Granulocyte-activating mediators (GRAM): III. Further functional characterization of monocyte-derived GRAM.
As shown previously monocytes upon stimulation with bacterial lipopolysaccharides (LPS) release granulocyte-activating mediator(s) (M-GRAM) which induced a long-lasting chemiluminescence (CL) response in human granulocytes. M-GRAM could be separated from interleukin-1 alpha and beta, interleukin-2, interferon alpha and gamma, granulocyte colony stimulating factor (G-CSF) and macrophage colony stimulating factor (M-CSF), since these cytokines are shown to be unable to induce a significant CL response. In contrast, granulocyte macrophage colony stimulating factor (GM-CSF) and particularly tumor necrosis factor (TNF) are important triggers of the oxidative burst and they are capable of inducing a CL response. TNF activity but not lymphotoxin (LT) activity could be demonstrated in M-GRAM samples. A polyclonal rabbit IgG as well as a monoclonal antibody to recombinant human TNF which neutralized the TNF activity in M-GRAM preparations did not substantially block the CL signal. Furthermore, M-GRAM-induced CL response was not significantly inhibited by a polyclonal calf antiserum to human recombinant GM-CSF. For further functional characterization of M-GRAM-induced granulocyte activation different assays were performed in order to compare GM-CSF and TNF: (a) SOD-inhibitable cytochrome C-reduction (.O2-); (b) horseradish peroxidase-mediated oxidation of phenol red (H2O2); (c) the release of peroxidase; (d) ultrastructural detection of hydrogen peroxide production; and (e) scanning and transmission electron microscopy (SEM and TEM). Significant release of .O2- was induced by M-GRAM, TNF, and GM-CSF, whereas H2O2 production was significantly stimulated only by M-GRAM and TNF, as shown by functional and ultrastructural assays.(ABSTRACT TRUNCATED AT 250 WORDS)
Kapp
A
A
Department of Dermatology, University of Freiburg, FRG.
Zeck-Kapp
G
G
Möller
A
A
Putz
R
R
D001685:Biological Factors / Q000494:pharmacology; D003115:Colony-Stimulating Factors / Q000494:pharmacology; D016207:Cytokines; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006098:Granulocytes / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D006133:Growth Substances / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D066298:In Vitro Techniques; D008163:Luminescent Measurements; D008854:Microscopy, Electron; D009000:Monocytes / Q000378:metabolism*; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D013481:Superoxides / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D001685:Biological Factors; D003115:Colony-Stimulating Factors; D016207:Cytokines; D006133:Growth Substances; D014409:Tumor Necrosis Factor-alpha; D013481:Superoxides; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006861:Hydrogen Peroxide