Priming and Maintenance of Adaptive Immunity in the Liver.

The liver's unique characteristics have a profound impact on the priming and maintenance of adaptive immunity. This review delves into the cellular circuits that regulate adaptive immune responses in the liver, with a specific focus on hepatitis B virus infection as an illustrative example. A key aspect highlighted is the liver's specialized role in priming CD8+ T cells, leading to a distinct state of immune hyporesponsiveness. Additionally, the influence of the liver's hemodynamics and anatomical features, particularly during liver fibrosis and cirrhosis, on the differentiation and function of adaptive immune cells is discussed. While the primary emphasis is on CD8+ T cells, recent findings regarding the involvement of B cells and CD4+ T cells in hepatic immunity are also reviewed. Furthermore, we address the challenges ahead and propose integrating cutting-edge techniques, such as spatial biology, and combining mouse models with human sample analyses to gain comprehensive insights into the liver's adaptive immunity. This understanding could pave the way for novel therapeutic strategies targeting infectious diseases, malignancies, and inflammatory liver conditions like metabolic dysfunction-associated steatohepatitis and autoimmune hepatitis.

Attenuated effector T cells are linked to control of chronic HBV infection.

Hepatitis B virus (HBV)-specific CD8+ T cells play a dominant role during acute-resolving HBV infection but are functionally impaired during chronic HBV infection in humans. These functional deficits have been linked with metabolic and phenotypic heterogeneity, but it has remained unclear to what extent different subsets of HBV-specific CD8+ T cells still suppress viral replication. We addressed this issue by deep profiling, functional testing and perturbation of HBV-specific CD8+ T cells during different phases of chronic HBV infection. Our data revealed a mechanism of effector CD8+ T cell attenuation that emerges alongside classical CD8+ T cell exhaustion. Attenuated HBV-specific CD8+ T cells were characterized by cytotoxic properties and a dampened effector differentiation program, determined by antigen recognition and TGFß signaling, and were associated with viral control during chronic HBV infection. These observations identify a distinct subset of CD8+ T cells linked with immune efficacy in the context of a chronic human viral infection with immunotherapeutic potential.

Non-terminally exhausted tumor-resident memory HBV-specific T cell responses correlate with relapse-free survival in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) often develops following chronic hepatitis B virus (HBV) infection and responds poorly to immune checkpoint blockade. Here, we examined the antigen specificities of HCC-infiltrating T cells and their relevance to tumor control. Using highly multiplexed peptide-MHC tetramer staining of unexpanded cells from blood, liver, and tumor tissues from 46 HCC patients, we detected 91 different antigen-specific CD8+ T cell populations targeting HBV, neoantigen, tumor-associated, and disease-unrelated antigens. Parallel high-dimensional analysis delineated five distinct antigen-specific tissue-resident memory T (Trm) cell populations. Intratumoral and intrahepatic HBV-specific T cells were enriched for two Trm cell subsets that were PD-1loTOXlo, despite being clonally expanded. High frequencies of intratumoral terminally exhausted T cells were uncommon. Patients with tumor-infiltrating HBV-specific CD8+ Trm cells exhibited longer-term relapse-free survival. Thus, non-terminally exhausted HBV-specific CD8+ Trm cells show hallmarks of active involvement and effective antitumor response, implying that these cells could be harnessed for therapeutic purposes.

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.

De novo design of modular and tunable protein biosensors.

