Maternal Immunity Influences Vertical Transmission of Hepatitis B to Newborns

Understanding the influence of cytokines in intrauterine hepatitis B transmission: A cross-sectional study in China

Cytokines may related to intrauterine Hepatitis B virus (HBV) transmission. 205 HBsAg(+) pregnant cases and 74 HBsAg(-) women were included. Neonatal blood samples were taken within 24 h of delivery and before HBV vaccinations. Serological HBV biomarkers and cytokines were detected. 21.9 % of the newborns from HBsAg(+) women were intrauterinally transmitted, including 7.3 % with dominant transmission (DBT) and 14.6 % occult transmission (OBT). HBV DNA load (odd ratio [OR], 1.44; 95 % confidence interval [CI], 1.05-1.98), interferon-γ (IFN-γ) (OR, 1.01; 95 %CI, 1.00-1.02) and toll-like receptor 9 (TLR9) (OR, 1.27; 95 %CI, 1.06-1.52) positively correlated with DBT. Only IFN-γ (OR, 1.01; 95 %CI, 1.00-1.01) positively associated with OBT. According to the generated restricted cubic spline, TLR9 was positively correlates with rise of DBT in a log-shape. It may be possible to develop a nomogram which intercalates these factors to predict intrauterine HBV transmissions. Further research should consider immune processes involved in chorioamnionitis.

Altered TLR7 Expression-Mediated Immune Modulation Is Supportive of Persistent Replication and Intrauterine Transmission of HBV

Hepatitis B Virus (HBV) is posing as a serious public health threat mainly due to its asymptomatic nature of infection in pregnancy and vertical transmission. Viral sensing toll-like receptors (TLR) and Interleukins (IL) are important molecules in providing an antiviral state. The study aimed to assess the role of TLR7-mediated immune modulation, which might have an impact in the intrauterine transmission of HBV leading to mother to child transmission of the virus. We investigated the expression pattern of TLR7, IL-3, and IL-6 by RT-PCR in the placentas of HBV-infected pregnant women to see their role in the intrauterine transmission of HBV. We further validated the expression of TLR7 in placentas using Immunohistochemistry. Expression analysis by RT-PCR of TLR7 revealed significant downregulation among the Cord blood (CB) HBV DNA positive and negative cases with mean ± standard deviation (SD) of 0.43 ± 0.22 (28) and 1.14 ± 0.57 (44) with p = 0.001. IL-3 and IL-6 expression revealed significant upregulation in the CB HBV DNA-positive cases with p = 0.001. Multinomial logistic regression analysis revealed that TLR7 and IL-3 fold change and mother HBeAg status are important predictors for HBV mother to child transmission. Immunohistochemistry revealed the decreased expression of TLR7 in CB HBV DNA-positive cases. This study reveals that the downregulation of TLR7 in the placenta along with CB HBV DNA-positive status may lead to intrauterine transmission of HBV, which may lead to vertical transmission of HBV.

Modulation of CD8+T cells, NK cells and Th1cytokines by metabolic milieu in decline of HBV-viremia in pregnant women treated with tenofovir-disoproxil from second trimester of pregnancy

High HBV DNA levels predispose to mother to child transmission (MTCT) of HBV. Early nucleotide analogue (NA) therapy can reduce HBV DNA and minimize MTCT. We analysed immune-metabolic profile in pregnant mothers who received NA from 2nd trimester compared with untreated mothers. In 2nd trimester, there was no difference in immune profiles between Gr.1 and Gr.2 but high viral load women had downregulated pyruvate, NAD+ metabolism but in 3rd trimester, Gr.1 had significant reduction in HBV-DNA, upregulated pyruvate and NAD with increased IFN-2αA, CD8Tcells, NK cells and decreased Tregs, IL15, IL18, IL29, TGFβ3 compared to Gr.2. In Gr.1, three eAg-ve women showed undetectable DNA and HBsAg. At delivery, Gr.1 showed no MTCT, with undetectable HBV DNA, HBsAg, high CD8 and NK cells in two women. We conclude, that starting NA from second trimester, reduces HBV load and MTCT, modulates NAD, induces immunity and suggest use of NA in early gestation in future trials.

Maternal Th17 Profile after Zika Virus Infection Is Involved in Congenital Zika Syndrome Development in Children

Brazil is one of the countries that experienced an epidemic of microcephaly and other congenital manifestations related to maternal Zika virus infection which can result in Congenital Zika Syndrome (CZS). Since the Zika virus can modulate the immune system, studying mothers' and children's immune profiles become essential to better understanding CZS development. Therefore, we investigated the lymphocyte population profile of children who developed CZS and their mothers' immune response in this study. The study groups were formed from the Plaque Reduction Neutralization Test (PRNT) (CZS+ group) result. To evaluate the lymphocyte population profile, we performed phenotyping of peripheral lymphocytes and quantification of serum cytokine levels. The immunophenotyping and cytokine profile was correlated between CSZ+ children and their mothers. Both groups exhibited increased interleukin-17 levels and a reduction in the subpopulation of CD4+ T lymphocytes. In contrast, the maternal group showed a reduction in the population of B lymphocytes. Thus, the development of CZS is related to the presence of an inflammatory immune profile in children and their mothers characterized by Th17 activation.

