IFN-Gamma and TNF-Alpha as a Priming Strategy to Enhance the Immunomodulatory Capacity of Secretomes from Menstrual Blood-Derived Stromal Cells

Mesenchymal stromal cells isolated from menstrual blood (MenSCs) exhibit a potent pro-angiogenic and immunomodulatory capacity. Their therapeutic effect is mediated by paracrine mediators released by their secretomes. In this work, we aimed to evaluate the effect of a specific priming condition on the phenotype and secretome content of MenSCs. Our results revealed that the optimal condition for priming MenSCs was the combination of interferon gamma (IFNγ) and tumor necrosis factor alpha (TNFα) that produced a synergistic and additive effect on IDO1 release and immune-related molecule expression. The analyses of MenSC-derived secretomes after IFNγ and TNFα priming also revealed an increase in EV release and in the differentially expressed miRNAs involved in the immune response and inflammation. Proliferation assays on lymphocyte subsets demonstrated a decrease in CD4+ T cells and CD8+ T cells co-cultured with secretomes, especially in the lymphocytes co-cultured with secretomes from primed cells. Additionally, the expression of immune checkpoints (PD-1 and CTLA-4) was increased in the CD4+ T cells co-cultured with MenSC-derived secretomes. These findings demonstrate that the combination of IFNγ and TNFα represents an excellent priming strategy to enhance the immunomodulatory capacity of MenSCs. Moreover, the secretome derived from primed MenSCs may be postulated as a therapeutic option for the regulation of adverse inflammatory reactions.

The Role of MSCs and Cell Fusion in Tissue Regeneration

Regenerative medicine is concerned with the investigation of therapeutic agents that can be used to promote the process of regeneration after injury or in different diseases. Mesenchymal stem/stromal cells (MSCs) and their secretome – including extracellular vesicles (EVs) are of great interest, due to their role in tissue regeneration, immunomodulatory capacity and low immunogenicity. So far, clinical studies are not very conclusive as they show conflicting efficacies regarding the use of MSCs. An additional process possibly involved in regeneration might be cell fusion. This process occurs in both a physiological and a pathophysiological context and can be affected by immune response due to inflammation. In this review the role of MSCs and cell fusion in tissue regeneration is discussed.

Interferon-gamma and TNF-alpha synergistically enhance the immunomodulatory capacity of Endometrial-Derived Mesenchymal Stromal Cell secretomes by differential microRNA and extracellular vesicle release

Endometrial Mesenchymal Stromal Cells (endMSCs) can be easily isolated from menstrual blood by plastic adherence. These cells have a potent pro-angiogenic and immunomodulatory capacity, and their therapeutic effect is mediated by paracrine mechanisms where secretome have a key role. In this paper, we aimed to evaluate different priming conditions in endMSCs using pro-inflammatory cytokines and Toll-Like Receptor ligands. Our in vitro results revealed a synergistic and additive effect of IFNγ and TNFα on endMSCs. The combination of these pro-inflammatory cytokines significantly increased the release of Indoleamine 2,3-dioxygenase (IDO1) in endMSCs. Additionally, this study was focused on the phenotype of IFNγ/TNFα-primed endMSCs (endMSCs*). Here we found that immune system-related molecules such as CD49d, CD49e, CD54, CD56, CD58, CD63, CD126, CD152, or CD274 were significantly altered in endMSCs* when compared to control cells. Afterward, our study was completed with the characterization of released miRNAs by Next Generation Sequencing (NGS). Briefly, our system biology approaches demonstrated that endMSCs* showed an increased release of 25 miRNAs whose target genes were involved in immune response and inflammation. Finally, the cellular and molecular characterization was completed with in vitro functional assays. In summary, the relevance of our results lies in the therapeutic potential of endMSCs*. The differences in cell surface molecules involved in migration, adhesion and immunogenicity, allowed us to hypothesize that endMSCs* may have an optimal homing and migration capacity towards inflammatory lesions. Secondly, the analysis of miRNAs, target genes and the subsequent lymphocyte activation assays demonstrated that IFNγ/TNFα-primed secretome may exert a potent effect on the regulation of adverse inflammatory reactions.

