Source Of Mesenchymal Stromal Cells Research Articles

Interest of interleukin-1β priming on various sources of MSC for wound healing: role of interleukin-6, a MSC secreted factor

Background & Aim Deep and extensive skin wounds and burns are treated with autologous Split-Thickness Skin Grafts, with a possible combination of adjuvant therapy, or grafted with Cultured Epidermal Autografts (CEAs) when donor sites are limited. Despite many years of use and the allowing of patient survival, CEA still fail to provide satisfactory clinical outcomes due to poor engraftment rates and reduced skin functionality. In the past few decades, Mesenchymal Stromal Cells (MSCs) therapy have been proposed as a novel therapeutic tool to promote wound healing through anti-inflammatory, pro-trophic and pro-remodeling effects. MSCs are also able to interact with their environment and modify their secretory profile depending on cellular, molecular or physical environment. Our team recently shown that, IL-1β-primed gingival MSCs promoted wound healing in vitro, and in vivo through the secretion of a mix of secreted products and extracellular vesicles. Paracrine mechanism involving MMPs and TGF-βs signaling has been shown to be implicated in MSC primed effect on wound healing. Preliminary results also indicated that IL-6 could also been involved. Therefore, in the present work, we investigated whether other source of MSC could respond similarly to Interleukin 1β to favor wound healing through the secretion of extracellular vesicles and secreted products. Methods, Results & Conclusion Naive and IL-1β-primed MSCs from gingival or bone marrow sources were evaluated in in vitro models of migration, inflammation and Dermal-Epidermal Junction (DEJ) formation. Extracellular vesicles and IL-6 expression were analyzed by NTA and ELISA respectively in the Conditioned Media (CM) of MSC culture. To investigate the mechanism of action of IL-6 in particular, we used human recombinant IL-6 at the concentration found in IL-CM by ELISA and specific blocking antibody in our different in vitro models. Preliminary results indicated that both MSC sources responds similarly to Interleukin-1β priming and have been shown to promote skin cell migration, favor extracellular matrix deposition and reduce inflammation. In vivo studies will be performed to confirm the results observed in vitro. Overall, these results underline the benefit of the IL-1β priming strategy in the treatment of severe skin defects using MSC and epidermal substitute. We hope that this approach could soon improve the current medical treatment of full-thickness burn wounds.

Human induced pluripotent stem cells as a source of mesenchymal stromal cells for the treatment of cutaneous radiation injuries

Background & Aim The current management of victims of radiological burns, resulting from industrial or medical accidental exposure, consists in autologous mesenchymal stromal cell (MSC) injection associated with reparative surgery. MSCs were shown to promote tissue regeneration and angiogenesis, and control inflammation. However, several limits inherent to the use of adult stem cells were identified, such as the limited capacity for large-scale production of clinical grade MSCs, or the loss of functionality of the graft. We hypothesized that MSCs derived from pluripotent stem cells (PSCs) could represent a relevant alternative source of cell therapy product for the treatment of radiological burns. Methods, Results & Conclusion PSC-MSCs were derived from six independent human embryonic or induced pluripotent (iPS-MSCs) stem cell lines, adult MSCs were isolated from fat tissue by explant culture, and all cell lines were expanded in clinical grade-compatible culture conditions. Cutaneous radiation injury was induced by exposing mouse skin to 20 Gy X-ray irradiation, followed by full-thickness skin excision. Mice then received a local injection of 106 human adult or PSC-derived MSCs, or PBS. Animals were monitored for 2 weeks by assessing wound closure kinetics, cutaneous perfusion by laser Doppler imaging, and skin functional parameters using a Cutometer. Blood and skin tissue were collected for histological and molecular analyses, and angiogenesis assessment. Animals injected with adult or iPS-MSCs displayed accelerated wound healing kinetics compared to PBS injection, with significant 1.25-fold reduction of wound area at day 3 post-injury (p These results suggest that iPS-MSCs exert a beneficial effect on irradiated skin wound healing, by promoting reepithelialization and enhancing angiogenesis.

Dissecting adipose tissue derived mesenchymal stromal cell heterogeneity using single cell rna sequencing and multiparameter spectral flow cytometry

