Browsing by Subject "Immunomodulation"

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3D-MSCs A151 ODN-loaded exosomes are immunomodulatory and reveal a proteomic cargo that sustains wound resolution
(Elsevier B.V., 2022-11) Camões, Sérgio P.; Bulut, Özlem; Yazar, Volkan; Gaspar, Maria M.; Simões, Sandra; Ferreira, Rita; Vitorino, Rui; Santos, Jorge M.; Gürsel, İhsan; Miranda, Joana P.
Introduction: Non-healing wounds remain a major burden due to the lack of effective treatments. Mesenchymal stem cell-derived exosomes (MSC-Exo) have emerged as therapeutic options given their pro-regenerative and immunomodulatory features. Still, little is known on the exact mechanisms mediated by MSC-Exo. Importantly, modulation of their efficacy through 3D-physiologic cultures together with loading strategies continues underexplored. Objectives: To uncover the MSC-Exo-mediated mechanism via proteomic analyses, and to use 3D-culture and loading technologies to expand MSC-Exo efficacy for cutaneous wound healing. Methods: MSC-Exo were produced in either 3D or 2D cultures (Exo3D/Exo2D) and loaded with an exogenous immunosuppressive oligodeoxynucleotide (A151 ODN). Both, loaded and naïve exosomes were characterised regarding size, morphology and the presence of specific protein markers; while IPA analyses enabled to correlate their protein content with the effects observed in vitro and in vivo. The Exo3D/Exo2D regenerative potential was evaluated in vitro by assessing keratinocyte and fibroblast mitogenicity, motogenicity, and cytokine secretion as well as using an in vivo wound splinting model. Accordingly, the modulation of inflammatory and immune responses by A151-loaded Exo3D/Exo2D was also assessed. Results: Exo3D stimulated mitogenically and motogenically keratinocytes and fibroblasts in vitro, with upregulation of IL-1α and VEGF-α or increased secretion of TGF-β, TNF-α and IL-10. In vivo, Exo3D reduced the granulation tissue area and promoted complete re-epithelization of the wound. These observations were sustained by the proteomic profiling of the Exo3D cargo that identified wound healing-related proteins, such as TGF-β, ITGA1-3/5, IL-6, CDC151, S100A10 and Wnt5α. Moreover, when loaded with A151 ODN, Exo3D differentially mediated wound healing-related trophic factors reducing the systemic levels of IL-6 and TNF-α at the late stage of wound healing in vivo. Conclusion: Our results support the potential of A151-loaded Exo3D for the treatment of chronic wounds by promoting skin regeneration, while modulating the systemic levels of the pro-inflammatory cytokines. © 2022
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Contribution of toll-like receptors to mesenchymal stem cell differentiation and immunomodulation
(2010) Taş, İbrahim Fırat
characteristics along with several stem cell features such as lineage dependent differentiation and self-renewal capacity. MSCs are known to induce immunomodulatory activity and homing capacity to damaged tissue sites. Such diverse capabilities of MSCs make them distinct from adult stem cells and can be harnessed in several therapeutic applications. Toll-like receptors (TLR) can recognize conserved microbial byproducts and are mainly expressed by innate immune system cells as well as epithelial or endothelial cells. Recent findings suggest that in vitro generated MSCs express some of these pathogen recognition receptors. In our view, to broaden the breath of the therapeutic potential, TLR mediated activation of MSCs and demonstrate its impact on differentiation and immunomodulatory activity is critical. First, bone marrow-derived MSCs were generated and characterized via their surface marker expression by FACS (CD90, CD106 and CD45) at protein level and their message transcripts by RT-PCR (CD11b, CD29, CD34, CD45, CD71, CD73, CD90 and CD166). The most abundant marker was found to be CD90 over several passages. Following determination of TLR expression profile by RT-PCR, contribution of TLR ligands addition (TLR2, TLR3, TLR7 and TLR9) to MSCs during adipogenic or osteogenic differentiation was studied. TLR3 was found to be the most abundant type over several passages. The adipogenic differentiation of rMSCs was found to be facilitated in the presence of TLR2 TLR3 and TLR7 ligands. Additionally, changes in the adipogenic and osteogenic markers (LPL, PPAR-g for adipogenesis, and ALP, OC-1, RUNX for osteogenesis) were analyzed by RT-PCR. While adipogenic markers upregulated osteogenic markers were downregulated in response to TLR ligand treatment. The final part of this study was performed with mouse mesenchymal stem cells. In order to define the immunostimulatory/immunosuppressive potential of mouse MSCs, immunomodulatory character of MSCs were examined in the presence or absence of mouse spleen cells. Our data suggested that when mMSCs are primed with TLRL, a pro-inflammatory cascade as evidenced by increased IL-6 and IFN-γ secretion is initiated either alone or in co-culture with splenocytes. In conclusion, TLR priming of MSCs augments their differentiation primarily into adipogenesis, and mainly these cells are immunostimulatory.
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Immunomodulatory function and in vivo properties of pediococcus pentosaceus OZF, a promising probiotic strain
(Springer, 2013) Osmanagaoglu, O.; Kiran, F.; Yagci, F. C.; Gursel, I.
Some of the important properties of probiotics are the ability to survive during gastrointestinal transit and to modulate the immune functions. The objectives of the reported study were to assess in vivo gastrointestinal survival of orally administered Pediococcus pentosaceus OZF using an animal model BALB/c mice, and to examine its effects on the immune response. Following oral administration to mice, the ability of Pediococcus pentosaceus OZF to pass and survive through the mouse gastrointestinal system was investigated by analyzing the recovery of the strain in fecal samples. Microbiological and polymerase chain reaction (PCR) methods proved that the strain OZF could overcome specific conditions in the gastrointestinal tract of mice and reach the intestine alive after ingestion. To observe the effect of oral administration on immune response, IL-6, IL-12 and IFN-γ were measured by ELISA, and the strain OZF was found to cause increases in IL-6 synthesis in regularly fed mice. However, stimulation was carried out with various concentrations of bacterial ssDNA and heat killed cells of Pediococcus pentosaceus OZF. The heat killed cells of the strain OZF were shown to produce IFN- γ independently from IL-12. On the other hand, a significant difference between control and experimental group was noticed when lipopolysaccharide, a TLR4 (toll like receptor) ligand, was used. Overall, Pediococcus pentosaceus OZF may be a valuable probiotic strain for therapeutic uses. Nevertheless, further studies on the mechanisms of immunomodulatory effect will allow for better clarification of the immune functions of this strain. © Springer-Verlag Berlin Heidelberg and the University of Milan 2012.