CARs derived from broadly neutralizing, human monoclonal antibodies identified by single B cell sorting target hepatitis B virus-positive cells.

To design new CARs targeting hepatitis B virus (HBV), we isolated human monoclonal antibodies recognizing the HBV envelope proteins from single B cells of a patient with a resolved infection. HBV-specific memory B cells were isolated by incubating peripheral blood mononuclear cells with biotinylated hepatitis B surface antigen (HBsAg), followed by single-cell flow cytometry-based sorting of live, CD19+ IgG+ HBsAg+ cells. Amplification and sequencing of immunoglobulin genes from single memory B cells identified variable heavy and light chain sequences. Corresponding immunoglobulin chains were cloned into IgG1 expression vectors and expressed in mammalian cells. Two antibodies named 4D06 and 4D08 were found to be highly specific for HBsAg, recognized a conformational and a linear epitope, respectively, and showed broad reactivity and neutralization capacity against all major HBV genotypes. 4D06 and 4D08 variable chain fragments were cloned into a 2nd generation CAR format with CD28 and CD3zeta intracellular signaling domains. The new CAR constructs displayed a high functional avidity when expressed on primary human T cells. CAR-grafted T cells proved to be polyfunctional regarding cytokine secretion and killed HBV-positive target cells. Interestingly, background activation of the 4D08-CAR recognizing a linear instead of a conformational epitope was consistently low. In a preclinical model of chronic HBV infection, murine T cells grafted with the 4D06 and the 4D08 CAR showed on target activity indicated by a transient increase in serum transaminases, and a lower number of HBV-positive hepatocytes in the mice treated. This study demonstrates an efficient and fast approach to identifying pathogen-specific monoclonal human antibodies from small donor cell numbers for the subsequent generation of new CARs.

Impact of Hepatitis B Surface and Core Antibody Levels on Hepatitis B Virus Reactivation.

Hepatitis B virus reactivation (HBV-R) is a serious complication that can occur in patients with resolved HBV infection during cancer chemotherapy. We examined the levels of HBV surface antibody (HBsAb) and HBV core antibody (HBcAb) to assess the incidence of HBV-R in cancer patients including hematopoietic stem cell transplantation (HSCT) and rituximab administration. This retrospective cohort study included 590 patients with resolved HBV infection. The incidence of HBV-R was evaluated 761.5 (range, 90-3898) days after the inititiation of chemotherapy. Of the patients, 13 (2.2%) developed HBV-R after the start of chemotherapy. All 13 patients exhibited lower HBsAb (<100 mIU/mL) levels at baseline. A higher level of HBcAb (≥100 cut off index (C.O.I.)) was a possible risk factor for HBV-R as well as HSCT and rituximab administration. The simultaneous presence of HBsAb <100 mIU/mL and HBcAb ≥100 C.O.I. increased the risk of HBV-R by 18.5%. Patients treated with rituximab were at a higher risk of HBV-R (18.4%) despite having HBcAb <100 C.O.I. Our results suggest that assessment of HBsAb and HBcAb levels prior to the chemotherapy is important for identifying patients at high risk of HBV-R, especially in solid cancers without HSCT and rituximab administration.

Dismantling Barriers to Hepatitis B and Delta Screening, Prevention, and Linkage to Care among the PWUD Community in Philadelphia.

The prevalence of hepatitis B and delta viruses (HBV/HDV) among people who use drugs (PWUD) remains largely unknown. In the context of one Philadelphia-based harm reduction organization (HRO), this study aimed to assess HBV/HDV prevalence and facilitate linkage to care. Participants completed a demographic HBV/HDV risk factor survey and were screened for HBV and reflexively for HDV if positive for HBV surface antigen or isolated core antibody. Fisher's exact tests and regression were used to understand relationships between risks and HBV blood markers. Of the 498 participants, 126 (25.3%) did not have hepatitis B immunity, 52.6% had been vaccinated against HBV, and 17.9% had recovered from a past infection. Eleven (2.2%) participants tested positive for isolated HBV core antibody, 10 (2.0%) for HBV surface antigen, and one (0.2%) for HDV antibody. History of incarceration was associated with current HBV infection, while transactional sex and experience of homelessness were predictive of previous exposure. This study found high rates of current and past HBV infection, and a 10% HBV/HDV co-infection rate. Despite availability of vaccine, one quarter of participants remained vulnerable to infection. Findings demonstrate the need to improve low-threshold HBV/HDV screening, vaccination, and linkage to care among PWUD. The study also identified gaps in the HBV/HDV care cascade, including lack of point-of-care diagnostics and lack of support for HROs to provide HBV services.

