Semiliki forest virus vector carrying the bovine viral diarrhea virus NS3 (p80) cDNA induced immune responses in mice and expressed BVDV protein in mammalian cells

Bovine viral diarrhea virus (BVDV) is a primary pathogen responsible for bo vine enteric, respiratory and reproductive failure. A genetic region is enc oding the p80 (NS3) of BVDV as the most conserved protein among Pestiviruse s. BVDV infection in cattle induces NS3 specific lymphocyte proliferation a nd humoral responses. To generate a DNA vaccine against BVDV, the gene for BVDV-NADL NS3 was cloned into an eukaryotic expression vector of Semiliki F orest virus (pSFV-1). Quadriceps muscles of BALB/c mice were injected with recombinant DNA generated statistically significant cytotoxic T-lymphocyte activity (CTL) and cell mediated immune (CMI) responses against cytopathic and noncytopathic BVDV. Whereas, the BVDV-NS3 did not generate neutralizing antibodies against BVDV in mice. pSFV-1-NS3 DNA was subjected to in vitro transcription into mRNA. The mRNA was transfected into baby hamster kidney cells (BHK-21) and Madin-Darby bovine kidney cells (MDBK). The recombinant cells were used in the detection of DNA antigen responses by immunological assays. This report establishes the ability of BVDV-NS3 DNA inoculation to induce a strong cellular immune responses in mice. (C) 1999 Elsevier Scienc e Ltd. All rights reserved.