title: Differential TLR activation of murine mesenchymal stem cells generates distinct immunomodulatory effects in EAE.
abstract: Recently, it has been observed that mesenchymal stem cells (MSCs) can modulate their immunoregulatory properties depending on the specific in-vitro activation of different Toll-like receptors (TLR), such as TLR3 and TLR4. In the present study, we evaluated the effect of polyinosinic:polycytidylic acid (poly(I:C)) and lipopolysaccharide (LPS) pretreatment on the immunological capacity of MSCs in vitro and in vivo.
  
  
  
  C57BL/6 bone marrow-derived MSCs were pretreated with poly(I:C) and LPS for 1 hour and their immunomodulatory capacity was evaluated. T-cell proliferation and their effect on Th1, Th17, and Treg differentiation/activation were measured. Next, we evaluated the therapeutic effect of MSCs in an experimental autoimmune encephalomyelitis (EAE) model, which was induced for 27 days with MOG35-55peptide following the standard protocol. Mice were subjected to a single intraperitoneal injection (2 × 106MSCs/100 μl) on day 4. Clinical score and body weight were monitored daily by blinded analysis. At day 27, mice were euthanized and draining lymph nodes were extracted for Th1, Th17, and Treg detection by flow cytometry.
  
  
  
  Pretreatment of MSCs with poly(I:C) significantly reduced the proliferation of CD3+T cells as well as nitric oxide secretion, an important immunosuppressive factor. Furthermore, MSCs treated with poly(I:C) reduced the differentiation/activation of proinflammatory lymphocytes, Th1 and Th17. In contrast, MSCs pretreated with LPS increased CD3+T-cell proliferation, and induced Th1 and Th17 cells, as well as the levels of proinflammatory cytokine IL-6. Finally, we observed that intraperitoneal administration of MSCs pretreated with poly(I:C) significantly reduced the severity of EAE as well as the percentages of Th1 and Th17 proinflammatory subsets, while the pretreatment of MSCs with LPS completely reversed the therapeutic immunosuppressive effect of MSCs.
  
  
  
  Taken together, these data show that pretreatment of MSCs with poly(I:C) improved their immunosuppressive abilities. This may provide an opportunity to better define strategies for cell-based therapies to autoimmune diseases.
authors.affiliation: Laboratory of Cellular and Molecular Immunology, Faculty of Medicine, Universidad de los Andes, Monseñor Álvaro del Portillo N°12.455, Las Condes, Santiago, 750000, Chile.|Cell Culture Laboratory Animals, School of of Biochemical Engineering, Pontificia Universidad Católica de Valparaíso, Av. Brasil 2085, Valparaíso, 2362803, Chile.
authors.forename: Ana María
authors.initials: AM
authors.lastname: Vega-Letter
authors.affiliation: Laboratory of Cellular and Molecular Immunology, Faculty of Medicine, Universidad de los Andes, Monseñor Álvaro del Portillo N°12.455, Las Condes, Santiago, 750000, Chile.
authors.forename: Mónica
authors.initials: M
authors.lastname: Kurte
authors.affiliation: Laboratory of Cellular and Molecular Immunology, Faculty of Medicine, Universidad de los Andes, Monseñor Álvaro del Portillo N°12.455, Las Condes, Santiago, 750000, Chile.
authors.forename: Catalina
authors.initials: C
authors.lastname: Fernández-O'Ryan
authors.affiliation: Laboratory of Cellular and Molecular Immunology, Faculty of Medicine, Universidad de los Andes, Monseñor Álvaro del Portillo N°12.455, Las Condes, Santiago, 750000, Chile.
authors.forename: Melanie
authors.initials: M
authors.lastname: Gauthier-Abeliuk
authors.affiliation: Laboratory of Cellular and Molecular Immunology, Faculty of Medicine, Universidad de los Andes, Monseñor Álvaro del Portillo N°12.455, Las Condes, Santiago, 750000, Chile.
authors.forename: Patricia
authors.initials: P
authors.lastname: Fuenzalida
authors.affiliation: Laboratory of Cellular and Molecular Immunology, Faculty of Medicine, Universidad de los Andes, Monseñor Álvaro del Portillo N°12.455, Las Condes, Santiago, 750000, Chile.
authors.forename: Ivón
authors.initials: I
authors.lastname: Moya-Uribe
authors.affiliation: Cell Culture Laboratory Animals, School of of Biochemical Engineering, Pontificia Universidad Católica de Valparaíso, Av. Brasil 2085, Valparaíso, 2362803, Chile.
authors.forename: Claudia
authors.initials: C
authors.lastname: Altamirano
authors.affiliation: Laboratory of Cellular and Molecular Immunology, Faculty of Medicine, Universidad de los Andes, Monseñor Álvaro del Portillo N°12.455, Las Condes, Santiago, 750000, Chile.
authors.forename: Fernando
authors.initials: F
authors.lastname: Figueroa
authors.affiliation: Laboratory of Integrative and Molecular Physiology, Faculty of Medicine, Universidad de los Andes, Monseñor Álvaro del Portillo N°12.455, Las Condes, Santiago, 750000, Chile.
authors.forename: Carlos
authors.initials: C
authors.lastname: Irarrázabal
authors.affiliation: Laboratory of Cellular and Molecular Immunology, Faculty of Medicine, Universidad de los Andes, Monseñor Álvaro del Portillo N°12.455, Las Condes, Santiago, 750000, Chile. flaviocarrion@yahoo.com.
authors.forename: Flavio
authors.initials: F
authors.lastname: Carrión
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000276:immunology / Q000502:physiology*; D049109:Cell Proliferation / Q000502:physiology; D064987:Cell- and Tissue-Based Therapy; D002478:Cells, Cultured; D016207:Cytokines / Q000276:immunology / Q000378:metabolism; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000276:immunology* / Q000378:metabolism*; D005260:Female; D007155:Immunologic Factors / Q000276:immunology* / Q000378:metabolism; D015850:Interleukin-6 / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology / Q000502:physiology; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods; D059630:Mesenchymal Stem Cells / Q000276:immunology* / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000378:metabolism; D018417:Th1 Cells / Q000276:immunology / Q000378:metabolism; D058504:Th17 Cells / Q000276:immunology / Q000378:metabolism; D051193:Toll-Like Receptors / Q000276:immunology / Q000378:metabolism*
chemical_list: D016207:Cytokines; D007155:Immunologic Factors; D015850:Interleukin-6; D051193:Toll-Like Receptors
keywords: Autoimmunity; Experimental autoimmune encephalomyelitis; Immunomodulation; Mesenchymal stem cells; Toll-like receptors 3 and 4