Blockade of CCR4 breaks immune tolerance in chronic hepatitis B patients by modulating regulatory pathways.

BACKGROUND: Immunotargets including checkpoint inhibitors and toll-like receptor 8 agonists have recently gained attention for the recovery of hepatitis B virus (HBV)-specific T cell exhaustion in chronic hepatitis B(CHB). Chemokine receptors have a similar significant role during viral infections; however, their role in CHB remains poorly understood. Therefore, in this study we evaluated the role of chemokine receptor 4 (CCR4) in deriving immunosuppression during CHB. METHODS: We characterized CCR4+CD8+ T cells in CHB and identified their involvement in immunosuppression. Further, we examined if CCR4 blockade with mogamulizumab antibody can recover the functional exhaustion in HBsAg-specific T cells. RESULTS: CHB patients exhibit higher frequency of CCR4+CD8+ T cells that increase with higher HBsAg levels and fibrosis scores. In vitro, HBs antigen triggers CCR4 expression. These cells express multiple inhibitory receptors and exhibit immunosuppressive functions by producing excessive immunoregulatory cytokines IL-4, IL-5, IL-10 and TGF-ß1. CCR4 Blockade significantly boosted HBsAg-specific antiviral-cytokine production(IFN-γ, TNF-α and IL-21) in T cells through enhancing their proliferation capacity and polarizing these cells towards T helper 1(Th1) and T follicular helper cells(TFH) in case of CD4 cells, and cytotoxic T cell 1(TC1) and cytotoxic T follicular(TCF) cells in case of CD8. Cytotoxic potential was improved, while no induction of immunosuppressive-cytokines was seen after anti-CCR4 treatment thereby eliminating the risk of treatment-induced immunosuppression. CCR4 blockade inhibited the development and effector function of Tregs by controlling their expansion and TGF-ß1 production preventing Tregs-induced immunotolearance. CONCLUSIONS: CCR4 blockade reconstitutes antiviral immune response in T cells and limits the immunosuppressive functions of Tregs, representing them as a promising immunotherapeutic target for functional cure of CHB.

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.

New Therapeutics for HCC: Does Tumor Immune Microenvironment Matter?

The incidence of liver cancer is continuously rising where hepatocellular carcinoma (HCC) remains the most common form of liver cancer accounting for approximately 80-90% of the cases. HCC is strongly prejudiced by the tumor microenvironment and being an inflammation-associated condition, the contribution of various immune mechanisms is critical in its development, progression, and metastasis. The tumor immune microenvironment is initially inflammatory which is subsequently replenished by the immunosuppressive cells contributing to tumor immune escape. Regardless of substantial advancement in systemic therapy, HCC has poor prognosis and outcomes attributed to the drug resistance, recurrence, and its metastatic behavior. Therefore, currently, new immunotherapeutic strategies are extensively targeted in preclinical and clinical settings in order to elicit robust HCC-specific immune responses and appear to be quite effective, extending current treatment alternatives. Understanding the complex interplay between the tumor and the immune cells and its microenvironment will provide new insights into designing novel immunotherapeutics to overcome existing treatment hurdles. In this review, we have provided a recent update on immunological mechanisms associated with HCC and discussed potential advancement in immunotherapies for HCC treatment.

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.

Increased interleukin-23 receptor (IL-23R) expression is associated with disease severity in acute-on-chronic liver failure.

