Immune Modulatory Treatment of Trinitrobenzene Sulfonic Acid Colitis with Calcitriol Is Associated with a Change of a T Helper (Th) 1/Th17 to a Th2 and Regulatory T Cell Profile Carolin Daniel, Nico A. Sartory, Nadine Zahn, Heinfried H. Radeke, and Ju ¨ rgen M. Stein First Department of Internal Medicine Zentrums fuer Arzneimittelforschung, Entwicklung und Sicherheit (ZAFES) (C.D., N.A.S., N.Z., J.M.S.), Pharmazentrum Frankfurt ZAFES (C.D., H.H.R.), Johann Wolfgang Goethe University of Frankfurt am Main, Frankfurt, Germany Received June 13, 2007; accepted September 28, 2007 ABSTRACT A number of recent studies testify that calcitriol alone or in combination with corticosteroids exerts strong immune modu- latory activity. As a new approach, we evaluated the protolero- genic potential of calcitriol and dexamethasone in acute T helper (Th)1-mediated colitis in mice. A rectal enema of trini- trobenzene sulfonic acid (TNBS) (100 mg/kg) was applied to BALB/c mice. Calcitriol and/or dexamethasone were adminis- tered i.p. from days 0 to 3 or 3 to 5 following the instillation of the haptenating agent. Assessment of colitis severity was per- formed daily. Colon tissue was analyzed macroscopically and microscopically, and myeloperoxidase activity, as well as cyto- kine levels [tumor necrosis factor-, interferon-, interleukin (IL)-12p70, IL-1, IL-10, IL-4] were determined by enzyme- linked immunosorbent assay, T-bet, GATA family of transcrip- tion factors 3, a Th2 master regulator (GATA3), Foxp3, cyto- toxic T-lymphocyte-associated antigen 4 (CTLA4), IL-23p19 and IL-17 expression by immunoblot analysis. The combination of the steroids most effectively reduced the clinical and his- topathologic severity of TNBS colitis. Th1-related parameters were down-regulated, whereas Th2 markers like IL-4 and GATA3 were up-regulated. Apart from known steroid effects, calcitriol in particular promoted regulatory T cell profiles as indicated by a marked increase of IL-10, TGF, FoxP3, and CTLA4. Furthermore, analysis of dendritic cell mediators re- sponsible for a proinflammatory differentiation of T cells re- vealed a significant reduction of IL-12p70 and IL23p19 as well as IL-6 and IL-17. Thus, our data support a rationale for a steroid-sparing, clinical application of calcitriol derivatives in inflammatory bowel disease. Furthermore they suggest that early markers of inflammatory dendritic cell and Th17 differen- tiation qualify as new target molecules for both calcitriol and highly selective immune-modulating vitamin D analogs. Calcitriol has been identified in a number of studies as a prominent negative regulator of T helper (Th1)-type immune responses, whereas Th2 responses are not affected or even augmented as indicated by an induction of T1/ST2 (Schmitz et al., 2005; Wang et al., 2005). Although these effects have been preferentially explained by direct effects on lympho- cytes, subsequent studies clearly supported a role of calcitriol in modulating monocyte differentiation or dendritic cell (DC) maturation (Griffin et al., 2003). Calcitriol clearly reduced the transition of the innate immune stimulation to an adap- tive inflammatory immune response by interfering with sig- nal transducers and activators of transcription, interferon regulatory factor 1/4, and possibly with the molecular ele- ments involved in cross-presentation (Penna and Adorini, 2000; Muthian et al., 2006). With respect to myeloid DC development, the phenotype of calcitriol-conditioned DC re- flects an immature status with poor capacity to induce anti- gen-specific T cell proliferation and a tendency to promote tolerance in vivo (Mellman and Steinman, 2001). The immunoregulatory properties of calcitriol have been demonstrated in different models of autoimmune diseases (systemic lupus erythematosus, allograft rejection, autoim- mune diabetes mellitus, and experimental allergic encepha- lomyelitis), in which a substantial amelioration was observed following treatment with calcitriol. These data from animal This work was supported by the Else Kroener-Fresenius-Foundation (Bad Homburg, Germany). H.H.R. is supported by the Dr.-Hans-Schleussner-Foundation. C.D. is sup- ported by the Deutsche Forschungsgemeinschaft (GRK 757). H.H.R. and J.M.S. contributed equally to this work. Article, publication date, and citation information can be found at http://jpet.aspetjournals.org. doi:10.1124/jpet.107.127209. ABBREVIATIONS: Th, T helper; DC, dendritic cell; VDR, vitamin D receptor; GC, glucocorticoid; IL, interleukin; IBD, inflammatory bowel disease; CD, Crohn’s disease; TNBS, trinitrobenzene sulfonic acid; BW, body weight; TNF, tumor necrosis factor; Dex, dexamethasone; GR, glucocorticoid receptor; IB, immunoblot; GATA3, GATA family of transcription factors 3, a Th2 master regulator; CTLA, cytotoxic T-lymphocyte-associated antigen. 0022-3565/08/3241-23–33$20.00 THE JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS Vol. 324, No. 1 Copyright © 2008 by The American Society for Pharmacology and Experimental Therapeutics 127209/3283895 JPET 324:23–33, 2008 Printed in U.S.A. 23 at Bibliothekszentrum Niederursel / Team Chemie/Pharmazie on February 10, 2009 jpet.aspetjournals.org Downloaded from