Prokaryotic Expression Of Equine Influenza Virus HA1Gene Of H3N8Subtype And Serology Survey About Horse Influenza In Some Regions Of Xinjiang

Equine influenza caused by Equine Influenza virus (EIV) is an acute and highly contagious i nfectious disease, which has seriously threatened horse husbandry. The disease which spreads rapidl y and can cause fever, depression, cough, sneezing, hard breath, loss of appetite, abortion in mares and other symptoms.Hemagglutinin protein (HA), whose subunits are very different from the the a ntigenicity and immunogenicity between each other, is the most important structure protein of EIV. Some research show that the immunogenicity and antigenicity of HA1is stronger than the HA2. A ccordingly, the expression and purification of HA1protein is of great significance to diagnose Equ ine Influenza quickly and accurately.A/equine/Xin Jiang/07(H3N8) of EIV was inoculated into allantoic cavity of chicken embr yo, from which viral RNA was extracted. One pair of specific primers was designed according to t he published EIV-HA1gene sequences, and RT-PCR was used to amplify purpose gene which was cloned into pMD18-T. After digestion of the recombinant plasmid pMD18-T-HAl, the HA1gene was inserted into pET28a to produce prokaryotic expression vector of pET28a-HAl was transforme d into E.coli. Rosetta (DE3). A53ku recombinant protein was expressed after induction by isoprop yl-P-D-thiogalactoside (IPTG). The westernblot showed the recombinant protein can be specifically recognized by El-positive serum, and have good biological activity.Meanwhile, in order to further know the development and popularity of the Equine influenza i n Xinjiang. In the reaerch, a total of854serum samples from Xinjiang Yili Zhaosu County, Altay Fuyun County and Yili Zhaosu County in Xinjiang, were detected by HI test. The results showed that among the332serum samples of Yili Zhaosu County,266serum samples were positive and the positive rate is80.1%; Among the299serum samples of Altay Fuyun County,228serum sam pies were positive and the positive rate is76.3%; Among the223serum samples of Yili Xinyuan County,0serum sample was positive and the positive rate is0%. So it is indicated that the equin e influenza still spreads in Xinjiang, and the effective immune protection has not been formed, an d the serological epidemiological survey can provide a basis for the prevention and control of the infectious diseases.