1: J Infect Dis.  2004 Jun 1;189(11):2101-9. Epub 2004 May 12. 

Impairment of Growth of Listeria monocytogenes in THP-1 Macrophages by
Granulocyte Macrophage Colony-Stimulating Factor: Release of Tumor Necrosis
Factor- alpha and Nitric Oxide.

Carryn S, Van De Velde S, Van Bambeke F, Mingeot-Leclercq MP, Tulkens PM.

Unite de Pharmacologie Cellulaire et Moleculaire, Universite Catholique de
Louvain, Brussels, Belgium.

Background. Listeria monocytogenes tends to survive in phagocytes. Granulocyte
macrophage colony-stimulating factor (GM-CSF) protects mice against L.
monocytogenes infection, and mice knocked out for the GM-CSF gene are more
susceptible to these infections.Methods. THP-1 cells were used to characterize
the GM-CSF receptor (binding isotherms; STAT5 phosphorylation), measure the
intracellular growth of L. monocytogenes (5 h after phagocytosis), examine the
influence of a 24-h incubation with GM-CSF before infection, measure the
production of tumor necrosis factor (TNF)- alpha and the expression of nitric
oxide synthase (iNOS), and evaluate the influence of anti-GM-CSF receptor
(GM-CSFR alpha ) and anti--TNF- alpha antibodies and the addition of N( omega
)-nitro-l-arginine methyl ester (l-NAME) and catalase.Results. THP-1 cells
display functional GM-CSFR alpha. GM-CSF impairs the intracellular growth of L.
monocytogenes to ~65% of its value in unstimulated cells. This effect is
abolished by anti-GM-CSFR alpha, anti-TNF- alpha antibodies, and catalase (and,
to a lesser extent, by l-NAME). GM-CSF stimulates the release of TNF- alpha and
the expression of iNOS. TNF- alpha added to unstimulated cells (even in large
amounts) does not fully reproduce the impairment in the growth of L.
monocytogenes caused by GM-CSF.Conclusions. GM-CSF impairs the intracellular
growth of L. monocytogenes by a synergistic action of the GM-CSF-triggered
release of autocrine TNF- alpha and hydrogen peroxide and the production of NO
(associated with the stimulation of the expression of iNOS).

PMID: 15143479 [PubMed - in process]