A liver immune rheostat regulates CD8 T cell immunity in chronic HBV infection.

Chronic hepatitis B virus (HBV) infection affects 300 million patients worldwide1,2, in whom virus-specific CD8 T cells by still ill-defined mechanisms lose their function and cannot eliminate HBV-infected hepatocytes3-7. Here we demonstrate that a liver immune rheostat renders virus-specific CD8 T cells refractory to activation and leads to their loss of effector functions. In preclinical models of persistent infection with hepatotropic viruses such as HBV, dysfunctional virus-specific CXCR6+ CD8 T cells accumulated in the liver and, as a characteristic hallmark, showed enhanced transcriptional activity of cAMP-responsive element modulator (CREM) distinct from T cell exhaustion. In patients with chronic hepatitis B, circulating and intrahepatic HBV-specific CXCR6+ CD8 T cells with enhanced CREM expression and transcriptional activity were detected at a frequency of 12-22% of HBV-specific CD8 T cells. Knocking out the inhibitory CREM/ICER isoform in T cells, however, failed to rescue T cell immunity. This indicates that CREM activity was a consequence, rather than the cause, of loss in T cell function, further supported by the observation of enhanced phosphorylation of protein kinase A (PKA) which is upstream of CREM. Indeed, we found that enhanced cAMP-PKA-signalling from increased T cell adenylyl cyclase activity augmented CREM activity and curbed T cell activation and effector function in persistent hepatic infection. Mechanistically, CD8 T cells recognizing their antigen on hepatocytes established close and extensive contact with liver sinusoidal endothelial cells, thereby enhancing adenylyl cyclase-cAMP-PKA signalling in T cells. In these hepatic CD8 T cells, which recognize their antigen on hepatocytes, phosphorylation of key signalling kinases of the T cell receptor signalling pathway was impaired, which rendered them refractory to activation. Thus, close contact with liver sinusoidal endothelial cells curbs the activation and effector function of HBV-specific CD8 T cells that target hepatocytes expressing viral antigens by means of the adenylyl cyclase-cAMP-PKA axis in an immune rheostat-like fashion.

Corrigendum: A natural sustained-intestinal release formulation of red chili pepper extracted capsaicinoids (Capsifen®) safely modulates energy balance and endurance performance: a randomized, double-blind, placebo-controlled study.

[This corrects the article DOI: 10.3389/fnut.2024.1348328.].

A natural sustained-intestinal release formulation of red chili pepper extracted capsaicinoids (Capsifen®) safely modulates energy balance and endurance performance: a randomized, double-blind, placebo-controlled study.

Introduction: Overweight and obesity are major public health concerns, with a sharp increase in prevalence over the last few decades. The primary cause is an imbalance between calorie intake and expenditure due to a rise in calorie-rich processed food and reduced physical activity. Energy balance in humans involves complex processes including thermogenesis, a crucial factor in regulating energy expenditure. Methods: In this randomized, double-blinded, placebo-controlled three-arm three-sequence study, we investigated the efficacy of Capsifen® (CapF), a pungency-masked sustained-intestinal release formulation of red chili extract, on energy expenditure, fat oxidation, and endurance using the Quark C-PET system in healthy overweight participants, with and without exercise. In the study, 105 healthy participants were randomized to receive either placebo, CapF 100 mg/day, or CapF 200 mg/day for 28 days. Results: CapF demonstrated a dose-dependent response to increased energy expenditure and fatty acid oxidation with a concomitant reduction in body weight. Both CapF 100 and CapF 200 also increased the time to exhaustion. Discussion: These results demonstrate the plausible efficacy of CapF in energy expenditure and physical performance in otherwise healthy adults who have a high body mass index. Clinical trial registration: https://ctri.nic.in/Clinicaltrials/pmaindet2.php?EncHid=MjQzNTg=&Enc=&userName=CTRI/2018/04/013157 dated 04 October 2018.