Interferon-γ+ Th1 activates intrahepatic resident memory T cells to promote HBsAg loss by inducing M1 macrophage polarization.

The immune mechanism underlying hepatitis B surface antigen (HBsAg) loss, particularly type I inflammatory response, during pegylated interferon-α (PEG-IFN) therapy remains unclear. In this study, we aimed to elucidate such immune mechanisms. Overall, 82 patients with chronic hepatitis B (CHB), including 41 with HBsAg loss (cured group) and 41 uncured patients, received nucleos(t)ide analogue and PEG-IFN treatments. Blood samples from all patients, liver tissues from 14 patients with CHB, and hepatic perfusate from 8 liver donors were collected for immune analysis. Jurkat, THP-1 and HepG2.2.15 cell lines were used in cell experiments. The proportion of IFN-γ+ Th1 cells was higher in the cured group than in the uncured group, which was linearly correlated with HBsAg decline and alanine aminotransferase (ALT) levels during treatment. However, CD8+ T cells were weakly associated with HBsAg loss. Serum and intrahepatic levels of Th1 cell-associated chemokines (C-X-C motif chemokine ligand [CXCL] 9, CXCL10, CXCL11, IFN-γ) were significantly lower in the cured patients than in patients with a higher HBsAg quantification during therapy. Serum from cured patients induced more M1 (CD68+CD86+ macrophage) cells than that from uncured patients. Patients with chronic HBV infection had significantly lower proportions of CD86+ M1 and CD206+ M2 macrophages in their livers than healthy controls. M1 polarization of intrahepatic Kupffer cells promoted HBsAg loss by upregulating the effector function of tissue-resident memory T cells with increased ALT levels. IFN-γ+ Th1 activates intrahepatic resident memory T cells to promote HBsAg loss by inducing M1 macrophage polarization.

The orientation of CpG conjugation on aluminum oxyhydroxide nanoparticles determines the immunostimulatory effects of combination adjuvants.

In subunit vaccines, aluminum salts (Alum) are commonly used as adjuvants, but with limited cellular immune responses. To overcome this limitation, CpG oligodeoxynucleotides (ODNs) have been used in combination with Alum. However, current combined usage of Alum and CpG is limited to linear mixtures, and the underlying interaction mechanism between CpG and Alum is not well understood. Thus, we propose to chemically conjugate Alum nanoparticles and CpG (with 5' or 3' end exposed) to design combination adjuvants. Our study demonstrates that compared to the 3'-end exposure, the 5'-end exposure of CpG in combination adjuvants (Al-CpG-5') enhances the activation of bone-marrow derived dendritic cells (BMDCs) and promotes Th1 and Th2 cytokine secretion. We used the SARS-CoV-2 receptor binding domain (RBD) and hepatitis B surface antigen (HBsAg) as model antigens to demonstrate that Al-CpG-5' enhanced antigen-specific antibody production and upregulated cytotoxic T lymphocyte markers. Additionally, Al-CpG-5' allows for coordinated adaptive immune responses even at lower doses of both CpG ODNs and HBsAg antigens, and enhances lymph node transport of antigens and activation of dendritic cells, promoting Tfh cell differentiation and B cell activation. Our novel Alum-CPG strategy points the way towards broadening the use of nanoadjuvants for both prophylactic and therapeutic vaccines.

Effect of S-region mutations on HBsAg in HBsAg-negative HBV-infected patients.

