Stem cells, Blastema and Regeneration
The project of the group focus on the dialogue between stem cells and immune cells in two different contexts: rheumatoid arthritis characterized by inflammation as well as bone and cartilage degradation and epimorphic regeneration.
The first axis leans on the immunomodulatory properties of Mesenchymal stem cells (MSCs) that we have described both in vitro when co-cultured with T cells, macrophages and B cells and in vivo in arthritis. These characteristics are currently extensively used for the treatment of several inflammatory diseases. MSCs may exert their therapeutic effect through a rapid 'hit and run' mechanism leading to the generation of regulatory cells however such a phenomenon has never been clearly demonstrated.
The second axis concerns the regenerative potential of zebrafish larva (Danio rerio) and mouse embryo that require the formation of a heterogeneous structure named blastema that contains proliferating somatic cells, entering a state of stem cell (SC) activity that regenerates the lost organ. Although the source of these SC has received a substantial attention, our knowledge of how SC activation is initiated and coordinated with other cellular events including cell mediated-immune response during regeneration remains poorly understood.
The main objectives of the group are to 1) define the regulatory function of immune cells generated in vitro after co-culture with MSC or in vivo in arthritis and, 2) decipher the basis of the dialogue between stem cells and immune cell subsets during epimorphic regeneration.
Understanding the immunosuppressive properties of MSC
Immunomodulatory properties of immune cells generated in vitro after coculture with MSC.
We have previously shown that MSC promote the generation of regulatory T cells when cultured under the conditions specific for Th1 and Th17 cell differentiation in vitro. Going further, we demonstrated that the therapeutic effectiveness of MSC in arthritis is mediated through the polarization of Th17 cells towards a regulatory phenotype. Our objective is to evaluate the regulatory and therapeutic functions of the regulatory immune cells generated in vitro in the experimental model of collagen-induced arthritis (CIA).
Immunomodulatory properties of MSC.
We have recently identified some factors that play a critical role in the immunosuppressive properties of MSC. In vivo, in CIA the therapeutic effect of MSC was correlated with the generation of Treg bearing the CD4+RORγT+IL17LowIL10+ signature and this polarization was GILZ (glucocorticoid-induced leucine zipper )-dependent. Our objective is to decipher the basis of the immunomodulatory dialogue between MSC and immune cells.
Understanding the molecular and cellular basis of epimorphic regeneration
Characterization of blastema cells.
Using the specific advantages of the zebrafish larvae model - i.e. regenerative capacity, transparency and genetic tractability - and the genetic lineage tracing in mouse embryo leaning on the Cre-loxP system, our goal is to characterize the origin of the different cell types contained in the blastema and determine their function during regeneration.
Study of the dialogue between stem cells and immune cells during regeneration.
We aim at dissecting the basis of the communication between SC and immune cell subsets during epimorphic regeneration in both zebrafish larva and mouse embryo by: 1) characterizing the sub-population of cells that are recruited at the molecular level and, 2) defining the contribution of the different cell subsets during regeneration and, 3) investigating the functional relevance of SC and immune cell dialogue.
- Nguyen-Chi M et al. Identification of macrophage subsets in zebrafish. eLife. 2015;10.7554/eLife.07288
- Luz-Crawford P et al. Gilz governs the therapeutic potential of mesenchymal stem cell by inducing a switch from pathogenic to regulatory Th17 cells. Arthritis Rheum, 2015, 67:1514-1524.
- Djouad F et al. PLZF induction signs mesenchymal stem cell commitment: identification of a key marker for stemness maintenance? Stem Cell Res Ther, 2014, 5:27.
- Djouad F. et al. Functional cartilage repair capacity of de-differentiated, chondrocyte- and mesenchymal stem cell-laden hydrogels in vitro. Osteoarthritis Cartilage. 2014 Jun 2.
- Scholtysek C et al. (2013) PPARβ governs Wnt signaling and bone turnover. Nat. Medicine. 2013 May;19(5):608-13.
- Luz-Crawford P et al. MSCs generate a CD4+CD25+Foxp3+ regulatory T cell population during the differentiation process of Th1 and Th17 cells. Stem Cell Res Ther. 2013 Jun 4;4(3):65.
- Luz-Crawford P. et al. MSC repress Th17 molecular program through the PD-1 pathway. PLoSONE. 2012 ;7(9) :e45272.
- Djouad F. et al. Activin A expression regulates multipotency of mesenchymal progenitor cells. Stem cell res and ther. 2010; 4;1(2):11.
- Huang GT. et al. Stem/Progenitor cell-mediated de novo regeneration of dental pulp with newly deposited continuous layer of dentin in an in vivo model. Tissue Engineering, Part A. 2010; 16(2):605-15.
- Djouad F et al. Pro-inflammatory cytokines activate ERK1/2 pathway and compromise integration of chondrocyte-laden hydrogels into articular cartilage, Tissue Engineering, Part A. 2009; 15(10):2825-35.
- Mathieu M. et al. Involvement of angiopoietin-like 4 in matrix remodeling during chondrogenic differentiation of mesenchymal stem cells. J Biol Chem. 2014 Mar 21;289(12):8402-12
More references, click on PubMed:
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DJOUAD Farida (CR1/Inserm)
MATHIEU Marc (CR1/Inserm)
SAPEDE Dora (Post-doc/UM)
BARTHELAIX Audrey (IE/Inserm)
TEJEDOR Gautier (IE/Inserm)
BODIC Benoit (Doctorant)
CONTRERAS LOPEZ Rafael (Doctorant)
LAPLACE-BUILHE Béryl (Doctorante)
RIQUIER Sébastien (Doctorant)
SARRE Charlotte (Doctorant)
BAHRAOUI Sarah (Doctorante)
Cell biology: primary mesenchymal stem cell; differentiation and polarization of CD4+ T cells, macrophages and B cells; flow cytometry; immunologic techniques (ELISA, CBA, IF, Western blot)
Mouse embryo culture
proliferation assay; identification of immune cell subsets
Molecular biology: RT-qPCR; TLDA
Animal experimentation: collagen-induced arthritis model
3D imaging: confocal laser microscopy, in vivo µCT
4-Dimentional high resolution imaging
Embryology and molecular genetic of the zebrafish