HIV/HBV coinfection remodels the immune landscape and natural killer cell ADCC functional responses.

BACKGROUND AND AIMS: HBV and HIV coinfection is a common occurrence globally, with significant morbidity and mortality. Both viruses lead to immune dysregulation including changes in natural killer (NK) cells, a key component of antiviral defense and a promising target for HBV cure strategies. Here we used high-throughput single-cell analysis to explore the immune cell landscape in people with HBV mono-infection and HIV/HBV coinfection, on antiviral therapy, with emphasis on identifying the distinctive characteristics of NK cell subsets that can be therapeutically harnessed. APPROACH AND RESULTS: Our data show striking differences in the transcriptional programs of NK cells. HIV/HBV coinfection was characterized by an over-representation of adaptive, KLRC2 -expressing NK cells, including a higher abundance of a chemokine-enriched ( CCL3/CCL4 ) adaptive cluster. The NK cell remodeling in HIV/HBV coinfection was reflected in enriched activation pathways, including CD3ζ phosphorylation and ZAP-70 translocation that can mediate stronger antibody-dependent cellular cytotoxicity responses and a bias toward chemokine/cytokine signaling. By contrast, HBV mono-infection imposed a stronger cytotoxic profile on NK cells and a more prominent signature of "exhaustion" with higher circulating levels of HBsAg. Phenotypic alterations in the NK cell pool in coinfection were consistent with increased "adaptiveness" and better capacity for antibody-dependent cellular cytotoxicity compared to HBV mono-infection. Overall, an adaptive NK cell signature correlated inversely with circulating levels of HBsAg and HBV-RNA in our cohort. CONCLUSIONS: This study provides new insights into the differential signature and functional profile of NK cells in HBV and HIV/HBV coinfection, highlighting pathways that can be manipulated to tailor NK cell-focused approaches to advance HBV cure strategies in different patient groups.

Chronic Hepatitis B Finite Treatment: Similar and Different Concerns With New Drug Classes.

Chronic hepatitis B, a major cause of liver disease and cancer, affects >250 million people worldwide. Currently there is no cure, only suppressive therapies. Efforts to develop finite curative hepatitis B virus (HBV) therapies are underway, consisting of combinations of multiple novel agents with or without nucleos(t)ide reverse-transcriptase inhibitors. The HBV Forum convened a webinar in July 2021, along with subsequent working group discussions to address how and when to stop finite therapy for demonstration of sustained off-treatment efficacy and safety responses. Participants included leading experts in academia, clinical practice, pharmaceutical companies, patient representatives, and regulatory agencies. This Viewpoints article outlines areas of consensus within our multistakeholder group for stopping finite therapies in chronic hepatitis B investigational studies, including trial design, patient selection, outcomes, biomarkers, predefined stopping criteria, predefined retreatment criteria, duration of investigational therapies, and follow-up after stopping therapy. Future research of unmet needs are discussed.

Tissue T cells in prophylactic and therapeutic vaccination responses.

In this conference report, I highlight the potential to target tissue-resident T cells to enhance prophylactic and therapeutic vaccine immunity. I describe our recent findings on exploiting frontline sentinal immunosurveillance by liver-resident immunity for functional cure of hepatitis B. We showed that therapeutic vaccine-induced HBV-specific T cells are constrained by liver-resident NK cells; cytokine-activation and PD-L1 blockade of NK cells converted them into helpers able to instead boost HBV-specific T cells. Turning to tissue-resident T cells in the lung, we found this pool can include T cells able to recognise SARS-CoV-2, including cross-reactive responses present prior to the pandemic. The importance of inducing T cells with future prophylactic vaccines was underscored by their selective expansion in a subset of donors aborting SARS-CoV-2 infection without detectable antibodies.

Semi-automation of keratopathy visual acuity grading of corneal events in belantamab mafodotin clinical trials: clinical decision support software.

