Granulocyte-macrophage colony-stimulating factor is not involved in production of reactive nitrogen intermediates by or toxoplasmastatic activity of gamma interferon-activated murine macrophages.
The induction of reactive nitrogen intermediates (RNI) and toxoplasmastatic activity of murine macrophages by recombinant gamma interferon (rIFN-gamma) is mediated by an autocrine pathway involving tumor necrosis factor alpha (TNF-alpha). To investigate whether cytokines other than TNF-alpha play a role in the activation of these effector functions, granulocyte-macrophage colony-stimulating factor (GM-CSF) was studied. Recombinant GM-CSF (rGM-CSF) could stimulate peritoneal macrophages, since this cytokine stimulated the production of prostaglandin E2 by these cells. However, rGM-CSF did not induce either the release of RNI by or the toxoplasmastatic activity of macrophages. rGM-CSF in combination with various concentrations of rIFN-gamma did not enhance these effector functions more than rIFN-gamma alone. Furthermore, neutralization of endogenously produced GM-CSF by monoclonal antibodies did not affect the release of RNI by or the toxoplasmastatic activity of rIFN-gamma-activated macrophages. Together these results indicate that GM-CSF is not involved in RNI production by and toxoplasmastatic activity of IFN-gamma-activated murine macrophages.
Buisman
A
A
Department of Infectious Diseases, University Hospital, Leiden, The Netherlands.
van Dissel
J T
JT
Langermans
J A
JA
van Furth
R
R
D000818:Animals; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D007371:Interferon-gamma / Q000494:pharmacology*; D008262:Macrophage Activation / Q000187:drug effects*; D008264:Macrophages / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D009584:Nitrogen / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D014122:Toxoplasma / Q000276:immunology*
D011994:Recombinant Proteins; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D009584:Nitrogen