccines: first, the safety of the vaccines was assessed by questionnaires; second, the titers of anti-receptor binding domain IgG (anti-RBD-IgG) and neutralizing antibodies (NAbs) were measured; third, we detected the frequency of RBD-specific memory B cells (RBD-specific MBCs) to explore the cellular immunity of T2DM patients. RESULTS: The overall incidence of adverse events was similar between T2DM patients and HCs, and no serious adverse events were recorded in either group. Compared with HCs, significantly lower titers of anti-RBD-IgG (p = 0.004) and NAbs (p = 0.013) were observed in T2DM patients. Moreover, the frequency of RBD-specific MBCs was lower in T2DM patients than in HCs (p = 0.027). Among the 89 T2DM patients, individuals with lower body mass index (BMI) had higher antibody titers (anti-RBD-IgG: p = 0.009; NAbs: p = 0.084). Furthermore, we found that sex, BMI, and days after vaccination were correlated with antibody titers. CONCLUSIONS: Inactivated COVID-19 vaccines were safe in patients with T2DM, but the antibody responses and memory B-cell responses were significantly decreased compared to HCs. TRIAL REGISTRATION NUMBER AND DATE: NCT05043246. September 14, 2021. (Clinical Trials.gov).

A2AR limits IL-15-induced generation of CD39+ NK cells with high cytotoxicity.

CD39-mediated inhibition of natural killer (NK) cell activity has been demonstrated, but the characteristics of CD39+ NK cells in humans are not known. We investigated the characteristics of human circulating CD39+ NK cells. In healthy donors, the proportion of circulating CD39+ NK cells in total NK cells was relatively low compared with that of CD39- NK cells. Nonetheless, a higher proportion of CD39+ NK cells expressed CD107a. Similarly, a higher proportion of CD39+ NK cells expressed CD107a in patients with hepatitis B virus or patients with hepatocellular carcinoma. Stimulation with NK-sensitive K562 cells or interleukin (IL)-12/IL-18 activated CD39+ NK cells to express higher levels of CD107a, IFN-γ and TNF-α, relative to CD39- NK cells. Importantly, IL-15 induced the generation of CD39+ NK cells. In contrast, A2A adenosine receptor (A2AR) ligation suppressed the generation of CD39+ NK cells by inhibiting IL-15 signaling. These data for the first time demonstrated that A2AR counteracts IL-15-induced generation of human CD39+ NK cells, which have a stronger cytotoxicity than CD39- NK cells. IL-15-induced human CD39+ NK cells might be better choice for immunotherapy based on adoptive transfer of NK cells.

Kynurenic acid ameliorates NLRP3 inflammasome activation by blocking calcium mobilization via GPR35.

The inflammasome has been linked to diverse inflammatory and metabolic diseases, and tight control of inflammasome activation is necessary to avoid excessive inflammation. Kynurenic acid (KA) is a tryptophan metabolite in the kynurenine pathway. However, the roles and mechanisms of the regulation of inflammasome activation by KA have not yet been fully elucidated. Here, we found that KA suppressed caspase-1 activation and IL-1ß production in macrophages by specifically inhibiting canonical and noncanonical activation of the NLRP3 inflammasome. Mechanistically, KA reduced calcium mobilization through G-protein receptor 35 (GPR35), resulting in reduced mitochondrial damage and decreased mtROS production, thus blocking NLRP3 inflammasome assembly and activation. Importantly, KA prevented lipopolysaccharide-induced systemic inflammation, monosodium urate-induced peritoneal inflammation, and high-fat diet-induced metabolic disorder. Thus, KA ameliorated inflammation and metabolic disorders by blocking calcium mobilization-mediated NLRP3 inflammasome activation via GPR35. Our data reveal a novel mechanism for KA in the modulation of inflammasome activation and suggest that GPR35 might be a promising target for improving NLRP3 inflammasome-associated diseases by regulating calcium mobilization.

Increased ILT2 expression contributes to dysfunction of CD56dimCD16+NK cells in chronic hepatitis B virus infection.