Background: Belantamab mafodotin (belamaf) has demonstrated clinically meaningful antimyeloma activity in patients with heavily pretreated multiple myeloma. However, it is highly active against dividing cells, contributing to off-target adverse events, particularly ocular toxicity. Changes in best corrected visual acuity (BCVA) and corneal examination findings are routinely monitored to determine Keratopathy Visual Acuity (KVA) grade to inform belamaf dose modification. Objective: We aimed to develop a semiautomated mobile app to facilitate the grading of ocular events in clinical trials involving belamaf. Methods: The paper process was semiautomated by creating a library of finite-state automaton (FSA) models to represent all permutations of KVA grade changes from baseline BCVA readings. The transition states in the FSA models operated independently of eye measurement units (e.g., Snellen, logMAR, decimal) and provided a uniform approach to determining KVA grade changes. Together with the FSA, the complex decision tree for determining the grade change based on corneal examination findings was converted into logical statements for accurate and efficient overall KVA grade computation. First, a web-based user interface, conforming to clinical practice settings, was developed to simplify the input of key KVA grading criteria. Subsequently, a mobile app was developed that included additional guided steps to assist in clinical decision-making. Results: The app underwent a robust Good Clinical Practice validation process. Outcomes were reviewed by key stakeholders, our belamaf medical lead, and the systems integration team. The time to compute a patient's overall KVA grade using the Belamaf Eye Exam (BEE) app was reduced from a 20- to 30-min process to <1-2 min. The BEE app was well received, with most investigators surveyed selecting "satisfied" or "highly satisfied" for its accuracy and time efficiency. Conclusions: Our semiautomated approach provides for an accurate, simplified method of assessment of patients' corneal status that reduces errors and quickly delivers information critical for potential belamaf dose modifications. The app is currently available on the Apple iOS and Android platforms for use by investigators of the DREAMM clinical trials, and its use could easily be extended to the clinic to support healthcare providers who need to make informed belamaf treatment decisions.

Respiratory mucosal immune memory to SARS-CoV-2 after infection and vaccination.

Respiratory mucosal immunity induced by vaccination is vital for protection from coronavirus infection in animal models. In humans, the capacity of peripheral vaccination to generate sustained immunity in the lung mucosa, and how this is influenced by prior SARS-CoV-2 infection, is unknown. Here we show using bronchoalveolar lavage samples that donors with history of both infection and vaccination have more airway mucosal SARS-CoV-2 antibodies and memory B cells than those only vaccinated. Infection also induces populations of airway spike-specific memory CD4+ and CD8+ T cells that are not expanded by vaccination alone. Airway mucosal T cells induced by infection have a distinct hierarchy of antigen specificity compared to the periphery. Spike-specific T cells persist in the lung mucosa for 7 months after the last immunising event. Thus, peripheral vaccination alone does not appear to induce durable lung mucosal immunity against SARS-CoV-2, supporting an argument for the need for vaccines targeting the airways.

T cell control of SARS-CoV-2: When, which, and where?

Efficient immune protection against viruses such as SARS-CoV-2 requires the coordinated activity of innate immunity, B and T cells. Accumulating data point to a critical role for T cells not only in the clearance of established infection, but also for aborting viral replication independently of humoral immunity. Here we review the evidence supporting the contribution of antiviral T cells and consider which of their qualitative features favour efficient control of infection. We highlight how studies of SARS-CoV-2 and other coronaviridae in animals and humans have provided important lessons on the optimal timing (When), functionality and specificity (Which), and location (Where) of antiviral T cells. We discuss the clinical implications, particularly for the development of next-generation vaccines, and emphasise areas requiring further study.

Persistent symptoms after COVID-19 are not associated with differential SARS-CoV-2 antibody or T cell immunity.