Naturally occurring protein switches have been repurposed for the development of biosensors and reporters for cellular and clinical applications1. However, the number of such switches is limited, and reengineering them is challenging. Here we show that a general class of protein-based biosensors can be created by inverting the flow of information through de novo designed protein switches in which the binding of a peptide key triggers biological outputs of interest2. The designed sensors are modular molecular devices with a closed dark state and an open luminescent state; analyte binding drives the switch from the closed to the open state. Because the sensor is based on the thermodynamic coupling of analyte binding to sensor activation, only one target binding domain is required, which simplifies sensor design and allows direct readout in solution. We create biosensors that can sensitively detect the anti-apoptosis protein BCL-2, the IgG1 Fc domain, the HER2 receptor, and Botulinum neurotoxin B, as well as biosensors for cardiac troponin I and an anti-hepatitis B virus antibody with the high sensitivity required to detect these molecules clinically. Given the need for diagnostic tools to track the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)3, we used the approach to design sensors for the SARS-CoV-2 spike protein and antibodies against the membrane and nucleocapsid proteins. The former, which incorporates a de novo designed spike receptor binding domain (RBD) binder4, has a limit of detection of 15 pM and a luminescence signal 50-fold higher than the background level. The modularity and sensitivity of the platform should enable the rapid construction of sensors for a wide range of analytes, and highlights the power of de novo protein design to create multi-state protein systems with new and useful functions.

Restoration of CD3+CD56+ NKT-like cell function by TIGIT blockade in inactive carrier and immune tolerant patients of chronic hepatitis B virus infection.

Chronic hepatitis B (CHB) virus infection, which can be divided into immune-tolerant (IT), immune-active (IA), inactive carrier (IC) phases, and HBeAg-negative hepatitis (ENEG), can induce liver cirrhosis and eventually hepatocellular carcinoma (HCC). CD3+CD56+ NKT-like cells play an important role in antiviral immune response. However, the mechanism of NKT-like cells to mediate immune tolerance remains largely elusive. In this study, we observed circulating NKT-like cells from IC and IT CHB patients were phenotypically and functionally impaired, manifested by increased expression of inhibitory receptor TIGIT and decreased capacity of secreting antiviral cytokines. Besides, TIGIT+ NKT-like cells of IC and IT CHB patients expressed lower levels of cytotoxic cytokines than the TIGIT- subset. Furthermore, increased expression of CD155, the ligand of TIGIT, on plasmacytoid dendritic cells (pDCs) was detected in IC and IT CHB patients. Importantly, the co-culture of NKT-like cells and pDCs showed that NKT-like cells restored their antiviral ability after TIGIT blockade upon HBV peptide stimulation in IC and IT CHB patients. In conclusion, our findings suggest that the TIGIT pathway may mediate immune tolerance in IT CHB patients and lead to functional impairment in IC patients, indicating that TIGIT may be a potential therapeutic checkpoint for immunotherapy of CHB patients.

Both middle and large envelope proteins can mediate neutralization of hepatitis B virus infectivity by anti-preS2 antibodies: escape by naturally occurring preS2 deletions.

Hepatitis B virus (HBV) expresses co-terminal large (L), middle (M), and small (S) envelope proteins containing preS1/preS2/S, preS2/S, and S domain alone, respectively. S and preS1 domains mediate sequential virion attachment to heparan sulfate proteoglycans and sodium taurocholate cotransporting polypeptide (NTCP), respectively, which can be blocked by anti-S and anti-preS1 antibodies. How anti-preS2 antibodies neutralize HBV infectivity remains enigmatic. The late stage of chronic HBV infection often selects for mutated preS2 translation initiation codon to prevent M protein expression, or in-frame preS2 deletions to shorten both L and M proteins. When introduced to infectious clone of genotype C or D, both M-minus mutations and most 5' preS2 deletions sustained virion production. Such mutant progeny viral particles were infectious in NTCP-reconstituted HepG2 cells. Neutralization experiments were performed on the genotype D clone. Although remaining susceptible to anti-preS1 and anti-S neutralizing antibodies, M-minus mutants were only partially neutralized by two anti-preS2 antibodies tested while preS2 deletion mutants were resistant. By infection experiments using viral particles with lost versus increased M protein expression, or a neutralization escaping preS2 deletion only present on L or M protein, we found that both full-length L and M proteins contributed to virus neutralization by the two anti-preS2 antibodies. Thus, immune escape could be a driving force for the selection of M-minus mutations, and especially preS2 deletions. The fact that both L and M proteins could mediate neutralization by anti-preS2 antibodies may shed light on the underlying molecular mechanism.IMPORTANCEThe large (L), middle (M), and small (S) envelope proteins of hepatitis B virus (HBV) contain preS1/preS2/S, preS2/S, and S domain alone, respectively. The discovery of heparan sulfate proteoglycans and sodium taurocholate cotransporting polypeptide (NTCP) as the low- and high-affinity HBV receptors could explain neutralizing potential of anti-S and anti-preS1 antibodies, respectively, but how anti-preS2 neutralizing antibodies work remains enigmatic. In this study, we found two M-minus mutants in the context of genotype D partially escaped two anti-preS2 neutralizing antibodies in NTCP-reconstituted HepG2 cells, while several naturally occurring preS2 deletion mutants escaped both antibodies. By point mutations to eliminate or enhance M protein expression, and by introducing preS2 deletion selectively to L or M protein, we found binding of anti-preS2 antibodies to both L and M proteins contributed to neutralization of wild-type HBV infectivity. Our finding may shed light on the possible mechanism(s) whereby anti-preS2 antibodies neutralize HBV infectivity.