Immune predictors of hepatitis B surface antigen seroconversion in patients with hepatitis B reactivation

BACKGROUND

Hepatitis B surface antigen (HBsAg) seroconversion is sometimes observed in hepatitis B reactivation (rHBV), probably due to immune resetting and differentiation.

AIMS

To investigate sequential immune differentiation and abrogation of tolerance in patients with rHBV who achieved HBsAg seroconversion.

METHODS

We included 19 patients with chronic hepatitis B (CHBV; HBV DNA log10^3-8 ), 67 with rHBV (raised ALT [>5XULN], HBV DNAlog10^4-8 ) and 10 healthy controls. Immune differentiation, tolerance and functional status of CD4, CD8, T regulatory cells (Tregs), B cells and follicular T helper (Tfh) cells were assessed at baseline and 24 weeks.

RESULTS

At 24 weeks, 81% rHBV (n = 67) lost HBV DNA and HBeAg (41%), and 12 (19%) lost HBsAg and made anti-HBs titers >10 IU/ml. rHBV patients had higher Th1/17, T_EM , Tfh, Tfh1/17, plasma and ATM B cells, and lower Tregs, Th2, Th17 and TEMRA expression. rHBV showed lower PD1, TIM3, LAG3, SLAM and TOX compared to CHBV. There was a significant increase in CD8, CD8EM, Tfh, Tfh1/17 and plasma B cells in seroconverters than non-seroconverters. At 24 weeks, we also observed increased plasma B cell frequency in seroconverters. While non-seroconverters showed higher expression of PD1, TIM3, LAG3, SLAM and TOX on CD4/CD8 T cells, blockade of PD1, TIM3, LAG3 and CTLA4 significantly enhanced IFN-γ, TNF-α, IL-4 and IL-21 expression on CD4/CD8 and Tfh cells in non-seroconverters.

CONCLUSIONS

Non-seroconverters have increased inhibitory markers on CD4/CD8 T cells. There is a critical play of CD8, Tfh and B cells and subsets in seroclearance, along with checkpoint molecules as a potential therapy for non-seroconverters in HBV infection.

Asian Pacific association for the study of liver (APASL) guidelines: hepatitis B virus in pregnancy

Hepatitis B virus (HBV) infection still remains a major public health issue in the Asia-Pacific region. Most of the burden of HBV-related disease results from infections acquired in infancy through perinatal or early childhood exposure to HBV in Asia-Pacific. Hepatitis B during pregnancy presents unique management issues for both the mother and fetus. These APASL guidelines provide a comprehensive review and recommendations based on available evidence in the literature, for the management of females with HBV infection through every stage of pregnancy and postpartum. These also address the concerns, management challenges, and required follow-up of children born to hepatitis B-positive mothers.

Cytokines and Chemokines in HBV Infection

Chronic hepatitis B virus (HBV) infection remains a leading cause of hepatic inflammation and damage. The pathogenesis of chronic hepatitis B (CHB) infection is predominantly mediated by persistent intrahepatic immunopathology. With the characterization of unique anatomical and immunological structure, the liver is also deemed an immunological organ, which gives rise to massive cytokines and chemokines under pathogenesis conditions, having significant implications for the progression of HBV infection. The intrahepatic innate immune system is responsible for the formidable source of cytokines and chemokines, with the latter also derived from hepatic parenchymal cells. In addition, systemic cytokines and chemokines are disturbed along with the disease course. Since HBV is a stealth virus, persistent exposure to HBV-related antigens confers to immune exhaustion, whereby regulatory cells are recruited by intrahepatic chemokines and cytokines, including interleukin-10 and transforming growth factor β, are involved in such series of causal events. Although the considerable value of two types of available approved treatment, interferons and nucleos(t)ide analogues, effectively suppress HBV replication, neither of them is sufficient for optimal restoration of the immunological attrition state to win the battle of the functional or virological cure of CHB infection. Notably, cytokines and chemokines play a crucial role in regulating the immune response. They exert effects by directly acting on HBV or indirectly manipulating target immune cells. As such, specific cytokines and chemokines, with a potential possibility to serve as novel immunological interventions, combined with those that target the virus itself, seem to be promising prospects in curative CHB infection. Here, we systematically review the recent literature that elucidates cytokine and chemokine-mediated pathogenesis and immune exhaustion of HBV infection and their dynamics triggered by current mainstream anti-HBV therapy. The predictive value of disease progression or control and the immunotherapies target of specific major cytokines and chemokines in CHB infection will also be delineated.

