Vascular endothelial cells and granulopoiesis: interleukin-1 stimulates release of G-CSF and GM-CSF.
Cultured mononuclear phagocytes produce soluble factors that stimulate endothelial cells to release GM-colony-stimulating activity (GM-CSA). One such factor was recently identified as interleukin 1 (IL 1). Studies were designed to determine which types of granulopoietic factors are released by IL 1-stimulated endothelial cells. Supernatants from endothelial cells cultured for 3 days in medium containing IL 1 alpha and beta were tested in both murine and human CFU-GM colony growth assays. The effect of conditioned media on differentiation of WEHI-3B myelomonocytic leukemic cells was also examined. Control media containing IL 1 alone or unstimulated endothelial cell-conditioned media contained no detectable CSA in any bioassay. Medium conditioned by IL 1-stimulated endothelial cells stimulated the clonal growth of both human and murine CFU-GM and induced macrophage differentiation of WEHI-3B cells. Treatment of these conditioned media with a highly specific neutralizing monoclonal G-CSF antibody completely inhibited their activity in the murine CFU-GM assay, but only partially inhibited GM colony growth by human marrow. Treatment of the active conditioned media with a neutralizing rabbit anti-human GM-CSF antibody partially reduced the activity of the media in the human GM-colony growth assay. G-CSF radioimmunoassay of endothelial cell culture supernatants and Northern blot analysis of endothelial cell cytoplasmic RNA for GM-CSF gene transcripts confirmed that IL 1 induced expression of both G-CSF and GM-CSF genes. Because treatment of media with both antibodies abrogated all activity in the human GM colony growth assay, we conclude that IL 1-stimulated endothelial cells release both G and GM-CSF and that these are the only granulopoietic factors detectable in clonogenic assays released by these cells in vitro.
Zsebo
K M
KM
Amgen, Thousand Oaks, CA 91320.
Yuschenkoff
V N
VN
Schiffer
S
S
Chang
D
D
McCall
E
E
Dinarello
C A
CA
Brown
M A
MA
Altrock
B
B
Bagby
G C
GC
D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D003115:Colony-Stimulating Factors / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006410:Hematopoiesis / Q000187:drug effects*; D006801:Humans; D007231:Infant, Newborn; D007375:Interleukin-1 / Q000494:pharmacology*; D051379:Mice; D011994:Recombinant Proteins / Q000494:pharmacology; D012636:Secretory Rate / Q000187:drug effects; D013268:Stimulation, Chemical; D014407:Tumor Cells, Cultured / Q000187:drug effects
D003115:Colony-Stimulating Factors; D007375:Interleukin-1; D011994:Recombinant Proteins