BACKGROUND: Occult HBV infection (OBI) is a special form of hepatitis B virus (HBV) infection that may cause Liver cirrhosis and hepatocellular carcinoma, causing significant harm to patients. Given the insidious nature of OBI, it is usually not easy to be detected. Most of the samples currently studied are concentrated on blood donors, however, patients in this special state have not been fully studied. This project aimed to study the effect of HBV S region mutations on HBsAg in patients with clinical OBI. METHODS: Collect 107 HBsAg-/HBV DNA + blood samples from Beijing Youan Hospital, Capital Medical University from August 2022 to April 2023. Next, the successfully extracted and amplified HBV DNA S regions were sequenced. Construct mutant plasmids to verify the cell function of the high-frequency mutation sites and explore the possible molecular mechanism. RESULTS: Sixty-eight HBsAg-negative samples were sequenced, revealing high-frequency amino acid substitution sites in the HBV S protein, including immune escape mutations (i.e., sY100C、sK122R、sI126T、sT131P、and sS114T) and TMD (Transmembrane domain) region substitutions (i.e., sT5A、sG10D、sF20S、and sS3N). We constructed a portion of the mutant plasmids and found that sT5A, sF20S, sG10D, sS3N, sI68T, and sI126T single point mutations or combined mutations may decrease HBsAg expression or change the antigenicity of HBsAg leading to detection failure. CONCLUSIONS: HBsAg-negative patients may show various mutations and amino acid replacement sites at high frequency in the HBV S-region, and these mutations may lead to undetectable Hepatitis B surface antigen (HBsAg), HBsAg antigenic changes or secretion inhibition.

Isolated Hepatitis B Core Antibody Positivity and Long-Term Liver-Related Mortality in Korea: A Cohort Study.

INTRODUCTION: Whether isolated hepatitis B core antibody (anti-HBc) positivity is a risk factor for long-term liver-related outcomes in hepatitis B virus (HBV)-endemic areas remains unclear. We aimed to investigate liver-related and liver cancer mortality of isolated anti-HBc positivity in Korean adults. METHODS: A cohort study comprised 609,299 Korean adults who underwent hepatitis B serologic markers, as a part of health examination. Liver-related and liver cancer mortality were determined using the National Death Records. RESULTS: During a median follow-up of 9.0 years (interquartile range, 5.5-13.7 years), 554 liver-related deaths were identified (liver-related mortality, 9.6 cases per 10 5 person-years). The prevalence of isolated anti-HBc positivity was 3.8% (n = 23,399) and was age-dependent. After adjustment for age, sex, and other confounders, hazard ratios (95% confidence interval) for liver-related mortality in isolated anti-HBc-positive and hepatitis B surface antigen-positive subjects compared with HBV-unexposed subjects were 1.69 (1.22-2.33) and 27.02 (21.45-34.04), respectively. These associations were pronounced in the analyses using liver cancer mortality as an outcome. Among isolated anti-HBc-positive patients, the risks of liver-related and liver cancer mortality were significantly higher in those with high fibrosis-4 scores compared with patients unexposed to HBV with the multivariable-adjusted hazard ratios (95% confidence interval) of 15.59 (9.21-26.37) and 72.66 (36.96-142.86), respectively. DISCUSSION: In this cohort of Korean adults, isolated anti-HBc positivity was associated with an increased risk of liver-related and liver cancer mortality, especially when accompanied by a high fibrosis score. Isolated anti-HBc positivity may be an independent risk factor for liver-related outcomes, especially in high-endemic areas.

O-glycosylated HBsAg peptide can induce specific antibody neutralizing HBV infection.

