Autophagy genes and signaling pathways in endometrial decidualization and pregnancy complications.

Autophagy is a process that occurs in almost all eukaryotic cells and this process is controlled by several molecular processes. Its biological roles include the provision of energy, the maintenance of cell homeostasis, and the promotion of aberrant cell death. The importance of autophagy in pregnancy is gradually becoming recognized. In literature, it has been indicated that autophagy has three different effects on the onset and maintenance of pregnancy: embryo (embryonic development), feto-maternal immune crosstalk, and maternal (decidualization). In humans, proper decidualization is a major predictor of pregnancy accomplishment and it can be influenced by different factors. This review highlights the genes, pathways, regulation, and function of autophagy in endometrial decidualization and other involved factors in this process.

Chemo-immune cell therapy by intratumoral injection of adoptive NK cells with capecitabine in gastric cancer xenograft model.

Introduction: Gastric cancer is one of the most commonly known malignancies and is the fifth cancer-related death globally. Whereas natural killer (NK) cells play a critical role in tumor elimination; therefore, adoptive NK cell therapy has become a promising approach in cancer cytotherapy. Hence, this study investigated the chemo-immune cell therapy in MKN-45 derived xenograft gastric cancer model. Methods: Three groups of animals have received the following treatments separately: activated NK cells, capecitabine, the combination of capecitabine and activated NK cells, and one was considered as the control group. Morphometric properties of tumor samples were evaluated at the end of the study. NK cells infiltration was evaluated by immunohistochemistry (IHC) of hCD56. Mitotic count and treatment response was assessed by hematoxylin and eosin (H&E) staining. The proliferation ratio to apoptosis was determined by IHC assessment of Ki67 and caspase 3. Results: The results indicated that the NK cell therapy could effectively decrease the mitotic count in pathology assessment, but the tumor was not completely eradicated. In combination with metronomic chemotherapy (MC) of capecitabine, NK cell therapy demonstrated a significant difference in tumor morphometric properties compared to the control group. The proliferation ratio to apoptosis was also in line with pathology data. Conclusion: Although NK cell therapy could effectively decrease the mitotic count in vivo, the obtained findings indicated lesser potency than MC despite ex vivo activation. In order to enhance NK cell therapy effectiveness, suppressive features of the tumor microenvironment and inhibitory immune checkpoints blockade should be considered.

Effect of miR-18a-5p, miR-19a-3p, and miR-20a-5p on In Vitro Cardiomyocyte Differentiation of Human Endometrium Tissue-Derived Stem Cells Through Regulation of Smad4 Expression.

Background: Smad4 regulates the expression of the genes required for heart homeostasis. Regarding the central role of microRNAs in cardiac biology, we investigated the expression of the three Smad4-targeting miRNAs, namely miR-18a-5p, miR-19a-3p, and miR-20a-5p, as well as Smad4 during differentiation of human endometrium-derived mesenchymal stem cells (hEMSCs) into cardiomyocytes (CMs). Methods: To evaluate mesenchymal phenotype and multi-lineage differentiation ability of hEMSCs, immunophenotyping by flow cytometry and differentiation into osteoblasts and adipocytes were performed, respectively. For transdifferentiation into CMs, hEMSCs were exposed to a cardiomyogenic medium composed of 5-aza and bFGF for 30 days. The comparison between transcriptional expression levels of Nkx2-5, GATA4, Smad4, TNNT2, TBX5, miR-18a-5p, miR-19a-3p, and miR-20a-5p by qRT-PCR, as well as protein levels of Nkx2-5, Smad4, and cTnT by immunofluorescence staining, was conducted in every 6 days. Results: In vitro, the mesenchymal stem cell phenotype of hEMSCs and their potency for differentiation into other MSCs were confirmed. Differentiated hEMSCs had morphological characteristics of CMs. The percentage of positive cells for Nkx2-5, Smad4, and cTnT proteins was increased following induction and culminated on the 24th day. Also, mRNA levels of Nkx2-5, GATA4, Smad4, TNNT2, and TBX5 exhibited the same trend. The expression of investigated miRNAs was significantly decreased sequentially. A significant negative correlation between expressions of Smad4 and investigated miRNAs was observed. Conclusion: Our results indicate that miR-18a-5p, miR-19a-3p, and miR-20a-5p are involved in the cardiac differentiation propensity of hEMSCs potentially by regulation of Smad levels. Although, more mechanistic experiments are required to confirm this idea.