Background & Aim Human adipose derived mesenchymal stromal cells (ASC) are showing promise for use in clinical cell-based therapies. However, it is becoming more apparent that mesenchymal stromal cells (MSC), despite their tissue of origin, are in fact are a heterogenous population, and deeper characterisation is required to realise their true clinical utility. Human subcutaneous fat is an abundant and accessible source of mesenchymal stromal cells (ASC), found within the heterogenous milieu of the stromal vascular fraction (SVF). However, the precise subpopulation within the SVF with the greatest therapeutic potential remains unclear; which likely contributes to variability, complicating the utility of MSCs in clinical applications. Single cell technologies have emerged as powerful tools to explore cellular heterogeneity of complex systems. We sought to use single cell transcriptomics and multiparameter spectral flow cytometry as an integrative approach to explore subcellular heterogeneity within the ASC population. Methods, Results & Conclusion Single cell RNA sequencing (scRNAseq) was employed to first identify novel cell surface MSC markers in human SVF. Stromal cell populations were enriched by fluorescence-activated cell sorting, and scRNAseq was performed using the Chromium 10x Genomics system. scRNAseq analyses revealed several subpopulations and identified candidate cell surface MSC antigens. Spectral flow cytometry was subsequently performed to validate these novel antigens and screen multiple donors. Spectral flow cytometry, unlike conventional flow cytometry, not only allows multi-parametric, high dimensional analyses at the single cell level, it also enables management of autofluorescent cells, providing high resolution of cellular populations. We developed the most comprehensive 23 colour flow cytometry panel reported to date, incorporating the IFATS/ISCT defined cell surface markers (CD45, CD235a, CD31, CD34, CD90, CD73), to validate novel antigens identified by scRNAseq. Using advanced high dimensional data analysis algorithms, our data shows that ASC from human adipose tissue is indeed more diverse than previously appreciated. Taken together, the integration of spectral flow and genomic cytometric techniques provides a unique tool set to address the urgent need to characterise the subcellular heterogeneity of MSC in complex tissues. A deeper understanding of this heterogeneity will potentially lead to an improvement in the targeted utility of SVF products for clinical applications.

Comparison of functional attributes of mscs isolated by explant and digestion umbilical cord tissue using a split manufacturing model

Background & Aim Umbilical cord tissue (CT) is a rich source of mesenchymal stromal cells (MSCs) and many newborn stem cell banks have established programs for cryopreservation of CT as a source material for future clinical use. Here we utilize a split manufacturing model to compare MSCs isolated after thawing cord tissue cryopreserved as composite cord tissue (c-CT MSCs) and MSCs isolated from previously-cryopreserved, heterogeneous, single-cell suspensions of enzymatically-digested cord tissue (d-CT MSCs) to determine if growth kinetics and differentiation capacity are impacted by the two predominant CT storage strategies adopted by the banking industry. Methods, Results & Conclusion Methods: 10 umbilical cords were obtained for research from consenting mothers. Each CT was divided in half with one half cut into small pieces cryopreserved as whole, composite material, and the other half enzymatically digested to obtain a heterogeneous cell suspension that was cryopreserved. After at least 1 week, thawed composite tissue was explanted in MSC-selective medium for 2 weeks while cells from digested tissue were seeded directly into culture. Cells from both methods were expanded to the end of the third passage (P3) and assessed by flow cytometry, viability, and differentiation capacity. Results Cell yield/gr41 and post-thaw recovery were greater for explanted material (Table 1). Initial heterogeneity of d-CT is addressed by serial culture; P3 d-CT populations are enriched for MSCs, with no differences between CD73, CD90, and CD34/45 compared to c-CT populations (Figure 1). Viabilities and doubling times at P3 were similar (Table 2). Similar qualitative adipo-, and chondrogenic differentiation capabilities were observed for c-CT and d-CT cells while osteogenic capacity was confirmed with calcium deposition as well as an increase in ALP activity (2.7 and 2.9 fold increase for c-CT and d-CT, p=0.8). Conclusion The processes for cryopreservation and isolation of c-CT and d-CT MSCs differ, but once a purified population is obtained, MSCs from the same donor are indistinguishable with regards to growth kinetics and tri-lineage differentiation potential. These results build on our previous report that cells from the same donor are not notably different in secreted factors. While these studies highlight that either CT cryopreservation strategy is suitable for maintaining MSC properties, storage of composite tissue is advantageous due to the greater purity of cells and higher per-gram yield.

Modulation of the in vitro angiogenic potential of human mesenchymal stromal cells from different tissue sources.

Mesenchymal stromal cells (MSCs) have been widely exploited for the treatment of several conditions due to their intrinsic regenerative and immunomodulatory properties. MSC have demonstrated to be particularly relevant for the treatment of ischemic diseases, where MSC-based therapies can stimulate angiogenesis and induce tissue regeneration. Regardless of the condition targeted, recent analyses of MSC-based clinical trials have demonstrated limited benefits indicating a need to improve the efficacy of this cell product. Preconditioning MSC ex vivo through microenvironment modulation was found to improve MSC survival rate and thus prolong their therapeutic effect. This workstudy aims at enhancing the in vitro angiogenic capacity of a potential MSC-based medicinal product by comparing different sources of MSC and culture conditions. MSC from three different sources (bone marrow [BM], adipose tissue [AT], and umbilical cord matrix [UCM]) were cultured with xenogeneic-/serum-free culture medium under static conditions and their angiogenic potential was studied. Results indicated a higher in vitro angiogenic capacity of UCM MSC, compared with cells derived from BM and AT. Physicochemical preconditioning of UCM MSC through a microcarrier-based culture platform and low oxygen concentration (2% O2 , compared with atmospheric air) increased the in vitro angiogenic potential of the cultured cells. Envisaging the clinical manufacturing of an allogeneic, off-the-shelf MSC-based product, preconditioned UCM MSC maintain the angiogenic gene expression profile upon cryopreservation and delivery processes in the conditions of our study. These results are expected to contribute to the development of MSC-based therapies in the context of angiogenesis.