BACKGROUND: Hepatitis B virus (HBV), which causes hepatitis, liver cirrhosis, and hepatocellular carcinoma, is a global human health problem. HBV contains three envelope proteins, S-, M-, and L-hepatitis B surface antigen (HBsAg). We recently found that O-glycosylated M-HBsAg, reactive with jacalin lectin, is one of the primary components of HBV DNA-containing virus particles. Thus, we aimed to analyze and target the glycosylation of HBsAg. METHODS: HBsAg prepared from the serum of Japanese patients with HBV were analyzed using mass spectrometry. The glycopeptide modified with O-glycan was generated and used for immunization. The specificity of the generated antibody and the HBV infection inhibition activity was examined. RESULTS: Mass spectrometry analysis revealed that T37 and/or T38 on M-HBsAg of genotype C were modulated by ±NeuAc(α2,3)Gal(ß1,3)GalNAc. Chemically and enzymatically synthesized O-glycosylated peptide (Glyco-PS2) induced antibodies that recognize mainly PreS2 in M-HBsAg not in L-HBsAg, whereas the non-glycosylated peptide (PS2) induced antisera recognizing L-HBsAg but not O-glycosylated M-HBsAg. The removal of O-glycan from M-HBsAg partly decreased the reactivity of the Glyco-PS2 antibody, suggesting that peptide part was also recognized by the antibody. The antibody further demonstrated the inhibition of HBV infection in human hepatic cells in vitro. CONCLUSIONS: Glycosylation of HBsAg occurs differently in different HBsAgs in a site-specific manner. The new Glyco-PS2 antibody, recognizing O-glycosylated M-HBsAg of genotype C, could inhibit HBV infection. GENERAL SIGNIFICANCE: The detailed analysis of HBsAg identified different glycosylations of HBV surface. The glycosylated peptide based on mass spectrometry analysis showed higher potential to induce functional antibody against HBV.

[Sero-epidemiological characteristics of the hepatitis D virus infection among hepatitis B virus infected-patients at a single center in Xinjiang region].

Objective: To investigate the sero-epidemiological characteristics of the hepatitis D virus (HDV) infection among hepatitis B virus (HBV)-infected patients in Xinjiang region. Methods: A single-center cross-sectional analysis method was used to select 264 cases of hepatitis B virus infection who were hospitalized in the Center for Infectious Diseases and Liver Diseases of the First Affiliated Hospital of Xinjiang Medical University from August 2021 to January 2022. All patients were tested for HDV Ag, HDV IgM, HDV IgG, and HDV RNA. The infection status of hepatitis D virus was analyzed by grouping according to their clinical type, HBV viral load, and HBsAg level. A paired t-test was used for data with measurement data conforming to normal distribution. A paired rank sum test was used for data that did not conform to normal distribution before and after treatment. Results: A total of 36 cases (13.64%) and 26 cases (9.85%) were positive for HDV serological markers and HDV RNA. According to clinical type grouping, the positive rates of HDV serum markers in patients with chronic hepatitis B, hepatitis B-related cirrhosis, liver cancer, and liver failure were 13.46%, 12.43%, and 20.83%, respectively, and there was no statistically significant difference among the three groups (χ2=0.86, P=0.649). The positive rates of HDV RNA were 11.54%, 8.11%, and 20.83%, respectively, and there was no statistically significant difference among the three groups (χ2=4.015, P=0.134). According to HBV viral load grouping, the positive rates of HDV serum markers among patients with viral loads <20, 20-2 000, and >2 000 IU/ml were 17.15%, 7.81%, and 6.67%, respectively, and the difference was not statistically significant among the three groups (χ2=4.846, P=0.089). The positive rates of HDV RNA were 9.47%, 10.94%, and 10%, respectively, and the difference was not statistically significant among the three groups (χ2=0.113, P=0.945). According to HBsAg level grouping, the positive rates of HDV serum markers in HBsAg<0.05, 0.05~250, and >250 IU/ml were 14.29%, 16.67%, and 10.85%, respectively, and there was no statistically significance between the three groups (χ2=1.745, P=0.418). The positive rates of HDV RNA were 4.76%, 8.77%, and 11.63%, respectively, and there was no statistically significant difference among the three groups (χ2=1.221, P=0.543). Clinical outcome, disease course, HBV DNA, serological markers of viral hepatitis, routine blood test, biochemical indicators, coagulation function, and other laboratory indicators were compared between HDV serum marker and/or nucleic acid positive and negative patients, and there was no statistically significant difference (P>0.05). Conclusion: The positive rate of HDV serological markers and HDV RNA is 13.64% and 9.85%, respectively, at a single center in the Xinjiang region, and there is still a high HDV infection rate among the HBV-infected patients with low levels of viral load and HBsAg.

