1Division of Veterinary Biotechnology, Indian Veterinary Research Institute, Izatnagar-243122, Uttar Pradesh.
2Division of Avian Diseases, Indian Veterinary Research Institute, Izatnagar-243122, Uttar Pradesh.
Abstracts of the papers presented at the 16th Annual Convention and International Symposium of Indian Virological Society on “Management of Vector-Borne Viruses” at International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru-502324, Hyderabad, India, February 7–10, 2006.
The complete coding sequence of F gene of Newcastle disease virus (NDV) was amplified from both avirulent and very virulent NDV strains by RT-PCR. After confirming the authenticity of fusion gene by its size and nested PCR, the same were cloned into mammalian expression vectors pcDNA3.1(+) and pVAX, respectively. Recombinant plasmid having F gene was found to express fusion protein in Vero cells upon transfection. The recombinant plasmids were purified by QIAquick midi prep columns and used to immunize birds in different combinations. For this 25 birds were divided in to 5 groups (A to E). Group A birds were immunized with 100 ìg of recombinant plasmid containing F gene from very virulent strain, group B was immunized with recombinant plasmid containing F gene from avirulent strain. Group C was immunized with 100 mg recombinant plasmid containing F gene of virulent + recombinant plasmid having HN gene and Group D was with recombinant plasmid containing F gene of avirulent + recombinant plasmid having HN gene. Group E served as uninfected control. Serum samples from all birds were taken at day 14 and birds were challenged with 104.5EID50 virus and observed for appearance of clinical symptoms. Virus neutralization study indicated that average VNT titre of sera was 44.8, 32, 51.2, 38.4 in group A to D, respectively. Overall, 60% birds were protected in groups A and C whereas only 40% protection was observed in-group B and D. All the birds of group E died.