Assessment of the Efficacy of an LL-37-Encapsulated Keratin Hydrogel for the Treatment of Full-Thickness Wounds.

Wound healing remains a burdensome healthcare problem due to moisture loss and bacterial infection. Advanced hydrogel dressings can help to resolve these issues by assisting and accelerating regenerative processes such as cell migration and angiogenesis because of the similarities between their composition and structure with natural skin. In this study, we aimed to develop a keratin-based hydrogel dressing and investigate the impact of the delivery of LL-37 antimicrobial peptide using this hydrogel in treating full-thickness rat wounds. Therefore, oxidized (keratose) and reduced (kerateine) keratins were utilized to prepare 10% (w/v) hydrogels with different ratios of keratose and kerateine. The mechanical properties of these hydrogels with compressive modulus of 6-32 kPa and tan δ <1 render them suitable for wound healing applications. Also, sustained release of LL-37 from the keratin hydrogel was achieved, which can lead to superior wound healing. In vitro studies confirmed that LL-37 containing 25:75% of keratose/kerateine (L-KO25:KN75) would result in significant fibroblast proliferation (∼85% on day 7), adhesion (∼90 cells/HPF), and migration (73% scratch closure after 12 h and complete closure after 24 h). Also, L-KO25:KN75 is capable of eradicating both Gram-negative and Gram-positive bacteria after 18 h. According to in vivo assessment of L-KO25:KN75, wound closure at day 21 was >98% and microvessel density (>30 vessels/HPF at day 14) was significantly superior in comparison to other treatment groups. The mRNA expression of VEGF and IL-6 was also increased in the L-KO25:KN75-treated group and contributed to proper wound healing. Therefore, the LL-37-containing keratin hydrogel ameliorated wound closure, and also angiogenesis was enhanced as a result of LL-37 delivery. These results suggested that the L-KO25:KN75 hydrogel could be a sustainable substitute for skin tissue regeneration in medical applications.

Recent advances in mesenchymal stem/stromal cells (MSCs)-based approaches for osteoarthritis (OA) therapy.

Recently, mesenchymal stem/stromal cells (MSCs) transplantation has been introduced as a promising option to support cartilage structure and improve its function in preclinical models and patients suffering from osteoarthritis (OA). MSCs strongly provoke their preferred influence in vivo by inhibiting the inflammatory responses and applying immunomodulation by releasing anti-inflammatory mediators such as transforming growth factor-ß and interleukin-10. Such mediators downregulate fibroblast-like synoviocytes growth and migration, leading to chondroprotection. Furthermore, improving the chondrocyte proliferation and extracellular matrix hemostasis in addition to the suppression of the matrix metalloproteinases activities can support cartilage tissue organization. In this light, various published results have demonstrated that MSCs therapy can considerably decrease pain and restore knee function in OA patients. In the current review, we have concentrated on recent advances in MSCs-based therapeutics to elicit both chondrogenic and chondroprotective impacts in OA patients, focusing on the last decade in vivo results.

Wharton's jelly-mesenchymal stem cells treatment for severe COVID 19 patients: 1-year follow-up.

