Colonization of Mice by Candida albicans Is Promoted by Chemically Induced Colitis and Augments Inflammatory Responses through Galectin-3

Samir Jawhara 0 2 3 Xavier Thuru 0 2 Annie Standaert-Vitse 1 2 3 Thierry Jouault 2 3 Serge Mordon 1 2 Boualem Sendid 2 3 4 Pierre Desreumaux 0 2 Daniel Poulain () 2 3 4 0 Inserm U 795, Physiopathologie des Maladies Inflammatoires Intestinales 1 Laboratoire de Parasitologie, Faculte de Pharmacie , Avenue du Professeur Laguesse 2 Received 4 May 2007; accepted 4 October 2007; electronically published 4 March 2008. Presented in part: 16th congress of the International Society for Human and Animal Mycology (ISHAM) , 25-29 June 2006, Paris , France ( abstract 0-0004). Potential conflicts of interest: none reported. Financial support: Institut National de la Sante et de la Recherche Medicale (Inserm), Region Nord Pas de Calais- FEDER (R06042EE), Region Nord Pas de Calais , France (03530111 to S.J.). Candidoses , Faculte de Medecine , 1, Place de Verdun, 59045 Lille Cedex , France 3 Inserm U 799, Physiopathologie des Candidoses, Faculte de Medecine, Centre Hospitalier Regional Universitaire de Lille, Institut Federatif de Recherche 114, Universite Lille 2 4 Laboratoire de Parasitologie-Mycologie, Pole de Microbiologie, Centre Hospitalier Universitaire , Lille , France 5 UPRES EA 2689, Detresses Respiratoires et Circulatoires , Pavillon Vancostenobel Background. Little is known about the relationship between colonic inflammation and Candida albicans colonization. Galectin-3 (Gal-3) is an intestinal lectin that binds to specific C. albicans glycans and is involved in inflammation. Methods. Colitis was experimentally induced in wild-type and Gal3/ mice using dextran sulfate sodium (DSS) before oral administration of C. albicans. Yeast recovered from stools was quantified. The presence of yeast and inflammation were evaluated in sections of colon by histologic examination, quantification of myeloperoxidase (MPO) activity, and by gene expression for cytokines and innate immune receptors. Serum from mice was collected for determination of anti-yeast mannan antibodies, including anti-Saccharomyces cerevisiae antibodies (ASCA), which are biomarkers of an inflammatory bowel disease. Results. Inflammation strongly promoted C. albicans colonization. Conversely, C. albicans augmented inflammation induced by DSS, as assessed by histologic scores, MPO activity, and tumor necrosis factor (TNF)- and Toll-like receptor (TLR)-2 expression. C. albicans colonization generated ASCA. The absence of Gal-3 reduced DSS inflammation and abolished the response of TLR-2 and TNF- to C. albicans colonization. Conclusions. DSS-induced colitis provides a model for establishing C. albicans colonization in mice. This model reveals that C. albicans augments inflammation and confirms the role of Gal-3 in both inflammation and the control of host responses to C. albicans. Candida albicans colonizes the human gut, which is the primary source of yeast for invasive infections in hospitalized, immunocompromised patients [1, 2]. Recently, a link was established between C. albicans and inflam- - matory bowel diseases through demonstration that this endogenous yeast could induce anti-oligomannose antibodies (antiSaccharomyces cerevisiae antibodies, or ASCA), which are markers of Crohn disease [3]. However, little is known about the molecular relationships between C. albicans and the host receptors that govern colonization, tolerance, inflammation, and invasion at the gut level [4]. Experimental studies in mice are limited by the fact that C. albicans is not a natural part of the murine digestive flora [5, 6]. Establishment of colonization therefore requires the use of either infant [5, 7] or antibiotic-treated adult mice [8 10]. In this study, we used dextran sulfate sodium (DSS)-induced colitis in mice, a model that is widely used to study the relationship between inflammation and the endoluminal microbiota [11], but which had never been adapted to C. albicans. With this model, we explored the effect of C. albicans colonization on inflammation, at both the macroscopic and molecular levels. We examined the involvement of innate immunity mediators and receptors, including galectin-3 (Gal-3), which is a pleiotropic lectin that participates in inflammation but has also been described as a specific receptor for C. albicans [12]. A recent study has confirmed that Gal-3 binds to C. albicans and that high levels of Gal-3 can be detected in human tissues infected by C. albicans [13]. Simultaneously, it was demonstrated that C. albicans promoted the association of Gal-3 with the innate receptor Toll-like receptor (TLR)-2 to induce a macrophage response, which included secretion of the proinflammatory cytokine tumor necrosis factor (TNF)- [14]. Using wild-type (WT) and Gal3 deficient mice (hereafter, Gal3/ mice), the objectives of this study were to investigate the following: (1) the effect of DSS-induced inflammation on C. albicans colonization; (2) the effect of C. albicans colonization on inflammation, as measured by histologic scores, neutrophil infiltration, gene expression of pathogen recognition receptors, and cytokines; and (3) the role of Gal-3 in the regulation of inflammation induced by C. albicans, specifically in relation to TLR-2 and TNF- secretion and ASCA generation. MATERIALS AND METHODS Animals. All animal experiments conformed to the Ministre de lAgriculture et de la Fort Resolution on the use of animals in research and were approved by the Subcommittee on Research Animal Care of the Regional Hospital Center of Lille (protocol 200335). The production of Gal3/ mice by use of genetargeting technology has been described elsewhere [15]. As controls, age- and sex-matched WT (C57BL/6) littermates were used. Mice were maintained by Charles River Laboratories (France). Six- to 8-week-old female mice were used in this study. Animals were housed in groups and had free access to regular rodent chow and tap water. Induction of colitis, C. albicans administration, and experimental design. Colitis was experimentally induced in mice by administration of 5% DSS (molecular weight, 36 50 kDa; MP Biomedicals) in drinking water from day 1 to day 7. Mice were inoculated on day 3 by single gavage with 200 L of PBS containing 107 live cells of C. albicans SC5314 reference strain [16]. No mortality was observed during the 7 days that DSS was administered. WT and Gal3/ mice were each distributed into 1 control group and 3 experimental groups. A group of healthy mice was used as controls (CTL) (5 WT and 6 Gal3/ mice). A second group of mice was gavaged orally with C. albicans without any other treatment (CaCTL) (5 WT and 8 Gal3/ mice). A third group was treated with DSS (DSS) (5 WT and 7 Gal3/ mice). A fourth group was treated with DSS and gavaged orally with C. albicans (CaDSS) (6 WT and 7 Gal3/ mice). At day 14, the animals were sacrificed by cervical dislocation. Blood was collected by cardiac puncture and serum samples were stored at 20C until use. The entire colon from the cecum to the anus was removed, and different anat (...truncated)