BACKGROUND: Th17 cells mediated immune response is important in chronic hepatitis B (CHB) infection and inflammation associated diseases; however, little is known about their immunopathogenic role in acute-on-chronic liver failure (ACLF). Interleukin-23 receptor (IL-23R) is essential for the generation of pathogenic Th17 cells; therefore, we aimed to evaluate IL-23R expression and its correlation with disease severity in ACLF. METHODS: Forty-two patients with ACLF (HBV and alcohol-related), thirty-two with CHB and twenty healthy controls (HC) were studied. Circulating and intrahepatic profile of Th17 cells and IL-23R was investigated. Association of IL-23R with disease severity was determined. RESULTS: Circulating Th17 cells were significantly increased in both ACLF groups (P = 0.03, P = 0.006) than CHB and HC. Percentage of Th17 cells was higher in liver than peripheral blood of ACLF patients (P = 0.04). Expression of IL-23R was immensely up-regulated on Th17 cells of ACLF patients. Importantly, IL-23R not only correlated with the increased percentage of Th17 cells but also had significant association with inflammation (P = 0.03) and clinical disease severity indices including Child-Turcotte-Pugh (P = 0.001) and Model for End-Stage Liver Disease (P = 0.002) scores. The ACLF non-survivors showed higher IL-23R expression (P = 0.01). Transcription factor retinoic acid receptor-related orphan nuclear receptor gamma-t (ROR-γt) was also high in circulation and in liver of ACLF patients and it positively correlated with ALT levels (P = 0.03). Surface receptors, including CCR6, IL-17R and pro-inflammatory cytokines IL-17A, IL-22, CXCL8 and GM-CSF were highly augmented in ACLF. CONCLUSION: ACLF patients express high IL-23R on Th17 cells which induces inflammation and strongly correlates with liver disease severity.

Impaired monocyte-macrophage functions and defective Toll-like receptor signaling in hepatitis E virus-infected pregnant women with acute liver failure.

UNLABELLED: Acute viral hepatitis resulting due to hepatitis E viral infection (AVH-E) is often serious in pregnancy and could result in acute liver failure (ALF). The role of monocytes and macrophages (mono-macs) in the pathogenesis of AVH-E and development of ALF-E in pregnancy is unclear. We investigated the functions of mono-macs in pregnant (P), AVH-E (n = 44), ALF-E (n = 12), healthy controls (HC; n = 20) and compared with nonpregnant (NP) AVH-E (n = 10), ALF-E (n = 5), and HC (n = 10). We also recruited non-hepatitis E virus-related pregnant (P), ALF-NE (n = 5) and non-pregnant (NP), ALF-NE (n = 12) patients with ALF. Mono-macs, dendritic cell (DC) phenotypes, and Toll-like receptor (TLR) expressions were studied by flow cytometry and reverse-transcriptase polymerase chain reaction. Mono-macs functionality was determined by analyzing their phagocytic activity and reactive oxygen species (ROS) generation by using flow cytometry. Frequency of mono-macs and DCs was increased during HEV infection compared to HC (P < 0.001). Macrophages were increased (P < 0.002) in ALF-E(P) compared to ALF-NE(P). The macrophage phagocytic activity and Escherichia coli-induced ROS production was significantly impaired in ALF-E(P) compared to AVH-E(P) (P < 0.001), ALF-E(NP), and ALF-NE(P) patients (P < 0.02). TLR3 and TLR9 expression and downstream MYD88 signalling molecules IRF3 and IRF7 were significantly down-regulated in ALF-E(P) (P < 0.00) compared to AVH-E(P) and ALF-NE(P). CONCLUSION: Functionality of mono-macs is impaired in pregnant ALF-E patients compared to AVH-E(P). Reduced TLR3 and TLR7 expression and TLR downstream-signaling molecules in pregnant ALF-E patients suggests inadequate triggers for the innate immune responses contributing to development and severity of ALF-E. Studies using TLR agonists to activate mono-macs may be of use and in vitro studies should be undertaken using patient samples.

Altered frequencies of dendritic cells and IFN-gamma-secreting T cells with granulocyte colony-stimulating factor (G-CSF) therapy in acute-on- chronic liver failure.