The Impact of HBV Quasispecies Features on Immune Status in HBsAg+/HBsAb+ Patients With HBV Genotype C Using Next-Generation Sequencing.

Background: This study aimed to explore the molecular mechanism of the coexistence of hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody (HBsAb) serological pattern via intensive characterization of HBV s gene in both chronic hepatitis B (CHB) and hepatocellular carcinoma (HCC) patients. Method: A total of 73 HBsAg+/HBsAb+ patients (CHB = 36, HCC = 37) and 96 HBsAg+/HBsAb- patients (CHB = 47, HCC = 49) were enrolled from 13 medical centers in China. The sequence features were elaborated based on the combination of next-generation sequencing (NGS) and multidimensional bioinformatics analysis. Results: The 16 high-frequency missense mutations, changes of stop codon mutation, clustering, and random forest models based on quasispecies features demonstrated the significant discrepancy power between HBsAg+/HBsAb+ and HBsAg+/HBsAb- in CHB and HCC, respectively. The immunogenicity for cytotoxic T lymphocyte (CTL) epitope Se and antigenicity for the major hydrophilic region (MHR) were both reduced in HBsAg+/HBsAb+ patients (CTL Se: p < 0.0001; MHR: p = 0.0216). Different mutation patterns were observed between HBsAg+/HBsAb+ patients with CHB and with HCC. Especially, mutations in antigenic epitopes, such as I126S in CHB and I126T in HCC, could impact the conformational structure and alter the antigenicity/immunogenicity of HBsAg. Conclusion: Based on NGS and bioinformatics analysis, this study indicates for the first time that point mutations and quasispecies diversities of HBV s gene could alter the MHR antigenicity and CTL Se immunogenicity and could contribute to the concurrent HBsAg+/HBsAb+ with different features in HCC and CHB. Our findings might renew the understanding of this special serological profile and benefit the clinical management in HBV-related diseases.

Identification and Mapping of HBsAg Loss-Related B-Cell Linear Epitopes in Chronic HBV Patients by Peptide Array.

Identification of immunogenic targets against hepatitis B virus (HBV)-encoded proteins will provide crucial advances in developing potential antibody therapies. In this study, 63 treatment-naïve patients with chronic HBV infection and 46 patients who achieved hepatitis B surface antigen loss (sAg loss) following antiviral treatment were recruited. Moreover, six patients who transitioned from the hepatitis B e antigen-positive chronic infection phase (eAg+CInf) to the hepatitis phase (eAg+CHep) were enrolled from real-life clinical practice. Additionally, telbivudine-treated eAg+CHep patients and relapsers or responders from an off-treatment cohort were longitudinally studied. The frequencies and function of B cells were assessed by flow cytometry. We devised a peptide array composed of 15-mer overlapping peptides of HBV-encoded surface (S), core (C), and polymerase (P) proteins and performed a screening on B-cell linear epitopes with sera. Naïve B cells and plasmablasts were increased, whereas total memory, activated memory (AM), and atypical memory (AtM) B cells were reduced in sAg- patients compared with sAg+ patients. Importantly, longitudinal observations found that AtM B cells were associated with successful treatment withdrawal. Interestingly, we identified six S-specific dominant epitopes (S33, S34, S45, S76, S78, and S89) and one C-specific dominant epitope (C37) that reacted with the majority of sera from sAg- patients. Of note, more B-cell linear epitopes were detected in CHep patients with alanine aminotransferase (ALT) flares than in nonflare CInf patients, and five B-cell linear epitopes (S4, S5, S10, S11, and S68) were overwhelmingly recognized by ALT flare patients. The recognition rates of epitopes on C and P proteins were significantly increased in CHep patients relative to CInf patients. Strikingly, a statistically significant elevation in the number of positive epitopes was observed when ALT nonflare patients shifted into the flare phase. Moreover, S76 identified at baseline was confirmed to be associated with a complete response after 48 weeks of telbivudine therapy. Taken together, we identified several functional cure-related B-cell linear epitopes of chronic HBV infection, and these epitopes may serve as vaccine candidates to elicit neutralizing antibodies to treat HBV infection.

Prevalence and associated risk factors for hepatitis B and C viruses among refugee populations living in Mahama, Rwanda: A cross-sectional study.