A procedure for in vitro evaluation of the immunosuppressive effect of mouse mesenchymal stem cells on activated T cell proliferation

Background Mesenchymal stem/stromal cells (MSC) represent adult cells with multipotent capacity. Besides their capacity to differentiate into multiple lineages in vitro and in vivo, increasing evidence points towards the immunomodulatory capacity of these cells, as an important feature for their therapeutic power. Although not included in the minimal criteria established by the International Society for Cellular Therapy as a defining MSC attribute, demonstration of the immunomodulatory capacity of MSC can be useful for the characterization of these cells before being considered MSC. Methods Here we present a simple and reliable protocol by which the immunosuppressive effect of mouse bone marrow-derived MSC can be evaluated in vitro. It is based on the measuring of the proliferation of activated T cells cultured in direct contact with irradiated MSC. Results Our results showed that mouse MSC have a dose-dependent inhibitory effect on activated T cell proliferation, which can be quantified as a percentage of maximum proliferation. Our data shows that batch-to-batch variability can be determined within one or multiple experiments, by extracting the area under curve of T cell proliferation plotted against the absolute number of MSC in co-culture. Conclusions The validation of the immunosupressive capacity of MSC could be added to the characterization of the cells before being used in various MSC-based approaches to treat immunological diseases. Our results showed that mouse MSC have a dose-dependent inhibitory effect on activated T cell proliferation. The immunosuppressive properties of MSC vary between batches, but not between different passages of the same batch.

IDO and CD40 May Be Key Molecules for Immunomodulatory Capacity of the Primed Tonsil-Derived Mesenchymal Stem Cells

Background: Tonsil-derived mesenchymal stem cells (T-MSCs) were reported to have suppressive effect on T cells, yet much remains unknown about the underlying mechanisms supporting this effect. We investigated the underlying mechanism of the immunomodulatory effect of T-MSCs on immune cell proliferation and cytokine production. Methods: We isolated T-MSCs from human palatine tonsil and evaluated the immunomodulatory capacity using RT-PCR, ELISA, and flow cytometry. Additionally, we assessed the expression of various soluble factors and several costimulatory molecules to detect the priming effect on T-MSCs. Results: T-MSCs significantly inhibited the immune cell proliferation and cytokine expression (TNF-α and IFN-γ) in the direct co-culture, but there was no suppressive effect in indirect co-culture. Additionally, we detected a remarkably higher expression of indoleamine 2,3-dioxygenase (IDO) in the primed T-MSCs having co-expression CD40. Moreover, immune cells or CD4+ T cells showed lower TNF-α, IFN-γ, and IL-4 expression when the primed T-MSC were added; whereas those findings were reversed when the inhibitor for IDO (not IL-4) or CD40 were added. Furthermore, T-bet and GATA3 levels were significantly decreased in the co-cultures of the primed T-MSCs and CD4+ T cells; whereas those findings were reversed when we added the neutralizing anti-CD40 antibody. Conclusions: Primed T-MSCs expressing IDO and CD40 may have immunomodulatory capacity via Th1-mediated and Th2-mediated immune response.

Leishmaniasis: effect of enalaprilat on the production of (ON) and cytokines in vitro

Leishmaniasis is neglected diseases; the drugs used have significant toxic effects that compromise patient compliance, and increased loss of efficacy due to increased resistant infectious strains. Assays on Swiss mice infected with Leishmania brasiliensis and treated with Angiotensin-Suppressing Enzyme (ACE) inhibitors showed that, in addition to the classical effects on the cardiovascular system, some of these inhibitors had effects on nonhemodynamic, immunomediated functions such as cytokine production. In this study, the effect of enalaprilate on nitric oxide (NO) production and cytokines were evaluated, i.e., interleukins-10 and 12 and IFN-γ in J774 A.1 macrophages infected by Leishmania braziliensis. Enalaprilate demonstrated in vitro immunomodulatory capacity, increasing the release of NO to induce IL-12 and IFN-γ also decreasing il-10 release.

Tetrahedral Framework Nucleic Acid-Based Delivery of Resveratrol Alleviates Insulin Resistance: From Innate to Adaptive Immunity

