Construction Of A Recombinant Baculovirus And A Recombinant Pseudorabies Virus Expressing Vp4 Of Porcine Rotavirus For Vaccine

Porcine Rotavirus (PRV) belongs to the rotavirus group of the reoviridae family. It is one of the major pathogens of porkling diarrhea. In piglets of age from 1 to 4 weeks, incidence rate of the virus is over 80%, and death rate to 20%. The disease distributes in all worldwide. Its infection, which is causes of diarrhea, already became to a cosmopolitan disease. It brought severe loss to many states in graziery. at present effective vaccination is a unique path of prevention of the disease. And present vaccines have some defect, for example, an easy reversionary virulence, a bad immune effect in heterotypes, and so on. Pseudorabies Virus (PrV) belongs to the varicellavirus group of the herpesvirudae family. Transmission of PrV in porcine group causes the propagative disturbance, like abortion of pregnant pigs, intrauterine death etc. and respiratory organs illness. Because of faster transmission, more paths of transmission, wider epidemic limits, and high lethality, it is bring huge loss to swine breeding. In prevention of pseudorabies, attenuate vaccine Bartha-K61 is widely used. Effect of the vaccine is great and successful, and was proved in world. At present researching direction goes to study and develop of recombinant pseudorabies virus for life vector vaccine using biotechnology.In our study, at first PRV/JL94 was cultured in MA104 cell and purified with supercentrifugal method. Then the viral nucleic acid was extracted for next work. According to view of scientists: vp4 gene takes a important effect for PRV virulence; vp4 is still a pivotal neutralizing antigen, which stimulation to animal body induces and produces neutralizing antibody and immunologic defence; And one VP4 serotype probably includes few VP7 serotype. So it is more positive action to research vp4 for develop novel vaccine to prevent and control the disease. Many specialists regard: the segment of 5'endpoint of vp4 (about 750bp) takes a part in biological character. It is a major antigen-function domain. Therefore, according to sequence of complete gene vp4, 5'endpoint from 1bp to 756bp(include whole vp8, trypsin domain and N endpoint of vp5) was cloned. It was named vp4 major antigen site gene (vp4-MASG). Sequence analysis for vp4-MASG with overseas strain CRW-8 and Gottfried reveals: The homology of amino acid sequences was 96.43% and 67%. Among homotypes the sequences is high conservative, but among heterotypes the difference is great. The most divergence of amino acid sequence is located in a region delimited by aa81-aa207.