Natural killer (NK) cells play a crucial role in the control of human viral infections but their activity is significantly impaired in patients infected with chronic hepatitis B (CHB). The mechanism that contributes to NK cell dysfunction in CHB needs further elucidation. In this study, we analyzed the expression and function of the novel inhibitory receptor immunoglobulin-like transcript-2 (ILT2) on NK cells from 131 CHB patients and 36 healthy controls. We observed that ILT2 expression on circulating CD56dimCD16+NK cells was increased in immune-tolerant, immune-active and HBeAg-negative hepatitis patients compared with inactive carriers and controls. The frequency of ILT2+CD56dimNK cells was positively correlated with serum viral load in immune-tolerant patients. The percentage of ILT2+CD56dimNK cells decreased along with HBV load in CHB patients who received antiviral therapy. Functional analysis showed that ILT2+CD56dimNK cells in CHB patients had significantly reduced degranulation and IFN-γ production. Upregulation of ILT2 was associated with high levels of apoptosis in CD56dimCD16+NK cells from CHB patients. ILT2 blockade was shown to increase the cytotoxicity and IFN-γ production of CD56dimNK cells in some CHB patients. Finally, ILT2 was found to be moderately upregulated by TGF-ß1, which was increased in immune-tolerant, immune-active and HBeAg-negative hepatitis patients. Our results show that chronic HBV infection increases the levels of the inhibitory receptor ILT2 on CD56dimNK cells and inhibits their functions, providing a new mechanism of NK-cell disability in CHB patients.

PD-1 blockade improves the anti-tumor potency of exhausted CD3+CD56+ NKT-like cells in patients with primary hepatocellular carcinoma.

CD3+CD56+ NKT-like cells play pivotal roles in the anti-tumor immune defense response. However, little is known regarding circulating NKT-like cells in patients with primary hepatocellular carcinoma (HCC). In the present study, we demonstrate that circulating NKT-like cells in HCC patients are functionally impaired and anti-PD-1 blockade improves their anti-tumor potency. Circulating NKT cells were mainly comprised of CD8+ T cells. The frequencies and absolute counts of circulating NKT-like cells were comparable between HCC patents compared to healthy donors. NKT-like cells in HCC patients were impaired in their production of TNF-α and IFN-γ as well as cytotoxicity. The level of activating receptor NKG2D was significantly decreased on NKT-like cells in HCC patients. In contrast, the expression of inhibitory receptors PD-1, Tim-3, and CTLA-4 were markedly increased on NKT-like cells in HCC patients. Meanwhile, the expression of PD-L1 was also upregulated on NKT-like cells in HCC patients. In detail, PD-1+ NKT-like cells expressed lower levels of NKG2D, higher levels of Tim-3, and CTLA-4, and less IFN-γ when compared with PD-1- NKT-like cells. Importantly, PD-1 blocked with anti-PD-1 antibody effectively improved the effector function of NKT-like cells from HCC patients or healthy donors. Our findings unveil the functional characterization of NKT-like cells in HCC patients and provide the potential targets to improve their function, which might benefit the optimization of HCC immunotherapy.

NOD1 Agonist Protects Against Lipopolysaccharide and D-Galactosamine-Induced Fatal Hepatitis Through the Upregulation of A20 Expression in Hepatocytes.

Increasing evidence suggests that NODs are involved in liver diseases; however, the underlying mechanisms remain obscure. In the present study, we analyzed the effect of NOD1 agonist pretreatment on acute liver failure induced by lipopolysaccharide (LPS) in D-galactosamine (D-GalN)-sensitized mice. We found that pretreatment with the NOD1 agonist markedly reduced LPS/D-GalN-induced mortality, elevation of serum ALT levels, and hepatocyte apoptosis. The protective effect of NOD1 agonist was independent of tumor necrosis factor (TNF)-α inhibition. NOD1 agonist pretreatment also attenuated TNF-α/D-GalN-induced apoptotic liver damage. The anti-apoptotic protein A20 expression was more pronounced in NOD1 agonist pretreated mice than in controls, and knockdown of A20 abrogated the protective effect of NOD1 agonist on LPS/D-GalN-induced liver injury and hepatocyte apoptosis. Further experiments showed that NOD1 agonist-induced A20 upregulation required the presence of kupffer cells and TNF-α. Taken together, our data strongly indicate that NOD1 is involved in the regulation of liver injury and could be a potential therapeutic target for liver diseases.

The Multiple Functions of B Cells in Chronic HBV Infection.

