INVITRO PROLIFERATION OF MACROPHAGE DEPLETED HUMAN PERIPHERAL-BLOOD LYMPHOCYTES

Abstract

Incorporation of thymidine by normal human peripheral blood lymphocytes was tested in vitro following various culture conditions. A significant increase of thymidine uptake was observed in cultures depleted of plastic adherent, nylon wool adherent or phagocytic cells. This proliferative activity occurred in the presence of various sera but was not due to a blastogenic response to a foreign protein, since it was also observed when autologous plasma was the only source of protein in the culture medium. Similarities and differences between this spontaneous proliferative phenomenon and other blastogenic responses which are regulated by macrophages are discussed.