Background: Recently, attention has been focused on mesenchymal stem cells (MSC) because of their unique ability to suppress inflammation induced by cytokine storms caused by COVID-19. Several patients have been successfully treated in this manner. After one year of treatment with Wharton's jelly-derived MSC injections, this study evaluated the safety and efficacy of injecting MSCs intravenously in patients with COVID-19. Methods: This study treated four patients with severe COVID-19 with Wharton's jelly-derived mesenchymal stem cells. In this study, patients were followed up for routine tests, tumor markers, and whole-body imaging (spiral neck CT scan (with contrast), spiral chest CT scan (with & without contrast), and spiral abdominopelvic CT scan (with IV & Oral contrast)) one year after cell therapy. Results: The results indicated that lymphocyte; lymph count significantly increased, and neutrophil, ESR, ferritin, and CRP significantly decreased. LDH showed a non-significant decrease (P-value<0.05). One year after the WJ-MSC injection, the tumor markers were normal, and no tumors were observed in patients after one year. Also, the CT scan result was normal. Conclusions: In patients, no serious complications were observed after a one-year follow-up. After monitoring the patient via laboratory tests, tumor markers, and whole-body imaging, we concluded that the Wharton jelly-derived mesenchymal stem cells did not cause severe complications, including tumor formation, in severe COVID19 patients within a year. More clinical trials with higher sample sizes need to be performed on cell therapy with Wharton jelly-derived mesenchymal stem cells in the future.

Angiogenesis and Its Targeting in Glioblastoma with Focus on Clinical Approaches.

Angiogenesis is a characteristic of glioblastoma (GBM), the most fatal and therapeutic-resistant brain tumor. Highly expressed angiogenic cytokines and proliferated microvascular system made anti-angiogenesis treatments a thoroughly plausible approach for GBM treatment. Many trials have proved to be not only as a safe but also as an effective approach in GBM retardation in a certain time window as seen in radiographic response rates; however, they have failed to implement significant improvements in clinical manifestation whether alone or in combination with radio/chemotherapy. Bevasizumab, an anti-vascular endothelial growth factor-A (VEGF-A) antibody, is the only agent that exerts meaningful clinical influence by improving progression-free survival (PFS) and partially alleviate clinical symptoms, nevertheless, it could not prolong the overall survival (OS) in patients with GBM. The data generated from phase II trials clearly revealed a correlation between elevated reperfusion, subsequent to vascular normalization induction, and improved clinical outcomes which explicitly indicates anti-angiogenesis treatments are beneficial. In order to prolong these initial benefits observed in a certain period of time after anti-angiogenesis targeting, some aspects of the therapy should be tackled: recognition of other bypass angiogenesis pathways activated following antiangiogenesis therapy, identification of probable pathways that induce insensitivity to shortage of blood supply, and classifying the patients by mapping their GBM-related gene profile as biomarkers to predict their responsiveness to therapy. Herein, the molecular basis of brain vasculature development in normal and tumoral conditions is briefly discussed and it is explained how "vascular normalization" concept opened a window to a better comprehension of some adverse effects observed in anti-angiogenesis therapy in clinical condition. Then, the most targeted angiogenesis pathways focused on ligand/receptor interactions in GBM clinical trials are reviewed. Lastly, different targeting strategies applied in anti-angiogenesis treatment are discussed.

Anti-inflammatory effect of mesenchymal stem cells on hepatocellular carcinoma in the xenograft mice model.

BACKGROUND: Hepatocellular carcinoma (HCC) is the fifth most diagnosed cancer and the second leading cause of cancer-related deaths worldwide. Sorafenib is the standard treatment used in the advanced stages of HCC. Cell therapy with mesenchymal stem cells (MSCs)-based cell therapy has proven effective in immune regulation and tumour growth inhibition. OBJECTIVES: In this study, we investigated the anti-inflammatory effect of MSCs on HCC xenografts. METHODS: Human HepG2 cell lines were subcutaneously implanted into the flank of 12 nude mice, divided into three groups: the control group, the IV group (intravenous MSCs injection) and the local group (local MSCs injection). Mice were sacrificed 6 weeks after tumour implantation, and tumours were resected entirety. Quantitative real-time polymerase chain reaction (qRT-PCR) measured the gene expression of inflammatory markers, including tumour necrosis factor-α (TNF-α), interleukin (IL)-1α and IL-10. Aspartate transaminase (AST), alanine transaminase (ALT) and urea levels were measured using spectrophotometry to ensure the safety of MSC therapy. RESULTS: Gene expressions for all three inflammatory markers were reduced in both MSCs groups compared to the control group. AST, ALT and urea levels remained in normal ranges. CONCLUSIONS: MSC therapy can reduce inflammation in HCC xenograft mouse models.