Chronic hepatitis B virus (HBV) infection is one of the main causes of liver diseases, of which the natural history and clinical outcomes are associated with the role of B cells. As humoral immune cells, B cells play a critical role in the process of anti-HBV antibody production. In addition, some studies have also characterized other B cell subsets involved in antigen presentation and regulating the immune response beyond antibody secretion. However, not all B cell subsets play a positive role in the immune response to chronic HBV infection, and various B cell subsets jointly mediate persistent HBV infection, tolerance, and liver damage. Thus, we further sought to elucidate the multiple functions of B cells to gain novel insight into the understanding of chronic hepatitis B (CHB) pathogenesis. We also reviewed the current immunotherapies targeting B cells to explore novel therapeutic interventions for the treatment of chronic HBV infection.

Efficacy of oral antiviral drugs to prevent mother-to-child transmission of hepatitis B virus: a network meta-analysis.

BACKGROUND: Hepatitis B is a serious global health problem. Mother-to-child transmission (MTCT) of hepatitis B virus (HBV) is a major risk factor in the endemicity of HBV infection. Oral antiviral drugs are recommended to highly viremic mothers to decrease MTCT of HBV. The present network analysis compared the efficacy of available treatments to prevent the MTCT of HBV. METHODS: The electronic databases of PubMed, Embase, Web of Science, Scopus, and Wanfang data were searched for eligible studies. Pair-wise meta-analysis and Bayesian network analysis were applied to compare the efficacy of antiviral drugs. RESULTS: Seventy-five studies involving 12,740 pregnant females were eligible for analysis. On pair-wise analysis, lamivudine (OR 0.15, 95% CI 0.09-0.25, I-squared = 0%), telbivudine (OR 0.07, 95% CI 0.05-0.10, I-squared = 0%) and tenofovir (OR 0.07, 95% CI 0.04-0.13, I-squared = 0%) significantly decreased the MTCT rate. Results of multiple comparisons with ranking probability based on Bayesian analysis showed that tenofovir (SUCRA = 96.83%) appeared more effective than the two other drugs. CONCLUSION: In addition to active and passive immunoprophylaxis, lamivudine, telbivudine and tenofovir in highly viremic mothers can further decrease MTCT of HBV. Based on direct and indirect evidence, tenofovir appears to be more effective than the two other drugs in the prevention of HBV MTCT.

Recovery of circulating CD56dim NK cells and the balance of Th17/Treg after nucleoside analog therapy in patients with chronic hepatitis B and low levels of HBsAg.

BACKGROUND AND AIMS: Much evidence indicates that the soluble antigens secreted by hepatitis B virus (HBV) inhibit the function of the immune system. The aim of this study is to investigate, after treatment with nucleoside (acid) analogs (NAs) and the inhibition of viral replication, whether the immune systems of patients with a peripheral blood HBV-DNA level <1000 IU/mL, hepatitis B e antigen (HBeAg) disappearance, and a decrease in hepatitis B surface antigen (HBsAg) levels could be reconstructed. METHODS: The frequency and phenotype of circulating natural killer (NK) cells, dendritic cells (DCs), T-helper (Th) cells, regulatory T (Treg) cells, CD4+, CD8+ T cells, T follicular helper (Tfh) cells and B cells subtypes were tested by flow cytometry in chronic hepatitis B (CHB) patients and healthy controls (HCs). The levels of HBV-related serum HBsAg, HBeAg, HBV-DNA load, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined. RESULTS: Regarding the innate immune system, an increased frequency of CD56dim NK cells was found in the therapeutic response (TR) group compared with that in the immune-active phase (IA) group. Additionally, regarding the adaptive immune system, the Th17/CD4+CD25+CD127dimTreg ratio was reduced in the TR group. Additionally, the frequency of CD40L+CXCR5+CD4+T cells and CD40+CD19+CD27+CD38+B cells was significantly higher than that of HCs, while that of PDL1+CD19+ B cells was lower. Furthermore, the frequencies of CTLA4+CD4+T cells and CTLA4+CD8+T cells in patients with CHB were significantly higher than those in HCs. CONCLUSION: After NA treatment and the inhibition of viral replication, circulating CD56dim NK cells and the balance of Th17/Treg can be recovered. Restoring circulating CD56dim NK cells and the Th17/Treg balance may help reduce HBsAg levels in patients.

