Rosiglitazone promotes the differentiation of Langerhans cells and inhibits that of other dendritic cell types from CD133 positive hematopoietic precursors
Maria Ida Bonetti1, Stefano Bacci1, Michela Santosuosso2, Benedetta Mazzanti2, Alessandra Aldinucci3, Clara Ballerini3, Daniele Guasti1, Laura Calosi1, Alberto Bosi1,2 and Paolo Romagnoli1
1Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy, 2Haematology Unit, University Hospital Careggi, Florence, Italy and 3Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence, Italy.
Offprint requests to: Dr. Stefano Bacci, University of Florence, Department of Experimental and Clinical Medicine, Laboratory “E Allara”, Viale Pieraccini 6, 50139 Firenze, Italy. e-mail: email@example.com
Summary. Dendritic cells and their precursors express PPAR-gamma, whose stimulation has inhibitory effects on the maturation and function of dendritic cells in vivo. Dendritic cells can differentiate in vitro from CD133+ progenitors; the influence of PPAR-gamma stimulation on this process is unknown. We have addressed the effect of PPAR-gamma agonist rosiglitazone, at a concentration as used in clinics, on the differentiation of dendritic cells from human CD133+ progenitors. Cells were harvested from cord blood by density gradient and immunomagnetic separation, and cultured for 18 days with fetal calf serum, cytokines and 1 µmol/L rosiglitazone. Analyses included flow cytometry, electron microscopy and mixed lymphocyte reaction. As expected, control cells generated without rosiglitazone were dendritic, expressed MHC-II, CD80, CD83 and CD86 and stimulated mixed reaction potently. A minority of cells expressed the Langerhans cell marker CD207/langerin, but none contained Birbeck granules. With rosiglitazone much fewer cells were generated; they were all dendritic, expressed differentiation and maturation-related antigens in higher percentage and were better stimulators of lymphocytes than those generated without the drug. The vast majority of cells expressed CD207/langerin and many contained Birbeck granules, i.e. were full-fledged Langerhans cells. We conclude that stimulation of PPAR-gamma, while negatively affecting the number of generated cells, promotes the maturation of human cord blood CD133 positive precursors into efficient, immunostimulating dendritic cells with a Langerhans cell phenotype. Histol Histopathol 29, 323-332 (2014)
Key words: Cell culture; Electron microscopy, Flow cytometry, Mixed lymphocyte reaction, Birbeck granules