Biosynthesis and Immunological Evaluation of a Dual-Antigen Nanoconjugate Vaccine Against Brucella melitensis

Brucellosis,caused by Brucella,is one of the most common zoonosis.However,there is still no vaccine for human use.Although some live attenuated vaccines have been approved for animals,the protection effect is not ideal.In this study,we developed a dual-antigen nanoconjugate vaccine containing both polysaccharide and protein antigens against Brucella.First,the antigenic polysaccharide was covalently coupled to the outer membrane protein Omp19 using protein glycan coupling technology,and then it was successfully loaded on a nano-carrier through the SpyTag/SpyCatcher system.After confirming the efficient immune activation and safety performance of the dual-antigen nanoconjugate vaccine,the potent serum antibody response against the two antigens and remarkable protective effect in non-lethal and lethal Brucella infection models were further demonstrated through different routes of administration.These results indicated that the dual-antigen nanoconjugate vaccine enhanced both T helper 1 cell(Th1)and Th2 immune responses and protected mice from Brucella infection.Furthermore,we found that this protective effect was maintained for at least 18 weeks.To our knowledge,this is the first Brucella vaccine bearing diverse antigens,including a protein and polysaccharide,on a single nanoparticle.Thus,we also present an attractive technology for co-delivery of different types of antigens using a strategy applicable to other vaccines against infectious diseases.

Construction of Entrepreneurship Courses in Tibetan Agriculture and Forestry Colleges and Universities

Both the state and the Tibet Autonomous Region always care about and attach great importance to the construction of entrepreneurship courses and enterprise education of college students.In the context of mass entrepreneurship and innovation,the entrepreneurship courses of Tibetan agriculture and forestry colleges and universities undertake the unique historical mission.As the important guarantee for cultivating entrepreneurship and innovative talents of Tibetan agriculture and forestry disciplines,the entrepreneurship courses of Tibetan agriculture and forestry colleges and universities have unique and important theoretical and realistic significance.Through the overall survey and analysis of the construction of entrepreneurship courses in Tibetan agriculture and forestry colleges and universities,this paper made clear problems and obstacles in the construction of entrepreneurship courses in Tibetan agriculture and forestry colleges and universities,and came up with scientific,reasonable,and feasible recommendations,to provide support for long-term mechanism construction of entrepreneurship courses in Tibetan agriculture and forestry colleges and universities and even other areas.

Media Effect of Students’ Ideological and Political Work in Tibetan Agricultural Colleges and Universities

Both the students’ ideological and political work and the media work in agricultural colleges and universities are priorities of agricultural higher education in Tibet. The economic and social development situation in Tibet,especially the modern agricultural development trend in Tibet,provides excellent development opportunities and challenges for both the students’ ideological and political work and the media work in Tibetan agricultural colleges and universities. On the whole,the students’ ideological and political work and the media work should not be treated with discrimination. Instead,they should be effectively integrated and coordinated,to form joint efforts,so as to create a bright spring for agricultural higher education of Tibet.

例谈柯西不等式的变式在竞赛中的应用

柯西不等式在国内外各级各类数学竞赛中屡见不鲜,能够灵活巧妙地运用柯西不等式将给一类竞赛不等式的证明带来方便.事实上,竞赛不等式中还有一类问题和柯西不等式的变式密切相关.本文从近几年国内外数学竞赛试题出发,谈谈它在证明不等式问题中的应用,希望对读者有所帮助.

霍乱弧菌检测技术研究进展

随着社会的发展,公共卫生及水体质量已得到明显提升,但到目前为止在发展中国家由霍乱疫情导致的死亡率依旧非常高,而霍乱弧菌即为霍乱疫情爆发的病原菌,且霍乱在我国被列为甲类传染病。目前国内外针对霍乱弧菌已经建立了多种有效的检测技术,对控制霍乱暴发作用显著。本文综述了近年来霍乱弧菌检测技术研究新进展,包括微生物学、免疫学、分子生物学等较成熟的检测方法,生物传感器、快速检测技术等新兴检测方法,并总结各种技术优缺点,展望未来霍乱弧菌检测的市场需求。

Orthogonal modular biosynthesis of nanoscale conjugate vaccines for vaccination against infection

Conjugate vaccines represent one of the most effective means for controlling the occurrence of bacterial diseases.Although nanotechnology has been greatly applied in the field of vaccines,it is seldom used for conjugate vaccine research because it is very difficult to connect polysaccharides and nanocarriers.In this work,an orthogonal and modular biosynthesis method was used to produce nanoconjugate vaccines using the SpyTag/SpyCatcher system.When SpyTag/SpyCatcher system is combined with protein glycosylation technology,bacterial O-polysaccharide obtained from Shigela flexneri 2a can be conjugated onto the surfaces of different virus-like particles(VLPs)in a biocompatible and controlled manner.After confirming the excellent lymph node targeting and humoral immune activation abilities,these nanoconjugate vaccines further induced efficient prophylactic effects against infection in a mouse model.These results demonstrated that natural polysaccharide antigens can be easily connected to VLPs to prepare highly efficient nanoconjugate vaccines.To the best of the researchers1 knowledge,this is the first time VLP-based nanoconjugate vaccines are produced efficiently,and this strategy could be applied to develop various pathogenic nanoconjugate vaccines.

O2血清型肺炎克雷伯氏菌多糖结合疫苗的生物合成

本研究旨在利用微生物体内合成肺炎克雷伯氏菌(Klebsiella pneumoniae,Kp)多糖结合疫苗并研究其保护效果。通过敲除Kp O抗原连接酶基因waaL阻断其LPS合成,再向缺失株中导入糖基工程载体,使细菌能够在体内合成糖蛋白,并将该糖蛋白免疫小鼠后评价其保护效果。结果表明,在构建的KpwaaL缺失株中导入糖基工程载体后,底物蛋白重组霍乱毒素B亚单位rCTB (Recombinant cholera toxin B subunit)能够被O糖化,从而得到糖蛋白;动物实验结果显示该疫苗能刺激小鼠产生较高的抗体效价,试验组小鼠攻毒后一周存活率可达75%。这种生物合成方法制备的多糖结合疫苗有望成为针对肺炎克雷伯氏菌的新型候选疫苗。

Bautype: Capsule and Lipopolysaccharide Serotype Prediction for Acinetobacter baumannii Genome

Acinetobacter baumannii has three clusters of genes for polysaccharide synthesis.Capsular polysaccharides and lipopolysaccharides are major virulence determinants in many Gram-negative bacteria,and play key roles in the overall fitness and virulence in A.baumannii,meanwhile poly-beta-1-6-N-acetylglucosamine was critical for biofilm formation.A variety of studies have been conducted which focused on the surveillance of antimicrobial resistance genes and clones in A.baumannii.However,a tool to perform serotype prediction in A.baumannii is still lacking.Here we present Bautype,a tool for whole genome sequencingbased K and O locus typing in A.baumannii.Using Bautype,users can upload and analyze the genome assembled in a web browser,with the results being displayed in a tabular or graphical format.We demonstrated the high accuracy of predicting K and O locus diversity using Bautype when analyzing more than 3000 A.baumannii genomes.Using our software,we were able to analyze K and O locus diversity among 593 genomes belonging to ST208(3 K and 8 O).These diverse loci can serve as epidemiological markers for Multi-drug Resistance(MDR)strain subtyping.We also identified 45 novel O locus types.Our findings highlight the importance in monitoring the capsule type and LOS of A.baumannii strains for which Bautype is a tailored clinical software.Bautype is available at http://BauType.net.