MicroRNA­497 attenuates cerebral infarction in patients via the TLR4 and CREB signaling pathways.

The aim of the present study was to investigate the function and mechanism of microRNA­497 (miRNA/miR­149) in the regulation of cerebral infarction. In patients with cerebral infarction, the serum of microRNA­497 expression was upregulated compared with that in healthy controls. In N2A cells, overexpression of miR­497 induced cell proliferation, decreased apoptosis and caspase­3 and caspase­9 activities, and suppressed Bax protein expression compared with that in the negative control group. Overexpression of miR­497 reduced inflammation factors, and suppressed the Toll­like receptor 4 (TLR4), myeloid differentiation primary response protein MyD88 (MyD88) and nuclear factor­κB (NF­κB) protein expression of the N2A cells. Next, miR­497 overexpression suppressed the protein expression of interleukin­1 receptor associated kinase (IRAK1) and phosphorylated cyclic AMP response element binding protein (p-CREB) in the N2A cells. Following miR­497 overexpression, TLR4 inhibitor was found to suppress the inflammation factors, suppress the TLR4, MyD88 and NF­κB protein expression, and reduce the IRAK1 and p­CREB protein expression of the N2A cells. Lastly, CREB inhibitor also suppressed p­CREB protein expression, induced cell proliferation, decreased apoptosis and caspase­3 and caspase­9 activities, and suppressed Bax protein expression in the N2A cells following miR­497 overexpression. Taken together, these data demonstrated that miR­497 attenuated cerebral infarction in patients by regulating the TLR4 and CREB signaling pathways.

Diagnostic accuracy of Xpert MTB/RIF for tuberculosis detection in different regions with different endemic burden: A systematic review and meta-analysis.

PURPOSE: To estimate the diagnostic accuracy of Xpert MTB/RIF, a systematic review and meta-analysis were carried out. METHODS: Up to June 20, 2015, multiple databases were screened for relevant studies. RESULTS: Accordingly, 106 studies included 52,410 samples were selected. Diagnostic accuracy of Xpert MTB/RIF for TB detection was validated against either culture or a composite reference standard (CRS). Additionally, selected studies were further subgrouped in four groups based on sample's type, subject's age, status of HIV co-infection and smear-positivity. The overall pooled sensitivity and specificity of Xpert MTB/RIF was 0.85 (95% confidence interval [CI] 0.82-0.88) and 0.98 (95% CI 0.96-0.98), respectively, compared to culture; while it was 0.59 (95% CI 0.44-0.72) and 0.99 (95% CI 0.97-1.00) compared to CRS. The overall sensitivity was lower in countries with high TB prevalence than countries with middle/low prevalence (0.84, 95% CI: 0.80-0.88 versus 0.89, 95% CI: 0.84-0.93). Furthermore, Xpert MTB/RIF has higher sensitivity in patients with positive smears (0.99, 95% CI 0.97-0.99), in patients with pulmonary TB samples (0.87, 95% CI 0.83-0.90), in adults (0.82, 95% CI 0.76-0.86) and in HIV-positive patients (0.81, 95% CI 0.73-0.87). CONCLUSIONS: Taken together, Xpert MTB/RIF is a quick and accurate diagnostic assay for TB which will significantly help the physicians to make their clinical decisions.

Natural killer cell activation contributes to hepatitis B viral control in a mouse model.

The roles of CD4 + T cells and CD8 + T cells in hepatitis B virus (HBV) infection have been well documented. However, the role of innate immunity in HBV infection remains obscure. Here we examined the effect of activation of innate immunity by polyinosinic: polycytidylic acid (PolyI:C) on HBV infection. A chronic HBV replication mouse model was established by hydrodynamical injection of pAAV/HBV1.2 plasmid into C57BL/6 mice. We found that HBV did not seem to induce an active NK-cell response in the mouse model. Early PolyI:C treatment markedly decreased serum HBV levels and led to HBV clearance. Following PolyI:C injection, NK cells were activated and accumulated in the liver. Depletion of NK cells markedly attenuated the anti-HBV activity of PolyI:C. Moreover, we found that IFN-γ production from NK cells was essential for the antiviral effect of PolyI:C in the model. Importantly, activation of NK cells by PolyI:C could also lead to HBV suppression in HBV-tolerant mice and HBV-transgenic mice. These results suggest that activated NK cells might suppress HBV and contribute to HBV clearance during natural HBV infection. In addition, therapeutic activation of NK cells may represent a new strategy for the treatment of chronic HBV infection.

