A single birth dose of Hepatitis B vaccine induces polyfunctional CD4+ T helper cells

A single birth-dose of Hepatitis B vaccine (HepB) can protect newborns from acquiring Hepatitis B infection through vertical transmission, though several follow-up doses are required to induce long-lived protection. In addition to stimulating antibodies, a birth-dose of HepB might also induce polyfunctional CD4+ T-cells, which may contribute to initial protection. We investigated whether vaccination with HepB in the first week of life induced detectable antigen-specific CD4+ T-cells after only a single dose and following completion of the entire HepB vaccine schedule (3 doses). Using HBsAg- stimulated peripheral blood mononuclear cells from 344 infants, we detected increased populations of antigen-specific polyfunctional CD154+IL-2+TNFα+ CD4+ T-cells following a single birth-dose of HepB in a proportion of infants. Frequencies of polyfunctional T-cells increased following the completion of the HepB schedule but increases in the proportion of responders as compared to following only one dose was marginal. Polyfunctional T-cells correlated positively with serum antibody titres following the birth dose (day30) and completion of the 3-dose primary HepB vaccine series (day 128). These data indicate that a single birth dose of HepB provides immune priming for both antigen-specific B- and T cells.

Seroepidemiological study on the spread of SARS-CoV-2 in populations in especially affected areas in Germany - Study protocol of the CORONA-MONITORING lokal study

At a regional and local level, the COVID-19 pandemic has not spread out uniformly and some German municipalities have been particularly affected. The seroepidemiological data from these areas helps estimate the proportion of the population that has been infected with SARS-CoV-2 (seroprevalence), as well as the number of undetected infections and asymptomatic cases. In four municipalities which were especially affected, 2,000 participants will be tested for an active SARS-CoV-2 infection (oropharyngeal swab) or a past infection (blood specimen IgG antibody test). Participants will also be asked to fill out a short written questionnaire at study centres and complete a follow-up questionnaire either online or by telephone, including information on issues such as possible exposure, susceptability, symptoms and medical history. The CORONA-MONITORING lokal study will allow to determine the proportion of the population with SARS-CoV-2 antibodies in four particularly affected locations. This study will increase the accuracy of estimates regarding the scope of the epidemic, help determine risk and protective factors for an infection and therefore also identify especially exposed groups and, as such, it will be crucial towards planning of prevention measures.

Corrigendum: Clinical Protocol for a Longitudinal Cohort Study Employing Systems Biology to Identify Markers of Vaccine Immunogenicity in Newborn Infants in The Gambia and Papua New Guinea

[This corrects the article DOI: 10.3389/fped.2020.00197.].

Clinical Protocol for a Longitudinal Cohort Study Employing Systems Biology to Identify Markers of Vaccine Immunogenicity in Newborn Infants in The Gambia and Papua New Guinea

Background: Infection contributes to significant morbidity and mortality particularly in the very young and in low- and middle-income countries. While vaccines are a highly cost-effective tool against infectious disease little is known regarding the cellular and molecular pathways by which vaccines induce protection at an early age. Immunity is distinct in early life and greater precision is required in our understanding of mechanisms of early life protection to inform development of new pediatric vaccines. Methods and Analysis: We will apply transcriptomic, proteomic, metabolomic, multiplex cytokine/chemokine, adenosine deaminase, and flow cytometry immune cell phenotyping to delineate early cellular and molecular signatures that correspond to vaccine immunogenicity. This approach will be applied to a neonatal cohort in The Gambia (N ~ 720) receiving at birth: (1) Hepatitis B (HepB) vaccine alone, (2) Bacille Calmette Guerin (BCG) vaccine alone, or (3) HepB and BCG vaccines, (4) HepB and BCG vaccines delayed till day 10 at the latest. Each study participant will have a baseline peripheral blood sample drawn at DOL0 and a second blood sample at DOL1,-3, or-7 as well as late timepoints to assess HepB vaccine immunogenicity. Blood will be fractionated via a "small sample big data" standard operating procedure that enables multiple downstream systems biology assays. We will apply both univariate and multivariate frameworks and multi-OMIC data integration to identify features associated with anti-Hepatitis B (anti-HB) titer, an established correlate of protection. Cord blood sample collection from a subset of participants will enable human in vitro modeling to test mechanistic hypotheses identified in silico regarding vaccine action. Maternal anti-HB titer and the infant microbiome will also be correlated with our findings which will be validated in a smaller cohort in Papua New Guinea (N ~ 80). Ethics and Dissemination: The study has been approved by The Gambia Government/MRCG Joint Ethics Committee and The Boston Children's Hospital Institutional Review Board. Ethics review is ongoing with the Papua New Guinea Medical Research Advisory Committee. All de-identified data will be uploaded to public repositories following submission of study output for publication. Feedback meetings will be organized to disseminate output to the study communities. Clinical Trial Registration: Clinicaltrials.gov Registration Number: NCT03246230.