INTRODUCTION: As part of the integration of refugees into Rwanda's national hepatitis C elimination agenda, a mass screening campaign for hepatitis B (HBV) and hepatitis C (HCV) was conducted among Burundian refugees living in Mahama Camp, Eastern Rwanda. This cross-sectional survey used data from the screening campaign to report on the epidemiology of viral hepatitis in this setting. METHODS: Rapid diagnostic tests (RDTs) were used to screen for hepatitis B surface antigen (HBsAg) and hepatitis C antibody (anti-HCV) among people of ≥15years old. We calculated seroprevalence for HBsAg and anti-HCV by age and sex and also calculated age-and-sex adjusted risk ratios (ARR) for other possible risk factors. RESULTS: Of the 26,498 screened refugees, 1,006 (3.8%) and 297 (1.1%) tested positive for HBsAg and Anti-HCV, respectively. HBsAg was more prevalent among men than women and most common among people 25-54 years old. Anti-HCV prevalence increased with age group with no difference between sexes. After adjusting for age and sex, having a household contact with HBsAg was associated with 1.59 times higher risk of having HBsAg (95% CI: 1.27, 1.99) and having a household contact with anti-HCV was associated with 3.66 times higher risk of Anti-HCV (95% CI: 2.26, 5.93). Self-reporting having HBV, HCV, liver disease, or previously screened for HBV and HCV were significantly associated with both HBsAg and anti-HCV, but RDT-confirmed HBsAg and anti-HCV statuses were not associated with each other. Other risk factors for HBsAg included diabetes (ARR = 1.97, 95% CI: 1.08, 3.59) and family history of hepatitis B (ARR = 1.32, 95% CI: 1.11, 1.56) and for anti-HCV included heart disease (ARR = 1.91, 95% CI: 1.30, 2.80) and history of surgery (ARR = 1.70, 95% CI: 1.24, 2.32). CONCLUSION: Sero-prevalence and risks factors for hepatitis B and C among Burundian were comparable to that in the Rwandan general population. Contact tracing among household members of identified HBsAg and anti-HCV infected case may be an effective approach to targeted hepatitis screening given the high risk among self-reported cases. Expanded access to voluntary testing may be needed to improve access to hepatitis treatment and care in other refugee settings.

Follicular Helper T (TFH) Cell Targeting by TLR8 Signaling For Improving HBsAg-Specific B Cell Response In Chronic Hepatitis B Patients.

Identifying signaling pathways that induce B cell response can aid functional cure strategies for chronic hepatitis B infection (CHB). TLR8 activation with ssRNA was shown to enhance follicular helper T cell (TFH) function leading to improved B cell responses in vitro. We investigated whether this mechanism can rescue an exhausted immune response in CHB infection. Effect of TLR8 agonism on supporting cytokines and TFH and B cells were evaluated using ex vivo and in vitro assays. The ability of an oral TLR8 agonist to promote TFH and B cell response was tested in samples from phase 1b clinical trial. TLR8 agonism induced TFH polarizing cytokine IL-12 in monocytes. Treatment of peripheral blood mononuclear cells (PBMCs) from CHB patients with TLR8 agonists induced cytokine IL-21 by TFH cells with enhanced IL-21+BCL-6+ and ICOS+BCL-6+ co-expression. Mechanistically, incubation of isolated naïve CD4+ T cells with TLR8 triggered monocytes resulted in their differentiation into IL-21+ICOS+BCL-6+ TFH in an IL-12 dependent manner. Furthermore, co-culture of these IL-21 producing TFH with autologous naïve B cells led to enhanced memory (CD19+CD27+) and plasma B cell generation (CD19+CD27++CD38+) and IgG production. Importantly, in TFH from CHB patients treated with an oral TLR8 agonist, HBsAg-specific BCL-6, ICOS, IL-21 and CD40L expression and rescue of defective activation induced marker (AIM) response along with partial restoration of HBsAg-specific B cell ELISPOT response was evident. TLR8 agonism can thus enhance HBV-specific B cell responses in CHB patients by improving monocyte-mediated TFH function and may play a role in achieving HBV functional cure.

