Effect of ribonuclease from Bacillus intermedius on human blood lymphocytes

By using a rosette formation test the effect of ribonuclease Bacillus intermedius (RNase Bi) on T- and B-lymphocytes in human peripheral blood has been studied in vitro. The RNase effect on T-lymphocytes depends on its concentration: low concentrations (10(-6)-10(-2) microg ml(-1)) stimulate E-rosette formation whereas high concentrations (10 microg ml(-1)) suppress it. The amount of B-lymphocytes decreases under RNase Bi influence in all concentrations tested. RNase Bi like thymus hormones influence immature lymphocytes (0-cells) by inducing the surface expression of E-receptors what leads to rosette formation and, thus, contributes to lymphocyte differentiation. The increase in the amount of active T-cells which represent the mature cell population also confirms the participation of RNase Bi in T-rank lymphocytes differentiation processes. The RNase Bi effect on the human lymphocytes depends on its catalytic activity.