Study Of DNA Vaccine Of Chicken Anemia Virus

Chicken Anemia Virus (CAV) is the pathogen of Chicken Infectious Anemia (CIA). CAV genome encodes three kinds of proteins: VPl(51.6kD), VP2(24.0kD) and VP3(13.6kD). VP1 is the only capsid protein of CAV. VP1 can induce immune protection of chickens with the help of VP2. VP2 is the disease-inducing protein.DNA vaccine is a new kind of vaccine. DNA vaccine can induce general and long-term immune reaction. The study and development of DNA vaccine break a new path to the prevention of CIA.In this study, two pairs of primers were designed and synthesized according to the DNA sequence of original CAV. In the primers, some changes were maken deliberately. By the method of PCR, mutations of three sites were maken: T(466) to C, C(472) to A and T(475) to G. These mutations restrain the expression of vp3 gene and have no effect on VP2. The DNA sequence was cloned into pET-30b(+) vector. The pET-CAVm was induced to express in E.coli DE3 by IPTG. Through SDS-PAGE, we can find that VP1 and VP2 were expressed and VP3 wasn't expressed. This means that the mutant of CAV has losen its ability of disease-inducing.Because CAV genome has promoter and enhancer, pUC18-CAVm can be used as DNA vaccine in animal experiment. From the result of animal experiment, we can conclude that pUC18-CAVm can induce immune protection although this protection is limited. This means that we can utilize DNA vaccine to prevent CIA. This study establishes a strong base for the successful manufacture of DNA vaccine of CAV.