Figure 5.

Peptides NS1(141) and NS1(522) are CD4 epitopes in sheep. PBLs from sheep infected experimentally with BTV-8 were cultured for 5 days with (A) NS1(141) or (B) NS1(522) peptides and proliferative responses were measured using ³H-thymidine incorporation. Three out of 4 sheep tested had specific proliferative responses to these peptides. Data are presented as stimulation index representing the ratio of cpm between peptide stimulated PBLs vs DMSO control culture PBLs. * p < 0.05 Unpaired Student t test NS1 peptide vs control. (C) To determine whether the proliferative response and IFN-γ production to these NS1 peptide in sheep was mediated by CD4+ or CD8+ T cells, intracellular IFN-γ staining of peptide-stimulated sheep PBL was performed and data were analysed by flow cytometry. The production of IFN-γ to NS1(141) and NS1(522) peptides was detected in CD4+ T cells but not in CD8+ T cells. Data presented are representative of 3 sheep.