BACKGROUND & AIMS: Acute-on-chronic liver failure (ACLF) is a serious hepatic ailment with impaired immunity and poor treatment options resulting high mortality. Treatment with granulocyte colony-stimulating factor(G-CSF) mobilizes CD34(+) cells in ACLF patients; however its effect on impaired immune responses remains to be elucidated. To analyse the effect of G-CSF in immune modulation in ACLF. METHODS: We have analysed the frequencies of circulating and intrahepatic myeloid (mDCs) and plasmacytoid(pDCs) dendritic cells (DCs) and T cells in ACLF patients treated with G-CSF (Group A; n = 23) and placebo (Group B; n = 24) using flow cytometry. IFN-c production was compared in both groups following stimulation of PBMCs with phorbol myristate acetate (PMA). RESULTS: In Group A, circulating and intrahepatic mDCs, pDCs (P < 0.04, P < 0.02) and T cells(CD3, CD4 and CD8) increased significantly post-G-CSF treatment in comparison to placebo group. Importantly in Group A, IFN-c-producing CD8 T cells were significantly decreased (P > 0.05) along with decreased serum bilirubin and international normalized ratio (INR). Intrahepatic DCs and IFN-clevel were compared in survivor and non-survivor. Non-survivors from both groups, showed decreased DCs, high IFN-c level and no improvement in clinical parameters including s-bilirubin and INR. CONCLUSIONS: G-CSF therapy increased the frequencies of dendritic cells and reduced IFN-c secreting CD8 T cells with improved clinical severity indices. Decreased IFN- c production may contribute to reduced hepatocellular damage in ACLF patients.Our observations support the basis for further use of G-CSF therapy as immune modulator in these patients.

A Review on Novel Applications of Nanotechnology in the Management of Prostate Cancer.

BACKGROUND: Prostate cancer continues to be a serious danger to men's health, despite advances in the field of cancer nanotechnology. Although different types of cancer have been studied using nanomaterials and theranostic systems derived from nanomaterials, they have not yet reached their full potential for prostate cancer due to issues with in vivo biologic compatibility, immune reaction responses, accurate targetability, as well as a therapeutic outcome related to the nano-structured mechanism. METHOD: The ultimate motive of this article is to understand the theranostic nanotechnology-based scheme for treating prostate cancer. The categorization of diverse nanomaterials in accordance with biofunctionalization tactics and biomolecule sources has been emphasized in this review so that they might potentially be used in clinical contexts and future advances. These opportunities can enhance the direct visualization of prostate tumors, early identification of prostate cancer-associated biomarkers at extremely low detection limits, and finally, the therapy for prostate cancer. RESULT: In December 2022, a thorough examination of the scientific literature was carried out utilizing the Web of Science, PubMed, and Medline databases. The goal was to analyze novel applications of nanotechnology in the treatment of prostate cancer, together with their structural layouts and functionalities. CONCLUSION: The various treatments and the reported revolutionary nanotechnology-based systems appear to be precise, safe, and generally successful; as a result, this might open up a new avenue for the detection and eradication of prostate cancer.

CD38: an ecto-enzyme with functional diversity in T cells.

CD38, a nicotinamide adenine dinucleotide (NAD)+ glycohydrolase, is considered an activation marker of T lymphocytes in humans that is highly expressed during certain chronic viral infections. T cells constitute a heterogeneous population; however, the expression and function of CD38 has been poorly defined in distinct T cell compartments. We investigated the expression and function of CD38 in naïve and effector T cell subsets in the peripheral blood mononuclear cells (PBMCs) from healthy donors and people with HIV (PWH) using flow cytometry. Further, we examined the impact of CD38 expression on intracellular NAD+ levels, mitochondrial function, and intracellular cytokine production in response to virus-specific peptide stimulation (HIV Group specific antigen; Gag). Naïve T cells from healthy donors showed remarkably higher levels of CD38 expression than those of effector cells with concomitant reduced intracellular NAD+ levels, decreased mitochondrial membrane potential and lower metabolic activity. Blockade of CD38 by a small molecule inhibitor, 78c, increased metabolic function, mitochondrial mass and mitochondrial membrane potential in the naïve T lymphocytes. PWH exhibited similar frequencies of CD38+ cells in the T cell subsets. However, CD38 expression increased on Gag-specific IFN-γ and TNF-α producing cell compartments among effector T cells. 78c treatment resulted in reduced cytokine production, indicating its distinct expression and functional profile in different T cell subsets. In summary, in naïve cells high CD38 expression reflects lower metabolic activity, while in effector cells it preferentially contributes to immunopathogenesis by increasing inflammatory cytokine production. Thus, CD38 may be considered as a therapeutic target in chronic viral infections to reduce ongoing immune activation.