3-Dimensional Model to Study Apoptosis Induction of Activated Natural Killer Cells Conditioned Medium Using Patient-Derived Colorectal Cancer Organoids.

Natural killer (NK) cells are innate lymphocytes that can kill tumor cells via different pathways, including the secretion of cytotoxic granules in immunological synapses and the binding of apoptosis-inducing ligands with cognate death receptors on tumor cells. These ligands are also soluble in NK cells conditioned medium (NK-CM). However, novel preclinical in vitro models are required for solid tumors such as colorectal cancer (CRC) to investigate apoptosis induction of activated NK-CM in a tissue-like structure. In the present study, we established a patient-derived CRC organoid culture system as a new tool for CRC research in the last decade. Tumor organoids were stained with hematoxylin and eosin (H&E) and compared with the original tumor taken from the patient. Goblet cell differentiation and mucus secretion were evaluated using periodic acid-Schiff and alcian blue histochemical staining. Moreover, tumor organoids were stained for CDX2 and Ki67 markers with immunohistochemistry (IHC) to investigate gastrointestinal origin and proliferation. Histopathological evaluations indicated tumor organoids represent patient tumor characteristics. Primary NK cells were isolated and characterized using CD56 marker expression and the lack of the CD3 marker. Flow cytometry results showed the purity of isolated CD3-and CD56 + NK cells about 93%. After further ex vivo expansion, IL-2-activated NK-CM was collected. Secretions of IFN-γ and TNF-α were measured to characterize activated NK-CM. Cytokines levels were significantly elevated in comparison to the control group. Soluble forms of apoptosis-inducing ligands, including TNF-related apoptosis-inducing ligand (TRAIL) and FasL, were detected by western blot assay. Colon cancer organoids were treated by IL-2-activated NK-CM. Apoptosis was assessed by Annexin V-FITC/PI staining and quantified by flow cytometry. In conclusion, despite the activated NK-CM containing apoptosis-inducing ligands, these ligands' soluble forms failed to induce apoptosis in patient-derived colon cancer organoids. Nevertheless, we report a reliable in vitro assessment platform in a personalized setting.

Mesenchymal Stem Cells Regenerate Diabetic Foot Ulcers: A Review Article.

Background: Diabetes is one of the metabolic diseases characterized by hyperglycemia, with many complications. Diabetic foot ulcer (DFU) is a significant complication of diabetes. Various therapy procedures have been recently described for DFU improvement. Methods: Using PubMed, Scopus, Science Direct, and Google Scholar to discover the therapeutic effects of bee products, this review study was conducted in 2018-2019 by searching PubMed, Scopus, Science Direct, and Google Scholar databases. Results: Cell therapies with various cell candidates such as mesenchymal stem cells (MSCs) are increasingly introduced into routine medical care to manage skin wounds. The applying of these cells for tissue regeneration was initially based on the capability of MSCs to differentiate into specialized cells within the injured tissue. Paracrine signaling and differentiation mechanisms have both been contributed to improving tissue repair by MCSs. However, the role of MSCs differentiation is less due to the poor survival of these cells at the site of injury. Conclusion: At the same time, paracrine signaling or their secretome is the primary mechanism of MSCs that stimulate neovascularization and re-epithelialization and mobilization of inhabitant stem cells. In this review study, we discuss the role of MSCs and their secretome that can improve the use of this new approach in treating ulcers and DFU.

Flow Cytometric Measurement of Reactive Oxygen Species to Assess the Effects of Preconditioning Total Body Irradiation on NOG Mice.

