Construction, Identification And Immunological Study Of VLPs Of RABV, CPV, CPV-RABV And CPV-CDV

Rabies, caused by rabies virus, is a kind of important zoonosis. Each year,approximately 55000 individuals worldwide die of rabies, while bite of the animals carrying rabies virus is mainly due to infectious disease, so elimination of animal rabies is one of the best way to control rabies in humans. Canine parvovirus and Canine distemper virus, are highly contagious pathogens, hold great harm to economic animal breeding and cause significant economic losses. Currently the vaccines for prevention of those virus infection are attenuated vaccine and inactivated vaccine, but there is corresponding problem. Therefore, it is significant to investigate the new generation vaccines against RABV, CPV and CDV.The study explored the VLP-based vaccines against RABV, CPV and CDV as followed.1. The construction and identification of rabies virus-like particles and the immunological studyAt present, many kinds of VLPs have been reported but rabies virus-like particles. In this study the Bac to Bac system was used to construct the recombinant baculovirus which expressed G protein and M protein of rabies virus.Then the two kinds of recombinant viruses were mixed and injected into silkworms and pupas. The expression of corresponding proteins and rabies virus-like paticles packaging were tested. The antibody levels of VLP-immunized mice,detected by ELISA,was increased. The results showed that the VLP was immunogenic and could stimulate the animals to produce corresponding antibodies.2. The construction and identification of canine parvovirus-like particles and the immunological study.the baculovirus expression system has many advantages and extensively applies to the production of recombinant protein, VLP, human vaccines and live vaccines. In the study Bac to Bac system and linear parental virus were used to construct recombinant baculovirus which could express VP2 of canine parvovirus and was injected into silkworms and silkworm pupas. The results demonstrated that the target protein was successfully expressed in silkworm and silkworm pupae and formed parvovirus-like particles. The antibody against canine parvovirus, produced by immunized with VLP, were determined by ELISA and hemagglutination inhibition assay. In addition, the expression of VP2 of linear parental virus DNA recombinant system was superior to the Bac to Bac system.3. The construction, identification and immunological research on chimeric parvovirus-like particlesVLPs can be directly used as immunogens, and also can be a carrier to deliver epitopes, DNA and small molecules. In this study two kinds of chimeric VLP were constructed: canine parvovirus/distemper virus chimeric VLP and canine parvovirus/rabies virus chimeric VLP. The protein expression and chimeric VLP packaging were detected in silkworm and silkworm pupae. The antibody against VP2 of canine parvovirus, produced by immunized with VLPs, was tested by ELISA and the hemagglutination inhibition test. The study determined that chimeric VLP packaging was formed with immunogenicity.The experimental results indicated that the production of VLP-based vaccines in the silkworm and pupae, through baculovirus expression vector, has a good prospect.