Protection of peritoneal macrophages by granulocyte/macrophage colony-stimulating factor (GM-CSF) against dexamethasone suppression of killing of Aspergillus, and the effect of human GM-CSF.
Murine peritoneal macrophages in vitro could kill Aspergillus fumigatus conidia, and this activity could be suppressed with dexamethasone. Treatment with granulocyte/macrophage colony-stimulating factor (GM-CSF) alone did not boost killing, but GM-CSF treatment concurrently with dexamethasone reversed the dexamethasone suppression. Both recombinant human and recombinant murine GM-CSF were equivalent in this activity, even though the human reagent reportedly does not stimulate differentiation of murine stem cells. Recombinant human GM-CSF could also reverse dexamethasone suppression of bronchoalveolar macrophage conidiacidal activity. Sequential studies with peritoneal macrophages indicated that recombinant human GM-CSF pretreatment also blocked dexamethasone suppression, but the GM-CSF treatment given after dexamethasone did not block the suppressive effect. Recombinant human GM-CSF did not boost spleen cell proliferation to a mitogenic stimulus, and did not reverse dexamethasone suppression of proliferation. These studies suggest GM-CSF treatment prior to and concurrent with steroid immunosuppression may ameliorate the steroid effect on tissue macrophage antifungal activity, but does not affect steroid suppression of T-cell immunity.
Brummer
Elmer
E
Department of Medicine, Division of Infectious Diseases, Santa Clara Valley Medical Center and California Institute for Medical Research, San Jose 95128-2699, USA. e.brummer@juno.com
Maqbool
Anjum
A
Stevens
David A
DA
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D001232:Aspergillus fumigatus / Q000187:drug effects* / Q000502:physiology; D003907:Dexamethasone / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004353:Drug Evaluation, Preclinical; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D006801:Humans; D017737:Macrophages, Peritoneal / Q000166:cytology / Q000187:drug effects* / Q000276:immunology / Q000382:microbiology*; D051379:Mice; D010587:Phagocytosis / Q000187:drug effects
D000893:Anti-Inflammatory Agents; D003907:Dexamethasone; D016178:Granulocyte-Macrophage Colony-Stimulating Factor