The ovine cytotoxic T lymphocyte responses to bluetongue virus

This study uses recombinant vaccinia viruses expressing truncated or entire bluetongue virus (BTV) proteins to map the location of epitopes recognized by cytotoxic T lymphocytes (CTL) from Australian merino sheep. The non-structural protein, NS1, was recognised by CTL from all sheep, while VP2, VP3, VP5 and VP7 were recognised by CTL from only some sheep. The remaining proteins (except for VP1, which was not tested) did not contain CTL epitopes. When truncated genes were used to map the location of CTL epitopes, it was found that sheep often have CTL that recognise more than one epitope in NS1 or VP2. Overall there was considerable diversity in the CTL recognition patterns in the sheep tested.