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Despite recent advances in cancer immunotherapy, there have been limitations in cancer treatment and patient survival due to a lack of antigen recognition and immunosuppressive tumor microenvironment. To overcome this issue, we have shown that miRNA modified tumor-derived Extracellular Vesicles (mt-EVs) would be an advantageous prospect since they are tumor specific and associated antigen sources which cause increase in maturation and antigen-presenting function of dendritic cells. Also, miRNAs are promising candidates for cancer therapy because of their ability to control several host immune subsets to respond against cancer cells as well as tumor microenvironment remodeling. Here, we report that mt-EVs containing tumor specific antigens loaded with miRNAs (Let-7i, miR-142 and, miR-155) could increase the survival rate of tumor-bearing mice and induce reduction in tumor growth. Importantly, the administration of mt-EVs elicited cytotoxic T cells with increasing in IFNγ and Granzyme B production ability. Notably, intramuscular (IM) injection of let7i, miR142-EVs had a significant effect on dendritic cell (DC) maturation and T cell activation along with tumor shrinkage. Collectively, our findings suggest that administration of miRNA containing EVs may be effective immunotherapy against solid tumors.

Glioblastoma multiforme (GBM) is a unique aggressive tumor and mostly develops in the brain, while rarely spreading out of the central nervous system. It is associated with a high mortality rate; despite tremendous efforts having been made for effective therapy, tumor recurrence occurs with high prevalence. To elucidate the mechanisms that lead to new drug discovery, animal models of tumor progression is one of the oldest and most beneficial approaches to not only investigating the aggressive nature of the tumor, but also improving preclinical research. It is also a useful tool for predicting novel therapies' effectiveness as well as side effects. However, there are concerns that must be considered, such as the heterogeneity of tumor, biological properties, pharma dynamic, and anatomic shapes of the models, which have to be similar to humans as much as possible. Although several methods and various species have been used for this approach, the real recapitulation of the human tumor has been left under discussion. The GBM model, which has been verified in this study, has been established by using the Rat C6 cell line. By exploiting bioinformatic tools, the similarities between aberrant gene expression and pathways have been predicted. In this regard, 610 common genes and a number of pathways have been detected. Moreover, while magnetic resonance imaging analysis enables us to compare tumor features between these two specious, pathological findings provides most of the human GBM characteristics. Therefore, the present study provides genomics, pathologic, and imaging evidence for showing the similarities between human and rat GBM models.

Exosomes are nano vesicles from the larger family named Extracellular Vesicle (EV)s which are released by various cells including tumor cells, mast cells, dendritic cells, B lymphocytes, neurons, adipocytes, endothelial cells, and epithelial cells. They are considerable messengers that can exchange proteins and genetic materials between the cells. Within the past decade, Tumor derived exosomes (TEX) have been emerged as important mediators in cancer initiation, progression and metastasis as well as host immune suppression and drug resistance. Although tumor derived exosomes consist of tumor antigens and several Heat Shock Proteins such as HSP70 and HSP90 to stimulate immune response against tumor cells, they contain inhibitory molecules like Fas ligand (Fas-L), Transforming Growth Factor Beta (TGF-β) and Prostaglandin E2 (PGE2) leading to decrease the cytotoxicity and establish immunosuppressive tumor microenvironment (TME). To bypass this problem and enhance immune response, some macromolecules such as miRNAs, HSPs and activatory ligands have been recognized as potent immune inducers that could be used as anti-tumor agents to construct a nano sized tumor vaccine. Here, we discussed emerging engineered exosomes as a novel therapeutic strategy and considered the associated challenges., Graphical Abstract Imbalance between immune suppression and immune response by tumor derived exosomes. Potential role of engineered tumor derived exosomes in changing the fate of immune response. Image designed by Adeleh Taghikhani.