Variables affecting the presence of mesenchymal stromal cells in peripheral blood and their relationship with apheresis products.

Mesenchymal stromal cells (MSCs) demonstrate the properties of self-renewal, multipotentiality, and immunosuppression, which are responsible for their widespread clinical applications in tissue repair and regeneration. MSCs have been isolated from bone marrow, adipose tissue, and cord blood using culture in specialised media. Their presence in peripheral blood (PB) is debatable. We studied the presence of MSCs at baseline (PB) and following mobilisation with growth factors [PB and apheresis product (AP)] in patients undergoing autologous stem cell transplantation and healthy donors using flow cytometry. We conclude that both mobilised PB and AP are potential sources of MSCs. Given their small numbers in PB/AP, clinical use is feasible following ex-vivo expansion. Variables affecting the presence of MSCs in PB and AP are also discussed.

Autotransplantation of the Adipose Tissue-Derived Mesenchymal Stromal Cells in Therapy of Venous Stasis Ulcers.

Adipose tissue is a reliable source of mesenchymal stromal cells (MSC) for use in regenerative medicine. The aim of this pilot study was to describe the method, and assess the safety and the potential efficacy of transplantation of autologous adipose tissue-derived MSC for the treatment of chronic venous stasis ulcers. Study group consisted of 11 patients (mean age: 66.6 ± 9.5years) with chronic venous stasis ulcers. Adipose tissue was harvested by tumescent-aspiration method. Stromal cells were separated using a dedicated closed system in a real-time bedside manner. The phenotype of cells was determined immediately after separation. Cell concentrate was implanted subcutaneously around the wound and the wound bed. All ulcers were assessed planimetrically before autotransplantation and every two weeks during the six-month follow-up. During the study all patients received standard local and general treatment. The preparation contained an average of 5.6 × 106 ± 4 × 106 cells per milliliter. The phenotype of 65-82% of transplanted cells expressed MSC markers: CD73+ CD90+ and CD34+. An improvement was observed in 75% of ulcers. The data showed highly significant negative correlation (p < 0.0001) between wound size and wound closure degree. There was no correlation of ulcer healing with other parameters evaluated, including age of the patients. No serious side effects were observed. Autotransplantation of adipose tissue stromal cells may be a safe and promising treatment method for chronic venous ulcers.

Cardiac Nestin+ Mesenchymal Stromal Cells Enhance Healing of Ischemic Heart through Periostin-Mediated M2 Macrophage Polarization

Mesenchymal stromal cells (MSCs) show potential for treating cardiovascular diseases, but their therapeutic efficacy exhibits significant heterogeneity depending on the tissue of origin. This study sought to identify an optimal source of MSCs for cardiovascular disease therapy. We demonstrated that Nestin was a suitable marker for cardiac MSCs (Nes+cMSCs), which were identified by their self-renewal ability, tri-lineage differentiation potential, and expression of MSC markers. Furthermore, compared with bone marrow-derived MSCs (Nes+bmMSCs) or saline-treated myocardial infarction (MI) controls, intramyocardial injection of Nes+cMSCs significantly improved cardiac function and decreased infarct size after acute MI (AMI) through paracrine actions, rather than transdifferentiation into cardiac cells in infarcted heart. We further revealed that Nes+cMSC treatment notably reduced pan-macrophage infiltration while inducing macrophages toward an anti-inflammatory M2 phenotype in ischemic myocardium. Interestingly, Periostin, which was highly expressed in Nes+cMSCs, could promote the polarization of M2-subtype macrophages, and knockdown or neutralization of Periostin remarkably reduced the therapeutic effects of Nes+cMSCs by decreasing M2 macrophages at lesion sites. Thus, the present work systemically shows that Nes+cMSCs have greater efficacy than do Nes+bmMSCs for cardiac healing after AMI, and that this occurs at least partly through Periostin-mediated M2 macrophage polarization.

Stem cells out of the bag: characterization of ex vivo expanded mesenchymal stromal cells for possible clinical use.

