Analysis of pokeweed mitogen-induced in vitro proliferative and antibody responses of bovine lymphocytes

The functional role of subpopulations of bovine cells in the regulation of pokeweed mitogen (PwM)-induced proliferative and antibody responses of peripheral blood mononuclear cells (PBM) was analysed. Subpopulations of bovine PBM identified by specific monoclonal antibodies (mAbs) were isolated by sorting them through the fluorescence activated cells sorter (FRCS). The depletion from PBM of T cells bearing the CD4 marker, recognised by mAb IL-A12, resulted in a reduction of PwM-induced responses, which could be partly reversed by the addition of CD4 positive T cells. The depletion of cells belonging to the macrophage/monocyte lineage also resulted in a reduction of PwM-induced proliferative responses. PBM depleted of CDs positive T cells, recognised by mAb II.-A51, showed increased PwM-induced responses, which in turn were reduced by the addition of mAb II,-A51 positive cells. Proliferative and antibody responses were also obtained by PWM stimulation of FACS-purified B cells, in the presence of bovine T cell growth factor.