Class A capsid assembly modulator apoptotic elimination of hepatocytes with high HBV core antigen level in vivo is dependent on de novo core protein translation.

Capsid assembly is critical in the hepatitis B virus (HBV) life cycle, mediated by the viral core protein. Capsid assembly is the target for new anti-viral therapeutics known as capsid assembly modulators (CAMs) of which the CAM-aberrant (CAM-A) class induces aberrant shaped core protein structures and leads to hepatocyte cell death. This study aimed to identify the mechanism of action of CAM-A modulators leading to HBV-infected hepatocyte elimination where CAM-A-mediated hepatitis B surface antigen (HBsAg) reduction was evaluated in a stable HBV replicating cell line and in AAV-HBV-transduced C57BL/6, C57BL/6 SCID, and HBV-infected chimeric mice with humanized livers. Results showed that in vivo treatment with CAM-A modulators induced pronounced reductions in hepatitis B e antigen (HBeAg) and HBsAg, associated with a transient alanine amino transferase (ALT) increase. Both HBsAg and HBeAg reductions and ALT increase were delayed in C57BL/6 SCID and chimeric mice, suggesting that adaptive immune responses may indirectly contribute. However, CD8+ T cell depletion in transduced wild-type mice did not impact antigen reduction, indicating that CD8+ T cell responses are not essential. Transient ALT elevation in AAV-HBV-transduced mice coincided with a transient increase in endoplasmic reticulum stress and apoptosis markers, followed by detection of a proliferation marker. Microarray data revealed antigen presentation pathway (major histocompatibility complex class I molecules) upregulation, overlapping with the apoptosis. Combination treatment with HBV-specific siRNA demonstrated that CAM-A-mediated HBsAg reduction is dependent on de novo core protein translation. To conclude, CAM-A treatment eradicates HBV-infected hepatocytes with high core protein levels through the induction of apoptosis, which can be a promising approach as part of a regimen to achieve functional cure. IMPORTANCE: Treatment with hepatitis B virus (HBV) capsid assembly modulators that induce the formation of aberrant HBV core protein structures (CAM-A) leads to programmed cell death, apoptosis, of HBV-infected hepatocytes and subsequent reduction of HBV antigens, which differentiates CAM-A from other CAMs. The effect is dependent on the de novo synthesis and high levels of core protein.

Exosomes mediate the cell-to-cell transmission of IFN-α-induced antiviral activity.

The cell-to-cell transmission of viral resistance is a potential mechanism for amplifying the interferon-induced antiviral response. In this study, we report that interferon-α (IFN-α) induced the transfer of resistance to hepatitis B virus (HBV) from nonpermissive liver nonparenchymal cells (LNPCs) to permissive hepatocytes via exosomes. Exosomes from IFN-α-treated LNPCs were rich in molecules with antiviral activity. Moreover, exosomes from LNPCs were internalized by hepatocytes, which mediated the intercellular transfer of antiviral molecules. Finally, we found that exosomes also contributed to the antiviral response of IFN-α to mouse hepatitis virus A59 and adenovirus in mice. Thus, we propose an antiviral mechanism of IFN-α activity that involves the induction and intercellular transfer of antiviral molecules via exosomes.

