Relative Ability of Mitogens to Stimulate Production of Interferon by Lymphoid Cells and to Induce Suppression of the in Vitro Immune Response

Abstract

Several T [thymus-derived] cell mitogens, concanavalin A (Con A), phytohemagglutinin P (PHA-P) and staphylococcal enterotoxin A (SEA), were compared for their ability to inhibit the in vitro antibody response and to stimulate the production of mitogen (antigen)-type interferon in mouse spleen cell cultures. The ability to inhibit the plaque-forming cell (PFC) response to sheep red blood cells was proportional to the ability of these mitogens to induce interferon in the cultures. SEA was the most effective inhibitor of the PFC response and the best inducer of mitogen-type interferon, followed by Con A, with PHA-P being the least effective. SEA would probably be the most suitable inducer of mitogen-type interferon in quantity as a prerequisite to purification and characterization of the molecule. The data are supportive of previous studies suggesting a role for mitogen (antigen) -type interferon in regulation of the immune response via suppressor T cells.