Keratinocyte growth regulation by the products of immune cells.
We describe a bioassay that allows the in vitro investigation of the stimulatory and suppressive factors derived from immune cells in short-term cultures of human keratinocytes. In agreement with other assays, epidermal growth factor is not mitogenic for human keratinocytes. Supernatant fluid from human PBMC stimulated with Con A, from allo-MLRs, as well as supernatants from nonstimulated PBMC, possess growth-promoting molecules. Our results show that both activated and nonactivated T cells release growth factors. Suppressive molecules are produced preferentially by monocyte cultures. Two T cell products, IFN-gamma and transforming growth factor beta are both inhibitory for keratinocyte proliferation. Two other T cell products, IL-3 and GM-CSF, stimulate keratinocyte proliferation at nanogram concentrations. These results suggest the existence of regulatory circuits between the T cells of a dermal inflammatory infiltrate and the overlying epidermal keratinocytes. This may determine the fine control of epidermal proliferation and turnover leading either to enhanced wound repair or skin pathology.
Hancock
G E
GE
Rockefeller University, New York, New York 10021.
Kaplan
G
G
Cohn
Z A
ZA
D002454:Cell Differentiation; D002455:Cell Division; D002478:Cells, Cultured; D003115:Colony-Stimulating Factors / Q000378:metabolism / Q000494:pharmacology; D003470:Culture Media; D000078404:Epidermal Cells; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006133:Growth Substances / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism / Q000494:pharmacology; D007377:Interleukin-3 / Q000378:metabolism / Q000494:pharmacology; D007633:Keratins / Q000096:biosynthesis*; D007700:Kinetics; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D015291:Transforming Growth Factors / Q000378:metabolism / Q000494:pharmacology
D003115:Colony-Stimulating Factors; D003470:Culture Media; D006133:Growth Substances; D007377:Interleukin-3; D007633:Keratins; D015291:Transforming Growth Factors; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor