Generation and characterisation of bovine antigen-specific T cell lines

15 antigen-specific T cell lines have been generated from eight individual cattle immunised with ovalbumin. Several sources of interleukin-2 (IL-2) were used, including a supernatant from a gibbon cell line (MLA-Sup), human recombinant IL-2 (hrIL-2) and bovine recombinant IL-2 (brIL-2). These IL-2 sources were used alternately with autologous peripheral blood mononuclear cells (PBM) together with ovalbumin to generate the lines. They grew least well in MLA-Sup and best in brIL-2. FACS analysis indicated that the lines generated with the recombinant IL-2s were extremely homogeneous in that the majority of cells were BoCD4+ (bovine CD4 equivalent) and therefore of TH phenotype. The lines were antigen specific and responded to antigen only in the presence of autologous PBM and not allogeneic (MHC class I nonidentical) PBM. However, allogeneic PBM did support their proliferation to ConA. No MLR response was observed by the cell lines to allogeneic PBM. The response to antigen was inhibited by anti bovine class II mAbs but not an anti bovine class I mAb. The subpopulation of PBM which acted as antigen presenting cells for these bovine TH cell lines had typical macrophage characteristics.