title: Keratinocyte-derived granulocyte/macrophage colony-stimulating factor induces DNA synthesis by peritoneal macrophages.
abstract: Keratinocytes have been demonstrated to produce a number of cytokines, including growth factors such as the CSF IL-3. Circulating blood monocytes and some elicited macrophages retain a significant proliferative potential in response to colony-stimulating activity. Because a macrophage response is prominent in a variety of cutaneous immune reactions, we have studied the ability of conditioned media (CM) from a transformed murine keratinocyte cell line (PAM 212) and from normal murine keratinocytes to induce growth of peritoneal macrophages. CM from both normal and transformed keratinocyte cultures induces [3H]thymidine incorporation by thioglycollate-elicited, but not resident, peritoneal macrophages. IEF of PAM 212 CM reveals peaks of activity at pI 4.8 and less than or equal to 4.2. Analysis of CM by reversed-phase HPLC demonstrates active fractions that elute at 46 to 48% and 53 to 55% acetonitrile. The Mr of the 46 to 48% acetonitrile factor is 25 to 30 kDa by gel filtration HPLC. Polyclonal anti-granulocyte/macrophage (GM) CSF antibody blocks the induction of macrophage [3H]thymidine incorporation by factors with pI 4.8 and eluting at 46 to 48% acetonitrile but does not reduce the activity of crude CM or the factor eluting at 53 to 55% acetonitrile. Based on both physiochemical criteria and antibody neutralization, keratinocytes produce GM-CSF. Keratinocyte-derived factors, including GM-CSF, may play an important role in regulating cutaneous macrophage responses.
authors.affiliation: Department of Medicine, Yale University School of Medicine, New Haven, CT.
authors.forename: J A
authors.initials: JA
authors.lastname: Chodakewitz
authors.forename: T S
authors.initials: TS
authors.lastname: Kupper
authors.forename: D L
authors.initials: DL
authors.lastname: Coleman
mesh_terms: D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002460:Cell Line; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003470:Culture Media / Q000032:analysis; D004247:DNA / Q000096:biosynthesis*; D000078404:Epidermal Cells; D004817:Epidermis / Q000378:metabolism*; D005260:Female; D007377:Interleukin-3 / Q000276:immunology / Q000302:isolation & purification* / Q000494:pharmacology; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D010529:Peritoneal Cavity / Q000166:cytology; D013936:Thymidine / Q000378:metabolism
chemical_list: D000906:Antibodies; D003470:Culture Media; D007377:Interleukin-3; D004247:DNA; D013936:Thymidine