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Background: AT-MSCs display great immunoregulatory features, making them potential candidates for cell-based therapy. This study aimed to evaluate the "RBC lysis buffer" isolation protocol and immunological profiling of the so-obtained AT-MSCs., Methods: We established an immune-comparative screening of AT-MSCs throughout in vitro cell expansion (PM, P1, P2, P3, P4) and inflammatory priming regarding the expression of 28 cell-surface markers, 6 cytokines/chemokines, and 10 TLR patterns., Findings: AT-MSCs were highly expandable and sensitive to microenvironment challenges, hereby showing plasticity in distinct expression profiles. Both cell expansion and inflammation differentially modulated the expression profile of CD34, HLA-DR, CD40, CD62L, CD200 and CD155, CD252, CD54, CD58, CD106, CD274 and CD112. Inflammation resulted in a significant increase in the expression of the cytokines IL-6 , IL-8 , IL-1β , IL-1Ra , CCL5 , and TNFα . Depending on the culture conditions, the expression of the TLR pattern was distinctively altered with TLR1-4 , TLR7 , and TLR10 being increased, whereas TLR6 was downregulated. Protein network and functional enrichment analysis showed that several trophic and immune responses are likely linked to these immunological changes., Conclusions: AT-MSCs may sense and actively respond to tissue challenges by modulating distinct and specific pathways to create an appropriate immuno-reparative environment. These mechanisms need to be further characterized to identify and assess a molecular target that can enhance or impede the therapeutic ability of AT-MSCs, which therefore will help improve the quality, safety, and efficacy of the therapeutic strategy.

Adult human subcutaneous adipose tissue (AT) harbors a rich population of mesenchymal stromal cells (MSCs) that are of interest for tissue repair. For this purpose, it is of utmost importance to determine the response of AT-MSCs to proliferative and inflammatory signals within the damaged tissue. We have characterized the transcriptional profile of cytokines, regulatory mediators and Toll-like receptors (TLR) relevant to the response of MSCs. AT-MSCs constitutively present a distinct profile for each gene and differentially responded to inflammation and cell-passaging. Inflammation leads to an upregulation of IL-6, IL-8, IL-1β, TNFα and CCL5 cytokine expression. Inflammation and cell-passaging increased the expression of HGF, IDO1, PTGS1, PTGS2 and TGFβ. The expression of the TLR pattern was differentially modulated with TLR 1, 2, 3, 4, 9 and 10 being increased, whereas TLR 5 and 6 downregulated. Functional enrichment analysis demonstrated a complex interplay between cytokines, TLR and regulatory mediators central for tissue repair. This profiling highlights that following a combination of inflammatory and proliferative signals, the sensitivity and responsive capacity of AT-MSCs may be significantly modified. Understanding these transcriptional changes may help the development of novel therapeutic approaches.

The progression of mesenchymal stem cell-based therapy from concept to cure closely depends on the optimization of conditions that allow a better survival and favor the cells to achieve efficient liver regeneration. We have previously demonstrated that adult-derived human liver stem/progenitor cells (ADHLSC) display significant features that support their clinical development. The current work aims at studying the impact of a sustained pro-inflammatory environment on the principal biological features of ADHLSC in vitro., Methods: ADHLSC from passages 4-7 were exposed to a cocktail of inflammatory cytokines for 24 h and 9 days and subsequently analyzed for their viability, expression, and secretion profiles by using flow cytometry, RT-qPCR, and antibody array assay. The impact of inflammation on the hepatocytic differentiation potential of ADHLSC was also evaluated., Results: ADHLSC treated with a pro-inflammatory cocktail displayed significant decrease of cell yield at both times of treatment while cell mortality was observed at 9 days post-priming. After 24 h, no significant changes in the immuno-phenotype of ADHLSC expression profile could be noticed while after 9 days, the expression profile of relevant markers has changed both in the basal conditions and after inflammation treatment. Inflammation cocktail enhanced the release of IL-6, IL-8, CCL5, monocyte-chemo-attractant protein-2 and 3, CXCL1/GRO, and CXCL5/ENA78. Furthermore, while IP-10 secretion was increased after 24 h priming, granulocyte macrophage colony-stimulating factor enhanced secretion was noticed after 9 days treatment. Finally, priming of ADHLSC did not affect their potential to differentiate into hepatocyte-like cells., Conclusion: These results indicate that ADHLSCs are highly sensitive to inflammation and respond to such signals by adjusting their gene and protein expression. Accordingly, monitoring the inflammatory status of patients at the time of cell transplantation, will certainly help in enhancing ADHLSC safety and efficiency.

