Action of phytohemagglutinin on transplantable human cells

Abstract

Agglutinating and growth-stimulating properties of phytohemagglutinin (PHA) preparations were studied in experiments on transplantable human cells (clonal line HeLa k-41 and Cave). PHA and its γ-globulin fraction were found to possess weak hemagglutinating properties for human erythrocytes of groups A, B, and O, but strong cytoagglutinating properties with respect to HeLa k-41 and Cave cells. With large doses of PHA (100 and 500 μg/ml) proliferation and the mitotic index of the cells of the cultures were lower but the percentage of dead cells and the agglutinin titer in the preparations were higher (1:256). With smaller doses of PHA (5 and 25 μg/ml) growth was much more intensive and the percentage of dead cells was smaller. The agglutinin titer in the preparation fell to 1:16–1:32. The γ-globulin fraction of PHA had the strongest growth-stimulating action and gave the smallest number of dead cells. However, the agglutinin titer in the preparations was high (1:128). It is concluded that the inhibitory and growth-stimulating action of PHA preparations on transplantable human cells is directly linked with the agglutinin content in the preparations, for the γ-globulin fraction of PHA had the strongest cytoagglutinating and growth-stimulating action.