Recombinant capriposviruses expressing proteins of bluetongue virus : evaluation of immune response and protection in small ruminants

Abstract

Bluetongue is an infectious arthropod-borne viral disease affecting sheep, domestic and wild ruminants caused by Bluetongue Virus (BTV) and transmitted by few species of Culicoides (Diptera: Ceratopogonidae). Since 1998, outbreaks of BT involving 6 distinct serotypes have occurred in the Mediterranean basin. The only BTV vaccines currently available are serotype specific. Objectives: The development of recombinants capripoxvirus for protective immunization of ruminants against bluetongue virus (BTV) infection is described here. Methodology: Sheep (n=11) and goats (n=4) were immunized with bluetongue recombinant capripoxvirus (BTV-Cpox) expressing individually four different genes encoding two capsid proteins (VP2 and VP7) and two non-structural proteins (NS1, NS3) of Bluetongue virus serotype 2 (BTV-2). Results: Seroconversion was observed against NS3, VP7 and VP2 in both groups of animals. A specific BTV antigens lymphoproliferation observed in goats corroborates with a partial protection in sheep challenged with a virulent strain of BTV-2