title: PPARγ ligands switched high fat diet-induced macrophage M2b polarization toward M2a thereby improving intestinal Candida elimination.
abstract: Obesity is associated with a chronic low-grade inflammation that predisposes to insulin resistance and the development of type 2 diabetes. In this metabolic context, gastrointestinal (GI) candidiasis is common. We recently demonstrated that the PPARγ ligand rosiglitazone promotes the clearance of Candida albicans through the activation of alternative M2 macrophage polarization. Here, we evaluated the impact of high fat diet (HFD)-induced obesity and the effect of rosiglitazone (PPARγ ligand) or WY14643 (PPARα ligand) both on the phenotypic M1/M2 polarization of peritoneal and cecal tissue macrophages and on the outcome of GI candidiasis. We demonstrated that the peritoneal macrophages and the cell types present in the cecal tissue from HF fed mice present a M2b polarization (TNF-α(high), IL-10(high), MR, Dectin-1). Interestingly, rosiglitazone induces a phenotypic M2b-to-M2a (TNF-α(low), IL-10(low), MR(high), Dectin-1(high)) switch of peritoneal macrophages and of the cells present in the cecal tissue. The incapacity of WY14643 to switch this polarization toward M2a state, strongly suggests the specific involvement of PPARγ in this mechanism. We showed that in insulin resistant mice, M2b polarization of macrophages present on the site of infection is associated with an increased susceptibility to GI candidiasis, whereas M2a polarization after rosiglitazone treatment favours the GI fungal elimination independently of reduced blood glucose. In conclusion, our data demonstrate a dual benefit of PPARγ ligands because they promote mucosal defence mechanisms against GI candidiasis through M2a macrophage polarization while regulating blood glucose level.
authors.affiliation: UMR-MD3 EA2405 Polarisation des Macrophages et Récepteurs Nucléaires dans les Pathologies Inflammatoires et Infectieuses, Université de Toulouse III, Toulouse, France.
authors.forename: Lise
authors.initials: L
authors.lastname: Lefèvre
authors.forename: Amandine
authors.initials: A
authors.lastname: Galès
authors.forename: David
authors.initials: D
authors.lastname: Olagnier
authors.forename: José
authors.initials: J
authors.lastname: Bernad
authors.forename: Laurence
authors.initials: L
authors.lastname: Perez
authors.forename: Rémy
authors.initials: R
authors.lastname: Burcelin
authors.forename: Alexis
authors.initials: A
authors.lastname: Valentin
authors.forename: Johan
authors.initials: J
authors.lastname: Auwerx
authors.forename: Bernard
authors.initials: B
authors.lastname: Pipy
authors.forename: Agnès
authors.initials: A
authors.lastname: Coste
mesh_terms: D000818:Animals; D002176:Candida albicans / Q000276:immunology / Q000502:physiology; D002177:Candidiasis / Q000276:immunology* / Q000382:microbiology; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D004041:Dietary Fats / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007422:Intestines / Q000276:immunology* / Q000382:microbiology; D008262:Macrophage Activation / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects / Q000276:immunology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D047495:PPAR gamma / Q000819:agonists* / Q000276:immunology; D000077154:Rosiglitazone; D045162:Thiazolidinediones / Q000008:administration & dosage*
chemical_list: D004041:Dietary Fats; D047495:PPAR gamma; D045162:Thiazolidinediones; D000077154:Rosiglitazone