Clone And Analysis Of Canine Distemper Virus H Gene And DNA Vaccine Research

Canine distemper is caused by canine distemper virus(CDV).Its a acute, highly contagious dieases.The disease is prevalent worldwide, and often occurs in our country. Currently it is one of the most serious diseases threaten the dog industry. CDV often infect minks, foxes and other animals as well as dogs. The mortality rates amoung dogs, minks, foxes are 30%-80%, ferrets suffer a 100% mortality rate. The CDV gene has been found in human patients with Page's disease. Recent development of molecular biology techniques has pushed the study of CDV forwards, CDV has also promoted the need for further research.This experiment was conducted to study the genetic variations and to phylogenetic analysis of Canine Distemper Viurs of pet dogs. Conjunctival and nasal cavity swab samples were diagnosised by RT-PCR and 7 Heamagglutinin(H) gene was amplified and a phylogenetic tree was built. Basis of sequense similarity that we clusted the sequences and found that's according to geographical distribution. The potential N-linked glycosylation site reveals the disparity bettwen vaccine and wild virus but the proline residue and the cysteine residue are consistant. The samples we detected were all Asia-I strain, and the change of antigenicity was on account about the diversity about N-linked glycosylation site.To explore the CDV DNA vaccine perspective immunity, This study amplified part of the coding sequence of CDV H/N protein, and connected with the eukaryotic expression vector pVAX, injected BALB/c inbred mouse vastus medialis. An indirect ELISA assay was developed to detected serum antibody of mice. In order to optimize the immune results, we established the injected dose gradient, and used pVAX-CDV-H, pVAX-CDV-N, pVAX-CDV-HN fragments of different exogenous as control. The results show that immunization in this experiment at 10 ~ 30μg dose, and theN and H gene combined have the highest immunization effect.