Among the unknowns in decoding the pathogenesis of SARS-CoV-2 persistent symptoms in Long Covid is whether there is a contributory role of abnormal immunity during acute infection. It has been proposed that Long Covid is a consequence of either an excessive or inadequate initial immune response. Here, we analyze SARS-CoV-2 humoral and cellular immunity in 86 healthcare workers with laboratory confirmed mild or asymptomatic SARS-CoV-2 infection during the first wave. Symptom questionnaires allow stratification into those with persistent symptoms and those without for comparison. During the period up to 18-weeks post-infection, we observe no difference in antibody responses to spike RBD or nucleoprotein, virus neutralization, or T cell responses. Also, there is no difference in the profile of antibody waning. Analysis at 1-year, after two vaccine doses, comparing those with persistent symptoms to those without, again shows similar SARS-CoV-2 immunity. Thus, quantitative differences in these measured parameters of SARS-CoV-2 adaptive immunity following mild or asymptomatic acute infection are unlikely to have contributed to Long Covid causality. ClinicalTrials.gov (NCT04318314).

Human resident liver myeloid cells protect against metabolic stress in obesity.

Although multiple populations of macrophages have been described in the human liver, their function and turnover in patients with obesity at high risk of developing non-alcoholic fatty liver disease (NAFLD) and cirrhosis are currently unknown. Herein, we identify a specific human population of resident liver myeloid cells that protects against the metabolic impairment associated with obesity. By studying the turnover of liver myeloid cells in individuals undergoing liver transplantation, we find that liver myeloid cell turnover differs between humans and mice. Using single-cell techniques and flow cytometry, we determine that the proportion of the protective resident liver myeloid cells, denoted liver myeloid cells 2 (LM2), decreases during obesity. Functional validation approaches using human 2D and 3D cultures reveal that the presence of LM2 ameliorates the oxidative stress associated with obese conditions. Our study indicates that resident myeloid cells could be a therapeutic target to decrease the oxidative stress associated with NAFLD.

Large clones of pre-existing T cells drive early immunity against SARS-COV-2 and LCMV infection.

T cell responses precede antibody and may provide early control of infection. We analyzed the clonal basis of this rapid response following SARS-COV-2 infection. We applied T cell receptor (TCR) sequencing to define the trajectories of individual T cell clones immediately. In SARS-COV-2 PCR+ individuals, a wave of TCRs strongly but transiently expand, frequently peaking the same week as the first positive PCR test. These expanding TCR CDR3s were enriched for sequences functionally annotated as SARS-COV-2 specific. Epitopes recognized by the expanding TCRs were highly conserved between SARS-COV-2 strains but not with circulating human coronaviruses. Many expanding CDR3s were present at high frequency in pre-pandemic repertoires. Early response TCRs specific for lymphocytic choriomeningitis virus epitopes were also found at high frequency in the preinfection naive repertoire. High-frequency naive precursors may allow the T cell response to respond rapidly during the crucial early phases of acute viral infection.

An ACAT inhibitor suppresses SARS-CoV-2 replication and boosts antiviral T cell activity.

The severity of disease following infection with SARS-CoV-2 is determined by viral replication kinetics and host immunity, with early T cell responses and/or suppression of viraemia driving a favourable outcome. Recent studies uncovered a role for cholesterol metabolism in the SARS-CoV-2 life cycle and in T cell function. Here we show that blockade of the enzyme Acyl-CoA:cholesterol acyltransferase (ACAT) with Avasimibe inhibits SARS-CoV-2 pseudoparticle infection and disrupts the association of ACE2 and GM1 lipid rafts on the cell membrane, perturbing viral attachment. Imaging SARS-CoV-2 RNAs at the single cell level using a viral replicon model identifies the capacity of Avasimibe to limit the establishment of replication complexes required for RNA replication. Genetic studies to transiently silence or overexpress ACAT isoforms confirmed a role for ACAT in SARS-CoV-2 infection. Furthermore, Avasimibe boosts the expansion of functional SARS-CoV-2-specific T cells from the blood of patients sampled during the acute phase of infection. Thus, re-purposing of ACAT inhibitors provides a compelling therapeutic strategy for the treatment of COVID-19 to achieve both antiviral and immunomodulatory effects. Trial registration: NCT04318314.

