A Real-world Prospective Study of Mother-to-child Transmission of HBV in China Using a Mobile Health Application (Shield 01).

Background and Aims: The World Health Organization (WHO) Western Pacific Region set a target of eliminating mother-to-child transmission (MTCT) of hepatitis B virus (HBV) by 2030. To assess the feasibility of this target in China, we carried out an epidemiological study to investigate the status quo of MTCT in the real-world setting. Methods: One thousand and eight hepatitis B surface antigen-positive pregnant women were enrolled at 10 hospitals. Immunoprophylaxis was administered to infants. In addition, mothers with HBV DNA level >2,000,000 IU/mL were advised to initiate antiviral therapy during late pregnancy. A health application called SHIELD was used to manage the study. Results: Nine hundred and five of the enrolled mothers, with 924 infants, completed the follow-up. Birth-dose hepatitis B vaccine and hepatitis B immunoglobulin were received by 99.7% and 99.7% of infants, respectively, within 24 h after birth. There were 446 mothers who received antiviral therapy, including 72.3% of the mothers with HBV DNA level >2,000,000 IU/mL and 21.0% of the mothers with HBV DNA level <2,000,000 IU/mL. Eight infants were infected with HBV. The overall rate of MTCT was 0.9%. Birth defects were rare (0.5% among infants with maternal antiviral exposure versus 0.7% among infants without exposure; p=1.00). Conclusions: The MTCT rate was lower than the WHO Western Pacific Region elimination MTCT target in this real-world study, indicating that a comprehensive management composed of immunoprophylaxis to infants and antiviral prophylaxis to mothers may be a feasible strategy to achieve the 2030 WHO elimination goal.

Dynamic changes of T cell receptor repertoires in patients with hepatitis B virus-related acute-on-chronic liver failure.

BACKGROUND AND AIMS: T cell-mediated immune injury plays a critical role in the pathogenesis of hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF). Given the high short-term mortality and crucial role of T cells in the disease progression, it is necessary to investigate the dynamics of T cell clones during HBV-ACLF. The aim of this study was to longitudinally investigate dynamic changes in the composition and perturbation of T cell receptor ß (TCRß) chain repertoires and to determine whether TCR repertoire characteristics were associated with HBV-ACLF patient outcomes. METHODS: Peripheral blood mononuclear cells (PBMCs) were collected at two time points from 5 HBV-ACLF patients. Global CD4+ and CD8+ T cells were sorted using magnetic beads. TCRß complementarity-determining region 3 was analyzed by unbiased high-throughput sequencing. RESULTS: During HBV-ACLF, there was a significant decrease in the diversity of T cell repertoires and an increase in proportion of the most 100 abundant clonotypes of CD8 T cells but not CD4. Decreased CD8 repertoire diversity was positively correlated with the reduction of the Model for End-Stage Liver Disease (MELD) score. CONCLUSIONS: There was significant clonal expansion in CD8 but not in CD4 T cell repertoires in HBV-ACLF patients during disease progression. Patients with greater clonal expansions in CD8 T cell repertoires may have better outcomes. CD8 TCRß repertoire diversity may serve as a potential predictive marker for disease outcome.

Duck HBV DNA copy numbers in isolated hepatocyte nuclei vary dramatically and decline during entecavir therapy.

