Modulation of conconavalin-A-induced suppressor cell activation by prostaglandin E₂

This paper examines the relationship between prostaglandin-mediated immunosuppression and the induction of the conconavalin-A-induced suppressor cell. PBMC preincubated with conconavalin A caused 51% suppression when added to a subsequent mixed lymphocyte culture. However, when the prostaglandin production was blocked in the induction phase by the addition of indomethacin, the suppression in the subsequent mixed lymphocyte culture increased to 80%. When 30 nM PGE₂ was added to the induction cultures to mimick the effect of the PG-producing suppressor cell, the amount of suppression in the subsequent MLC dropped to 33%. This would suggest an inverse relationship between the activity of the conconavalin-A-activated suppressor cell and the prostaglandin-producing suppressor cell.