Aim:Mesenchymal stromal cells (MSC) are a promising tool for cellular therapy and regenerative medicine. One major difficulty in establishing a MSC expansion protocol is the large volume of bone marrow (BM) required. We studied whether cells trapped within a collection bag and filter system could be considered as a source of MSC.Results:From the 20 BM collection bag and filter systems, we recovered an average of 1.68 × 108 mononuclear cells, which is the equivalent to 60 ml of filtered BM. Mononuclear cells were expanded ex vivo to 17 × 106 MSC, with purity shown by a CD44+, CD105+, CD90+ and CD73+ immunophenotype, a reduction of 20% proliferating cells in a mixed lymphocyte reaction and also the ability of adipocyte differentiation.Conclusion:Long-term MSC cultures were established from the usually discarded BM collection bag and filter, maintaining an appropriate phenotype and function, being suitable for both investigation and clinical settings.

Endometrial stromal cells exhibit a distinct phenotypic and immunomodulatory profile

BackgroundIn Asherman’s syndrome (AS), intrauterine scarring and fibrotic adhesions lead to menstrual disorders, pregnancy loss, or infertility. A few clinical trials have piloted cell therapy to overcome AS. Understanding the role of the stromal compartment in endometrial regeneration remains poorly understood. We hypothesize that endometrial stromal cells (eSCs) represent a relevant cell population to establish novel cell-based therapeutics for endometrial disorders. The aim of this study was to characterize eSCs and evaluate their immune-cell interactions.MethodseSCs were isolated from healthy donors, during the proliferative stage of the menstrual cycle. Cells were characterized for expression of mesenchymal stromal cell (MSC) markers and assessed for their tumorigenic potential. eSCs were co-cultured with interferon γ and tumor necrosis factor α, and cell surface expression of their respective receptors and human leukocyte antigen (HLA) I and II determined by flow cytometry. Secreted levels of key immunomodulatory factors were established. eSCs were cultured with activated peripheral blood mononuclear cells, and T cell differentiation and proliferation determined.ResultseSCs demonstrated an MSC surface phenotype and exhibited multipotency. Expanded eSCs retained chromosomal stability and demonstrated no tumorigenicity. Upon stimulation, eSCs licensed to an anti-inflammatory phenotype with upregulated secretion of immunomodulatory factors. Stimulated eSCs did not express HLA class II. eSCs suppressed the proliferation and activation of CD4+ T cells, with the eSC secretome further downregulating central memory T cells and upregulating effector memory (EM) cells.ConclusionsDifferential responsiveness to inflammation by eSCs, compared to other MSC sources, demonstrates the need to understand the specific functional effects of individual stromal cell sources. A lack of HLA class II and triggering of EM T cell differentiation strongly links to innate in vivo roles of eSCs in tissue repair and immune tolerance during pregnancy. We conclude that eSCs may be an ideal cell therapy candidate for endometrial disorders.

Reliable isolation of human mesenchymal stromal cells from bone marrow biopsy specimens in patients after allogeneic hematopoietic cell transplantation

Isolation of mesenchymal stromal cells (MSCs) from pretreated, hematologic patients is challenging. Especially after allogeneic hematopoietic cell transplantation (HCT), standard protocols using bone marrow aspirates fail to reliably recover sufficient cell numbers. Because MSCs are considered to contribute to processes that mainly affect the outcome after transplantation, such as an efficient lymphohematopoietic recovery, extent of graft-versus-host disease as well as the occurrence of leukemic relapse, it is of great clinical relevance to investigate MSC function in this context. Previous studies showed that MSCs can be isolated by collagenase digestion of large bone fragments of hematologically healthy patients undergoing hip replacement or knee surgeries. We have now further developed this procedure for the isolation of MSCs from hematologic patients after allogeneic HCT by using trephine biopsy specimens obtained during routine examinations. Comparison of aspirates and trephine biopsy specimens from patients after allogeneic HCT revealed a significantly higher frequency of clonogenic MSCs (colony-forming unit–fibroblast [CFU-F]) in trephine biopsy specimens (mean, 289.8 ± standard deviation 322.5 CFU-F colonies/1 × 106 total nucleated cells versus 4.2 ± 9.9; P < 0.0001). Subsequent expansion of functional MSCs isolated from trephine biopsy specimen was more robust and led to a significantly higher yield compared with control samples expanded from aspirates (median, 1.6 × 106; range, 0–2.3 × 107 P0 MSCs versus 5.4 × 104; range, 0–8.9 × 106; P < 0.0001). Using trephine biopsy specimens as MSC source facilitates the investigation of various clinical questions.