Exploring the effect of case management in homelessness per components: A systematic review of effectiveness and implementation, with meta-analysis and thematic synthesis.

Background: Adequate housing is a basic human right. The many millions of people experiencing homelessness (PEH) have a lower life expectancy and more physical and mental health problems. Practical and effective interventions to provide appropriate housing are a public health priority. Objectives: To summarise the best available evidence relating to the components of case-management interventions for PEH via a mixed methods review that explored both the effectiveness of interventions and factors that may influence its impact. Search Methods: We searched 10 bibliographic databases from 1990 to March 2021. We also included studies from Campbell Collaboration Evidence and Gap Maps and searched 28 web sites. Reference lists of included papers and systematic reviews were examined and experts contacted for additional studies. Selection Criteria: We included all randomised and non-randomised study designs exploring case management interventions where a comparison group was used. The primary outcome of interest was homelessness. Secondary outcomes included health, wellbeing, employment and costs. We also included all studies where data were collected on views and experiences that may impact on implementation. Data Collection and Analysis: We assessed risk of bias using tools developed by the Campbell Collaboration. We conducted meta-analyses of the intervention studies where possible and carried out a framework synthesis of a set of implementation studies identified by purposive sampling to represent the most 'rich' and 'thick' data. Main Results: We included 64 intervention studies and 41 implementation studies. The evidence base was dominated by studies from the USA and Canada. Participants were largely (though not exclusively) people who were literally homeless, that is, living on the streets or in shelters, and who had additional support needs. Many studies were assessed as having a medium or high risk of bias. However, there was some consistency in outcomes across studies that improved confidence in the main findings. Case Management and Housing Outcomes: Case management of any description was superior to usual care for homelessness outcomes (standardised mean difference [SMD] = -0.51 [95% confidence interval [CI]: -0.71, -0.30]; p < 0.01). For studies included in the meta-analyses, Housing First had the largest observed impact, followed by Assertive Community Treatment, Critical Time Intervention and Intensive Case Management. The only statistically significant difference was between Housing First and Intensive Case Management (SMD = -0.6 [-1.1, -0.1]; p = 0.03) at ≥12 months. There was not enough evidence to compare the above approaches with standard case management within the meta-analyses. A narrative comparison across all studies was inconclusive, though suggestive of a trend in favour of more intensive approaches. Case Management and Mental Health Outcomes: The overall evidence suggested that case management of any description was not more or less effective compared to usual care for an individual's mental health (SMD = 0.02 [-0.15, 0.18]; p = 0.817). Case Management and Other Outcomes: Based on meta-analyses, case management was superior to usual care for capability and wellbeing outcomes up to 1 year (an improvement of around one-third of an SMD; p < 0.01) but was not statistically significantly different for substance use outcomes, physical health, and employment. Case Management Components: For homelessness outcomes, there was a non-significant trend for benefits to be greater in the medium term (≤3 years) compared to long term (>3 years) (SMD = -0.64 [-1.04, -0.24] vs. -0.27 [-0.53, 0]; p = 0.16) and for in-person meetings in comparison to mixed (in-person and remote) approaches (SMD = -0.73 [-1.25,-0.21]) versus -0.26 [-0.5,-0.02]; p = 0.13). There was no evidence from meta-analyses to suggest that an individual case manager led to better outcomes then a team, and interventions with no dedicated case manager may have better outcomes than those with a named case manager (SMD = -0.36 [-0.55, -0.18] vs. -1.00 [-2.00, 0.00]; p = 0.02). There was not enough evidence from meta-analysis to assess whether the case manager should have a professional qualification, or if frequency of contact, case manager availability or conditionality (barriers due to conditions attached to service provision) influenced outcomes. However, the main theme from implementation studies concerned barriers where conditions were attached to services. Characteristics of Persons Experiencing Homelessness: No conclusions could be drawn from meta-analysis other than a trend for greater reductions in homelessness for persons with high complexity of need (two or more support needs in addition to homelessness) as compared to those with medium complexity of need (one additional support need); effect sizes were SMD = -0.61 [-0.91, -0.31] versus -0.36 [-0.68, -0.05]; p = 0.3. The Broader Context of Delivery of Case Management Programmes: Other major themes from the implementation studies included the importance of interagency partnership; provision for non-housing support and training needs of PEH (such as independent living skills), intensive community support following the move to new housing; emotional support and training needs of case managers; and an emphasis on housing safety, security and choice. Cost Effectiveness: The 12 studies with cost data provided contrasting results and no clear conclusions. Some case management costs may be largely off-set by reductions in the use of other services. Cost estimates from three North American studies were $45-52 for each additional day housed. Authors' Conclusions: Case management interventions improve housing outcomes for PEH with one or more additional support needs, with more intense interventions leading to greater benefits. Those with greater support needs may gain greater benefit. There is also evidence for improvements to capabilities and wellbeing. Current approaches do not appear to lead to mental health benefits. In terms of case management components, there is evidence in support of a team approach and in-person meetings and, from the implementation evidence, that conditions associated with service provision should be minimised. The approach within Housing First could explain the finding that overall benefits may be greater than for other types of case management. Four of its principles were identified as key themes within the implementation studies: No conditionality, offer choice, provide an individualised approach and support community building. Recommendations for further research include an expansion of the research base outside North America and further exploration of case management components and intervention cost-effectiveness.

