GM-CSF priming drives bone marrow-derived macrophages to a pro-inflammatory pattern and downmodulates PGE2 in response to TLR2 ligands

• Published in: PloS one 2012-07, Vol.7 (7), p.e40523
• Main Authors: Sorgi, Carlos Arterio, Rose, Stephanie, Court, Nathalie, Carlos, Daniela, Paula-Silva, Francisco Wanderley Garcia, Assis, Patricia Aparecida, Frantz, Fabiani Gai, Ryffel, Bernhard, Quesniaux, Valerie, Faccioli, Lúcia Helena
• Format: Article
• Language: English
• Subjects: Adaptor Proteins, Signal Transducing - metabolism; Animals; Bacteria - metabolism; Biology; Bone marrow; CD14 antigen; Cell surface; Chemokines; Colony-stimulating factor; Cytokines; Dendritic cells; Dinoprostone - metabolism; Down-Regulation - drug effects; Embryology; Female; Gene expression; Granulocyte-macrophage colony-stimulating factor; Granulocyte-Macrophage Colony-Stimulating Factor - pharmacology; Granulocytes; Immune clearance; Immune response; Immune system; Immunology; Infections; Inflammation; Inflammation - metabolism; Inflammation - pathology; Interferon-gamma - pharmacology; Interleukin-10 - biosynthesis; Kinases; Laboratory animals; Leukotriene B4 - metabolism; Ligands; Lipids; Lipids - secretion; Macrophages; Macrophages - drug effects; Macrophages - pathology; Macrophages - secretion; Male; Medicine; Metabolism; Metabolites; Mice; Mice, Inbred C57BL; Microorganisms; Mycobacterium; MyD88 protein; Myeloid Differentiation Factor 88 - metabolism; Neutrophils; NF-kappa B - metabolism; NF-κB protein; Nitric oxide; Nitric Oxide - secretion; Nuclear transport; Pathogenesis; Peroxisome proliferator-activated receptors; PPAR gamma - metabolism; Priming; Prostaglandin E2; Protein Transport - drug effects; Proteins; Receptors; RNA, Messenger - genetics; RNA, Messenger - metabolism; Streptococcus infections; Thyroid gland; TLR1 protein; TLR2 protein; TLR4 protein; Toll-Like Receptor 2 - metabolism; Toll-like receptors; Translocation; Tumor Necrosis Factor-alpha - secretion; Tumor necrosis factor-α; γ-Interferon
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0040523

In response to pathogen recognition by Toll-like receptors (TLRs) on their cell surface, macrophages release lipid mediators and cytokines that are widely distributed throughout the body and play essential roles in host responses. Granulocyte macrophage colony-stimulating factor (GM-CSF) is important for the immune response during infections to improve the clearance of microorganisms. In this study, we examined the release of mediators in response to TLR2 ligands by bone marrow-derived macrophages (BMDMs) primed with GM-CSF. We demonstrated that when stimulated with TLR2 ligands, non-primed BMDMs preferentially produced PGE(2) in greater amounts than LTB(4). However, GM-CSF priming shifted the release of lipid mediators by BMDMs, resulting in a significant decrease of PGE(2) production in response to the same stimuli. The decrease of PGE(2) production from primed BMDMs was accompanied by a decrease in PGE-synthase mRNA expression and an increase in TNF-α and nitric oxide (NO) production. Moreover, some GM-CSF effects were potentiated by the addition of IFN-γ. Using a variety of TLR2 ligands, we established that PGE(2) release by GM-CSF-primed BMDMs was dependent on TLR2 co-receptors (TLR1, TLR6), CD14, MyD88 and the nuclear translocation of NFκB but was not dependent on peroxisome proliferator-activated receptor-γ (PPAR-γ) activation. Indeed, GM-CSF priming enhanced TLR2, TLR4 and MyD88 mRNA expression and phospho-IκBα formation. These findings demonstrate that GM-CSF drives BMDMs to present a profile relevant to the host during infections.