[Interaction of polyanion molecules with the plasma membrane of lymphocytes differing in density of charged groups on the cell surface].

The authors studied the activation effect in vitro of polyanionic mitogen-polyacrylic acid (PAA) on several types of mouse lymphocytes. The action of PAA was evaluated from an early effect on membrane (Na+, K+)- and Ca2+-ATPases. PAA was demonstrated to interact with the membrane of B cells from the spleen and immature T lymphocytes from the thymus, producing no effect on mature T cells from the spleen. The lack of the PAA effect on mature T lymphocytes was found to be linked with high density of negatively charged groups on the surface of these cells. Artificial lessening of the density of the negatively charged groups by the cleavage of the terminal N-acetylneuraminic residues with the aid neuraminidase leads to the change of mature T cells into PAA-sensitive ones.