Can T Cells Abort SARS-CoV-2 and Other Viral Infections?

Despite the highly infectious nature of the SARS-CoV-2 virus, it is clear that some individuals with potential exposure, or even experimental challenge with the virus, resist developing a detectable infection. While a proportion of seronegative individuals will have completely avoided exposure to the virus, a growing body of evidence suggests a subset of individuals are exposed, but mediate rapid viral clearance before the infection is detected by PCR or seroconversion. This type of "abortive" infection likely represents a dead-end in transmission and precludes the possibility for development of disease. It is, therefore, a desirable outcome on exposure and a setting in which highly effective immunity can be studied. Here, we describe how early sampling of a new pandemic virus using sensitive immunoassays and a novel transcriptomic signature can identify abortive infections. Despite the challenges in identifying abortive infections, we highlight diverse lines of evidence supporting their occurrence. In particular, expansion of virus-specific T cells in seronegative individuals suggests abortive infections occur not only after exposure to SARS-CoV-2, but for other coronaviridae, and diverse viral infections of global health importance (e.g., HIV, HCV, HBV). We discuss unanswered questions related to abortive infection, such as: 'Are we just missing antibodies? Are T cells an epiphenomenon? What is the influence of the dose of viral inoculum?' Finally, we argue for a refinement of the current paradigm that T cells are only involved in clearing established infection; instead, we emphasise the importance of considering their role in terminating early viral replication by studying abortive infections.

Tissue CD14+CD8+ T cells reprogrammed by myeloid cells and modulated by LPS.

The liver is bathed in bacterial products, including lipopolysaccharide transported from the intestinal portal vasculature, but maintains a state of tolerance that is exploited by persistent pathogens and tumours1-4. The cellular basis mediating this tolerance, yet allowing a switch to immunity or immunopathology, needs to be better understood for successful immunotherapy of liver diseases. Here we show that a variable proportion of CD8+ T cells compartmentalized in the human liver co-stain for CD14 and other prototypic myeloid membrane proteins and are enriched in close proximity to CD14high myeloid cells in hepatic zone 2. CD14+CD8+ T cells preferentially accumulate within the donor pool in liver allografts, among hepatic virus-specific and tumour-infiltrating responses, and in cirrhotic ascites. CD14+CD8+ T cells exhibit increased turnover, activation and constitutive immunomodulatory features with high homeostatic IL-10 and IL-2 production ex vivo, and enhanced antiviral/anti-tumour effector function after TCR engagement. This CD14+CD8+ T cell profile can be recapitulated by the acquisition of membrane proteins-including the lipopolysaccharide receptor complex-from mononuclear phagocytes, resulting in augmented tumour killing by TCR-redirected T cells in vitro. CD14+CD8+ T cells express integrins and chemokine receptors that favour interactions with the local stroma, which can promote their induction through CXCL12. Lipopolysaccharide can also increase the frequency of CD14+CD8+ T cells in vitro and in vivo, and skew their function towards the production of chemotactic and regenerative cytokines. Thus, bacterial products in the gut-liver axis and tissue stromal factors can tune liver immunity by driving myeloid instruction of CD8+ T cells with immunomodulatory ability.

