The Expression Of S1 Gene Of IBV In E.coli And The Preliminary Identification Of It's Biological Activity

Infectious bronchitis (IB) is an acute and highly contagious disease in chickens caused by infectious bronchitis virus (IBV) which is a member of Coronavrindae family and contains a single stranded, positive sense RNA genome of about 27.6kb. The S1 protein of IBV is the main ptotective antigen, induces neutralization antibody and hemagglutination inhibition antibody and plays an important role in the serology taxology. The S1 protein has good specificity and varys very frequency. Because of variation of S1 protein, new serotype of IBV appears very frequently. So, IB is very diffuclt to controll.The S1 gene of IBV was cloned into expression vector pGEX-6p-1 by gene recombination technology. E. coli transformed by the recombinant plasmid containing IBV S1gene was induced by IPTG.. The results of SDS-PAGE showed that GST fusion proteins were expressed successfully. And, obvious bands in pGEX-IBV-S1A and pGEX-IBV-S1B were showed by Western-blot.GST fusion proteins of pGEX-IBV-S1A and pGEX-IBV-S1B were purified with Glutathione Sepharose 4B, when pGEX-IBV-S1A and pGEX-IBV-S1B were induced by IPTG in 16℃incubator overnight. The results of ELISA assays showed that the A and B GST fusion proteins had good antigenicity. Rabbits were vaccinated with the purified GST fusion proteins. The antibody was gotten after three times immunization. The antibody and IBV were incubated in 37℃incubator for 30 minutes, and then TOC experiment was made. In the TOC experiment period, the oscillation of annulus trachealis ciliary was observed and the PH of medium maintained at 7.2-7.4. The result showed that the antibody induced by segment A could inhibit the partial activity of IBV with SN endpoint of 1:18 while the antibody induced by segment B could completely inhibit the activity of virus with SN endpoint of...