Obesity-induced insulin resistance is the hallmark of metabolic syndrome, and chronic, low-grade tissue inflammation links obesity to insulin resistance through the activation of tissue-infiltrating immune cells. Current therapeutic approaches lack efficacy and immunomodulatory capacity. Thus, a new therapeutic approach is needed to prevent chronic inflammation and alleviate insulin resistance. Here, we synthesized a tetrahedral framework nucleic acid (tFNA) nanoparticle that carried resveratrol (RSV) to inhibit tissue inflammation and improve insulin sensitivity in obese mice. The prepared nanoparticles, namely tFNAs-RSV, possessed the characteristics of simple synthesis, stable properties, good water solubility, and superior biocompatibility. The tFNA-based delivery ameliorated the lability of RSV and enhanced its therapeutic efficacy. In high-fat diet (HFD)-fed mice, the administration of tFNAs-RSV ameliorated insulin resistance by alleviating inflammation status. tFNAs-RSV could reverse M1 phenotype macrophages in tissues to M2 phenotype macrophages. As for adaptive immunity, the prepared nanoparticles could repress the activation of Th1 and Th17 and promote Th2 and Treg, leading to the alleviation of insulin resistance. Furthermore, this study is the first to demonstrate that tFNAs, a nucleic acid material, possess immunomodulatory capacity. Collectively, our findings demonstrate that tFNAs-RSV alleviate insulin resistance and ameliorate inflammation in HFD mice, suggesting that nucleic acid materials or nucleic acid-based delivery systems may be a potential agent for the treatment of insulin resistance and obesity-related metabolic diseases.

Impact of Digestive Inflammatory Environment and Genipin Crosslinking on Immunomodulatory Capacity of Injectable Musculoskeletal Tissue Scaffold

The paracrine and autocrine processes of the host response play an integral role in the success of scaffold-based tissue regeneration. Recently, the immunomodulatory scaffolds have received huge attention for modulating inflammation around the host tissue through releasing anti-inflammatory cytokine. However, controlling the inflammation and providing a sustained release of anti-inflammatory cytokine from the scaffold in the digestive inflammatory environment are predicated upon a comprehensive understanding of three fundamental questions. (1) How does the release rate of cytokine from the scaffold change in the digestive inflammatory environment? (2) Can we prevent the premature scaffold degradation and burst release of the loaded cytokine in the digestive inflammatory environment? (3) How does the scaffold degradation prevention technique affect the immunomodulatory capacity of the scaffold? This study investigated the impacts of the digestive inflammatory environment on scaffold degradation and how pre-mature degradation can be prevented using genipin crosslinking and how genipin crosslinking affects the interleukin-4 (IL-4) release from the scaffold and differentiation of naïve macrophages (M0). Our results demonstrated that the digestive inflammatory environment (DIE) attenuates protein retention within the scaffold. Over 14 days, the encapsulated protein released 46% more in DIE than in phosphate buffer saline (PBS), which was improved through genipin crosslinking. We have identified the 0.5 (w/v) genipin concentration as an optimal concentration for improved IL-4 released from the scaffold, cell viability, mechanical strength, and scaffold porosity, and immunomodulation studies. The IL-4 released from the injectable scaffold could differentiate naïve macrophages to an anti-inflammatory (M2) lineage; however, upon genipin crosslinking, the immunomodulatory capacity of the scaffold diminished significantly, and pro-inflammatory markers were expressed dominantly.

Vertebral Bone Marrow-Derived Mesenchymal Stromal Cells from Osteoporotic and Healthy Patients Possess Similar Differentiation Properties In Vitro

Osteoporosis is a disease characterized by low bone mass and an increased risk of fractures. Although several cellular players leading to osteoporosis have been identified, the role of mesenchymal stromal cells (MSC) is still not fully elaborated. The aim of this study was, therefore, to isolate and characterize MSCs from vertebral body of healthy non-osteoporotic and osteoporotic patients, with a particular focus on their osteogenic differentiation potential. Isolated MSCs were characterized by their osteogenic, adipogenic, and chondrogenic differentiation, as well as surface marker expression, proliferation behavior, and immunomodulatory capacity. The mineralization process was confirmed using Alizarin Red S and alkaline phosphatase (ALP) stains and further evaluated by determining ALP activity, mineral deposition, and free phosphate ion release. MSCs from both healthy and osteoporotic patients showed common fibroblast-like morphology and similar proliferation behavior. They expressed the typical MSC surface markers and possessed immunomodulatory capacity. Both groups demonstrated solid trilineage differentiation potential; osteogenic differentiation was further confirmed by increased ALP activity, deposition of inorganic crystals, phosphate ion release, and expression of osteoblast marker genes. Overall, MSCs from osteoporotic and non-osteoporotic patients showed neither a difference in general MSC features nor in the detailed analysis regarding osteogenic differentiation. These data suggest that vertebral body MSCs from osteoporotic patients were not impaired; rather, they possessed full osteogenic potential compared to MSCs from non-osteoporotic patients.