Estimating the key outcomes and hepatocellular carcinoma risk in patients in immune-tolerant phase of chronic hepatitis B virus infection: A systematic review and meta-analysis.

The question of whether patients in the immune-tolerant (IT) phase of chronic hepatitis B virus (HBV) infection should undergo antiviral therapy and determine the optimal regimen remains unclear. A comprehensive search of PubMed, Embase, MEDLINE, Cochrane Library, and Wanfang Data from inception to 5 December 2023, was conducted. Studies reporting on key outcomes such as HBV DNA undetectability, HBeAg loss or seroconversion, HBsAg loss or seroconversion, and hepatocellular carcinoma (HCC) incidence in patients in the IT phase of chronic HBV infection were included. In total, 23 studies were incorporated. Approximately 4% of patients in the IT phase achieved spontaneous HBeAg loss over 48 weeks of follow-up. Antiviral therapy demonstrated a favourable impact on HBV DNA negative conversion (Children: risk ratios [RR] = 6.83, 95% CI: 2.90-16.05; Adults: RR = 25.84, 95% CI: 6.47-103.31) and HBsAg loss rates (Children: RR = 9.49, 95% CI: 1.74-51.76; Adults: RR = 7.35, 95% CI: 1.41-38.27) for patients in the IT phase. Subgroup analysis revealed that in adult patients in the IT phase, interferon plus nucleos(t)ide analogues (NA)-treated patients exhibited a higher pooled rate of HBsAg loss or seroconversion than those treated with NA monotherapy (9% vs. 0%). Additionally, the pooled annual HCC incidence for patients in the IT phase was 3.03 cases per 1000 person-years (95% CI: 0.99-5.88). Adult patients in the IT phase had a significantly lower HCC incidence risk than HBeAg-positive indeterminate phase patients (RR = 0.46, 95% CI: 0.32-0.66), with no significant differences observed between IT and immune-active phases. Presently, there is insufficient evidence solely based on reducing the risk of HCC incidence, to recommend treating patients in the IT phase of chronic HBV infection. However, both adult and paediatric patients in the IT phase responded well to antiviral therapy, showing favourable rates of HBsAg loss or seroconversion.

Dynamics and genomic landscape of CD8+ T cells undergoing hepatic priming.

The responses of CD8+ T cells to hepatotropic viruses such as hepatitis B range from dysfunction to differentiation into effector cells, but the mechanisms that underlie these distinct outcomes remain poorly understood. Here we show that priming by Kupffer cells, which are not natural targets of hepatitis B, leads to differentiation of CD8+ T cells into effector cells that form dense, extravascular clusters of immotile cells scattered throughout the liver. By contrast, priming by hepatocytes, which are natural targets of hepatitis B, leads to local activation and proliferation of CD8+ T cells but not to differentiation into effector cells; these cells form loose, intravascular clusters of motile cells that coalesce around portal tracts. Transcriptomic and chromatin accessibility analyses reveal unique features of these dysfunctional CD8+ T cells, with limited overlap with those of exhausted or tolerant T cells; accordingly, CD8+ T cells primed by hepatocytes cannot be rescued by treatment with anti-PD-L1, but instead respond to IL-2. These findings suggest immunotherapeutic strategies against chronic hepatitis B infection.

Lymph node-targeted STING agonist nanovaccine against chronic HBV infection.

