Induction of prostaglandin E synthesis in normal and neoplastic macrophages: role for colony-stimulating factor(s) distinct from effects on myeloid progenitor cell proliferation.

The biosynthesis of prostaglandin E (PGE) by normal and neoplastic macrophages is intrinsically linked to their synthesis of, and exposure to, myeloid colony-stimulating factors (CS-factors). The defect in responsiveness to endotoxin lipopolysaccharide (LPS) by macrophages from C3H/HeJ mice extends equally to the synthesis of CS-factor and PGE. However, C3H/HeJ macrophages can be stimulated to synthesize PGE by treatment with agents other than LPS [zymosan, tuberculin purified protein derivative, concanavalin A, poly(I).poly(C)], which also stimulate CS-factor production, or by the addition of various preparations of soluble CS-factor. In peritoneal wash preparations, constitutive PGE synthesis occurred in rapidly sedimenting macrophage cells, whereas constitutive CS-factor production and inducible PGE synthesis occurred in slower sedimenting adherent cells. A similar functional heterogeneity in CS-factor and PGE production was found in neoplastic macrophagae cell lines. The association of elevated CS-factor levels and PGE synthesis by macrophages suggests a role for CS-factor in many of the physiological responses heretofore associated with elevated tissue levels of the E type prostaglandins.