Mesenchymal stromal cells (MSCs) can effectively contribute to tissue regeneration inside the inflammatory microenvironment mostly through modulating immune responses. MSC-derived extracellular vesicles (MSC-EVs) display immunoregulatory functions similar to parent cells. Interactions between MSC-EVs and immune cells make them an ideal therapeutic candidate for infectious, inflammatory, and autoimmune diseases. These properties of MSC-EVs have encouraged researchers to perform extensive studies on multiple factors that mediate MSC-EVs immunomodulatory effects. Investigation of proteins involved in the complex interplay of MSC-EVs and immune cells may help us to better understand their functions. Here, we performed a comprehensive proteomic analysis of MSC-EVs that was previously reported by ExoCarta database. A total of 938 proteins were identified as MSC-EV proteome using quantitative proteomics techniques. Kyoto Encyclopedia of Genes and Genomes analysis demonstrates that ECM-receptor interaction, focal adhesion, and disease-specific pathways are enriched in MSC-EVs. By detail analysis of proteins presence in immune system process, we found that expression of some cytokines, chemokines, and chemokine receptors such as IL10, HGF, LIF, CCL2, VEGFC, and CCL20, which leads to migration of MSC-EVs to injured sites, suppression of inflammation and promotion of regeneration in inflammatory and autoimmune diseases. Also, some chemoattractant proteins such as CXCL2, CXCL8, CXCL16, DEFA1, HERC5, and IFITM2 were found in MSC-EV proteome. They may actively recruit immune cells to the proximity of MSC or MSC-EVs, may result in boosting immune response under specific circumstances, and may have protective role in infectious diseases. In this review, we summarize available information about immunomodulation of MSC-EVs with particular emphasis on their proteomics analysis.

Organoids can be regarded as a beneficial tool for discovery of new therapeutics for diabetes and/or maturation of pancreatic progenitors (PP) towards β cells. Here, we devised a strategy to enhance maturation of PP by assembly of three-dimensional (3D) pancreatic organoids (PO) containing human embryonic stem (ES) cell derivatives including ES-derived pancreatic duodenal homeobox 1 (PDX1) + early PP, mesenchymal stem cells, and endothelial cells at an optimized cell ratio, on Matrigel. The PO was placed in a 3D-printed tissue trapper and heterotopically implanted into the peritoneal cavity of immunodeficient mice where it remained for 90 days. Our results indicated that, in contrast to corresponding early PP transplants, 3D PO developed more vascularization as indicated by greater area and number of vessels, a higher number of insulin-positive cells and improvement of human C-peptide secretions. Based on our findings, PO-derived β cells could be considered a novel strategy to study human β-cell development, novel therapeutics, and regenerative medicine for diabetes.

Various somatic tissue-derived mesenchymal stromal cells (MSCs) have been considered as an attractive therapeutic tool for treatment of liver diseases in which the secretion of soluble factors or extracellular vesicles (EVs) is the most probable mechanism. The experimental application of human embryonic stem cell-derived MSC (ES-MSC) increased rapidly and showed promising results, in vitro and in vivo. However, possible therapeutic effects of human ES-MSC and their EVs on Thioacetamide (TAA)-induced chronic liver injury have not been evaluated yet. Our data indicated that human ES-MSC can significantly suppress the proliferation of peripheral blood mononuclear cells compared to bone marrow (BM)-MSC and adipose (AD)-MSC. Moreover, ES-MSC increased the secretion of anti-inflammatory cytokines (i.e., TGF-β and IL-10) and decreased IFN-γ, compared to other MSCs. ES-MSC EVs demonstrated immunomodulatory activities comparable to parental cells and ameliorated cirrhosis in TAA-induced chronic rat liver injury, that is, reduction in fibrosis and collagen density, necrosis, caspase density, portal vein diameter, and transaminitis. The gene expression analyses also showed upregulation in collagenases (MMP9 and MMP13), anti-apoptotic gene (BCL-2) and anti-inflammatory cytokines (TGF-β1 and IL-10) and down-regulation of major contributors to fibrosis (Col1α, αSMA, and TIMP1), pro-apoptotic gene (BAX) and pro-inflammatory cytokines (TNFα and IL-2) following treatment with ES-MSC and ES-MSC-EV. These results demonstrated that human ES-MSC and ES-MSC EV as an off-the-shelf product, that needs further assessment to be suggested as an allogeneic product for therapeutic applications for liver fibrosis.

