Cultivation of bluetongue virus-specific ovine T cells and their cross-reactivity with different serotype viruses.

Bluetongue (BT) virus-specific ovine T-cell lines were prepared from BT virus-infected sheep by three cycles of alternate stimulation and resting culture in vitro. In antigen-specific proliferation assays and/or cytotoxicity assays, most of these T-cell lines responded not only to homologous serotype virus but also heterologous serotype viruses. This cross-reactivity did not correlate with the relatedness of serotypes as defined by cross-neutralizing antibodies. One cell line, 58-014, has grown continuously for more than 7 months without loss of antigen specificity. However, most of the cell lines lost their antigen specificity 2-4 months after cultivation. Certain BT virus-specific T-cell lines were able to reduce BT virus replication in autologous skin fibroblast cell culture.