Produzione di antigeni ricombinanti del virus della bluetongue

Bluetongue Virus is the type species of the genus Orbivirus, within the family Reoviridae. Ovens are infected with the virus by certain species of biting midges (Culicoides) and BTV is the aetiologic agent of catarrhal fever or Bluetongue. Disease is cause of important economic losses for country involved in; this reason make us consider BTV as an emergency and for this is necessary to carry on studies in order to find out solutions for preventing and fighting his proliferation. The purpose of this work was the production of recombinant antigen in eterologous system from BTV serotype 2, that arrived in Sardinia into 2001, to use them as diagnostic and preventives tools of the disease. In order to obtain this result, virus has been isolated, identified as BTV serogroup and as serotype 2 of Corsican strain and a library of the viral DNA has been created. Two of virus’s genes (L2 and S7) have been cloned in bacterial system , sequenced and the protein codified from S7, the VP7, expressed in recombinant form, purified, and characterized with Immunoblotting and ELISA. Moreover, the S7 gene was cloned into expression system for plants transformation. The attempts to stop disease with attenuated vaccines in 2000 get a lot of problems due to the virus reversion causing collateral effects as abortion and birth of lambs with physical deformity. At the moment, different attempts based on BTV sub unity for the production of recombinant vaccines have been done. They have been demonstrated extremely safe and effective in protecting sheep as they are suitable for DIVA diagnostic. Anyway, different inoculations are necessary for the tool efficacy as for inactivated vaccines and in addition the high production costs in conventional systems stop from their utilization in the prevent campaigns. A different way of work is to use plants as model of expression. Plants offer high expression level of proteins, in fact some vegetable organs cumulate a big quantity of proteins, moreover, it is very easy to increase or decrease the levels of production and the costs of production for recombinant vaccines in this system are cheapest. Protein’s antigenic properties product in plants could be tested in animals models. We hope this type of work will lead us to build up efficient disease controls system in the future.