Eosinophils in Homeostasis and Their Contrasting Roles during Inflammation and Helminth Infections

Eosinophil numbers are highly elevated during helminth infections and a range of allergic and inflammatory disorders, but eosinophils are also present in several tissues in the absence of infection. Indeed, new findings demonstrate that eosinophils may be involved in events as diverse as glucose metabolism, mammary gland development, intestinal health, tissue remodeling, thymic selection, and B-cell survival. Although eosinophils often correlate with pathological parameters during conditions such as inflammatory bowel disease and asthma, the evidence for their contribution to tissue pathology remains controversial. Recent research suggests that eosinophils may have additional roles in these settings that are related to control and resolution of inflammation. Controversy also surrounds the involvement of eosinophils in anti-helminth immunity. Their assumed role in fighting parasites has increasingly been questioned, particularly as a result of data from studies of eosinophil-ablated mouse strains in which either no or only very moderate effects on helminth survival has been reported. Helminths are masters of immune regulation, but whether they actively suppress eosinophil function has rarely been considered. Thus, the purpose of this review is threefold: (1) to summarize our knowledge of the wide range of functions of eosinophils during homeostasis, (2) to discuss the role of eosinophil during inflammation and the recent discovery of eosinophils as mediators of inflammatory resolution, and (3) to summarize data on the effect of eosinophils on helminth infections and discuss the possibility of helminth-mediated modulation of eosinophils.

Eosinophils are required to suppress Th2 responses in Peyer's patches during intestinal infection by nematodes

Infections with enteric nematodes result in systemic type 2 helper T (Th2) responses, expansion of immunoglobulin (Ig)G1 antibodies, and eosinophilia. Eosinophils have a supportive role in mucosal Th2 induction during airway hyperreactivity. Whether eosinophils affect the local T-cell and antibody response in the gut-associated lymphoid tissue during enteric infections is unknown. We infected eosinophil-deficient ΔdblGATA-1 mice with the Th2-inducing small intestinal nematode Heligmosomoides polygyrus and found that parasite fecundity was decreased in the absence of eosinophils. A lack of eosinophils resulted in significantly augmented expression of GATA-3 and IL-4 by CD4⁺ T cells during acute infection, a finding strictly limited to Peyer's patches (PP). The increase in IL-4-producing cells in ΔdblGATA-1 mice was particularly evident within the CXCR5⁺PD-1⁺ T-follicular helper cell population and was associated with a switch of germinal centre B cells to IgG1 production and elevated serum IgG1 levels. In contrast, infected wild-type mice had a modest IgG1 response in the PP, whereas successfully maintaining a population of IgA⁺ germinal center B cells. Our results suggest a novel role for eosinophils during intestinal infection whereby they restrict IL-4 responses by follicular T helper cells and IgG1 class switching in the PP to ensure maintenance of local IgA production.

Obesity, weight loss, and health

Obesity is a multifactorial, complicated condition or group of conditions that afflicts a growing number of people in the United States. Precise etiologies are not well understood, and both commercial and medical treatment programs are characterized by high rates of recidivism. A cultural preoccupation with slimness has created a huge industry serving millions of people who are attempting continually to reduce weight. Contradictory messages from professionals have led to confusion concerning the health implications of obesity and the potential risks of repeated dieting. This review summarizes the major areas of consensus and controversy concerning the health implications of obesity and weight loss and suggests directions for treatment that take into account the complex causes and consequences of obesity.