Immune-Mediated Pathogenesis in Dengue Virus Infection.

Dengue virus (DENV) infection is one of the major public health concerns around the globe, especially in the tropical regions of the world that contribute to 75% percent of dengue cases. While the majority of DENV infections are mild or asymptomatic, approximately 5% of the cases develop a severe form of the disease that is mainly attributed to sequential infection with different DENV serotypes. The severity of dengue depends on many immunopathogenic mechanisms involving both viral and host factors. Emerging evidence implicates an impaired immune response as contributing to disease progression and severity by restricting viral clearance and inducing severe inflammation, subsequently leading to dengue hemorrhagic fever and dengue shock syndrome. Moreover, the ability of DENV to infect a wide variety of immune cells, including monocytes, macrophages, dendritic cells, mast cells, and T and B cells, further dysregulates the antiviral functions of these cells, resulting in viral dissemination. Although several risk factors associated with disease progression have been proposed, gaps persist in the understanding of the disease pathogenesis and further investigations are warranted. In this review, we discuss known mechanisms of DENV-mediated immunopathogenesis and its association with disease progression and severity.

Circulating Tregs correlate with viral load reduction in chronic HBV-treated patients with tenofovir disoproxil fumarate.

Limited response to current hepatitis B virus (HBV) drugs is possibly due to inadequate host cytotoxic cellular responses. Circulating Tregs have been shown to be associated with chronicity of HBV infection, but their profile during antiviral therapy has not been studied. We analyzed the frequency and effect of Tregs on cellular immune responses against HBV in 35 chronic hepatitis B eAg-ve and eAg+ve patients treated with tenofovir 300 mg/day. Frequency of Tregs and their modulatory role in cytokine-secreting cells were determined after stimulation with HBsAg or HBcAg in the absence or presence of Tregs and after blockage of PD-1/PDL-1 in peripheral blood mononuclear cells (PBMCs). Prior to therapy, eAg-ve patients had lower HBV DNA levels, reduced CD8 T cells, increased Tregs, and T cells expressing PD1. After 12 weeks of therapy, >2 log HBV viral reduction was observed in both groups, along with an increase frequencies of CD8 T cells in eAg-ve patients and increased expression of chemokine receptors/Toll-like receptors in both groups. PD-1 expression on CD8 cells in PBMCs was decreased in both groups during therapy but not on Tregs. In eAg-ve group, sustained increase of Tregs was observed till week 12, which declined at week 24. In both groups, after 24 weeks, depletion of CD4(+)CD25(+) Tregs from PBMCs enhanced HBV-specific T cell responses, and blockage of PD-1/PDL1 pathway did enhance pro-inflammatory cytokine production in eAg+ve patients but not in eAg-ve. We conclude that Tregs induced by HBV replication in vivo are expanded in eAg-ve patients more. Reduction in HBV DNA by tenofovir partially restored adaptive immune responses and also reduced the Tregs. Blockage of PD-1/PDL1, enhanced cytokine production in eAg+ve patients but not in eAg-ve, suggests that distinctly different immunologic mechanisms are involved in eAg+ve and eAg-ve patients.

Acute-on-Chronic Liver Failure: Pathophysiological Mechanisms and Management.