Chronic hepatitis B virus (HBV) infection is a global health problem that substantially increases the risk of developing liver disease. The development of a novel strategy to induce anti-HB seroconversion and achieve a long-lasting immune response against chronic HBV infection remains challenging. Here, we found that chronic HBV infection affected the signaling pathway involved in STING-mediated induction of host immune responses in dendritic cells (DCs) and then generated a lymph node-targeted nanovaccine that co-delivered hepatitis B surface antigen (HBsAg) and cyclic diguanylate monophosphate (c-di-GMP) (named the PP-SG nanovaccine). The feasibility and efficiency of the PP-SG nanovaccine for CHB treatment were evaluated in HBV-carrier mice. Serum samples were analyzed for HBsAg, anti-HBs, HBV DNA, and alanine aminotransferase levels, and liver samples were evaluated for HBV DNA and RNA and HBcAg, accompanied by an analysis of HBV-specific cellular and humoral immune responses during PP-SG nanovaccine treatment. The PP-SG nanovaccine increased antigen phagocytosis and DC maturation, efficiently and safely eliminated HBV, achieved a long-lasting immune response against HBV reinjection, and disrupted chronic HBV infection-induced immune tolerance, as characterized by the generation and multifunctionality of HBV-specific CD8+ T and CD4+ T cells and the downregulation of immune checkpoint molecules. HBV-carrier mice immunized with the PP-SG nanovaccine achieved partial anti-HBs seroconversion. The PP-SG nanovaccine can induce sufficient and persistent viral suppression and achieve anti-HBs seroconversion, rendering it a promising vaccine candidate for clinical chronic hepatitis B therapy.

Neural Network Enables High Accuracy for Hepatitis B Surface Antigen Detection with a Plasmonic Platform.

The detection of hepatitis B surface antigen (HBsAg) is critical in diagnosing hepatitis B virus (HBV) infection. However, existing clinical detection technologies inevitably cause certain inaccuracies, leading to delayed or unwarranted treatment. Here, we introduce a label-free plasmonic biosensing method based on the thickness-sensitive plasmonic coupling, combined with supervised deep learning (DL) using neural networks. The strategy of utilizing neural networks to process output data can reduce the limit of detection (LOD) of the sensor and significantly improve the accuracy (from 93.1%-97.4% to 99%-99.6%). Compared with widely used emerging clinical technologies, our platform achieves accurate decisions with higher sensitivity in a short assay time (∼30 min). The integration of DL models considerably simplifies the readout procedure, resulting in a substantial decrease in processing time. Our findings offer a promising avenue for developing high-precision molecular detection tools for point-of-care (POC) applications.

High accuracy model for HBsAg loss based on longitudinal trajectories of serum qHBsAg throughout long-term antiviral therapy.

OBJECTIVE: Hepatitis B surface antigen (HBsAg) loss is the optimal outcome for patients with chronic hepatitis B (CHB) but this rarely occurs with currently approved therapies. We aimed to develop and validate a prognostic model for HBsAg loss on treatment using longitudinal data from a large, prospectively followed, nationwide cohort. DESIGN: CHB patients receiving nucleos(t)ide analogues as antiviral treatment were enrolled from 50 centres in China. Quantitative HBsAg (qHBsAg) testing was prospectively performed biannually per protocol. Longitudinal discriminant analysis algorithm was used to estimate the incidence of HBsAg loss, by integrating clinical data of each patient collected during follow-up. RESULTS: In total, 6792 CHB patients who had initiated antiviral treatment 41.3 (IQR 7.6-107.6) months before enrolment and had median qHBsAg 2.9 (IQR 2.3-3.3) log10IU/mL at entry were analysed. With a median follow-up of 65.6 (IQR 51.5-84.7) months, the 5-year cumulative incidence of HBsAg loss was 2.4%. A prediction model integrating all qHBsAg values of each patient during follow-up, designated GOLDEN model, was developed and validated. The AUCs of GOLDEN model were 0.981 (95% CI 0.974 to 0.987) and 0.979 (95% CI 0.974 to 0.983) in the training and external validation sets, respectively, and were significantly better than those of a single qHBsAg measurement. GOLDEN model identified 8.5%-10.4% of patients with a high probability of HBsAg loss (5-year cumulative incidence: 17.0%-29.1%) and was able to exclude 89.6%-91.5% of patients whose incidence of HBsAg loss is 0. Moreover, the GOLDEN model consistently showed excellent performance among various subgroups. CONCLUSION: The novel GOLDEN model, based on longitudinal qHBsAg data, accurately predicts HBsAg clearance, provides reliable estimates of functional hepatitis B virus (HBV) cure and may have the potential to stratify different subsets of patients for novel anti-HBV therapies.

