Studies On Recombinant Vaccine Of Newcastle Disease Virus In Chickens

Newcastle disease(ND), caused by Newcastle diseasevirus(NDV), is a highly contagious disease,and often makes agreat economic loss to avian industries. In the study, fordeveloping a new type of vaccine for controlling the disease,a recombinant baculovirus containing a eDNA which encodeshemagglutinin膎euraminidase (HN) of Newcastle disease virus(NDV) was constructed, which could produce a large amount ofHN glveoprotein successfully by infecting Spodopterafrugiperda (Sf) cells. Using the expressed recombinant proteins,liposome vaccines were developed and characterized. The resultsobtained in this study are summarized as follows.1.The recombinant protein expressed by haculovirus wasidentified by hemagglutination test and hemagglutinationinhibition test. The i-塻ults demonstrated the recombinanthacu]ovirus expressed HN protein of NDV specifically.2.Using the expressed HN protein, liposome vaccines weredeveloped, of which optimal mass ratio between lecithin andcholesterol 鵤nd the optimal pH of virus liquid weredetermined.3.The liposome vaccine was detected by electron microscope,spectrophotometer, asepsis test etc.,which demonstratedthat the lipsome vaccine developed in this study had a goodquality.4.Immune dose of the vaccine was determined by immune doseselection test, O.5m1 dose group of which produced higherW~駘Mki~antibodies than other groups.3.Antibody production in the 1 iposome vaccine膇noculatedchickens was examined by I-lI test. The results showed thatthe inoculated chickens produced HI antibodies, and the HItiters of the sera reached to 32.6.Protective effect of the liposome vaccine was examined invivo. 60% of the chickens inoculated with the vaccinesurvived from the challenge by the virulent NDV withoutshowing any clinical signs of Newcastle disease. On theother hand, the uninocuiated control chickens showedtypical clinical signs after the challenge.7.Expression of IL? (Jnterleukin 2), IFN膟 (Interferon膇)and cMGF(chicken Myelomonocytic Growth Factor),weredetected by RT腜CR (Reverse transcript ion膒olymerase chainreact ion) . The results demonstrated that expression of iL?increased due to inoculation of Iiposome vaccines.The results of the study provide important basic data fordevelopment of liposome vaccines using recombinant baculovirusexpressed proteins.