Comparison of the effectiveness of available sources of autologous colony-forming endothelial cells

Endothelial Colony-forming cells (ECFCs) are valuable material for tissue vascular engineering and cell therapy of ischemic tissues. Difficult isolation is the main problem for using of ECFCs. ECFCs isolation from peripheral blood and adipose tissue has been previously described. In the presented research we compared effectiveness of peripheral blood, subcutaneous and epicardial adipose tissue for the ECFCs isolation without cell sorting. ECFCs was isolated from peripheral blood, subcutaneous and epicardial adipose tissue obtained from coronary heart disease patients (males, n=8) undergoing elective coronary artery bypass surgery. The stromal-vascular fraction of subcutaneous (SVF-ST) and epicardial (SVF-ET) adipose tissue as well as the mononuclear blood fraction (MNF) were cultivated in the complied EGM-2 medium. Cell cultures phenotyping was performed by flow cytometry and confocal microscopy. Their angiogenic (Matrigel) and proliferative activity (xCELLigence analyzer) in vitro were studied. ECFCs were isolated from MNF in 50% of cases, from SVF-ST in 12.5% and SVF-ET in 37.5%. The proliferative activity of ECFCs isolated from adipose tissue was low while cultures from MNF showed high and medium activity in 75% of cases. Pure ECFCs (more 99%) were obtained from MNF to third passage without cell sorting. Cultures from adipose tissue were contaminated by mesenchymal-stromal cells (MSCs) and contained ECFCs and MSCs. Thus, peripheral blood is the most effective source of autologous ECFCs compared with adipose tissue for this isolation method. However, adipose tissue is a suitable source of MSC and mixed cultures of MSC and endothelial cells.

Methods and efficacy of extracellular vesicles derived from mesenchymal stromal cells in animal models of disease: a preclinical systematic review protocol

BackgroundOver the past decade, mesenchymal stromal cells have been increasingly investigated for their therapeutic potential in several different illnesses. However, cell therapy can be limited by potentially serious adverse events including cell embolus formation and tumorigenesis. Importantly, the protective effects of mesenchymal stromal cells are largely mediated by paracrine mechanisms including release of extracellular vesicles. This systematic review intends to synthesize the current knowledge of mesenchymal stromal cell-derived extracellular vesicles as a therapeutic option for preclinical models of disease, inflammation, or injury.MethodsA systematic literature search of MEDLINE, Embase, and BIOSIS databases will be conducted. Interventional preclinical in vivo studies using extracellular vesicles derived from any tissue source of mesenchymal stromal cells will be included. Studies will be screened by abstract, and full-text by two independent reviewers. Eligible studies will undergo data extraction with subcategorization into domains based on disease. Methods utilized for extracellular vesicle characterization and isolation will be collected, as well as information on interventional traits, such as tissue source of mesenchymal stromal cells, dosage regimen, and vesicle modifications. Reported outcomes will be collected to determine which diseases studied may be impacted most from treatment with mesenchymal stromal cell-derived extracellular vesicles.DiscussionThis systematic review will summarize preclinical studies investigating the therapeutic efficacy of both small and large extracellular vesicles derived by mesenchymal stromal cells. Extracellular vesicles represent a possibility to harness the benefits of mesenchymal stromal cells with added benefits of reduced manufacturing costs and an improved safety profile. Hence, there has been an exponential increase in interest for developing this cell-free therapy with hundreds of preclinical studies published to date. However, a vast amount of heterogeneity between groups relates to methods of extracellular vesicle isolation, characterization, and study design. This review will capture this heterogeneity and identify the most commonly used and optimal approaches to evaluate mesenchymal stromal cell-derived extracellular vesicle treatment. A meta-analysis of outcomes within each disease domain will help elucidate which fields of research demonstrate promise for developing extracellular vesicles as a novel cell-free therapy. Summarizing this robust information on extracellular vesicles as an intervention can provide guidance for designing preclinical studies with hopes of future clinical translation.

Preclinical Toxicity Evaluation of Clinical Grade Placenta-Derived Decidua Stromal Cells.

Placenta-derived decidua stromal cells (DSCs) are being investigated as an alternative to other sources of mesenchymal stromal cells (MSCs) for cellular therapy. DSCs are more effective in treating acute inflammatory diseases in human and this is our preclinical safety study of human DSCs in Sprague-Dawley rats and Balb/c mice. Human DSCs were cultured and expanded from fetal membranes obtained from placentas following cesarean section. In rats, 0.5 × 106 cells/kg were injected intravenously (n = 4) or intra-aortal (n = 4). In mice, DSCs were given intravenously at doses ranging from 4–40 × 106 cells/kg (total of n = 120 mice). In vivo tracking of human cells in mice was performed by using transduced DSC with luciferin gene, and in rats by using 18F-FDG PET. Clotting parameters were determined in vitro and in vivo. All intra-arterially DSC-treated rats had normal motility and behavior and histological examination was normal for liver, spleen kidneys and thigh muscles. Mice treated with DSCs showed no immediate or long-term side effects. None of the mice died or showed acute toxicity or adverse reactions 3 and 30 days after DSC infusion. Murine blood biochemistry profiles related to liver, kidney, heart, and inflammatory indices was not influenced by DSC infusion and complete blood counts were normal. In vivo tracking of infused DSCs detected a signal in the lungs for up to 4 days post infusion. Compared to bone marrow derived MSCs, the DSCs had better viability, smaller size, but stronger clotting in human blood and plasma. Both MSC- and DSC-induced coagulation and complement activation markers, thrombin-anti-thrombin complex (TAT) and C3a, and in vitro clotting parameters were decreased by heparin supplementation. In conclusion, DSCs are safe with almost no side effects even with doses 40 times higher than are used clinically, particularly when supplemented with low-dose heparin.

