Biomedical subjects

Matthieu Rouleau

Publications and source records attributed to Matthieu Rouleau.

3 recordsLinked to original sources

PubMed2005

[Embryonic stem cells and epidermal commitment].

Embryonic stem (ES) cells can be cultured indefinitely, differentiated into many cell types in vitro, thus providing a potentially unlimited supply of cells for cell-based therapy. We recently reported the efficient derivation of ectodermal and epidermal cells from murine ES cells. These differentiated ES cells are able to form, in culture, a multilayered epidermis coupled with an underlying dermal compartment, similar to native skin. This model demons- trates that ES cells have the potential to recapitulate the reciprocal instructive ectodermal-mesodermal commitments, characteristic of embryonic skin formation, clarifies the role of the morphogen BMP-4 in the binary neuroectodermal choice and provides a powerful tool for the study of molecular mechanisms controlling skin development and multipotent epidermal stem cell properties. Its potential for cutaneous cell therapy and dermatocosmetological applications is discussed.

Animals↗

PubMed2004

A role for CD2 antibodies (BTI-322 and its humanized form) in the in vivo elimination of human T lymphocytes infiltrating an allogeneic human skin graft in SCID mice: an Fcgamma receptor-related mechanism involving co-injected human NK cells.

BACKGROUND: Pilot clinical studies have shown that the rat anti-human-CD2 monoclonal antibody, LoCD2a/BTI-322, can efficiently prevent and treat acute kidney rejection. However, the in vivo mechanism by which it prevents allograft rejection has not been studied. BTI-322 and its humanized form have been shown to mediate in vitro antibody-dependent cell-mediated cytotoxicity (ADCC) against CD2 cells through the activation of monocytes or natural killer (NK) cells. METHODS: Human fetal skin samples were grafted into severe combined immunodeficient/nonobese diabetic mice. Five weeks later (day 0), the mice were injected with human allogeneic peripheral blood lymphocytes (PBL). Either on day 0 or on day 14, mice were treated with BTI-322, hu-BTI-322, or their F(ab')2 fragments. Peripheral blood mononuclear cells (PBMC) thoroughly devoid of NK cells were also assayed. RESULTS: After injection of PBL, the human skins became heavily infiltrated with activated human T lymphocytes, resulting in dermal microvascular injuries indicative of graft rejection. Early treatment with BTI-322 and hu-BTI-322 prevented all these events. These CD2 antibodies rapidly eliminated human T lymphocytes that had already infiltrated the grafts, with no evidence of recirculation toward the spleen. Their F(ab')2 fragments were, in contrast, ineffective. Elimination of NK cells from injected PBMC prevented the curative effect exerted by whole CD2 antibodies. It also abrogated their cytotoxicity potential against CD2 cells in ADCC assays. CONCLUSION: F(ab')2 fragments of the CD2 antibodies could not prevent allograft rejection, whereas whole immunoglobulin G could, and human NK cells were required for the curative effect exerted by these antibodies. The results are consistent with an FcgammaR-dependent ADCC mechanism mediated in vivo by human NK cells.

Acute Disease↗

PubMed2003

Reconstituted skin from murine embryonic stem cells.

Embryonic stem (ES) cell lines can be expanded indefinitely in culture while maintaining their potential to differentiate into any cell type. During embryonic development, the skin forms as a result of reciprocal interactions between mesoderm and ectoderm. Here, we report the in vitro differentiation and enrichment of keratinocytes from murine ES cells seeded on extracellular matrix (ECM) in the presence of Bone Morphogenic Protein-4 (BMP-4) or ascorbate. The enriched preparation of keratinocytes was able to form an epidermal equivalent composed of a stratified epithelium when cultured at the air-liquid interface on a collagen-coated acellular substratum. Interestingly, an underlying cellular compartment that belongs to the fibroblast lineage was systematically formed between the reconstituted epidermis and the inert membrane. The resulting tissue displayed morphological patterns similar to normal embryonic skin, as evidenced by light and transmission electron microscopy. Immunohistochemical studies revealed expression patterns of cytokeratins, basement membrane (BM) proteins and late differentiation markers of epidermis, as well as fibroblast markers, similar to native skin. The results demonstrate the capacity of ES cells to reconstitute in vitro a fully differentiated skin. This ES-derived bioengineered skin provides a powerful tool for studying the molecular mechanisms controlling epidermal and dermal commitments.

Animals↗