Characterization of immune responses induced by N. meningitidis PorB and its us as a vaccine adjuvant

Thesis (Ph.D.)--Boston UniversityVaccines play an essential role in public health. Adjuvants increase immunogenicity for many of these vaccines by stimulating the innate immune system: driving cytokine secretion to induce local and systemic pro-inflammatory states, upregulating costimulatory molecules on antigen presenting cells (APCs), and increasing antigen uptake and presentation to better engage T cell responses. Neisseria meningitidis porin PorB is a Toll-Like Receptor 2 (TLR2) ligand with broad immune stimulating functions and can act as a vaccine adjuvant. Our lab is interested in characterizing how PorB activates the immune system and how these effects relate to its adjuvant activity. An understanding of adjuvant functions will allow for the rational, rather than empiric, design of future vaccines. Here we further investigate the effects of PorB on the innate immune system as it may apply to the adjuvant activity of the porin. In a direct test of adjuvanticity we show that without the presence TLR2 the adjuvant activity of PorB, measured by antigen-specific IgG production, is diminished in immunized mice while loss of MyD88 entirely ablates PorB adjuvant activity. We demonstrate costimulatory molecule upregulation in response to PorB stimulation and its dependence on TLR2. We show that stimulation with PorB increases antigen uptake by APCs and drives APC migration to draining lymph nodes, which appears to be dependent on TLR2 and not on MyD88. Finally, we use systems vaccinology to uncover complex regulatory networks and dynamics. The inclusion of PorB as an adjuvant in a multi-injection vaccine formulation has two major effects on expression profiles in murine splenocytes. Vaccine preparations containing PorB as an adjuvant induce expression in inflammatory and immune signaling networks, in agreement with previous work, and accelerate the kinetics of the immune response, as demonstrated by induction of expression of cell cycle and proliferative genes and regulatory networks at earlier time points as compared to preparations not containing PorB. This systems biology approach reveals previously unappreciated aspects of reaction of the immune system to PorB. Together, these findings deepen our understanding of the immune response to PorB and offer potential insight into the mechanisms behind its adjuvanticity

Fusion, 2023

https://hsrc.himmelfarb.gwu.edu/smhs_fusion/1015/thumbnail.jp

Preventing overweight and improving parenting skills from birth to age 3 years: preliminary results

Background. Parenting has been associated with child weight status. This study aims to evaluate the effects on parenting skills and BMI-SDS of the BBOFT+ overweight prevention program, compared to care-as-usual (CAU). Method. In a cluster-randomized trial, 2500 parents participated. Parent-reported weight and length were used. Parenting was measured with subscales control and reinforcement of the parenting strategies for eating and activity scale (PEAS) and the warmth subscale from the Child Rearing Questionnaire. Results. The first univariate analyses show that at age 15 months, no statistically significant differences in BMI- SDS, parental control, reinforcement or warmth were found between the BBOFT+ and the CAU group. Further cluster analyses need to be conducted. Results from age 36 months will be presented during the conference, which will include all subscales of the PEAS and an assessment of parenting styles. Conclusion. The intervention does not seem to have an effect on BMI-SDS or parenting

VANISH-HBV: VACCINATION OF NEWBORNS – INNOVATIVE STRATEGIES TO HASTEN ELIMINATION OF HEPATITIS B VIRUS IN KINSHASA PROVINCE, THE DEMOCRATIC REPUBLIC OF THE CONGO

Across the globe, and specifically in sub-Saharan Africa (SSA), viral hepatitis is one of the leading global infectious killers despite the availability of an effective preventative vaccine. The Democratic Republic of the Congo (DRC) introduced the three-dose HBV vaccine (HepB3) in 2007, and yet HBV prevalence remains high, especially among children under age five. HBV exposure at a young age is associated with more severe liver disease; if infected at birth via mother-to-child transmission (MTCT), an infant has a 70-90% chance of developing chronic HBV infection and a 25% chance of mortality. Vaccination, particularly administration of the birth-dose (BD) vaccine against HBV (HepB-BD) within 24 hours of delivery, is one of the most effective tools to interrupt MTCT. Because few SSA countries currently distribute HepB-BD, little knowledge or guidance exists for effective implementation of timely HepB-BD vaccines, streamlined alongside ongoing BD vaccines (oral polio—OPV0—and tuberculosis—BCG).This study assesses determinants of ongoing BD vaccines’ (OPV0 and BCG) uptake at the community (i.e., vaccine stigma, mother’s socio-demographic characteristics, and care-seeking patterns) and facility (i.e., clinic’s capacity) levels. Guided by community input, the study develops an implementation strategy to overcome barriers and streamline vaccine delivery services by combining HepB-BD with other routine BD vaccines (OPV0 and BCG). Aim 1 evaluates immunization trends using existing survey data from an continuous quality improvement study in 105 maternity clinics uptake in the Kinshasa Province in order to understand barriers to uptake of timely infant vaccines. Aim 2 explores reported determinants at the community and facility levels and identifies solutions for effective BD delivery by conducting focus groups with key informants and expectant mothers. Aim 3 develops a proposed implementation strategy (streamlining administration of OPV0, BCG, and HepB-BD with an educational initiative) that addresses identified barriers to uptake of birth-dose vaccines. The proposed implementation strategy aims to reduce the prevalence of HBV and other vaccine-preventable illnesses among children in the DRC by developing an effective, streamlined implementation strategy for timely BD vaccine distribution.Doctor of Philosoph

