Studies on the differentiation of the human myelomonocytic cell line RC-2A in response to lymphocyte-derived factors.

Cells of the human myelomonocytic line RC-2A were induced to differentiate toward macrophages by culturing for up to 12 days in the presence of supernatant from phytohaemagglutinin stimulated human peripheral blood mononuclear cells (PHA-LCM). The process of differentiation was monitored by changes in expression of two-macrophage related enzymes (alpha-naphthol butyrate esterase and acid phosphatase), the changes in expression of the monocyte-macrophage cell surface markers detected by the monoclonal antibodies anti-Mo1 and anti-Mo2, HLA class 2 antigen detected by FMC-14, and alteration in cell morphology. Maturation induced by PHA-LCM was accompanied by a marked decrease in the proliferative potential of the cell population, and a reduced ability to form colonies in semi-solid medium. Induced RC-2A cells were able to stimulate in one-way mixed leukocyte culture more effectively than control cells.