Granulocyte-activating mediators (GRAM). II. Generation by human epidermal cells--relation to GM-CSF.
In the present study we investigated the capability of human epidermal cells to generate granulocyte-activating mediators (GRAM). It could be shown that human epidermal cells as well as an epidermoid carcinoma cell line (A431) produce an epidermal cell-derived granulocyte-activating mediator (EC-GRAM) which stimulates human granulocytes to release significant levels of toxic oxygen radicals as measured by a lucigenin-dependent chemiluminescence (CL). For further characterization of EC-GRAM the A431 cell line was used. Supernatants of A431 cells usually contained maximal EC-GRAM levels within 24 h of incubation. Factor production was enhanced by bacterial lipopolysaccharide (LPS), but not by silica particles and PHA. Moreover, freeze-thaw lysates of A431 cells and extracts of heat-separated human epidermis contained significant levels of EC-GRAM. Preincubation of granulocytes with EC-GRAM resulted in an enhanced response to subsequent stimulation with the chemotactic peptide f-met-phe. In contrast EC-GRAM did not affect the response to PMA or zymosan particles. However, EC-GRAM treated granulocytes were unresponsive to restimulation with EC-GRAM. Upon high performance liquid chromatography (HPLC) gel filtration EC-GRAM eluted within two major peaks exhibiting a molecular weight of 17 kD and 44 kD.(ABSTRACT TRUNCATED AT 250 WORDS)
Kapp
A
A
Department of Dermatology, University of Freiburg, Federal Republic of Germany.
Danner
M
M
Luger
T A
TA
Hauser
C
C
Schöpf
E
E
D001688:Biological Products / Q000096:biosynthesis* / Q000276:immunology; D002294:Carcinoma, Squamous Cell / Q000378:metabolism*; D002460:Cell Line; D002478:Cells, Cultured; D003115:Colony-Stimulating Factors / Q000096:biosynthesis* / Q000276:immunology; D016207:Cytokines; D004817:Epidermis / Q000378:metabolism*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006133:Growth Substances / Q000096:biosynthesis* / Q000276:immunology; D006801:Humans; D008970:Molecular Weight; D009504:Neutrophils / Q000276:immunology; D011994:Recombinant Proteins
D001688:Biological Products; D003115:Colony-Stimulating Factors; D016207:Cytokines; D006133:Growth Substances; D011994:Recombinant Proteins; D016178:Granulocyte-Macrophage Colony-Stimulating Factor