Wharton's Jelly Mesenchymal Stromal Cells from Human Umbilical Cord: a Close-up on Immunomodulatory Molecules Featured In Situ and In Vitro.

Therapeutic options for end-stage organ failure are often limited to whole organ transplantation. The tolerance or rejection of the transplanted organ is driven by both early non-specific innate and specific adaptive responses. The use of mesenchymal stromal cells (MSCs) is considered a promising tool in regenerative medicine. Human umbilical cord (HUC) is an easily available source of MSCs, without relevant ethical issues. Moreover, Wharton's jelly-derived MSCs (WJ-MSCs), showed consistent immunomodulatory features that may be useful to promote immune tolerance in the host after transplantation. Few data are available on the phenotype of WJ-MSCs in situ. We investigated the expression of immune-related molecules, such as HLAs, IDO, CD276/B7-H3, and others, both in situ (HUC) and in in vitro-cultured WJ-MSCs. Morphological and biochemical techniques were used to define the expression of such molecules. In addition, we focused on the possible role of CD276/B7-H3 on T cells proliferation inhibition. We assessed CD276/B7-H3 expression by WJ-MSCs both in situ and alongside cell culture. WJ-MSCs were able to suppress T cell proliferation in mixed lymphocyte reaction (MLR). Moreover, we describe for the first time a specific role for CD276/B7-H3, since the immunomodulatory ability of WJ-MSCs was abolished upon anti-CD276/B7-H3 antibody addition to the MLR. These results further detail the immune regulation properties and tolerance induction exerted by human WJ-MSCs, in particular pointing to CD276/B7-H3 as one of the main involved factors. These data further suggest WJ-MSCs as potent tools to modulate local immune response in "support-type" regenerative medicine approaches.

Immunosuppressive Diversity of Umbilical Cord-Derived Mesenchymal Stromal Cells

Recently, umbilical cord (UC) has become attracted source of mesenchymal stromal cells (MSCs) for immunotherapy such as treatment of severe acute graft versus host disease, because of abundant sources and ease of collection without invasive process. In previous reports on bone marrow-derived MSCs, there is diversity of immunosuppressive mechanisms of MSCs, which have not yet fully clarified in UC-MSCs. Here we studied the immunosuppressive properties of UC-MSCs on the activated immune system in vitro. Methods; UC was collected after obtaining informed consent from the mother. UC-MSCs were obtained from frozen-thawed UC tissue with explant method and expanded in culture medium. Mixed lymphocyte reaction (MLR) consisted with mononuclear cells (MNCs) stained with CFSE and allogeneic dendritic cell (DC) line (PMDC05) co-cultured with or without UC-MSCs was carried out, and the proliferation of CD4 and CD8-positive lymphocytes were analyzed by flowcytometry followed by FlowJo software. Migratory activities of UC-MSCs toward activated lymphocytes in MLR were evaluated by counting the migrating cells stained with DAPI through the insert filter under the microscope. The percentage of CD4+CD25+FOXP3+ regulatory T cells (Treg) before and after co-culture with UC-MSCs was analyzed by flowcytometry. Monocyte phenotypes co-cultured with UC-MSCs directly or separately by insert filter were analyzed with anti-CD14, CD206, and CD168 antibodies. Results: The UC-MSCs were positive for CD105, CD73, CD90, and negative for CD45 and HLA-DR. HLA-DR, CD80, CD86, and CD40 were negative even in the high concentration of IFN-γ, while BM-MSCs became positive for HLA-DR. PD-L2 was constitutively expressed in UC-MSC, while PD-L1 was induced upon the addition of IFN-γ. In MLR, responder T cell proliferation triggered by allogeneic DC was inhibited efficiently by 3rd party derived UC-MSCs. Mean+/- SD distribution index of proliferation in CD4- and CD8- positive cells co-cultured with UC-MSCs showed 7.6+/-4.4% and 8.8+/-3.9% compared to those without UC-MSCs (n=4, as different donor derived MSCs). This inhibition was attenuated by the addition of 1-Methyl-dl-tryptophan, Indoleamine 2, 3-dioxygenase (IDO-1) inhibitor, in a dose-dependent manner. The supernatant of MLR showed the increase of IFN-γ and TNF-α, which were also suppressed in MLR co-cultured with UC-MSCs. UC-MSCs migrated toward activated lymphocytes in MLR compared with those of non-activated lymphocytes significantly, which was inhibited by the addition of AG1296, known as platelet-derived growth factor inhibitor; and PPP as insulin-like growth factor (P&amp;lt;0.05). Cytokine beads array indicated the increase of RANTES, IL-8, and MIP-1. Regulatory T cells in CD4-positive T cells were significantly increased in the MNCs co-cultured with UC-MSCs. Interestingly, CD206-positive M2 monocytes were significantly increased in the MNCs cu-cultured with UC-MSC. Mean +/- SD percentage of CD206+CD80- M2 cells indicated 28.9+/-15.3% in MNCs and 83.3+/-11.2% in MNCs cu-cultured with UC-MSC (n=4, P&amp;lt;0.05). On the other hand, CD206-CD80+ M1 monocytes significantly increased in addition of LPS, which were inhibited by the co-culture with UC-MSCs (P&amp;lt;0.05). Furthermore IFN-γ and TNF-α secreted in the MNCs with LPS were suppressed by the co-culture of UC-MSCs. Discussions and Conclusion: These results demonstrated that UC-MSCs have the diverse immunosuppressive potency through migration toward the activated lymphocytes, suppressing activated T cells proliferation, regulatory T cells induction, and transition of monocyte phenotype. And UC-MSCs are the feasible and abundant source for immunotherapy. Disclosures Nagamura-Inoue: AMED: Research Funding. Nagamura:AMED: Research Funding. Tojo:AMED: Research Funding; Torii Pharmaceutical: Research Funding.

