ABSTRACT
In previous studies, we found that truncated rotavirus VP4* (aa 26-476) could be expressed in soluble form in Escherichia coli and confer high protection against rotavirus in the mouse mode. In this study, we further improved the immunogenicity of VP4* by polymerization. The purified VP4* was polymerized through incubation at 37 ℃ for 24 h, and then the homogeneity of the particles was analyzed by HPLC, TEM and AUC, while the thermal stability and antigenicity was analyzed by DSC and ELISA, respectively. Finally, the immunogenicity and protective efficacy of the polymers analyzed by a mouse maternal antibody model. The results showed that VP4* aggregated into homogeneous polymers, with high thermostability and neutralizing antibody binding activity. In addition, VP4* polymers (endotoxin <20 EU/dose) stimulated higher neutralizing antibodies and confer higher protection against rotavirus-induced diarrhoea compared with the VP4* trimers when immunized with aluminium adjuvant. In summary, the study in VP4* polymers provides a new strategy for the development of recombinant rotavirus vaccines.
Subject(s)
Animals , Mice , Antibodies, Viral , Antigens, Viral , Capsid , Capsid Proteins , Polymerization , Rotavirus , Rotavirus InfectionsABSTRACT
Echinococcosis (hydatid disease) caused by the metacestodes of Echinococcus granulosus tapeworm is a seri-ous zoonotic infection ,which leads to a large amount of economic loss in human and animals .It needs to be prevented urgently . The EG95 protein is highly conserved and crucial for survival and development of E .granulosus in the host ,which means that it is one of the potential candidate antigens for vaccines characterized so far .Great effort has been made to construct and ex-press the recombinant EG95 (rEG95) gene in various kinds of expression systems in order to obtain an efficient defined antigen . This review will summarize research progress on expression of rEG95 in different vector systems .
ABSTRACT
Objective To clone and express recombinant outer membrane protein P6, determine its optimal expression conditions and to investigate the immunoprotective effects of the P6 protein on mice. Methods The P6 gene of nontypeable Haemophilus influertzae(NTHi) was amplified by PCR from the NTHi genome and cloned into expression vector pET-32a (+) to generate the pET-32a-P6 recombinants. They were confirmed by nuclease digestion and sequence analysis. The verified recombinant was transformed into E. coli BL21 (DE3). Its optimal expression conditions were determined such as engineering strains, the concentration of IPTG, inducing temperature, inducing time, different medium etc. The recombinant protein was purified by Q Sepharose~(TM) XL ion exchange and gel filtration chromatography. The protein was analyzed by SDS-PAGE, Western blot and sequencing. BALB/c mice were immunized with recombinant protein be-fore challenged by NTHi through intraperitoneal injection. Then the mortality rate of different group was com-pared. Results The recombinant P6 of NTHi was successfully constructed and expressed in E. coli at a rel-atively high level. The purity was up to 95% after purification. The relative molecular mass of the protein is 14 145. 848. The recombinant protein was confirmed to show specific reaction on the antiserum through Western blot. The animal experiments showed the mortality rates of immunization groups were significantly lower than that of the control group (P < 0.05). Conclusion The successful expression of the recombinant P6 will be very helpful for the further study on development of vaccine, its purified, immunological activity and antibody preparation.