Abatacept is second to rituximab at risk of HBsAg reverse seroconversion in patients with rheumatic disease.

BACKGROUND: Hepatitis B surface antigen (HBsAg) reverse seroconversion (RS) can happen in patients with rheumatoid arthritis (RA) with resolved hepatitis B (RHB) undergoing biological disease-modifying antirheumatic drugs (bDMARDs). But the incidence and risk factors need to be delineated. METHODS: From 2003 to 2019, 1937 patients with RA with available HBsAg and antibody to hepatitis B virus (HBV) core antigen data were retrospectively reviewed, and 489 patients with RHB undergoing bDMARDs treatment were identified. Factors associated with HBsAg RS were analysed. RESULTS: During 67 828 person-months of follow-up, 27 (5.5%) patients developed HBsAg RS after bDMARD treatment. As compared with those without HBsAg RS, patients with HBsAg RS were older, had lower frequency of antibody to HBsAg (anti-HBs), and lower baseline anti-HBs levels. In multivariate analysis, rituximab, abatacept and baseline negative for anti-HBs were the independent risk factors for HBsAg RS (adjusted HR: 87.76, 95% CI: 11.50 to 669.73, p<0.001; adjusted HR: 60.57, 95% CI: 6.99 to 525.15, p<0.001; adjusted HR: 5.15, 95% CI: 2.21 to 12.02, p<0.001, respectively). The risk of HBsAg RS was inversely related to the level of anti-HBs. Both rituximab and abatacept might result in anti-HBs loss, and abatacept had a cumulative incidence of HBsAg RS of 35.4%-62.5% in patients with low titers or negative of anti-HBs. CONCLUSIONS: Not only rituximab, but also abatacept has a high risk of HBV reactivation in patient with RA with RHB. Anti-HBs positivity cannot confer HBV reactivation-free status if the anti-HBs levels are not high enough for patients with RHB on rituximab and abatacept treatment.

SIGLEC-3 (CD33) serves as an immune checkpoint receptor for HBV infection.

Chronic hepatitis B (CHB) infection is rarely eradicated by current antiviral nucleos(t)ide analogues. We found that α2,6-biantennary sialoglycans of HBV surface antigen (HBsAg) bound human SIGLEC-3 (CD33) by IP and ELISA, and the binding affinity between SIGLEC-3 and α2,6-biantennary sialoglycans was determined by biolayer interferometry (equilibrium dissociation constant [KD]: 1.95 × 10-10 ± 0.21 × 10-10 M). Moreover, HBV activated SIGLEC-3 on myeloid cells and induced immunosuppression by stimulating immunoreceptor tyrosine-based inhibitory motif phosphorylation and SHP-1/-2 recruitment via α2,6-biantennary sialoglycans on HBsAg. An antagonistic anti-SIGLEC-3 mAb reversed this effect and enhanced cytokine production in response to TLR-7 agonist GS-9620 in PBMCs from CHB patients. Moreover, anti-SIGLEC-3 mAb alone was able to upregulate the expression of molecules involved in antigen presentation, such as CD80, CD86, CD40, MHC-I, MHC-II, and PD-L1 in CD14+ cells. Furthermore, SIGLEC-3 SNP rs12459419 C, which expressed a higher amount of SIGLEC-3, was associated with increased risk of hepatocellular carcinoma (HCC) in CHB patients (HR: 1.256, 95% CI: 1.027-1.535, P = 0.0266). Thus, blockade of SIGLEC-3 is a promising strategy to reactivate host immunity to HBV and lower the incidence of HCC in the CHB patient population.

Genetic polymorphisms of regulatory T cell-related genes modulate systemic inflammation induced by viral hepatitis.

