Effect of TYB-2285 on antigen-induced histamine release from mouse bone marrow-derived persisting cells (P-cells) primed with interleukin-3-containing conditioned medium (IL3-CM)

1. The present study was carried out to investigate the effect of TYB-2285 [3,5-bis(acetoxyacethylamino)-4-chlorobenzonitrile] on histamine release from persisting cells (P-cells) primed with interleukin-3-containing conditioned medium (IL3-CM). 2. IL3-CM enhanced antigen-induced histamine release from P-cells, although IL3-CM did not affect spontaneous histamine release. 3. TYB-2285 inhibited antigen-induced histamine release in the presence of IL3-CM, although it did not inhibit histamine release in the absence of IL3-CM. 4. The enhancement of histamine release by IL3-CM was reproduced by recombinant IL-3 (1-100 U/ml). 5. These results demonstrate that TYB-2285 inhibits the histamine release primed with IL-3 and also suggests that TYB-2285 might regulate allergic inflammation in vivo by the suppression of mediator release primed with IL-3.