BACKGROUND: Preclinical development of new drugs for cancer immunotherapy requires preconditioning total body irradiation (TBI) of mice to be humanized via hematopoietic stem cell transplantation. To assess the effect of preconditioning TBI, we detected the reactive oxygen species (ROS), Annexin V, propidium iodide (PI) level in bone marrow samples by flow cytometer. METHODS: We divided all NOG mice between irradiated (n = 20) and control groups (n = 10) for two time points. Irradiated mice were exposed to 3.5 Gy of radiation. After sacrificing BM samples were collected, the flow cytometric percentage of ROS, Annexin V, and PI markers were investigated on days 2 and 14 after exposure. RESULTS: At the first time point, the level of ROS was higher in the irradiated group than in the control group, and this difference was statistically significant (P < 0.05). Also, at the second time point, the mean differences of all markers in the irradiated group were significantly compared to the control group (P < 0.05). CONCLUSION: Thus, in NOG mice, the measurement of ROS level is helpful to the assessment of preconditioning TBI.

The effects of Sorafenib and Natural killer cell co-injection in combinational treatment of hepatocellular carcinoma; an in vivo approach.

BACKGROUND: Natural killer cells (NKC) and Sorafenib (Sor) are two important agents for the treatment of hepatocellular carcinoma (HCC). Over the past decade, the interaction of Sor and NKC against HCC has been widely challenging. This study aimed to assess the efficacy of NKC & Sor for the treatment of HCC in vivo. METHODS: Subcutaneous xenograft models of HCC were established in nude mice. For safety assessment of treatment, the kidney and liver functions were analyzed. Paraffin embedded tumor sections were histopathologically studied and immunohistochemistry (IHC) tests were done to evaluate the angiogenesis (CD34) and proliferation (Ki67) indexes. The terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed to identify the tumor cells undergoing apoptosis. The serum levels of tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) were measured by enzyme-linked immunosorbent assay (ELISA) and expression levels of major inflammatory cytokines and cytoplasmic granules in xenograft HCC were quantified using real-time PCR. RESULTS: NKC & Sor significantly inhibited necrosis and apoptosis in tumor cells and increased angiogenesis and proliferation of HCC compared to the monotherapy of NKC or Sor alone. The serum levels of TNF-α, IFN-γ as well as the expression levels of TNF-α, IFN-γ, interleukins (ILs)-1, 6, 10, granzyme-B and perforin in the xenograft HCC tissues of the treated mice with NKC & Sor were significantly lower than those of treated with NKC or Sor alone. CONCLUSION: Therapy with the specific dosage of NKC & Sor could not inhibit the HCC xenograft growth rate through a synergistic effect in a mouse model of HCC.

Hypoxia preconditioned mesenchymal stem cell-derived exosomes induce ex vivo expansion of umbilical cord blood hematopoietic stem cells CD133+ by stimulation of Notch signaling pathway.

Mesenchymal stem cells (MSCs) are crucial cells that play an essential role in the maintenance, self-renewal, and proliferation of hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) in the bone marrow niche. It has been proven that MSCs can be used as a feeder layer for the proliferation of HSCs to enhance the number of HPCs and HSCs. Recently, it has been demonstrated that MSC-derived exosome (MSC-DE) has critical roles in different biological processes in bone marrow (BM). In the current research, we examined the importance of hypoxia-preconditioned MSC-derived exosomes (HP-MSC-DE) and normoxia-preconditioned MSC-derived exosomes (NP-MSC-DE) in the self-renewal and long-term clonogenic potential of umbilical cord blood hematopoietic stem cells (UCB-HSCs). We showed that the secretion rate and component of the exosome (EXO) were changed in HP-MSC-DE compared to NP-MSC-DE. Notably, the Jagged-1 (Notch ligand) content of EXO was much more plentiful in HP-MSC-DE compared to NP-MSC-DE. The addition of HP-MSC-DE enriched by Jagged-1 to the co-culture system stimulates the Notch pathway on the membrane of UCB-HSCs CD133+ and enhances proliferation. HP-MSC-DE induction using an anti-Jagged-1 antibody suppresses all biological functions of the Jagged-1 protein. Importantly, HP-MSC-DE containing Jagged-1 could change the biology of HSCs CD133+ and increase the self-renewal capacity, quiescence, and clonogenic potential of CD133+ cells. Moreover, they support generating a large number of primitive cells. Our study signified the importance of HP-MSC-DE in the proliferation of UCB-HSCs CD133+, which manifested therapeutic applications of EXO in the enhanced number of HSCs and subsequently alleviated bone marrow transplantation.