The scientific basis of combination therapy for chronic hepatitis B functional cure.

Functional cure of chronic hepatitis B (CHB) - or hepatitis B surface antigen (HBsAg) loss after 24 weeks off therapy - is now the goal of treatment, but is rarely achieved with current therapy. Understanding the hepatitis B virus (HBV) life cycle and immunological defects that lead to persistence can identify targets for novel therapy. Broadly, treatments fall into three categories: those that reduce viral replication, those that reduce antigen load and immunotherapies. Profound viral suppression alone does not achieve quantitative (q)HBsAg reduction or HBsAg loss. Combining nucleos(t)ide analogues and immunotherapy reduces qHBsAg levels and induces HBsAg loss in some patients, particularly those with low baseline qHBsAg levels. Even agents that are specifically designed to reduce viral antigen load might not be able to achieve sustained HBsAg loss when used alone. Thus, rationale exists for the use of combinations of all three therapy types. Monitoring during therapy is important not just to predict HBsAg loss but also to understand mechanisms of HBsAg loss using viral and immunological biomarkers, and in selected cases intrahepatic sampling. We consider various paths to functional cure of CHB and the need to individualize treatment of this heterogeneous infection until a therapeutic avenue for all patients with CHB is available.

Pro-fibrogenic role of alarmin high mobility group box 1 in HIV-hepatitis B virus coinfection.

OBJECTIVE: Liver disease is accelerated in people with HIV (PWH) with hepatitis B virus (HBV) coinfection. We hypothesized that liver fibrosis in HIV-HBV is triggered by increased hepatocyte apoptosis, microbial translocation and/or HIV/HBV viral products. DESIGN: Sera from PWH with HBV coinfection versus from those with HBV only or putative mediators were used to examine the pathogenesis of liver disease in HIV-HBV. METHODS: We applied sera from PWH and HBV coinfection versus HBV alone, or putative mediators (including HMGB1), to primary human hepatic stellate cells (hHSC) and examined pro-fibrogenic changes at the single cell level using flow cytometry. High mobility group box 1 (HMGB1) levels in the applied sera were assessed according to donor fibrosis stage. RESULTS: Quantitative flow cytometric assessment of pro-fibrogenic and inflammatory changes at the single cell level revealed an enhanced capacity for sera from PWH with HBV coinfection to activate hHSC. This effect was recapitulated by lipopolysaccharide, HIV-gp120, hepatocyte conditioned-media and the alarmin HMGB1. Induction of hepatocyte cell death increased their pro-fibrogenic potential, an effect blocked by HMGB1 antagonist glycyrrhizic acid. Consistent with a role for this alarmin, HMGB1 levels were elevated in sera from PWH and hepatitis B coinfection compared to HBV alone and higher in those with HIV-HBV with liver fibrosis compared to those without. CONCLUSIONS: Sera from PWH and HBV coinfection have an enhanced capacity to activate primary hHSC. We identified an increase in circulating HMGB1 which, in addition to HIV-gp120 and translocated microbial products, drove pro-fibrogenic changes in hHSC, as mechanisms contributing to accelerated liver disease in HIV-HBV.