Extracellular vesicles derived from mesenchymal stem cells (MSC-EVs) have been widely reported as promising cell-free products that show therapeutic effects of the parental cells but not their limitations. Due to the intrinsic liver tropism of MSC-EVs, they have been widely used as therapeutics or drug carriers for treatment of liver diseases. However, rapid clearance from the target site may attenuate the efficiency of systemically administered MSC-EVs. Herein, sustained release into the peritoneum has been proposed as a new strategy to prolong the bioavailability of the MSC-EVs in the target liver. During intraperitoneal injection, clickable polyethylene glycol (PEG) macromeres were mixed with MSC-EVs to form EV-encapsulated PEG hydrogels via a fast, biocompatible click reaction. Upon biodegradation, the EV-laden hydrogels were swollen gradually to release EVs in a sustained manner over 1 month. In vivo tracking of the labeled EVs revealed that the accumulation of EVs in the liver was extended by hydrogel-mediated delivery for 1 month. Four weeks after injection in a rat model of chronic liver fibrosis, the physical and histopathological investigations of the harvested liver showed superior antifibrosis, anti-apoptosis, and regenerative effects of the EVs when delivered by the sustained systemic release (Gel-EV) to the conventional bolus injection (Free-EV). Specifically, the Gel-EV system improved the antifibrosis, anti-inflammation, anti-apoptosis, and regenerative effects of the EVs to nearly 40, 50, 40, and 50% compared to Free-EV, respectively, as was specified by quantification of the fibrotic area, α-SMA density, and caspase-3 density in the harvested tissues and ALT enzyme in serum. This study may potentiate the use of MSC-EVs as cell-free therapeutics for chronic liver failure. The sustained systemic delivery strategy may open a new paradigm to extend the effects of disease-targeting EVs over time.

Being non-immunogenic and capable of achieving major metabolic liver functions, adult-derived human liver stem/progenitor cells (ADHLSCs) are of special interest in the field of liver cell therapy. The cytokine repertoire of engrafted cells may have critical impacts on the immune response balance, particularly during cell transplantation.In this work, we analyzed the cytokinome of ADHLSCs during hepatogenic differentiation (HD) following stimulation with a mixture of inflammatory cytokines (I) in vitro and compared it to that of mature hepatocytes.Independent of their hepatic state, ADHLSCs showed no constitutive expression of pro-inflammatory cytokines, which were significantly induced by inflammation (IL-1β, IL-6, IL-8, TNFα, CCL5, IL-12a, IL-12b, IL-23p19, IL-27p28 and EBI-3). IL1-RA and IDO-1, as immunoregulatory cytokines, were highly induced in undifferentiated ADHLSCs, whereas TGF-β was downregulated by both hepatic and inflammatory events. Interestingly, TDO-1 was exclusively expressed in ADHLSCs after hepatic differentiation and enhanced by inflammatory cytokines. Compared to mature hepatocytes, hepatic-differentiated ADHLSCs showed significantly different cytokine expression patterns.By establishing the cytokinome of ADHLSCs and highlighting their immunological and inflammatory features, we can enhance our knowledge about the safety and efficiency of the transplantation strategy.

The present study assessed the effects of intraportal infusions of autologous bone marrow-derived mononuclear cells (MNCs) and/or CD133+ cells on liver function in patients with decompensated cirrhosis. We randomly assigned 27 eligible patients to a placebo, MNCs, and/or CD133+ cells. Cell infusions were performed at baseline and month 3. We considered the absolute changes in the Model for End-Stage Liver Disease (MELD) scores at months 3 and 6 after infusion as the primary outcome. The participants and those who assessed the outcomes were unaware of the treatment intervention assignments. After 6 months, 9 patients were excluded because of liver transplantation (n = 3), hepatocellular carcinoma (n = 1), loss to follow-up (n = 3), and death (n = 2). The final analysis included 4 patients from the CD133+ group, 8 from the MNC group, and 6 from the placebo group. No improvement was seen in the MELD score at month 6 using either CD133+ cells or MNC infusions compared with placebo. However, at month 3 after infusion, a trend was seen toward a higher mean absolute change in the MELD score in patients who had received CD133+ cells compared with placebo (−2.00 ± 1.87 vs. −0.13 ± 1.46; p = .08). No significant adverse events occurred in the present study. A transient improvement in the MELD score was observed in subjects treated with CD133+ cells but not in the MNC or placebo group. Although the study was not powered to make definitive conclusions, the data justify further study of CD133+ therapy in cirrhotic patients. Significance Cell therapy is a new approach in liver disease. Several clinical experiments have been reported on the safety of bone marrow-derived stem cells to treat liver disorders. However, the effectiveness of these approaches in the long-term follow-ups of patients initiated controversial discussions among the scientific community. A double-blind randomized controlled trial was designed to address this concern scientifically. A transient improvement in the patients' signs occurred; however, for a sustainable result, more work is needed. The results of multiple administrations of cells reported in the present study can be compared with the results from other single-injection studies.

