Macrophage colony-stimulating factor production by murine and human keratinocytes. Enhancement by bacterial lipopolysaccharide.
CSF have a broad range of effects on differentiated cells outside the bone marrow. Site-specific elaboration of these factors may influence local immune reactions. Keratinocytes have been demonstrated to produce a number of immunoactive cytokines, including factors capable of modifying macrophage function. We have previously identified at least two products of keratinocytes that induce DNA synthesis by elicited peritoneal macrophages; one factor has been identified as granulocyte-macrophage CSF. In the present study, the second keratinocyte product has been characterized and identified as macrophage-CSF (M-CSF). Conditioned media from cultures of normal human keratinocytes and the transformed murine keratinocyte cell line PAM 212 induce formation of macrophage colonies in soft agar as well as dose-dependent proliferation of the M-CSF-dependent cell line BAC1.2F5. The bioactivity in both assays is blocked by neutralizing anti-M-CSF antibody. Western blot analysis of cell lysates from both PAM 212 and normal human keratinocytes demonstrates multiple molecular mass forms of M-CSF (45 to 98 kDa). Northern blot analysis (PAM 212 cells) and in situ hybridization (normal keratinocytes) demonstrate expression of M-CSF mRNA. Stimulation of keratinocytes with LPS increases M-CSF synthesis as measured both by bioactivity and level of mRNA expression. Thus, both murine and human keratinocytes produce M-CSF in vitro. Furthermore, production of keratinocyte-derived M-CSF is increased by bacterial LPS. CSF production by keratinocytes may play an important role in regulating the cutaneous immune response.
Chodakewitz
J A
JA
Department of Internal Medicine, Yale University School of Medicine, New Haven, CT.
Lacy
J
J
Edwards
S E
SE
Birchall
N
N
Coleman
D L
DL
D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D003115:Colony-Stimulating Factors / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D015870:Gene Expression; D006801:Humans; D066298:In Vitro Techniques; D015603:Keratinocytes / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology; D016173:Macrophage Colony-Stimulating Factor; D051379:Mice; D008970:Molecular Weight; D012333:RNA, Messenger / Q000235:genetics
D003115:Colony-Stimulating Factors; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D016173:Macrophage Colony-Stimulating Factor