Acute-on-chronic liver failure (ACLF) is a multifaceted condition with poor treatment options and high short-term mortality. ACLF can develop in patients with or without liver cirrhosis, where patients with decompensated cirrhosis display a higher risk of short-term mortality. Pathophysiological mechanisms include systemic inflammation due to bacterial and fungal infections and acute hepatic insult with drug, alcohol, and viral hepatitis. Cryptogenic factors also contribute to the development of ACLF. The clinical outcome of patients with ACLF gets further complicated by the occurrence of variceal hemorrhage, hepatorenal syndrome, hepatic encephalopathy, and systemic immune dysfunction. Regardless of the better understanding of pathophysiological mechanisms, no specific and definitive treatment is available except for liver transplantation. The recent approach of regenerative medicine using mesenchymal stem cells (MSCs) could be advantageous for the treatment of ACLF as these cells can downregulate inflammatory response by inducing antiinflammatory events and prevent hepatic damage and fibrosis by inhibiting hepatic stellate cell activation and collagen synthesis. Moreover, MSCs are involved in tissue repair by the process of liver regeneration. Considering the broad therapeutic potential of MSCs, it can serve as an alternative treatment to liver transplant in the near future, if promising results are achieved.

Pathophysiology and Treatment Options for Hepatic Fibrosis: Can It Be Completely Cured?

Hepatic fibrosis is a dynamic process that occurs as a wound healing response against liver injury. During fibrosis, crosstalk between parenchymal and non-parenchymal cells, activation of different immune cells and signaling pathways, as well as a release of several inflammatory mediators take place, resulting in inflammation. Excessive inflammation drives hepatic stellate cell (HSC) activation, which then encounters various morphological and functional changes before transforming into proliferative and extracellular matrix (ECM)-producing myofibroblasts. Finally, enormous ECM accumulation interferes with hepatic function and leads to liver failure. To overcome this condition, several therapeutic approaches have been developed to inhibit inflammatory responses, HSC proliferation and activation. Preclinical studies also suggest several targets for the development of anti-fibrotic therapies; however, very few advanced to clinical trials. The pathophysiology of hepatic fibrosis is extremely complex and requires comprehensive understanding to identify effective therapeutic targets; therefore, in this review, we focus on the various cellular and molecular mechanisms associated with the pathophysiology of hepatic fibrosis and discuss potential strategies to control or reverse the fibrosis.

Abnormal Innate Immunity in Acute-on-Chronic Liver Failure: Immunotargets for Therapeutics.

Acute-on-chronic liver failure (ACLF) is a severe life-threatening condition with high risk of multiorgan failure, sepsis, and mortality. ACLF activates a multifaceted interplay of both innate and adaptive immune response in the host which governs the overall outcome. Innate immune cells recognize the conserved elements of microbial and viral origin, both to extort instant defense by transforming into diverse modules of effector responses and to generate long-lasting immunity but can also trigger a massive intrahepatic immune inflammatory response. Acute insult results in the activation of innate immune cells which provokes cytokine and chemokine cascade and subsequently initiates aggressive systemic inflammatory response syndrome, hepatic damage, and high mortality in ACLF. Dysregulated innate immune response not only plays a critical role in disease progression but also potentially correlates with clinical disease severity indices including Child-Turcotte-Pugh, a model for end-stage liver disease, and sequential organ failure assessment score. A better understanding of the pathophysiological basis of the disease and precise immune mechanisms associated with liver injury offers a novel approach for the development of new and efficient therapies to treat this severely ill entity. Immunotherapies could be helpful in targeting immune-mediated organ damage which may constrain progression toward liver failure and eventually reduce the requirement for liver transplantation. Here, in this review we discuss the defects of different innate immune cells in ACLF which updates the current knowledge of innate immune response and provide potential targets for new therapeutic interventions.

Reconstitution of T follicular helper-humoral immune axis with elimination of hepatitis C virus.

