title: Potently immunosuppressive 5-fluorouracil-resistant mesenchymal stromal cells completely remit an experimental autoimmune disease.
abstract: We treated mice with 5-fluorouracil (5-FU) to isolate a quiescent and undifferentiated mesenchymal stromal cell (MSC) population from the bone marrow. We examined these 5-FU-resistant MSCs (5-FU-MSCs) free from hematopoietic components for CFU fibroblasts (CFU-Fs) and assessed their immunosuppressive potential in vitro and in vivo. We differentiated fibroblastic CFU-Fs (Fibro-CFU-Fs) from mixed CFU-Fs, based on the absence of in situ expression of CD11b and CD45 hematopoietic markers, as well as on their differentiation capacity. Fibro-CFU-Fs were associated with increased numbers of large-sized Fibro-CFU-Fs (≥9 mm(2)) that displayed enhanced capacity for differentiation into adipogenic and osteogenic mesenchymal lineages. Administration of these 5-FU-resistant CD11b(-)CD45(-) MSCs 6 d after myelin oligodendrocyte glycoprotein (MOG) immunization completely remitted MOG-induced experimental autoimmune encephalomyelitis after initial development of mild disease. The remission was accompanied by reduced CNS cellular infiltration and demyelination, as well as a significant reduction in anti-MOG Ab and splenocyte proliferation to MOG. MOG-stimulated splenocytes from these mice showed elevated levels of Th2 cytokines (IL-4, IL-5, and IL-6) and decreased IL-17. Compared with untreated MSCs, 5-FU-MSCs demonstrated potent immunosuppression of Con A-stimulated splenocytes in vitro, even at a 1:320 MSC/splenocyte ratio. Immunosuppression was accompanied by elevated IL-1ra, IL-10, and PGE(2). Blocking IL-1ra, IL-10, and PGE(2), but not IL-6, heme oxygenase-1, and NO, attenuated 5-FU-MSC-induced immunosuppression. Together, our findings suggested that immunosuppression by 5-FU-MSC is mediated by a combination of elevated IL-1ra, IL-10, and PGE(2), anti-inflammatory Th2 cytokines, and decreased IL-17. Our findings suggested that 5-FU treatment identifies a population of potently immunosuppressive 5-FU-MSCs that have the potential to be exploited to remit autoimmune diseases.
authors.affiliation: Centre for Inflammatory Disease, Monash University, Melbourne, Victoria 3163, Australia.
authors.forename: Ding Yuan
authors.initials: DY
authors.lastname: Oh
authors.forename: Peng
authors.initials: P
authors.lastname: Cui
authors.forename: Hamid
authors.initials: H
authors.lastname: Hosseini
authors.forename: Jennifer
authors.initials: J
authors.lastname: Mosse
authors.forename: Ban-Hock
authors.initials: BH
authors.lastname: Toh
authors.forename: James
authors.initials: J
authors.lastname: Chan
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000276:immunology; D002478:Cells, Cultured; D018920:Coculture Techniques; D004195:Disease Models, Animal; D015536:Down-Regulation / Q000276:immunology*; D004351:Drug Resistance / Q000276:immunology; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000276:immunology* / Q000473:pathology*; D005260:Female; D005472:Fluorouracil / Q000494:pharmacology*; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000276:immunology; D008648:Mesoderm / Q000276:immunology* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D017154:Stromal Cells / Q000187:drug effects / Q000276:immunology* / Q000473:pathology
chemical_list: D007166:Immunosuppressive Agents; D005472:Fluorouracil