Viral hepatitis is a devastating disease with the risk for cirrhosis and carcinogenicity. Regulatory T cells (Tregs) play important roles in the disease course of viral hepatitis via maintaining the balance between overt-immune responses and viral replications. We hypothesized that genetic polymorphisms of Treg-related genes, such as interleukin-2, transforming growth factor-ß 1 (TGF-ß1), forkhead box P3 (FOXP3), and adenylyl cyclase type 9 modulate the hosts' immune regulation under circumstances of viral hepatitis. We examined the effect of five single nucleotide polymorphisms (SNPs) of Treg-related genes on the levels of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), alanine aminotransferase, and non-invasive hepatic fibrosis marker (Fibrosis-4 index) in a total of 138 participants with viral hepatitis. The rs1800469 (a TGF-ß1 SNP) GG genotype is associated with higher serum CRP levels, and the rs3761547 (a FOXP3 SNP) C allele in the females is associated with higher ESR levels. Besides, female participants carrying the rs3761547 C allele had a significantly higher Fibrosis-4 (FIB-4) index than the females carrying the TT genotype, while the rs3761547 C allele had the opposite effect in males. With linear-regression moderation analysis, we found that sex moderated the impact of the FOXP3 SNP on the levels of FIB-4, whereas the FOXP3 SNP caused the opposite effect between males and females on the severity of hepatic fibrosis. These results provide evidence for the participation of TGF-ß1 and FOXP3 in the inflammatory responses associated with viral hepatitis, where FOXP3 function may be moderated by sex.

Prevalence of HBV Infection, Vaccine-Induced Immunity, and Susceptibility Among At-Risk Populations: US Households, 2013-2018.

BACKGROUND AND AIMS: In the USA, HBV is one of the leading causes of chronic liver disease and cirrhosis and is a major cause of liver cancer. We aimed to estimate the prevalence of past and present HBV infection, susceptibility to HBV infection, and vaccine-induced immunity to hepatitis B among the US population during 2013-2018. APPROACH AND RESULTS: Prevalence estimates and 95% CIs were analyzed using 2013-2018 data from the National Health and Nutrition Examination Survey. Serologic testing among noninstitutionalized persons aged ≥ 6 years was used for classifying persons as total hepatitis B core antibody (anti-HBc), indicative of current or previous (ever having had) HBV infection; HBsAg, indicative of current HBV infection; and antibody to ABsAg (anti-HBs), indicative of immunity attributable to hepatitis B vaccination. Persons who tested negative for anti-HBc, HBsAg, and anti-HBs were considered susceptible to HBV infection. Non-US-born residents accounted for 69.1% of the population with chronic HBV infection and were 9.1 times more likely to be living with chronic hepatitis B, compared with US-born persons. Among adults aged ≥ 25 years who resided in US households, an estimated 155.8 million persons (or 73.4%) were susceptible to HBV infection, and an estimated 45.4 million had vaccine-induced immunity to hepatitis B. Men who have sex with men (MSM) were 3.6 times more likely to have ever been infected with HBV; however, MSM were just as likely to have vaccine-induced immunity to hepatitis B as non-MSM. CONCLUSION: Despite increasing immune protection among young persons vaccinated after birth, the estimated prevalence of persons living with chronic hepatitis B in the USA has remained unchanged at 0.3% since 1999.

Homeostatic regulation of T follicular helper and antibody response to particle antigens by IL-1Ra of medullary sinus macrophage origin.

Hepatitis B virus (HBV) vaccines are composed of surface antigen HBsAg that spontaneously assembles into subviral particles. Factors that impede its humoral immunity in 5% to 10% of vaccinees remain elusive. Here, we showed that the low-level interleukin-1 receptor antagonist (IL-1Ra) can predict antibody protection both in mice and humans. Mechanistically, murine IL-1Ra-inhibited T follicular helper (Tfh) cell expansion and subsequent germinal center (GC)-dependent humoral immunity, resulting in significantly weakened protection against the HBV challenge. Compared to soluble antigens, HBsAg particle antigen displayed a unique capture/uptake and innate immune activation, including IL-1Ra expression, preferably of medullary sinus macrophages. In humans, a unique polymorphism in the RelA/p65 binding site of IL-1Ra enhancer associated IL-1Ra levels with ethnicity-dependent vaccination outcome. Therefore, the differential IL-1Ra response to particle antigens probably creates a suppressive milieu for Tfh/GC development, and neutralization of IL-1Ra would resurrect antibody response in HBV vaccine nonresponders.