Obejective The domainⅢof dengue virus type 2 envelope was cloned and expressed in Escherichia coli and the inhibited effects of recombinant protein on virus was detected.
Methods In this study, the domainⅢ(DⅢ) protein of the dengue virus type-2 (DENV-2) envelope (E) antigen was expressed in Escherichia coli by fusion with a carrier protein. The protein was puriifed using enzymatic cleavage and afifnity puriifcation. Rabbit immunization and antibody detection was carried out. Inhibition of DENV-2 infection was observed by DENV-2 EDⅢprotein and its immunity rabbits serum.
Results The recombinant expression DENV-2 EDⅢ protein plasmid was constructed successfully. After isopropyl thiogalactoside induction, a speciifc soluble 29 kD protein was obtained, and the expression product accounted for 68.87%of the total protein of the cell lysate. Western blot demonstrated the reactivity of the recombinant protein with his-tag and DENV (Ⅰ-Ⅳ) monoclonal antibodies. The protein was puriifed using enzymatic cleavage and affinity purification. The purified recombinant EDⅢ protein inhibited the entry of DENV-2 into BHK-21 cells. DENV-2 plaque neutralization assays were carried out using serially diluted antibodies against EDⅢprotein. At a 1︰16 dilution, the antibodies produced at least 90%neutralization of the DENV-2 virus. Furthermore, the antibodies continued to exhibit high neutralization effects (approximately 80%) until the anti-EDⅢantibody titer reached 1︰1 024.
Conclusions DENV-2 EDⅢwas cloned and expressed successfully. DENV-2 EDⅢprotein could be useful in the development of inexpensive dengue vaccine. The data also suggested that DENV-2 employed an attachment molecule or receptor for its entry into C6/36 mosquito cells.

预防肿瘤术后复发和转移的新疗法 :热休克蛋白 /肽复合物疫苗的研究与应用

Deepened understanding of the mechanism involved in the activation of T cells and improved molecular biology techniques have brought a promising strategy to active a patient's immune system to prevent tumor recurrence and metastasis. Heat shock proteins (HSPs) are chaperones of peptides,It can elicit array of immune responses,such as:present tumor antigens to T cells, stimulate antigen presenting cells to secrete cytokines,mediate maturation of dentritic cells,active NK cells and/T cells.Extract HSP/peptides complex from tumor cells can be used as a polyvalent vaccine for treatment of cancers,The elicited antigen specific immune response is restricted to the tumor from which the HSPs are purified.HSP/peptides complex vaccine has been started in third clinical trials.The rationale,feasibility,advantages and safety of this new approach were discussed.

Objective: To describe the expression and immunogenic efficacy of differently produced recombinant vaccines candidates against Pseudomonas aeruginosa infections. Methods: The hybrid protein OprF (aa 190-342)-Opr I (aa 21-83) was modified N-terminally, either with a minimal histidine tag or with a homologous sequence of OprF. Both recombinant proteins were purified by nickel chelate affinity chromatography under native and denaturing conditions. Results :This produced three suitable candidates for a vaccination trial: protein His-F- I , which was purified in its native as well as in its refolded form,and the native purified N-terminally extended protein ex-F- I . In mice, significantly higher antibody titers and survival rates after challenge with P. aeruginosa were observed, following immunization with protein His-F- I purified under native conditions. Conclusion: A hybrid OprF-Opr I molecule was cloned and a purification method which yields a protective vaccine against P. aeruginosa infections was established.

A novel avian influenza A (H7N9) virus recently emerged in the Yangtze River delta and caused diseases, often severe, in over 130 people. This H7N9 virus appeared to infect humans with greater ease than previous avian inlfuenza virus subtypes such as H5N1 and H9N2. While there are other potential explanations for this large number of human infections with an avian influenza virus, we investigated whether a lack of conserved T-cell epitopes between endemic H1N1 and H3N2 inlfuenza viruses and the novel H7N9 virus contributes to this observation. Here we demonstrate that a number of T cell epitopes are conserved between endemic H1N1 and H3N2 viruses and H7N9 virus. Most of these conserved epitopes are from viral internal proteins. The extent of conservation between endemic human seasonal inlfuenza and avian inlfuenza H7N9 was comparable to that with the highly pathogenic avian inlfuenza H5N1. Thus, the ease of inter-species transmission of H7N9 viruses (compared with avian H5N1 viruses) cannot be attributed to the lack of conservation of such T cell epitopes. On the contrary, our ifndings predict signiifcant T-cell based cross-reactions in the human population to the novel H7N9 virus. Our findings also have implications for H7N9 virus vaccine design.

Ebola virus disease (EVD) is an acute hemorrhagic infectious disease caused by ebola virus, with high infectivity and fatality rate. At present, it mainly occurs in areas of Central Africa and West Africa and no effective vaccine and antiviral drugs are available for the clinical treatment.