Genome Sequences and Phylogeny of Two Duck Hepatitis B Viruses

Duck hepatitis B virus (DHBV) infection in Pekin ducks is a model for human hepatitis B. Sequence variations may contribute to host therapy responses against the virus. We provide full genome sequences of two DHBVs from France, their phylogenetic classification, and their sequence variability.

Duck hepatitis B virus (DHBV) infection in Pekin ducks is a model for human hepatitis B. Sequence variations may contribute to host therapy responses against the virus. We provide full genome sequences of two DHBVs from France, their phylogenetic classification, and their sequence variability.

Humoral Immune Responses and Hepatitis B Infection

BACKGROUND

Chronicity or seroclearance of hepatitis B virus (HBV) antigens is determined by the host immune responses. Current approaches to treat HBV patients are based on inhibition of replication using different antivirals (nucleoside or nucleotide analogs) as monotherapy, or along with immune modulators as combination therapy is being used worldwide for reducing the viral load. Understanding the role of immune cellular therapies with currently available treatments for persistent viral-mediated responses in HBV patients is unexplored. However, the generation of antibodies against a surface (HBs) and envelop (HBe) antigen of hepatitis B remains an issue for future studies and needs to be explored.

SUMMARY

Humoral immunity, specifically T follicular helper (TFh) cells, may serve as a target for therapy for HBsAg seroconversion. In this review, we have been engrossed in the importance and role of the humoral immune responses in CHBV infection and vertical transmission. Key Message: TFh cells have been suggested as the potential target of immunotherapy which lead to seroconversion of HBe and HBs antigens of HBV. HBsAg seroconversion and eradication of covalently closed circular DNA are the main challenges for existing and forthcoming therapies in HBV infection.

Hepatitis B and Pregnancy: Virologic and Immunologic Characteristics

The hepatitis B virus (HBV) is an important human pathogen. Unvaccinated infants infected through mother-to-child transmission (MTCT) are at >95% risk of developing serum hepatitis B surface antigen-positive chronic hepatitis B (CHB). Despite complete passive-active HBV immunoprophylaxis, approximately 10% of infants born to mothers who are highly viremic develop CHB, and thus maternal treatment with nucleos(t)ide analogs (tenofovir disoproxil fumarate, lamivudine, or telbivudine) is recommended in the third trimester of pregnancy to reduce MTCT risk. Viral rebound usually occurs after stopping treatment and, in the context of maternal immunologic reconstitution postpartum, can also precipitate host immune-mediated hepatic (biochemical) flares. In this article, we review the epidemiology of HBV MTCT, discuss management and potential mechanisms of HBV vertical transmission, and highlight recent studies on virologic and immunologic aspects of hepatitis B in pregnancy and postpartum.

Innate and adaptive immunity associated with resolution of acute woodchuck hepatitis virus infection in adult woodchucks

Viral and/or host factors that are directly responsible for the acute versus chronic outcome of hepatitis B virus (HBV) infection have not been identified yet. Information on immune response during the early stages of HBV infection in humans is mainly derived from blood samples of patients with acute hepatitis B (AHB), which are usually obtained after the onset of clinical symptoms. Features of intrahepatic immune response in these patients are less studied due to the difficulty of obtaining multiple liver biopsies. Woodchuck hepatitis virus (WHV) infection in woodchucks is a model for HBV infection in humans. In the present study, five adult woodchucks were experimentally infected with WHV and then followed for 18 weeks. Blood and liver tissues were frequently collected for assaying markers of WHV replication and innate and adaptive immune responses. Liver tissues were further analyzed for pathological changes and stained for important immune cell subsets and cytokines. The increase and subsequent decline of viral replication markers in serum and liver, the elicitation of antibodies against viral proteins, and the induction of virus-specific T-cell responses indicated eventual resolution of acute WHV infection in all animals. Intrahepatic innate immune makers stayed unchanged immediately after the infection, but increased markedly during resolution, as determined by changes in transcript levels. The presence of interferon-gamma and expression of natural killer (NK) cell markers suggested that a non-cytolytic response mechanism is involved in the initial viral control in liver. This was followed by the expression of T-cell markers and cytolytic effector molecules, indicating the induction of a cytolytic response mechanism. Parallel increases in regulatory T-cell markers suggested that this cell subset participates in the overall immune cell infiltration in liver and/or has a role in regulating AHB induced by the cytolytic response mechanism. Since the transcript levels of immune cell markers in blood, when detectable, were lower than in liver, and the kinetics, except for NK-cells and interferon-gamma, did not correlate well with their intrahepatic expression, this further indicated enrichment of immune cells within liver. Conclusion: The coordinated interplay of innate and adaptive immunity mediates viral clearance in the woodchuck animal model of HBV infection. The initial presence of NK-cell associated interferon-gamma response points to an important role of this cytokine in HBV resolution.