Exhaustion of Hepatitis C Virus (HCV)-specific T cells and abnormal B cell function is a hallmark of chronic HCV infection. Direct-acting antiviral (DAA) therapies are effective in achieving sustained virologic response (SVR), however, whether successful DAA treatment reconstitute T follicular helper (TFH)-B cell axis in HCV patients is unclear. Here, we aimed to evaluate the immunological changes in global and HCV-specific CD4 + CXCR5 + TFH, CD4 + CXCR5-T and B cells in 20 HCV patients who achieved SVR with Sofosbuvir and Ledipasvir for 12 weeks and compared with 15 healthy controls (HC). Global and HCV-specific CD4 + CXCR5 + TFH, CD4 + CXCR5-T and CD19 + B cells had significant phenotypic and functional reconstitution post DAA therapy. Reconstitution of effector, central and terminally differentiated memory cell population and increased ICOS and BCL6 expression was seen in HCV patients at SVR12. HCV-specific cytokines were also improved post DAA. Exhausted and regulatory B cells were declined whereas memory B cells were expanded post DAA therapy. Importantly, frequencies of TFH cells were significantly associated with HCV RNA reduction, expansion of memory B and plasmablasts, while negatively associated with exhausted/regulatory B cells. Our results demonstrate that SVR with DAA therapy is effective in the reconstitution of phenotypic and functional abnormalities of TFH-B cell axis.

IL-21-Deficient T Follicular Helper Cells Support B Cell Responses Through IL-27 in Patients With Chronic Hepatitis B.

Chronic Hepatitis B (CHB) affects over 350 million people worldwide. Current treatment does result in reduced complications; however, a cure (development of antibodies to the S antigen) is not achieved, requiring life-long therapy. Humoral responses contribute to viral elimination by secreting neutralizing antibodies; though, effective induction of humoral immunity require CD4T cell differentiation into T follicular helper (TFH) cells that support B cell response through interleukin-21 (IL-21). In CHB, mechanism of TFH-B interactions is seldom described. During CHB, TFH cells are defective in producing IL-21 in response to hepatitis B surface antigen (HBsAg). However, regardless of low IL-21, TFH cells efficiently support B cell responses by producing interleukin-27 (IL-27), which directs the formation of plasmablasts and plasma cells from memory and naïve B cells by enhancing B lymphocyte-induced maturation protein-1. IL-27 not only improved total antibody production but HBsAg-specific IgG and IgM secretion that are essential for viral clearance. Importantly, IL-27+TFH cells were significantly associated with HBV DNA reduction. Therefore, these findings imply a novel mechanism of TFH mediated B cell help in CHB and suggest that IL-27 effectively compensate the function of IL-21 by supporting TFH-B cell function, required for protective antibody response and may contribute to viral clearance by providing potential target for achieving a functional cure.

Publisher Correction: Circulating serum HBsAg level is a biomarker for HBV-specific T and B cell responses in chronic hepatitis B patients.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Circulating serum HBsAg level is a biomarker for HBV-specific T and B cell responses in chronic hepatitis B patients.

Chronic hepatitis B (CHB) infection functional cure is defined as sustained loss of HBsAg and several therapeutic strategies are in clinical development designed to pharmacologically reduce serum HBsAg, break immune tolerance, and increase functional cure rates. However, little is known about pre-treatment HBsAg levels as an indicator of HBV immune potential. Here, we compared the phenotypes and HBV-specific response of lymphocytes in CHB patients stratified by serum HBsAg levels <500 (HBslo) or >50,000 IU/ml (HBshi) using immunological assays (flow cytometry, ICS, ELISPOT). HBshi patients had significantly higher expression of inhibitory PD-1 on CD4+ T cells, particularly among TEMRA subset, and higher FcRL5 expression on B cells. Upon HBcAg(core) or HBsAg(env)-stimulation, 85% and 60% of HBslo patients had IFNγ+TNFα+ and IFNγ+ IL2+ CD4+ T cell responses respectively, in comparison to 33% and 13% of HBshi patients. Checkpoint blockade with αPD-1 improved HBV-specific CD4+ T cell function only in HBslo patients. HBsAg-specific antibody-secreting cells (ASCs) response was not different between these groups, yet αPD-1 treatment resulted in significantly higher fold change in ASCs among patients with HBsAg <100 IU/ml compared to patients with HBsAg >5,000 IU/ml. Thus, serum HBsAg correlates with inhibitory receptor expression, HBV-specific CD4+ T cell responses, and augmentation by checkpoint blockade.

