[Sensitization of a cell line, CEM by indomethacin. A study of the underlying mechanism]

A cell line, CEM, was derived from a patient with acute lymphocytic leukemia. We investigated the underlying mechanisms for a phenomenon in which CEM became more sensitive to attack by antiserum and complement when cultured with indomethacin, a prostaglandin (PG) synthesis inhibitor. Other PG synthesis inhibitors also evoked similar sensitization. When PGE2 was further added to the culture, the sensitization was suppressed. Both findings indicate that a decrease of PG may be one of the mechanisms. Inhibition of metabolism, and decrease of CEM surface antigen shed from the cell into the supernatant also seem responsible for the sensitization.