FCE20696, a new synthetic immunomodulator: immunopharmacological profile.

A preliminary characterization of the immunopharmacological profile of the new immunomodulating agent FCE20696 (6H,6[2-(dimethylamino)-ethoxycarbonyl]-dibenzo[b,d]pyran-HCl) was performed in mice. Single i.p. doses of this chemical, concomitantly given with the antigen, increased the antibody response and decreased the delayed hypersensitivity reaction to a suboptimal dose of SRBC, the active doses ranging from 6.25 to 50 mg/kg. No activity was observed using a full antigen dose. Macrophage cytotoxic activity was enhanced 2-4 days after a single i.p. treatment with 50 and 10 mg/kg. Spleen cell proliferation to T and B mitogens was inhibited by a single dose of 30 mg/kg given i.p. 6 days before the test, or by 10 mg/kg x 3 days ending one day before the test. Finally, generation of suppressor cells was enhanced by the compound, given p.o. biweekly for at least 7 weeks, at doses ranging from 0.1 to 10 mg/kg. Collectively taken, these data suggest that FCE20696 has a broad range of immunomodulating activities and that macrophages and suppressor cells are presumed to be the main targets of its pharmacological activity.