Stem cell-based interventions for the prevention and treatment of germinal matrix-intraventricular haemorrhage in preterm infants.

Germinal matrix-intraventricular haemorrhage (GMH-IVH) remains a substantial issue in neonatal intensive care units worldwide. Current therapies to prevent or treat GMH-IVH are limited. Stem cell-based therapies offer a potential therapeutic approach to repair, restore, and/or regenerate injured brain tissue. These preclinical findings have now culminated in ongoing human neonatal studies. To determine the benefits and harms of stem cell-based interventionsfor prevention or treatment of germinal matrix-intraventricular haemorrhage (GM-IVH) in preterm infants. We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 1), in the Cochrane Library; MEDLINE via PubMed (1966 to 7 January 2019); Embase (1980 to 7 January 2019); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to 7 January 2019). We also searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. We attempted to identify randomised controlled trials, quasi-randomised controlled trials, and cluster trials comparing (1) stem cell-based interventions versus control; (2) mesenchymal stromal cells (MSCs)of type or source versus MSCs of other type or source; (3) stem cell-based interventions other than MSCs of type or source versus stem cell-based interventions other than MSCs of other type or source; or (4) MSCs versus stem cell-based interventions other than MSCs. For prevention studies, we included extremely preterm infants (less than 28 weeks' gestation), 24 hours of age or less, without ultrasound diagnosis of GM-IVH; for treatment studies, we included preterm infants (less than 37 weeks' gestation), of any postnatal age, with ultrasound diagnosis of GM-IVH. For each of the included trials, two review authors independently planned to extract data (e.g. number of participants, birth weight, gestational age, type and source of MSCs, other stem cell-based interventions) and assess the risk of bias (e.g. adequacy of randomisation, blinding, completeness of follow-up). Primary outcomes considered in this review are all-cause neonatal mortality, major neurodevelopmental disability, GM-IVH, and extension of pre-existing non-severe GM-IVH. We planned to use the GRADE approach to assess the quality of evidence. Our search strategy yielded 769 references. We did not find any completed studies for inclusion. One randomised controlled trial is currently registered and ongoing. Five phase 1 trials are described in the excluded studies. Currently no evidence is available to show the benefits or harms of stem cell-based interventions for treatment or prevention of GM-IVH in preterm infants.

Abstract 717: CGMP Expanded First Trimester Human Umbilical Cord Perivascular Cells (FTM HUCPVC) Induce Significant Angiogenesis, Myocardial Regeneration and Sustained Functional Recovery Exceeding Older MSC Sources in the Rat Myocardial Infarction (MI) Model

