GLYCOPROTEIN E-RNS OF PESTIVIRUSES INDUCES APOPTOSIS IN LYMPHOCYTES OF SEVERAL SPECIES

Classical swine fever virus and bovine virus diarrhea virus are member s of the genus pestivirus, which belongs to the family of the Flavivir idae, Recently, envelope glycoprotein E-rns was identified as an RNase , RNases can express different biological actions, They have been show n to be neurotoxic, antihelminthic, and immunosuppressive. We studied the immunosuppressive properties of E-rns in vitro, The glycoprotein t otally inhibited concanavalin A induced proliferation of porcine, bovi ne, ovine, and human lymphocytes, We then studied the direct cytotoxic effects of E-rns on lymphocytes and epithelial cells in protein synth esis assays. E-rns strongly inhibited the protein synthesis of lymphoc ytes of different species, without cell membrane damage, This suggeste d an apoptotic process, and indeed apoptosis of lymphocytes was detect ed after incubation with E-rns, Pestivirus infections are characterize d by leukopenia and immunosuppression, Our results suggest that E-rns plays an important role in the pathogenesis of pestiviruses.