Blockade of Neutrophil's Chemokine Receptors CXCR1/2 Abrogate Liver Damage in Acute-on-Chronic Liver Failure.

BACKGROUND: Neutrophils serve as critical players in the pathogenesis of liver diseases. Chemokine receptors CXCR1 and CXCR2 are required for neutrophil chemotaxis to the site of inflammation/injury and are crucial in hepatic inflammatory response. However, key mechanism of neutrophil-mediated liver injury in acute-on-chronic liver failure (ACLF) remains highly elusive; which could be targeted for the development of new therapeutic interventions. METHODS: To demonstrate the role of CXCR1/CXCR2-expressing neutrophils in hepatic injury, we investigated CXCR1/CXCR2 receptor expression in 17 hepatitis B virus-related ACLF patients in comparison to 42 chronic hepatitis B and 18 healthy controls. Mechanism of neutrophil-mediated cell death was analyzed by in vitro coculture assays and correlated with the patient data. In addition, to find out any etiological-based variations in ACLF, 19 alcohol-related ACLF patients were also included. RESULTS: In ACLF, neutrophils have high expression of CXCR1/CXCR2 receptors, which potentially participate in hepatocyte death through early apoptosis and necrosis in contact-dependent and -independent mechanisms. Importantly, blockade of CXCR1/CXCR2 with SCH 527123 antagonist significantly reduced cell death by targeting both the mechanisms. No etiology-based differences were seen between ACLF groups. Importantly, absolute neutrophil count was particularly higher in clinically severe ACLF patients and non-survivors (p < 0.0001). Multivariate analysis demonstrated ANC and CXCL8/IL-8 as a predictor of mortality. Further, receiver operating characteristics curve confirmed the cutoff of ANC >73.5% (sensitivity: 76.5% and specificity: 76.5%) and CXCL8/IL-8 >27% (sensitivity: 70% and specificity: 73%) in prediction of mortality. CONCLUSION: Blockade of CXCR1/CXCR2 diminished the production of inflammatory mediators and reduced cell death; therefore, pharmacological neutralization of CXCR1/CXCR2 could provide novel therapeutic target in the management of ACLF.

miRNA signatures can predict acute liver failure in hepatitis E infected pregnant females.

BACKGROUND: Acute viral hepatitis E (AVH-E) can often result in acute liver failure (ALF) during pregnancy. microRNAs serve as mediators in drug induced liver failure. We investigated their role as a biomarker in predicting ALF due to HEV (ALF-E). METHODS: We performed next generation sequencing and subsequent validation studies in PBMCs of pregnant (P) self limiting AVH-E, ALF due to HEV (ALF-E) and compared with AVH-E in non-pregnant (NP) females and healthy controls. FINDINGS: Eleven microRNAs were significantly expressed in response to HEV infection; importantly, miR- 431, 654, 1468 and 4435, were distinctly expressed in pregnant self-limiting AVH-E and healthy females (p = 0.0005), but not in ALF-E. Sixteen exclusive microRNAs differentiated ALF-E from self limiting AVH-E in pregnant females. miR-450b which affects cellular proliferation and metabolic processes through RNF20 and SECB was predominanlty upregulated and correlated with poor outcome (ROC 0.958, p = 0.001). INTERPRETATION: Our results reveal that a specific microRNA profile can predict fatality in ALF-E in pregnancy. These microRNAs could be exploited as prognostic biomarkers and help in the development of new therapeutic interventions.