Human lymphocytes induce a differential release of prostaglandin E2 and interleukin 1-like mononuclear cell factor from normal blood monocytes

Abstract

Lymphocytes influence the production of both prostaglandin E₂ (PGE₂) and interleukin 1 (IL1) by monocytes. We have examined whether these two products are released concomitantly or not under identical culture conditions using monocyte‐ and lymphocyte‐enriched populations obtained on Percoll gradient. IL1 was measured as mononuclear cell factor (IL1/MCF). When incubated with concanavalin A, the monocyte‐enriched fraction (MF; 80–91% monocytes), but not the lymphocyte‐enriched fraction (LF; 95% lymphocytes) produced increasing amounts of PGE₂ and MCF. However, when LF cells were added to MF cells in culture, a 40% to 60% decrease of PGE₂ secretion was observed whereas the MCF production remained unchanged or increased up to 26‐fold. Such a dissociation between IL1 and PGE₂ production by monocytes indicates independent regulation mechanisms in controlling the immune response under the influence of lymphocytes.