HBcrAg values may predict virological and immunological responses to pegIFN-α in NUC-suppressed HBeAg-negative chronic hepatitis B.

OBJECTIVE: Selected populations of patients with chronic hepatitis B (CHB) may benefit from a combined use of pegylated interferon-alpha (pegIFN-α) and nucleos(t)ides (NUCs). The aim of our study was to assess the immunomodulatory effect of pegIFN-α on T and natural killer (NK) cell responses in NUC-suppressed patients to identify cellular and/or serological parameters to predict better T cell-restoring effect and better control of infection in response to pegIFN-α for a tailored application of IFN-α add-on. DESIGN: 53 HBeAg-negative NUC-treated patients with CHB were randomised at a 1:1 ratio to receive pegIFN-α-2a for 48 weeks, or to continue NUC therapy and then followed up for at least 6 months maintaining NUCs. Serum hepatitis B surface antigen (HBsAg) and hepatitis B core-related antigen (HBcrAg) levels as well as peripheral blood NK cell phenotype and function and HBV-specific T cell responses upon in vitro stimulation with overlapping HBV peptides were measured longitudinally before, during and after pegIFN-α therapy. RESULTS: Two cohorts of pegIFN-α treated patients were identified according to HBsAg decline greater or less than 0.5 log at week 24 post-treatment. PegIFN-α add-on did not significantly improve HBV-specific T cell responses during therapy but elicited a significant multispecific and polyfunctional T cell improvement at week 24 post-pegIFN-α treatment compared with baseline. This improvement was maximal in patients who had a higher drop in serum HBsAg levels and a lower basal HBcrAg values. CONCLUSIONS: PegIFN-α treatment can induce greater functional T cell improvement and HBsAg decline in patients with lower baseline HBcrAg levels. Thus, HBcrAg may represent an easily and reliably applicable parameter to select patients who are more likely to achieve better response to pegIFN-α add-on to virally suppressed patients.

Optimization of Mother-to-Child Hepatitis B Virus Prevention Program: Integration of Maternal Screening and Infant Post-Vaccination Serologic Testing.

BACKGROUND: Evaluation of the impact of a hepatitis B virus (HBV) prevention program that incorporates maternal antiviral prophylaxis on mother-to-child transmission (MTCT) is limited using real-world data. METHODS: We analyzed data on maternal HBV screening, neonatal immunization, and post-vaccination serologic testing (PVST) for hepatitis B surface antigen (HBsAg) among at-risk infants born to HBV carrier mothers from the National Immunization Information System during 2008-2022. Through linkage with the National Health Insurance Database, information on maternal antiviral therapy was obtained. Multivariate logistic regression was performed to explore MTCT risk in relation to infant-mother characteristics and prevention strategies. RESULTS: In total, 2 460 218 deliveries with maternal HBV status were screened. Between 2008 and 2022, the annual HBsAg and hepatitis B e antigen (HBeAg) seropositivity rates among native pregnant women decreased from 12.2% to 2.6% and from 2.7% to 0.4%, respectively (P for both trends < .0001). Among the 22 859 at-risk infants who underwent PVST, the MTCT rates differed between infants born to HBsAg-positive/HBeAg-negative and HBeAg-positive mothers (0.75% and 6.33%, respectively; P < .001). MTCT risk increased with maternal HBeAg positivity (odds ratio [OR], 9.29; 95% confidence interval [CI], 6.79-12.73) and decreased with maternal antiviral prophylaxis (OR, 0.28; 95% CI, .16-.49). For infants with maternal HBeAg positivity, MTCT risk was associated with mothers born in the immunization era (OR, 1.40; 95% CI, 1.17-1.67). CONCLUSIONS: MTCT was related to maternal HBeAg positivity and effectively prevented by maternal prophylaxis in the immunized population. At-risk infants born to maternal vaccinated cohorts might possibly pose further risk.