Glioblastoma multiforme (GBM) is among the most incurable cancers. GBMs survival rate has not markedly improved, despite new radical surgery protocols, the introduction of new anticancer drugs, new treatment protocols, and advances in radiation techniques. The low efficacy of therapy, and short interval between remission and recurrence, could be attributed to the resistance of a small fraction of tumorigenic cells to treatment. The existence and importance of cancer stem cells (CSCs) is perceived by some as controversial. Experimental evidences suggest that the presence of therapy-resistant glioblastoma stem cells (GSCs) could explain tumor recurrence and metastasis. Some scientists, including most of the authors of this review, believe that GSCs are the driving force behind GBM relapses, whereas others however, question the existence of GSCs. Evidence has accumulated indicating that non-tumorigenic cancer cells with high heterogeneity, could undergo reprogramming and become GSCs. Hence, targeting GSCs as the "root cells" initiating malignancy has been proposed to eradicate this devastating disease. Most standard treatments fail to completely eradicate GSCs, which can then cause the recurrence of the disease. To effectively target GSCs, a comprehensive understanding of the biology of GSCs as well as the mechanisms by which these cells survive during treatment and develop into new tumor, is urgently needed. Herein, we provide an overview of the molecular features of GSCs, and elaborate how to facilitate their detection and efficient targeting for therapeutic interventions. We also discuss GBM classifications based on the molecular stem cell subtypes with a focus on potential therapeutic approaches.

Mesenchymal stem cells (MSCs) are adult multipotent cells that due to their ability to homing to damaged tissues and differentiate into specialized cells, are remarkable cells in the field of regenerative medicine. It's suggested that the predominant mechanism of MSCs in tissue repair might be related to their paracrine activity. The utilization of MSCs for tissue repair is initially based on the differentiation ability of these cells; however now it has been revealed that only a small fraction of the transplanted MSCs actually fuse and survive in host tissues. Indeed, MSCs supply the microenvironment with the secretion of soluble trophic factors, survival signals and the release of extracellular vesicles (EVs) such as exosome. Also, the paracrine activity of EVs could mediate the cellular communication to induce cell- differentiation/self-renewal. Recent findings suggest that EVs released by MSCs may also be critical in the physiological function of these cells. This review provides an overview of MSC-derived extracellular vesicles as a hopeful opportunity to advance novel cell-free therapy strategies that might prevail over the obstacles and risks associated with the use of native or engineered stem cells. EVs are very stable; they can pass the biological barriers without rejection and can shuttle bioactive molecules from one cell to another, causing the exchange of genetic information and reprogramming of the recipient cells. Moreover, extracellular vesicles may provide therapeutic cargo for a wide range of diseases and cancer therapy. Key Words: Mesenchymal Stem Cells, Extracellular vesicles, Exosome, Regenerative medicine.

Background In this study, we intend to assess the safety and tolerability of intra-articular knee implantation of autologous bone marrow–derived mesenchymal stromal cells (MSCs) in patients with rheumatoid arthritis (RA) and to determine the preliminary clinical efficacy data in this population. The trial registration numbers are as follows: Royan Institute Ethics Committee: AC/91/1133; NCT01873625. Methods This single-center, randomized, triple-blind, placebo-controlled phase 1/2 clinical trial randomized RA patients with knee involvement to receive either an intra-articular knee implantation of 40 million autologous bone marrow–derived MSCs per joint or normal saline (placebo). Patients were followed up for 12 months to assess therapy outcomes. Results A total of 30 patients, 15 in the MSC group and 15 in the placebo group, enrolled in this study. There were no adverse effects reported after MSC administration or during follow-up. Patients who received MSCs had superior findings according to the Western Ontario and McMaster Universities Arthritis Index (WOMAC), visual analogue scale (VAS), time to jelling and pain-free walking distance. However, this improvement could not be significantly sustained beyond 12 months. The MSC group exhibited improved standing time (P = 0.01). In addition, the MSCs appeared to contribute to reductions in methotrexate and prednisolone use. Conclusion Intra-articular knee implantation of MSCs appeared to be safe and well tolerated. In addition, we observed a trend toward clinical efficacy. These results, in our opinion, have justified the need for further investigations over an extended assessment period with larger numbers of RA patients who have knee involvement.