Effect of 2,7-bis(2-diethylamino)ethoxy)fluoren-9-one dihydrochloride (Tilorone) upon cell-mediated immunity in mice.

This occurred whether Tilorone was administered p.o. or i.p. When administered 24 hr after L1210 cells, an adjuvant effect of Tilorone upon CMI was not demonstrable unless glass-adherent spleen cells were removed before in vitro assay. In groups given Tilorone or L1210 alone, CMI was unchanged after removal of adherent cells. Release of lymphocyte-activating factor by the spleen was unaffected by Tilorone. It is suggested that Tilorone has a moderate direct stimulatory effect upon thymus-dependent lympho cytes but may elicit inhibitory effects mediated by adherent spleen cells (macrophages and/or sticky bursa-dependent lymphocytes) that have also been stimulated by antigen.