Hepatitis B Virus Reactivation after Switch to Cabotegravir/Rilpivirine in Patient with Low Hepatitis B Surface Antibody.

A patient in Japan with HIV began antiretroviral therapy because of acute hepatitis B virus (HBV) 15 years ago, with low hepatitis B surface antibody, and experienced breakthrough HBV reactivation 4 months after switching from bictegravir/emtricitabine/tenofovir alafenamide to cabotegravir/rilpivirine. An immune escape mutation, E164V, was identified in the isolated HBV DNA.

Prognostic and therapeutic potential of imbalance between PD-1+CD8 and ICOS+Treg cells in advanced HBV-HCC.

Over 50% of patients with hepatitis B virus-associated hepatocellular carcinoma (HBV-HCC) are diagnosed at an advanced stage, which is characterized by immune imbalance between CD8+ T cells and regulatory T (Treg) cells that accelerates disease progression. However, there is no imbalance indicator to predict clinical outcomes. Here, we show that the proportion of CD8+ T cells decreases and Treg cells increases in advanced HBV-HCC patients. During this stage, CD8+ T cells and Treg cells expressed the coinhibitory molecule PD-1 and the costimulatory molecule ICOS, respectively. Additionally, the ratio between PD-1+CD8 and ICOS+Tregs showed significant changes. Patients were further divided into high- and low-ratio groups: PD-1+CD8 and ICOS+Tregs high- (PD-1/ICOShi) and low-ratio (PD-1/ICOSlo) groups according to ratio median. Compared with PD-1/ICOSlo patients, the PD-1/ICOShi group had better clinical prognosis and weaker CD8+ T cells exhaustion, and the T cell-killing and proliferation functions were more conservative. Surprisingly, the small sample analysis found that PD-1/ICOShi patients exhibited a higher proportion of tissue-resident memory T (TRM) cells and had more stable killing capacity and lower apoptosis capacity than PD-1/ICOSlo advanced HBV-HCC patients treated with immune checkpoint inhibitors (ICIs). In conclusion, the ratio between PD-1+CD8 and ICOS+Tregs was associated with extreme immune imbalance and poor prognosis in advanced HBV-HCC. These findings provide significant clinical implications for the prognosis of advanced HBV-HCC and may serve as a theoretical basis for identifying new targets in immunotherapy.

Assessing vaccine-induced immunity against pneumococcus, hepatitis A and B over a 9-year follow-up in pediatric liver transplant recipients: A nationwide retrospective study.

Pediatric liver transplant recipients are particularly at risk of infections. The most cost-effective way to prevent infectious complications is through vaccination, which can potentially prevent infections due to hepatitis B (HBV) virus, hepatitis A virus (HAV), and invasive pneumococcal diseases. Here, we performed a retrospective analysis of HBV, HAV, and pneumococcal immunity in pediatric liver transplant recipients between January 1, 2009, and December 31, 2020, to collect data on immunization and vaccine serology. A total of 94% (58/62) patients had available vaccination records. At transplant, 90% (45/50) were seroprotected against HBV, 63% (19/30) against HAV, and 78% (18/23) had pneumococcal immunity, but immunity against these 3 pathogens remained suboptimal during the 9-year follow-up. A booster vaccine was administered to only 20% to 40% of patients. Children who had received >4 doses of HBV vaccine and > 2 doses of HAV vaccine pretransplant displayed a higher overall seroprotection over time post-solid organ transplant. Our findings suggest that a serology-based approach should be accompanied by a more systematic follow-up of vaccination, with special attention paid to patients with an incomplete vaccination status at time of transplant.