Human skin-derived precursors (SKP) represent a group of somatic stem/precursor cells that reside in dermal skin throughout life that harbor clinical potential. SKP have a high self-renewal capacity, the ability to differentiate into multiple cell types and low immunogenicity, rendering them key candidates for allogeneic cell-based, off-the-shelf therapy. However, potential clinical application of allogeneic SKP requires that these cells retain their therapeutic properties under all circumstances and, in particular, in the presence of an inflammation state. Therefore, in this study, we investigated the impact of pro-inflammatory stimulation on the secretome and immunosuppressive properties of SKP. We demonstrated that pro-inflammatory stimulation of SKP significantly changes their expression and the secretion profile of chemo/cytokines and growth factors. Most importantly, we observed that pro-inflammatory stimulated SKP were still able to suppress the graft-versus-host response when cotransplanted with human PBMC in severe-combined immune deficient (SCID) mice, albeit to a much lesser extent than unstimulated SKP. Altogether, this study demonstrates that an inflammatory microenvironment has a significant impact on the immunological properties of SKP. These alterations need to be taken into account when developing allogeneic SKP-based therapies.

Objective and Design: Bone marrow mesenchymal stromal cells (BM-MSCs) are referred as a promising immunotherapeutic cell product. New approaches using empowered MSCs should be developed as for the treatment or prevention of different immunological diseases. Such preconditioning by new licensing stimuli will empower the immune fate of BM-MSCs and, therefore, promote a better and more efficient biological. Here, our main goal was to establish the immunological profile of BM-MSCs following inflammatory priming and in particular their capacity to adjust their immune-related proteome and transcriptome., Material and Methods: To run this study, we have used BM-MSC cell cultures, a pro-inflammatory cytokine cocktail priming, flow cytometry analysis, qPCR and ELISA techniques., Results: Different expression levels of several immunological mediators such as COX-1, COX-2, LIF, HGF, Gal-1, HO-1, IL-11, IL-8, IL-6 and TGF-β were constitutively observed in BM-MSCs. Inflammation priming substantially but differentially modulated the gene and protein expression profiles of these mediators. Thus, expressions of COX-2, LIF, HGF, IL-11, IL-8 and IL-6 were highly increased/induced and those of COX-1, Gal-1, and TGF-β were reduced., Conclusions: Collectively, we demonstrated that BM-MSCs are endowed with a specific and modular regulatory machinery which is potentially involved in immunomodulation. Moreover, BM-MSCs are highly sensitive to inflammation and respond to such signal by properly adjusting their gene and protein expression of regulatory factors. Using such preconditioning may empower the immune fate of MSCs and, therefore, enhance their value for cell-based immunotherapy.

Mesenchymal stromal cells (MSCs) are multipotent adult cells with relevant biological properties making them interesting tools for cell-based therapy. These cells have the ability to home to sites of injury and secrete bioactive factors as part of their therapeutic functions. However, depending on the local environment, diverse functions of MSCs can be modulated and thus can influence their therapeutic value. The specific cytokine milieu within the site of inflammation is vital in determining the fate and cell behaviors of MSCs. Indeed, inflammatory signals (called as inflammatory priming), may induce critical changes on the phenotype, multilineage potential, hematopoietic support and immunomodulatory capacity of MSCs. Thus, for appropriate clinical application of MSCs, it is important to well know and understand these effects. In summary, investigating MSC interactions with the inflammatory environment is necessary to empower the therapeutic value of MSCs.

