ABSTRACT
Rabies is a zoonotic infectious disease caused by lyssavirus and characterized by central nervous system symptoms. The fatality rate of rabies is almost 100%. About 59 000 cases die of rabies worldwide every year, mainly in Asia and Africa. China is an epidemic country of rabies. Grade II and III exposures are the main types of rabies exposures in China. Standardized post-exposure prophylaxis (PEP) can prevent rabies almost 100%. Human Rabies Vaccine Technical Working Group, National Immunization Advisory Committee and invited experts reached an expert consensus on PEP by referring to the World Health Organization′s position paper on rabies vaccine in 2018 and related research progress in recent.
ABSTRACT
Objective To construct the eukaryotic expression plasmid of the rabies virus glycoprotein gene DNA,and detect the immunogenicity.Methods Using RT-PCR amplified the glycoprotein gene of rabies virus CTN strain,sequenced and cloned into pcDNA5.0 (+) vector to construct the recombinant plasmid pcDNA5.0-G plasmid.Detect glycoprotein transient expression with transfecting the plasmid into 293T cells.Intramuscular immunization of BALB/c mice by the recombinant plasmid on day 0 and 7,then challenge by rabies virus CVS strain observed the mice survived.Results The results of the transient expression of glycoprotein abundantly expressed.The survival ratio of mice with CVS challenge after routine intramuscular injection of pcDNA5.0-G plasmid is 73.3％,and 6.7％ for the control group.Conclusion Rabies virus glycoprotein eukaryotic expression plasmid pcDNA5.0-G was successfully constructed,and has been good immunogenicity.It's to be the foundation for candidate DNA vaccine research and development.
ABSTRACT
Objective To explore the application of atomic force microscopy( AFM ) on the research of morphology of the rabies viruses. Methods To prepare the rabies virus CTN-1v strains by ultracentrifugation, and observe it with transmission electron microscopy (TEM) which negatively stained by phosphotungstic acid. Then study the morphology of rabies virus with AFM based on the result of TEM. AFM image applies the tapping mode to rabies virus without any further treatment in air at room temperature. Results The TEM image is two-dimensional image which can be seen the classical bullet-shaped structure,and the spike structure can also be seen. The AFM image showed the rabies virus morphology with three-dimensional image which can shows the characteristics of the virus surface and edge. The rabies virus particle was successfully observed by TEM or AFM methods. Conclusion It's the first time to get the three-dimensional morphological structure of rabies virus by atomic force microscopy, compared with transmission electron microscopy, AFM is a new research tool for viral morphology study with the advantages of simple sample preparing and intuitionistic and visible interface for researchers.
ABSTRACT
Objective To identify the biological and molecular biological characteristics of SN7 virus isolated from Niviventer Confucianus in Sichuan province. Methods Monoclonal antibody, PRNT and PCR antigenicity analysis and genotyping of SN7 strain were performed. M and S segments of SN7 genome were also cloned and sequenced. The sequences were compared with those of other strains of Hantavirus. Results It was difficult to identify SN7 by using monocloncal antibody, PRNT and PCR. With sequence comparison, we found that strain SN7 had high homology(80.2%～87.1% of M segment and 76.6%～92.0% of S segment) with HTN type strains, and relatively low homology(70.0%～71.6% of M segment and 71.0%～72.2% of S segment) with SEO type strains. Strain SN7 was believed to belong to HTN type. Conclusions SN7 is a new subtype strain of HTN type viruses. It is possible that Hantavirus has immune escape in its natural hosts.