Cultured human umbilical vein endothelial cells, when exposed to soluble products of peripheral blood monocytes, elaborate granulocyte-macrophage colony-stimulating activity (GM-CSA) and erythroid burst-promoting activity (BPA). We have performed studies to determine if the monokine IL 1 can stimulate endothelial cells to release hematopoietic growth factors and whether such factors can also support human megakaryocyte (Meg) and mixed-cell colony growth. Various concentrations of recombinant human IL 1β (rIL 1) and media conditioned by monocytes (MCM), endothelial cells (ECM), and endothelial cells cultured for 3 days in 50% MCM (ECM(M)) or rIL 1 (ECM(rIL 1)) were added to marrow mononuclear cells cultured in methylcellulose. ECM(M) and ECM(rIL 1) stimulated, in a dose-dependent fashion, the growth of Meg, mixed-cell, and GM colonies and erythroid bursts. In contrast, ECM, MCM, and rIL 1 displayed little or no activity in the colony-forming assays. Preincubation with specific antisera to native human IL 1 or rIL 1 reduced by 75 to 100% the activity of MCM in stimulating endothelial cell release of BPA, GM-CSA, Meg-CSA, and mixed-cell CSA. Meg-CSA, although readily detectable at ECM(M) and ECM(rIL 1) concentrations in culture of 1 to 5%, was partially masked by lineage-specific inhibitors of Meg colony growth. When ECM(M) was analyzed by gel filtration chromatography, the megakaryocytopoietic inhibitory activity eluted in the high M(r) fractions (>75 kD). Meg-CSA co-eluted with GM-CSA and BPA in a single peak of 30 kD. We conclude that endothelial cells, in response to IL 1, produce one or more growth factors that probably act on multiple classes of progenitor cells.
|Original language||English (US)|
|Number of pages||7|
|Journal||Journal of Immunology|
|State||Published - Jan 1 1987|
ASJC Scopus subject areas
- Immunology and Allergy