Going viral : an integrated view on virological data analysis from basic research to clinical applications

Viruses are of considerable interest for several fields of life science research. The genomic richness of these entities, their environmen- tal abundance, as well as their high adaptability and, potentially, pathogenicity make treatment of viral diseases challenging. This thesis proposes three novel contributions to antiviral research that each concern analysis procedures of high-throughput experimen- tal genomics data. First, a sensitive approach for detecting viral genomes and transcripts in sequencing data of human cancers is presented that improves upon prior approaches by allowing de- tection of viral nucleotide sequences that consist of human-viral homologs or are diverged from known reference sequences. Sec- ond, a computational method for inferring physical protein contacts from experimental protein complex purification assays is put for- ward that allows statistically meaningful integration of multiple data sets and is able to infer protein contacts of transiently binding protein classes such as kinases and molecular chaperones. Third, an investigation of minute changes in viral genomic populations upon treatment of patients with the mutagen ribavirin is presented that first characterizes the mutagenic effect of this drug on the hepatitis C virus based on deep sequencing data.Viren sind von beträchtlichem Interesse für die biowissenschaftliche Forschung. Der genetische Reichtum, die hohe Vielfalt, wie auch die Anpassungsfähigkeit und mögliche Pathogenität dieser Organismen erschwert die Behandlung von viralen Erkrankungen. Diese Promotionsschrift enthält drei neuartige Beiträge zur antiviralen Forschung welche die Analyse von experimentellen Hochdurchsatzdaten der Genomik betreffen: erstens, ein sensitiver Ansatz zur Entdeckung viraler Genome und Transkripte in Sequenzdaten humaner Karzinome, der die Identifikation von viralen Nukleotidsequenzen ermöglicht, die von Referenzgenomen ab- weichen oder homolog zu humanen Faktoren sind. Zweitens, eine computergestützte Methode um physische Proteinkontakte von experimentellen Proteinkomplex-Purifikationsdaten abzuleiten welche die statistische Integration von mehreren Datensätzen erlaubt um insbesondere Proteinkontakte von flüchtig interagierenden Proteinklassen wie etwa Kinasen und Chaperonen aus den Daten ableiten zu können. Drittens, eine Untersuchung von kleinsten Änderungen viraler Genompopulationen während der Behandlung von Patienten mit dem Mutagen ribavirin die zum ersten Mal die mutagene Wirkung dieses Medikaments auf das Hepatitis C Virus mittels Tiefensequenzdaten nachweist

Incorporating standardised drift-tube ion mobility to enhance non-targeted assessment of the wine metabolome (LC×IM-MS)

Liquid chromatography with drift-tube ion mobility spectrometry-mass spectrometry (LCxIM-MS) is emerging as a powerful addition to existing LC-MS workflows for addressing a diverse range of metabolomics-related questions [1,2]. Importantly, excellent precision under repeatability and reproducibility conditions of drift-tube IM separations [3] supports the development of non-targeted approaches for complex metabolome assessment such as wine characterisation [4]. In this work, fundamentals of this new analytical metabolomics approach are introduced and application to the analysis of 90 authentic red and white wine samples originating from Macedonia is presented. Following measurements, intersample alignment of metabolites using non-targeted extraction and three-dimensional alignment of molecular features (retention time, collision cross section, and high-resolution mass spectra) provides confidence for metabolite identity confirmation. Applying a fingerprinting metabolomics workflow allows statistical assessment of the influence of geographic region, variety, and age. This approach is a state-of-the-art tool to assess wine chemodiversity and is particularly beneficial for the discovery of wine biomarkers and establishing product authenticity based on development of fingerprint libraries

Automated Spore Analysis using Bright-Field Imaging and Raman Microscopy

After the discovery of inadvertent shipments of viable B. anthracis spores by the United States Department of Defense in 2015, alternative and orthogonal methods were investigated to analyze spores to determine their viability. In this thesis we demonstrate a novel analysis technique that combines bright-field microscopy imaging with Raman chemical microscopy. We first developed an image segmentation routine based on the watershed method to locate individual spores within bright-field images. This routine was able to effectively demarcate 97.4% of the Bacillus spores within the bright-field images with minimal over-segmentation. Size and shape measurements, to include major and minor axis and area, were then extracted for 4048 viable spores which showed very good agreement with previously published values. When similar measurements were taken on 3627 gamma-irradiated spores, a statistically significant difference was noted for the minor axis length, ratio of major to minor axis, and total area when compared to the non-irradiated spores. Classification results show the ability to correctly classify 67% of viable spores with an 18% misclassification rate using the bright-field image by thresholding the minimum classification length. Raman chemical imaging microscopy (RCIM) was then used to measure populations of viable, gamma irradiated, and autoclaved spores of B. anthracis Sterne, B. atrophaeus. B. megaterium, and B. thuringiensis kurstaki. Significant spectral differences were observed between viable and inactivated spores due to the disappearance of features associated with calcium dipicolinate after irradiation. Principal component analysis was used which showed the ability to distinguish viable spores of B. anthracis Sterne and B. atrophaeus from each other and the other two Bacillus species. Finally, Raman microscopy was used to classify mixtures of viable and gamma inactivated spores. A technique was developed that fuses the size and shape characteristics obtained from the bright-field image to preferentially target viable spores. Simulating a scenario of a A practical demonstration of the technique was performed on a field of view containing approximately 7,000 total spores of which are only 12 were viable to simulate a sample that was not fully irradiated. Ten of these spores are properly classified while interrogating just 25% of the total spores