As a form of immunomodulatory therapeutics, mesenchymal stromal/stem cells (MSCs) from umbilical cord (UC) tissue were assessed for their dynamic interplay with the Th-17 immune response pathway. UC-MSCs were able to modulate lymphocyte response by promoting a Th-17-like profile. Such modulation depended on the cell ratio of the cocultures as well as the presence of an inflammatory setting underlying their plasticity. UC-MSCs significantly increased the expression of IL-17A and RORγt but differentially modulated T cell expression of IL-23R. In parallel, the secretion profile of the fifteen factors (IL1β, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-22, IL-21, IL-23, IL-25, IL-31, IL-33, INF-γ, sCD40, and TNF-α) involved in the Th-17 immune response pathway was substantially altered during these cocultures. The modulation of these factors demonstrates the capacity of UC-MSCs to sense and actively respond to tissue challenges. Protein network and functional enrichment analysis indicated that several biological processes, molecular functions, and cellular components linked to distinct Th-17 signaling interactions are involved in several trophic, inflammatory, and immune network responses. These immunological changes and interactions with the Th-17 pathway are likely critical to tissue healing and may help to identify molecular targets that will improve therapeutic strategies involving UC-MSCs. [ABSTRACT FROM AUTHOR]

Abstract: Mesenchymal stromal cells (MSCs) display a special immunological profile that allows their potential use as immunotherapeutic cells. Nowadays, foreskin (FSK) represents a valuable reservoir of MSCs with International Society for Cellular Therapy (ISCT) compliant criteria and relevant functional properties. However, their mode of action is poorly understood and needs to be more elucidated to optimize their therapeutic use. Because microRNAs (miRNAs) act as key regulators in a wide variety of biological processes, we decided to establish the micronome of FSK‐MSCs, the influence of inflammation and the predicted target pathways. Here, we provide the full list of unchanged and additional four differentially expressed miRNAs, miR‐199b, ‐296‐3p and ‐589‐5p being downregulated whilst miR‐146‐3p being upregulated, in MSCs following their exposure to a cocktail of proinflammatory cytokines. MicroRNA target prediction in addition to Pathway enrichment analysis performed using miRNet, showed that miR‐296‐3p is linked to antigen processing and presentation pathway. Collectively, our data indicate that the micronome of FSK‐MSCs is partially responsive to inflammation. Differentially expressed miRNAs are subsequently modulated by inflammation and seem to be involved in regulating the immunological fate of FSK‐MSCs. These miRNAs deserve more attention in order to optimize MSC‐based therapy and achieve the appropriate therapeutic effect. [ABSTRACT FROM AUTHOR]

Background: As a cell-based therapeutic, AT-MSCs need to create an immuno-reparative environment appropriate for tissue repair. In the presence of injury, MSCs may have to proliferate and face inflammation. Clinical application requires repeated administrations of a high number of cells with a well-established immune profile. Methods: We have established an immuno-comparative screening by determining the expression of 28 molecules implicated in immune regulation. This screening was performed during cell-expansion and inflammatory priming of AT-MSCs. Results: Our study confirms that AT-MSCs are highly expandable and sensitive to inflammation. Both conditions have substantially modulated the expression of a panel of immunological marker. Specifically, CD34 expression was substantially decreased upon cell-passaging. HLA-ABC, CD40 CD54, CD106, CD274 and CD112 were significantly increased by inflammation. In vitro cell-expansion also significantly altered the expression profile of HLA-DR, CD40, CD62L, CD106, CD166, HLA-G, CD200, HO-1, CD155 and ULBP-3. Conclusion: This study points out the response and characteristics of MSCs following expansion and inflammatory priming. It will strength our knowledge about the molecular mechanisms that may improve or hamper the therapeutic potential of MSCs. These immunological changes need to be further characterized to guarantee a safe cellular product with consistent quality and high therapeutic efficacy. [ABSTRACT FROM AUTHOR]