Effects of Wy-18,251 (3-p-chlorophenyl)thiazolo[3,2-a]benzimidazole- 2-acetic acid), levamisole and indomethacin on the generation of murine T suppressor cells in vitro.

In vitro culture of normal BALB/c spleen cells with staphylococcal enterotoxin B (SEB) activates antigen non-specific suppressor T cells (Ts) which can be assayed by their ability to suppress antibody production in a plaque assay. Addition of the experimental immunomodulatory drug Wy-18,251 (10-100 microM) to cultures of spleen cells plus SEB significantly increased Ts activity relative to cultures without the drug. Similar results were obtained with levamisole, but, in contrast, indomethacin (0.1-10 microM) inhibited SEB-induced suppressor cell activity. The ability of Wy-18,251 to augment Ts activity could be therapeutically useful in the treatment of those autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus, in which hyperactive B cell function is a characteristic feature.