[Effect of the preliminary incubation of human peripheral blood lymphocytes on the intensity of transformation in phytohemagglutin stimulation].

Preincubation of lymphocytes in leukocytic suspension or those separated on verografin-Ficoll gradient at 37 degrees C leads to enhancement of blast transformation in response to phytohemagglutinin (PHA) stimulation. This effect is reversed by preincubation in the presence of soybean trypsin inhibitor (500 micrograms/ml). The results obtained suggest the participation of neutral proteinases from neutrophils or monocytes in the modification of PHA response.