Recombinant <em>Mycobacterium bovis</em> BCG producing the N-terminal half of SIVmac251 Env antigen induces neutralizing antibodies and cytotoxic T lymphocyte responses in mice and guinea pigs

International audienceRecombinant Mycobacterium bovis bacillus Calmette-Guerin (rBCG) represents a good candidate for the development of vaccines against AIDS, Several HIV or SIV genes including nef, gag, and env have already been expressed by rBCG strains and shown to induce strong humoral and cellular immune responses in experimental animals, Because a broad immune response directed to multiple HIV/SIV antigens is highly desirable in order to develop effective vaccines, me have also investigated the immune response induced by an rBCG strain expressing a large N-terminal portion of the SIVmac251 Env gp110-encoding gene, The rBCG(SIVmac251Env) strain obtained was able to induce strong CTL responses in mice as well as humoral immune responses in mice and guinea pigs immunized by parenteral routes, The anti-gp110 IgGs produced mere able to neutralize in vitro growth of virulent SIVmac251 field isolates, Moreover, guinea pigs immunized by the oral route produced significant levels of anti-gp110 IgAs in the feces, demonstrating that rBCG is able to induce local humoral immunity in the intestinal mucosa. These data provide further evidence of the utility of BCG as a candidate vaccine vector against AIDS

Characterization of the gene encoding the immunodominant 35 kDa protein of <em>Mycobacterium leprae</em>

International audienceAnalysis of the interaction between the host immune system and the intracellular parasite Mycobacterium leprae has identified a 35 kDa protein as a dominant antigen, The native 35 kDa protein was purified from the membrane fraction of M. leprae and termed MMPI (major membrane protein I). As the purified protein was not amenable to N-terminal sequencing, partial proteolysis was used to establish the sequences of 21 peptides, A fragment of the 35 kDa proteinen-coding gene was amplified by the polymerase chain reaction from M. leprae chromosomal DNA with oligonucleotide primers derived from internal peptide sequences and the whole gene was subsequently isolated from a M. leprae cosmid library. The nucleotide sequence of the gene revealed an open reading frame of 307 amino acids containing most of the peptide sequences derived from the native 35 kDa protein, The calculated subunit mass was 33.7 kDa, but the native protein exists as a multimer of 950 kDa, Database searches revealed no identity between the 35 kDa antigen and known protein sequences. The gene was expressed in Mycobacterium smegmatis under the control of its own promoter or at a higher level using an 'up-regulated' promoter derived from Mycobacterium fortuitum. The gene product reacted with monoclonal antibodies raised to the native protein, Using the bacterial alkaline phosphatase reporter system, we observed that the 35 kDa protein was unable to be exported across the membrane of recombinant M. smegmatis. The 35 kDa protein-encoding gene is absent from members of the Mycobacterium tuberculosis complex, but homologous sequences were detected in Mycobacterium avium, Mycobacterium haemophilum and M. smegmatis, The avaibility of the recombinant 35 kDa protein will permit dissection of both antibody- and T-cell-mediated immune responses in leprosy patients

Multiparametric Magnetic Resonance Imaging and Magnetic Resonance Elastography to Evaluate the Early Effects of Bariatric Surgery on Nonalcoholic Fatty Liver Disease

Background. Bariatric surgery is the most effective treatment for morbid obesity and reduces the severity of nonalcoholic fatty liver disease (NAFLD) in the long term. Less is known about the effects of bariatric surgery on liver fat, inflammation, and fibrosis during the early stages following bariatric surgery. Aims. This exploratory study utilises advanced imaging methods to investigate NAFLD and fibrosis changes during the early metabolic transitional period following bariatric surgery. Methods. Nine participants with morbid obesity underwent sleeve gastrectomy. Multiparametric MRI (mpMRI) and magnetic resonance elastography (MRE) were performed at baseline, during the immediate (1 month), and late (6 months) postsurgery period. Liver fat was measured using proton density fat fraction (PDFF), disease activity using iron-correct T1 (cT1), and liver stiffness using MRE. Repeated measured ANOVA was used to assess longitudinal changes and Dunnett’s method for multiple comparisons. Results. All participants (Age 45.1±9.0 years, BMI 39.7±5.3 kg/m2) had elevated hepatic steatosis at baseline (PDFF >5%). In the immediate postsurgery period, PDFF decreased significantly from 14.1±7.4% to 8.9±4.4% (p=0.016) and cT1 from 826.9±80.6 ms to 768.4±50.9 ms (p=0.047). These improvements continued to the later postsurgery period. Bariatric surgery did not reduce liver stiffness measurements. Conclusion. Our findings support using MRI as a noninvasive tool to monitor NAFLD in patient with morbid obesity during the early stages following bariatric surgery