BACKGROUND: We aimed to develop a quantitative assay to measure duck HBV (DHBV) DNA in single hepatocyte nuclei from DHBV-infected animals and to observe intranuclear DHBV DNA kinetics undergoing entecavir (ETV) therapy. METHODS: DHBV DNA in isolated nuclei was amplified by quantitative real-time PCR. Liver tissues from chronically-infected ducks with or without ETV treatment were assessed. Cell cycle phases were defined with flow cytometry in single nuclei. RESULTS: We successfully established a quantitative assay to measure intranuclear DHBV DNA in single nuclei with high specificity, sensitivity and acceptable interassay variations. The intranuclear viral DNA copy numbers varied dramatically (2-204 copies/nuclei) in 11 ducks with active viral replication. Average intranuclear DHBV DNA copies from individual animals (7.57-57.67 copies/nuclei) significantly correlated with total intranuclear (rs=0.955, P<0.001) and serum (rs=0.745, P=0.008) viral DNA levels. The median intranuclear DHBV DNA copies in virus-positive nuclei were greater in gap 0/1 than those in gap 2/mitosis and synthesis phases (P<0.001). Median intranuclear viral DNA copies in virus-positive nuclei decreased from 21 to 6 (P<0.001) under 14-19 weeks of ETV therapy. However, subsequently, further reductions were not achieved in four animals after extended 16 week treatment (6 versus 11, P=0.034). CONCLUSIONS: Intranuclear DHBV DNA levels varied significantly, which could be partially attributed to effects of cell cycle phases, and could be decreased by ETV therapy.

[Construction of a duck hepatitis B virus YMDD mutant and identification of its resistance phenotype].

OBJECTIVE: To construct a lamivudine-resistant plasmid containing 1.2 unit genome of duck hepatitis B virus and identify its replication and drug-resistance in avian LMH hepatica cells. METHODS: The recombinant plasmid PBS-DHBV1.2 was constructed using the 1.2-genome length DHBV DNA sequence from a dimer DHBV genome with pcDNA3.1 as the template. With site-directed mutagenesis, we obtained PBS-DHBV1.2-M512V plasmids with polymerase gene mutation from PBS-DHBV1.2. Two constructed plasmids were transiently transfected into LMH cells using FuGENETM6 transfection reagent and cultured in the medium containing different concentrations of lamivudine. Southern blot hybridization was performed to detect DHBV replication intermediates. RESULTS: PCR amplification, restriction digestion and plasmid sequencing all confirmed successful construction of PBS-DHBV1.2-M512V recombinant plasmid. Southern blot analysis identified the presence of all the expected DHBV replication intermediates in LMH cells. The replication capacity of the mutant plasmid was decreased by 2.7 times compared with that of the wild plasmid. The IC(50) of lamivudine was 37.12∓8.81 ng/ml for the mutant, greater than that of the wild plasmid (10.90∓4.80 ng/ml). CONCLUSION: Compared with the wild plasmid, the mutant plasmid has a lower replication capacity and sensitivity to lamivudine in vitro.

[Molecular mechanisms of plant resistance to cadmium toxicity].

Cadmium (Cd) is a non-essential trace element for plants, and has strong toxicity at low concentrations. It can suppress the elongation growth of plant cell, inhibit oxidative mitochondrial phosphorylation, induce oxidative stress, inhibit the activities of several antioxidative enzymes, affect photosynthesis by inhibiting ferrous reductase or damaging photosynthesis apparatus, and cause the alteration of chromatin and the change of plasma membrane ATPase activity. In response to Cd stress, the cells of cadmium-resistant plant species can produce a number of proteins such as phytochelatins, metallothioneins and stress proteins to detoxify Cd ions, and efficiently repair Cd damage. The plant cells can also resort to other defense systems to detoxify Cd ions, e.g., the immobilization of Cd by cell wall, exclusion of Cd through the action of plasma membrane, compartmentalization of Cd by vacuolar, and release of plant glands. The phytochelatin synthase (PCS) genes of Arabidopsin, wheat and Schizosaccharomyces pombe had been identified by using different approaches, and the metallothioneins (MT) in plants was also identified recently. By introducing animal MT genes, transgenic plants could increase the resistant ability to Cd toxicity. Subjected to Cd, plant cells often start to synthesize stress proteins such as heat shock proteins, and the plants having been transformed the stress protein genes could enhance their resistant capacity to Cd ions. It was reported that zinc (Zn) ion-transporting proteins could also transport Cd ion. Some minor genes not conferring tolerance on their own could modify the major gene (s), and enhance Cd tolerance. Cd detoxification in wild type plants could be a complex phenomenon, probably under polygenic control to Cd, while acute Cd stress seemed to be a simpler mechanism, apparently involving only one or a few specific major genes.