Effect of isoprinosine on interleukin 1 and 2 production and on suppressor cell activity in pokeweed mitogen stimulated cultures of B and T cells.

Isoprinosine appeared to potentiate the production of interleukin 1 and interleukin 2 in cultures of lipopolysaccharide stimulated human monocytes and phytohemagglutinin stimulated cultures of blood mononuclear cells respectively at pharmacological drug levels. Administration of the drug in vivo was associated with increased activity of radiation sensitive suppressor T cell activity against immunoglobulin production in pokeweed mitogen stimulated cultures of B and T cells. Addition of isoprinosine to the latter cultures in vitro appeared to enhance immunoglobulin production consistent with inhibition of suppressor cell activity or stimulation of helper activity. It is not clear from these studies whether the contrasting effects of the drug in vitro and in vivo represent different actions of metabolites or alteration of the proportion of lymphocyte subsets in the circulation. Further studies are required to answer these questions and to determine whether the changes persist with long term administration of the drug.