Introduction: FTM HUCPVC are a novel source of young, immunoprivileged mesenchymal stromal cells (MSC). FTM HUCPVC demonstrate significant homing, angiogenic and tissue remodelling capacities in vitro . We aimed to explore the therapeutic potential of cGMP compliant FTM HUCPVC for myocardial infarction (MI). Methods: FTM HUCPVC and term HUCPVC were expanded in cGMP compliant xeno-free (5% HPL) multilayer cultures (Corning) and Quantum Bioreactor (Terumo). One week post-MI Fox rnu rats (n=6) were intramyocardially injected with 3 million FTM HUCPVC, term HUCPVC, bone marrow MSC (BMSC) or basal media. Cardiac function (echocardiography, pressure/volume catheter and ECG telemetry), infarct scar (Trichrome), ECM remodelling activity (DQ collagenase substrate) vascular density (IB4) and contractile proteins (SarcA) were quantified 4 weeks and 6 months after cell implantation. Myocardial apoptosis (caspase-3) and macrophage infiltration (eNOS, CD68, CD80) were assessed at 5 days after cell treatment. Results: FTM HUCPVC significantly reduced apoptosis at 5 days and infarct size at 4 weeks (5.3±1.1, p&lt;0.05) compared to other treatment groups. Histological analysis showed that the infarcted region of FTM HUCPVC treated hearts displayed significantly higher: M2 macrophage ratio, perivascular gelatinase activity, capillary density (543.4±118.6 vs. 276.5±42.69; p&lt;0.05), abundance of contractile sarcomeric actinin (48.9±6.1 vs. 19.5±7.0; p&lt;0.05), and Ca 2+ pump SERCA (69.9±5.9 vs. 49.8±3.7) over other experimental groups. FTM HUCPVCs induced significant and superior improvements in all measures of contractile function (ESV, EF, dPdt, tau) relative to cell-free media (p&lt;0.001), BMSC (p&lt;0.001) and term HUCPVC (p&lt;0.001). Improvements in inotropy and lusitropy were maintained to 6 months (δ dPdt max 3.8±6.0; δ dPdt min 3.2±8.78) and resulted in near complete abolishment of premature ventricular contractions (&lt;1/min). Conclusion: FTM HUCPVC treatment after MI induces superior structural and functional recovery compared to older MSC sources; characteristics that were maintained during xeno-free upscaling and for up to 6 months post injection. FTM HUCPVC are a promising option as a novel cell therapy for optimal cardiovascular regeneration.

Banking Mesenchymal Stromal Cells from Umbilical Cord Tissue: Large Sample Size Analysis Reveals Consistency Between Donors.

Mesenchymal stromal cells (MSCs) have emerged as candidate cells with therapeutic potential to treat different pathologies. The underlying mechanism is paracrine signaling. The cells secrete proteins that can impact inflammation, apoptosis, angiogenesis, and cell proliferation. All are important in wound healing and tissue regeneration. Although the bone marrow has been the most widely used source of MSCs, umbilical cord tissue (CT) presents a source that is just starting to be used in the clinic, yet can be obtained with more ease and easily stored. Here, we characterize CT‐MSCs obtained from multiple donors by analyzing cell surface proteins, differentiation capacity, and proteome profile. Analysis of low, medium, and high passage cells indicates that the morphology and proliferation rate stay constant and with the exception of cluster of differentiation (CD) 105 at late passage, there are no changes in the cell surface protein characteristics, indicating the population does not change with passage. TNF‐stimulated gene 6 protein was measured in a subset of samples and variable expression was observed, but this did not impact the ability of the cells to enhance skin regeneration. In conclusion, CT‐MSC represents a consistent, easily accessible source of cells for cell therapy. stem cells translational medicine 2019;8:1041–1054

The comparative study of chondrogenic differentiation of mesenchymal stromal cells allocated from different sources

Introduction. As an alternative to autochondral transplantation, variants of chondrocyte replacement with mesenchymal stromal cells (MSCs) were considered, since these cells are present in all organs and tissues of human body and possess multilinear potential for differentiation. A number of studies demonstrate that the ability for chondrogenic differentiation of MSCs from different tissues varies, however, those studies are few and controversial. In accordance with the ethical principles and the technical ease of obtaining, adipose tissue, Wharton’s jelly (stroma) and dental pulp are the most attractive sources of MSCs for tissue engineering.Aim: to compare the chondrogenic potential of MSCs allocated from adipose tissue, Wharton’s jelly of the umbilical cord, and human deciduous teeth pulp cultured in the composition of microspheres (pellets).Materials and methods. The phenotype of primary cultures of MSCs was studied via flow microscopy. Chondrogenic differentiation was performed with 3D-culture in microspheres in the presence of TGFβ1 for two weeks under standard conditions. Human chondroblasts were used as a positive control. Cell viability was determined by fluorescent staining. Morphological study was performed using histological and immunohistochemical staining methods.Results. Cultures of MSCs from all sources had similar phenotypes CD29+, CD34–, CD44+, CD49b+, CD45–, CD73+, CD90+, HLADR. In the mass of living cells in microspheres only singular dead cells were visualized. A significant production of extracellular matrix (ECM) was observed in the chondroblast and adipose tissue microspheres, whereas in the microspheres of dental pulp and umbilical cord stroma derived MSCs, no significant ECM was detected. Among the MSCs, the highest production of collagen and glycosaminoglycans (GAG) in the ECM was observed in the microspheres of adipose tissue-derived MSCs, and the lowest production – in the microspheres of dental pulp-derived MSCs. Conclusion. A histological analysis of all microspheres after 14 days of culturing in the chondrogenic medium revealed the signs of differentiation in the chondrogenic direction, a progressive increase of the ECM produced by cells, and the presence of total collagen and GAG in it. Of all the MSCs studied, the greatest chondrogenic potential in vitro (the intensity of development of ECM components) is possessed by the adipose tissue-derived MSCs.