Restoration of diminished splenic responses to phytohemagglutinin and concanavalin A in adjuvant-induced disease by virazole: possible pathogenetic role of a virus and suppressor cells.

Adjuvant arthritis is inhibited by the interferon-inducing anti-viral agents statolon, pyran copolymer and tilorone, and by the passive transfer of interferon. The present experiments demonstrate that Virazole, a non-interferon-inducing, anti-viral agent also inhibits adjuvant arthritis. The responses of splenic lymphocytes to phytohemagglutinin and concanavalin A are diminished in active adjuvant disease, due to suppressor cells. Suppressor cells are absent during spontaneous, methodrexate or corticosteroid-induced remissions. Suppressor cells are also absent during Virazole-induced inhibition of adjuvant disease. Methotrexate and corticosteroids inhibit suppressor cells in preference to mitogen-responsive cells in vitro. The preferential inhibition with Virazole is superior to that noted with methotrexate or corticosteroids.