Liver-infiltrating CD11b-CD27- NK subsets account for NK-cell dysfunction in patients with hepatocellular carcinoma and are associated with tumor progression.

Natural killer (NK) cells have a vital role in killing hepatocellular carcinoma (HCC) cells; however, the mechanism underlying tumor-infiltrating NK (TINK)-cell dysfunction remains poorly understood. Using flow cytometry staining, we precisely characterized the frequency, phenotype and function of NK subsets distinguished by CD27 and CD11b in 30 patients with HCC in comparison to 30 healthy controls. Interestingly, we found a substantial proportion of liver-infiltrating CD11b-CD27- (DN) NK subsets in tumor tissue from HCC patients. Remarkably, these relatively expanded DN NK subsets exhibited an inactive and immature phenotype. By detecting the expression of CD107a and interferon-gamma (IFN-γ) on NK subsets and NK cells, we demonstrated that DN NK subsets exhibited a poor cytotoxic capacity and deficient potential to produce IFN-γ in comparison to the other three subsets, which contributed to the dysfunction of TINK cells in HCC patients. In addition, we found that the presence of DN NK cells was closely associated with the clinical outcomes of HCC patients, as the frequency of DN NK cells among TINK cells was positively correlated with tumor stage and size. A large percentage of DN NK cells among TINK cells was an independent prognostic factor for lower survival in the 60-month follow-up period. In conclusion, a substantial proportion of CD11b-CD27-NK subsets among TINK cells accounts for NK-cell dysfunction in patients with HCC and is associated with tumor progression. Our study may provide a novel therapeutic target for the treatment of patients with HCC.

Altered Immune Profiles of Natural Killer Cells in Chronic Hepatitis B Patients: A Systematic Review and Meta-Analysis.

BACKGROUND: Natural killer (NK) cells are the main effective component of the innate immune system that responds to chronic hepatitis B (CHB) infection. Although numerous studies have reported the immune profiles of NK cells in CHB patients, they are limited by inconsistent results. Thus, we performed a meta-analysis to characterize reliably the immune profiles of NK cells after CHB infection, specifically frequency, phenotype, and function. METHODS: A literature search of the computer databases MEDLINE, PUBMED, EMBASE, and Cochrane Center Register of Controlled Trails was performed and 19 studies were selected. The standard mean difference (SMD) and 95% confidence interval (CI) of each continuous variable was estimated with a fixed effects model when I2 < 50% for the test for heterogeneity, or the random effects model otherwise. Publication bias was evaluated using Begg's and Egger's tests. RESULTS: The meta-analysis of publications that reported frequency of peripheral NK cells showed that NK cell levels in CHB patients were significantly lower compared with that of healthy controls. A higher frequency of CD56bright NK subsets was found in CHB patients, but the CD56dim NK subsets of CHB patients and healthy controls were similar. CHB patients before and after antiviral therapy with nucleotide analogues (NUCs) showed no statistical difference in NK frequency. The activating receptors were upregulated, whereas inhibitory receptors were comparable in the peripheral NK cells of CHB individuals and healthy controls. NK cells of CHB patients displayed higher cytotoxic potency as evidenced by CD107a protein levels and conserved potency to produce interferon-gamma (IFNγ), compared with their healthy counterparts. CONCLUSION: Our results revealed that CHB patients had a lower frequency of NK cells compared with healthy individuals not treatable with antiviral NUC therapy. With an activating phenotype, NK cells in CHB patients showed better cytotoxic potency and conserved IFNγ production.

Functional dichotomy of Vδ2 γδ T cells in chronic hepatitis C virus infections: role in cytotoxicity but not for IFN-γ production.

