Reaginic antibody formation in the mouse. IX. Enhancement of suppressor and helper cell activites of primed spleen cells

Attempts were made to increase the activity of suppressor cells in vitro. Antigen specific suppressor cells were induced by i.v. injections of urea denatured ovalbumin (UD OA) into OA primed mice. Nonadherent splenic lymphocytes from the UD OA treated mice were incubated at 37°C for 24 hr with either OA or OA bearing macrophages and lymphocytes harvested from the culture were examined for the ability to suppress primary antihapten antibody response of nonirradiated mice to DNP OA. The results showed that the suppressive activity of the lymphocytes increased after culture of the cells with OA or OA bearing macrophages. Similar results were obtained when nylon column purified T cell rich fraction of the lymphocytes were similarly cultured. The suppressive activity was associated with theta bearing lymphocytes and was specific for OA. Suppressor cells were not induced by the culture of OA primed lymphocytes with OA. The helper function of splenic lymphocytes from both UD OA treated mice and OA primed mice was enhanced by the culture of the cells with OA bearing macrophages but not by culture with OA in the absence of macrophages.