Macrophage colony-stimulating factor in human fetal astrocytes and microglia. Differential regulation by cytokines and lipopolysaccharide, and modulation of class II MHC on microglia.
CSF-1 is a growth factor that selectively promotes the proliferation, survival, and differentiation of cells of the mononuclear phagocyte series. As part of a study on the role of cytokine and hematopoietic growth factors in central nervous system (CNS) development and inflammation, we examined the expression of CSF-1 in dissociated glial cells cultured from human fetal CNS tissue. CSF-1 mRNA and protein were constitutively expressed by astrocytes. The steady state level of CSF-1 mRNA was markedly up-regulated by both IL-1 beta and TNF-alpha in a time- and dose-dependent manner, whereas only a minimal increase was detected after stimulation with LPS. In unstimulated astrocyte cultures, CSF-1 protein levels gradually increased to 3.5-fold base-line values by 96 h and were significantly increased by all three stimulants in the order of IL-1 > or = TNF > LPS. Low levels of CSF-1 mRNA and protein were also detected in unstimulated microglia cultures. In contrast to astrocyte cultures, CSF-1 mRNA and protein increased significantly after stimulation with LPS, but changed only minimally after exposure to TNF-alpha or IL-1 beta. The effect of CSF-1 on cell proliferation, morphology, and class II MHC Ag expression was determined in highly enriched cultures of microglia and astrocytes. Microglia treated with CSF-1 showed a modest level of proliferation and differentiation into rod-shaped cells, whereas neither cell number nor shape was changed in astrocyte cultures. Interestingly, marked inhibition of both basal and IFN gamma-induced class II MHC Ag expression was observed in microglial cells cultured in the presence of CSF-1, whereas no effect was detected in astrocytes. These results suggest the possibility that in situ production of CSF-1 in the CNS may regulate normal glial cell development and contribute to the immunologic status of the CNS through the down-regulation of class II MHC expression.
Lee
S C
SC
Department of Pathology (Neuropathology), Albert Einstein College of Medicine, Bronx, NY 10461.
Liu
W
W
Roth
P
P
Dickson
D W
DW
Berman
J W
JW
Brosnan
C F
CF
D001253:Astrocytes / Q000276:immunology / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D005260:Female; D005786:Gene Expression Regulation; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006684:HLA-DR Antigens / Q000032:analysis*; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D016173:Macrophage Colony-Stimulating Factor / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology; D009457:Neuroglia / Q000276:immunology / Q000378:metabolism*; D011247:Pregnancy; D011994:Recombinant Proteins / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D006684:HLA-DR Antigens; D007375:Interleukin-1; D008070:Lipopolysaccharides; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D016173:Macrophage Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor