Bovine interleukin 2: production by an E-rosette-defined lymphocyte subpopulation.

E-rosette-separated bovine peripheral blood lymphocyte subpopulations were examined for ability to produce interleukin 2 (IL 2). Sequential E-rosetting techniques resulted in three T-cell subpopulations and a non-T population. Separated cells were stimulated with Con A and the resulting culture supernatants were assayed for IL 2 activity on IL 2-dependent cells. The bovine T-cell subpopulation which rosetted with both neuraminidase-treated and 2-aminoethylisothiouronium bromide (AET)-treated erythrocytes was found to produce significantly more IL 2 than the other T-cell subpopulations or the non-T population. These results suggest that this population may have a T-helper cell function. IL 2-dependent cells were found to be predominately T-cells by E-rosetting, were lymphoblastoid in appearance and surface immunoglobulin negative. Conditioned media containing IL 2 were used to demonstrate cytotoxic T-cell activity against allogeneic lymphocytes in peripheral blood lymphocytes.