The Singapore national precision medicine strategy

Precision medicine promises to transform healthcare for groups and individuals through early disease detection, refining diagnoses and tailoring treatments. Analysis of large-scale genomic-phenotypic databases is a critical enabler of precision medicine. Although Asia is home to 60% of the world's population, many Asian ancestries are under-represented in existing databases, leading to missed opportunities for new discoveries, particularly for diseases most relevant for these populations. The Singapore National Precision Medicine initiative is a whole-of-government 10-year initiative aiming to generate precision medicine data of up to one million individuals, integrating genomic, lifestyle, health, social and environmental data. Beyond technologies, routine adoption of precision medicine in clinical practice requires social, ethical, legal and regulatory barriers to be addressed. Identifying driver use cases in which precision medicine results in standardized changes to clinical workflows or improvements in population health, coupled with health economic analysis to demonstrate value-based healthcare, is a vital prerequisite for responsible health system adoption.Agency for Science, Technology and Research (A*STAR)Ministry of Health (MOH)National Medical Research Council (NMRC)National Research Foundation (NRF)We thank all investigators, staf members and study participants of the contributing cohorts and studies: (1) the HELIOS study at the Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore; (2) the GUSTO study jointly hosted by the National University Hospital, KK Women’s and Children’s Hospital, the National University of Singapore and the Singapore Institute for Clinical Sciences, the Agency for Science Technology and Research (A*STAR); (3) the SEED cohort at the Singapore Eye Research Institute; (4) the MEC, National University of Singapore; (5) the PRISM cohort; and (6) the TTSH Personalised Medicine Normal Controls cohort. We also thank the National Supercomputing Centre, Singapore (https://www.ncss.sg) for computation resources. The SG10K_Health project is funded by the Industry Alignment Fund (Pre-Positioning) (IAF-PP, H17/01/a0/007); the project made use of participating study cohorts supported by the following funding sources: (1) the HELIOS study by grants from a Strategic Initiative at Lee Kong Chian School of Medicine, the Singapore MOH under its Singapore Translational Research Investigator Award (NMRC/STaR/0028/2017) and the IAF-PP (H18/01/a0/016); (2) the GUSTO study by the Singapore National Research Foundation under its Translational and Clinical Research Flagship Program and administered by the Singapore MOH’s National Medical Research Council Singapore (NMRC/TCR/004-NUS/2008, NMRC/ TCR/012-NUHS/2014) with additional funding support available through the A*STAR and the IAF-PP (H17/01/a0/005); (3) the SEED study by NMRC/CIRG/1417/2015, NMRC/CIRG/1488/2018 and NMRC/OFLCG/004/2018; (4) the MEC by individual research and clinical scientist award schemes from the Singapore National Medical Research Council (including MOH-000271-00) and the Singapore Biomedical Research Council, the Singapore MOH, the National University of Singapore and the Singapore National University Health System; (5) the PRISM cohort study by NMRC/CG/ M006/2017_NHCS, NMRC/STaR/0011/2012, NMRC/STaR/0026/2015, the Lee Foundation and the Tanoto Foundation; and (6) the TTSH cohort study by NMRC/CG12AUG2017 and CGAug16M012. This research is also supported by the National Research Foundation Singapore under its NPM program Phase II funding (MOH-000588) and administered by the Singapore MOH’s National Medical Research Council

A five-safes approach to a secure and scalable genomics data repository

Summary: Genomic researchers increasingly utilize commercial cloud service providers (CSPs) to manage data and analytics needs. CSPs allow researchers to grow Information Technology (IT) infrastructure on demand to overcome bottlenecks when combining large datasets. However, without adequate security controls, the risk of unauthorized access may be higher for data stored on the cloud. Additionally, regulators are mandating data access patterns and specific security protocols for the storage and use of genomic data. While CSP provides tools for security and regulatory compliance, building the necessary controls required for cloud solutions is not trivial. Research Assets Provisioning and Tracking Online Repository (RAPTOR) by the Genome Institute of Singapore is a cloud-native genomics data repository and analytics platform that implements a “five-safes” framework to provide security and governance controls to data contributors and users, leveraging CSP for sharing and analysis of genomic datasets without the risk of security breaches or running afoul of regulations

Large-Scale Whole-Genome Sequencing of Three Diverse Asian Populations in Singapore

Because of Singapore's unique history of immigration, whole-genome sequence analysis of 4,810 Singaporeans provides a snapshot of the genetic diversity across East, Southeast, and South Asia.</p