Vδ2 γδ (Vδ2) T cells, a major human γδ T cell subset, exhibit broad anti-tumor and anti-infective activity; however, their precise role in chronic hepatitis C virus (HCV) infections remains unclear. In this study, we analyzed the phenotype and function of Vδ2 T cells in 43 HCV-infected patients compared to 39 healthy controls (HCs). Vδ2 T cells from HCV-infected patients were activated and differentiated into effector cells. Vδ2 T cells in patients expressed significantly higher levels of natural killer (NK) cell markers CD56 and CD16 than in HCs, acquiring cytotoxic NK-like phenotype. The Vδ2 T cell phenotype was associated with increased cytolytic effector molecules expression in HCV-infected patients with elevated serum ALT levels. Surprisingly, Vδ2 T cells in patients had a markedly impaired capacity to produce IFN-γ. Further in vitro and in vivo analysis showed that interferon-α, which was induced during HCV infection, caused Vδ2 T cell function bias toward cytotoxicity. These results suggest a functional dichotomy for Vδ2 T cells in chronic HCV infections: a role in cytotoxicity but not for IFN-γ production, which may contribute to both the liver inflammation and HCV persistence.

Efficacy of Tenofovir-Based Combination Therapy versus Tenofovir Monotherapy in Chronic Hepatitis B Patients Presenting with Suboptimal Responses to Pretreatment: A Meta-Analysis.

Background/Aims. It remains unclear whether tenofovir disoproxil fumarate- (TDF-) based combination therapy produces better outcomes than TDF monotherapy in chronic hepatitis B (CHB) patients. The aim of this study was to compare the efficacy of the two regimens by performing a meta-analysis. Methods. A comprehensive literature search was performed on the comparison of TDF-based combination therapy and monotherapy for CHB patients in the PubMed, Embase, Web of Science, and the Cochrane Libraries. Both dichotomous and continuous variables were extracted and pooled outcomes were expressed as risk ratio (RR) or standard mean difference (SMD). Results. Nine eligible studies (1089 subjects in total) were included in our analysis. The proportion of patients with undetectable HBV DNA at 24, 48, and 96 weeks were similar between the two comparable groups (62.5% versus 70.9%, P = 0.086; 78.1% versus 83.7%, P = 0.118; 86.4% versus 87.9%, P = 0.626, resp.). HBV DNA reduction, rates of ALT normalization, hepatitis B e antigen (HBeAg) loss, and HBeAg seroconversion were also similar between the two groups. Conclusions. On the current data, TDF-based combination therapy seemed to be no better than those achieved by monotherapy. Further studies are needed to verify this comparison.

Kupffer Cells Support Hepatitis B Virus-Mediated CD8+ T Cell Exhaustion via Hepatitis B Core Antigen-TLR2 Interactions in Mice.

Hepatitis B virus (HBV) persistence is a fundamental process in chronic HBV infection and a key factor in all related liver diseases; however, the mechanisms have yet to be elucidated. We studied the role of TLR2 in HBV persistence using a well-established HBV-carrier mouse model generated by hydrodynamically injecting a phospho-adeno-associated virus/HBV1.2 plasmid into mice. We found that a genetic deficiency in TLR2 improves HBV elimination, whereas activating TLR2 led to more stable HBV persistence, suggesting that TLR2 activation is critical in HBV persistence. Furthermore, we noted that TLR2 activation could inhibit CD8(+) T cell function, causing the exhaustion phenotype in HBV-carrier mice, because TLR2 deficiency might rescue CD8(+) T cell function in a cellular adoptive experiment. TLR2 expression on Kupffer cells (KCs) was upregulated in HBV-carrier mice, which accounts for HBV persistence, because the difference in anti-HBV immunity between HBV-carrier wild-type and Tlr2(-/-) mice did not exist after KC depletion. In addition, similar to TLR2 deficiency, after KC depletion, CD8(+) T cells were more efficiently activated in HBV-carrier mice, leading to rapid HBV elimination. KCs produced more IL-10 upon TLR2 activation in response to direct hepatitis B core Ag stimulation, and the elevated IL-10 inhibited CD8(+) T cell function in HBV-carrier mice, because IL-10 deficiency or anti-IL-10R treatment resulted in CD8(+) T cells with stronger antiviral function. In conclusion, KCs support liver tolerance by inducing anti-HBV CD8(+) T cell exhaustion via IL-10 production after TLR2 activation by hepatitis B core Ag stimulation.