Different rates of interleukin 2 receptor expression by ovine gamma/delta and alpha/beta T cells.

We have used the monoclonal antibodies IL-A111, CACT116A, to investigate the expression of interleukin 2 receptors (IL-2R) by ovine peripheral blood T cells. Monoclonal antibodies (MAbs) IL-A111 and CACT116A reacted with concanavalin A (Con A) activated ovine lymphocytes and both mAbs did so with similar FACS (fluorescence activated cell sorting) profiles and fluorescence intensity. Following activation by Con A all three major ovine T cell subsets, namely CD4+, CD8+ and gamma/delta T cells, express the IL-2R. All gamma/delta T cells express IL-2R within 12 h following activation by Con A in vitro whereas alpha/beta T cells do not express the IL-2R until 24 h after the start of culture with the mitogen. In freshly isolated peripheral blood a small percentage of lymphocytes, which are almost all CD4+, express the IL-2R.