Feasibility of outer membrane protein C as a protein presenting platform targeting antigen to surface of outer membrane vesicle / 中国生物制品学杂志

@#Abstract：Objective To investigate the feasibility of outer membrane protein C（OmpC）as a protein presenting platform targeting antigen to the surface of outer membrane vesicle（OMV）. Methods The recombinant expression plasmid containing ompC gene fragment and Staphylococcus aureus EsxA antigen gene（esxA gene）was constructed，transformed to competent E. coli BL21（DE3），inducedbyIPTG，andanalyzedforexpressedproductby 12%SDS⁃PAGE. Thetotalproteinofrecombinant strain OMV was analyzed by 12% SDS⁃PAGE，and the localization of fusion protein on the surface of OMV was detected by Western blot and Flow NanoAnalyzer. Results The recombinant expression plasmid containing ompC gene and esxA gene was constructed correctly as proved by sequencing. 12% SDS⁃PAGE showed that the fusion protein OmpC⁃EsxA had a relative molecular mass of about 57 000，which was consistent with the expected size，while the total protein of OMV showed multiple target protein bands，indicating that recombinant strain OMV was successfully extracted. The fusion protein OmpC⁃ EsxA on the surface of recombinant strain OMV specifically bound to mouse antibody against His⁃Tag，and OMVs labeled with fluorescent antibody were detected by Flow NanoAnalyzer. Conclusion OmpC may be used as a protein presenting plat⁃ form to locate antigen to OMV surface，which was expected to be applied in the development of antigen presentation vaccine. Keywords：Outer membrane protein C（OmpC）；Protein presentation；Outer membrane vesicle（OMV）

Advance and challenge in research on meningococcal group B vaccines / 药物评价研究

It is generally accepted that vaccinations are one of the most effective tool for control of infectious diseases.In recent years,the research on meningococcal group B vaccines has made progress extensively.A new meningococcal group B vaccine,developed by the reverse vaccinology technology,has been approved by the European Medicines Agency and the Food and Drag Administration.Although no related products has been approve till now in China,some meningococcal group B vaccines are also developing in domestic companies and research institutes.Therefore,to further understand these vaccines and facilitate the development of meningococcal group B vaccines,this paper reviews advance and challenge in research on meningococcal group B vaccines.

Advance and challenge in research on meningococcal group B vaccines / 药物评价研究

It is generally accepted that vaccinations are one of the most effective tool for control of infectious diseases.In recent years,the research on meningococcal group B vaccines has made progress extensively.A new meningococcal group B vaccine,developed by the reverse vaccinology technology,has been approved by the European Medicines Agency and the Food and Drag Administration.Although no related products has been approve till now in China,some meningococcal group B vaccines are also developing in domestic companies and research institutes.Therefore,to further understand these vaccines and facilitate the development of meningococcal group B vaccines,this paper reviews advance and challenge in research on meningococcal group B vaccines.

Roles of Outer Membrane Vesicles (OMVs) in Bacterial Virulence

Outer membrane vesicles (OMVs) are ubiquitous membranous structures in all Gram-negative bacteria, including pathogens and non-pathogens. Gram-positive bacteria also release membrane-derived vesicles (MV). Originating from the cell envelope, OMVs are enriched with bacterial antigen molecules that conduct multiple functions as decoys to manipulate the host immune system. Besides, OMVs and their components play diverse roles in nutrient acquisition, biofilm formation, and resistance to antibiotics. Despite the diverse benefits ascribed to OMVs, many questions remain unanswered with regard to OMV biogenesis and cargo selectivity. In this report, we review the advantages of vesiculation in the context of all bacteria and then focus on additional benefits acquired by OMVs in pathogenic bacteria.

New versus old meningococcal Group B vaccines: How the new ones may benefit infants & toddlers.

Invasive disease caused by Neisseria meningitidis is associated with high mortality and high disability rates and mainly affects children under one year of age. Vaccination is the best way to prevent meningococcal disease, especially in infants and toddlers. The introduction of massive meningococcal serogroup C vaccination has drastically reduced the incidence of disease caused by this serogroup, and serogroup B has now become the main causative agent in several industrialized countries. The first serogroup B vaccines, which were used for more than two decades, were based on outer membrane vesicles and proved to be protective only against specific epidemic strains in Cuba, Norway, Brazil and New Zealand. Moreover, these often elicited a scant immune response in young children. Innovative genomics-based reverse vaccinology subsequently enabled researchers to identify genes encoding for surface proteins that are able to elicit a strong immune response against several B strains. This important discovery led to the development and recent approval in Europe of the four-component meningococcal serogroup B (4CMenB) vaccine. Large clinical trials have shown high immunogenicity and tolerability and acceptable safety levels of 4CMenB in infants and toddlers. This vaccine is expected to cover a large number of circulating invasive strains and may also be efficacious against other serogroups. Young children are particularly vulnerable to the devastating consequences of meningococcal disease. Given the high performance of 4CMenB and its non-interference with routine vaccinations, this age-group will be the first to benefit from the introduction of this vaccine.

Cinética do cultivo de Neisseria lactamica em biorreator / Bioreactor cultivation kinetics of Neisseria lactamica

Neisseria lactamica está envolvida na aquisição da imunidade natural contra Neisseria meningitidis, causadora da doença meningocócica. Vesículas de membrana externa (OMV) de N. lactamica são antígenos potenciais contra N. meningitidis. Analisou-se a cinética de biomassa, de produção de OMV, da fonte de carbono (lactato), e dos metabólitos, para maximizar a produção de OMV. Realizaram-se ensaios em biorreator, em batelada simples, batelada alimentada com lactato, com ou sem pulsos de aminoácidos e extrato de levedura (YE). Utilizou-se o meio de Catlin (MC) como meio mínimo, e analisaram-se efeitos das concentrações do lactato, aminoácidos e YE. Lactato foi consumido e citrato e acetato produzidos. Os melhores resultados obtidos foram no meio com adição de 2 g/L de YE e concentrações dobradas de lactato e 5 aminoácidos constitutivos do MC, em batelada alimentada com pulsos. O lactato apresentou efeito positivo sobre o rendimento de OMV e o YE sobre a biomassa. Os 5 aminoácidos constitutivos do MC foram necessários para obtenção de biomassa e rendimento de OMV.

Neisseria lactamica is involved with the acquisition of natural immunity to Neisseria meningitidis. N. lactamica outer membrane vesicles (OMV) are potential antigens against N. meningitidis, the pathogen of meningococcal disease. The objective of this work was to analyze the kinetics of bacterial growth, OMV production, the carbon source (lactate), and products of metabolism, to improve growing conditions and OMV production. Groups were studied in batch process, fed-batch process with lactate, fed-batch process with pulses of amino acids and YE. MC was considered as minimal medium and it was analyzed the effect of lactate, amino acids and YE. Lactate was consumed and citrate and acetate increased in the medium. The best results were in fed-batch with pulses, in MC with the double concentrations of lactate and amino acids, added with 2 g/L of YE. The lactate had a positive effect over OMV yield and YE had a positive effect over biomass. 5 amino acids of MC were necessary to obtain biomass and OMV yield.