IMMUNOMODULATORY EFFECT OF A NEWLY SYNTHESIZED COMPOUND, TOK-8801 (N-(2-PHENYLETHYL)-3,6,6-TRIMETHYL-5, 6-DIHYDROIMIDAZO [2,1-B]THIAZOLE-2-CARBOXAMIDE) ON ANTIBODY-PRODUCTION INVIVO AND DELAYED-TYPE HYPERSENSITIVITY IN MICE

The immunopharmacological effects of a newly synthesized compound in vitro, TOK-8801 (N-(2-phenylethyl)-3,6,6-dihydroimidazol[2,1-b]thiazole-2-carboxamine), on the anti-SRBC plaque-forming cell (PFC) response and delayed-type hypersensitivity (DTH) reaction were investigated. Oral administration of TOK-8801 (0.1-10 mg/kg) resulted in the suppression of the PFC responses to varying doses of antigen (5×106, 2×107, 1×108) in C3H/HE strain mice (7 W) which are high responders to SRBC antigen. On the other hand, the compound augmented the PFC response in aged mice (8-9 months) in which the PFC response was markedly depressed compared with that in young mice. In the experiment of the methylated human serum albumin-induced DTH reaction, TOK-8801 augmented the reaction,in low responder (C57BL/6) mice by oral administration of 0.1-1 mg/kg for 5 days from the sensitization, whereas suppressed the reaction in high responder (ICR) mice. These immunopharmacological actions of TOK-8801 were compared in dose and activity with those of lobenzarit and bucillamine. Thus, these results suggest that TOK-8801 may act as an immunomodulating agent and would be expected to be a useful agent for autoimmune diseases such as rheumatoid arthritis. © 1990.