Development and Clinical Application of Tumor-derived Exosomes in Patients with Cancer.

A tumor is an abnormal growth of cells within a tissue that can lead to death due to late diagnosis, poor prognosis, drug resistance, and finally enhanced metastasis formation. Exosomes are nanovesicles that have been derived from all the different cell types. These vesicles can transfer various molecules, including the distinct form of nucleic acids (mRNA, miRNA, and circRNA) and proteins. Tumor-derived exosomes (TEXs) have exceptionally important roles through multiple molecular and cellular pathways like progression, tumorigenesis, drug resistance, and as well as metastasis. TEXs are detectable in all body fluids such as serum and urine, a convenient and non-invasive way to access these nano-sized vesicles. TEXs lead to the symptom expression of genetic aberrations in the tumor cell population, making them an accurate and sensitive biomarker for the diagnosis and prognosis of tumors. On the other hand, TEXs contain major histocompatibility complexes (MHCs) and play important dual roles in regulating tumor immune responses: they can mediate both immune activation and suppression through tumor-associated immunity. Despite numerous scientific studies, there are still many technical barriers to distinguish TEXs from non-tumor-derived exosomes. Even so, removing exosomes leading to a wide difference in outcomes inside a patient's body. Hence, controversial pieces of evidence have demonstrated the vital role of TEXs as hopeful biomarkers for the early detection of cancers, evaluation of therapeutic effects, and monitoring of the patient.

Genetically-modified Stem Cell in Regenerative Medicine and Cancer Therapy; A New Era.

Recently, genetic engineering by various strategies to stimulate gene expression in a specific and controllable mode is a speedily growing therapeutic approach. Genetic modification of human stem or progenitor cells, such as Embryonic Stem Cells (ESCs), Neural Progenitor Cells (NPCs), Mesenchymal Stem/Stromal Cells (MSCs), and Hematopoietic Stem Cells (HSCs) for direct delivery of specific therapeutic molecules or genes has been evidenced as an opportune plan in the context of regenerative medicine due to their supported viability, proliferative features, and metabolic qualities. On the other hand, a large number of studies have investigated the efficacy of modified stem cells in cancer therapy using cells from various sources, disparate transfection means for gene delivery, different transfected yields, and wide variability of tumor models. Accordingly, cell-based gene therapy holds substantial aptitude for the treatment of human malignancy as it could relieve signs or even cure cancer succeeding expression of therapeutic or suicide transgene products; however, there exist inconsistent results in this regard. Herein, we deliver a brief overview of stem cell potential to use in cancer therapy and regenerative medicine and importantly discuss stem cells based gene delivery competencies to stimulate tissue repair and replacement in concomitant with their potential to use as an anti-cancer therapeutic strategy, focusing on the last two decades' in vivo studies.

MicroRNAs and exosomes: Cardiac stem cells in heart diseases.

Treating cardiovascular diseases with cardiac stem cells (CSCs) is a valid treatment among various stem cell-based therapies. With supplying the physiological need for cardiovascular cells as their main function, under pathological circumstances, CSCs can also reproduce the myocardial cells. Although studies have identified many of CSCs' functions, our knowledge of molecular pathways that regulate these functions is not complete enough. Either physiological or pathological studies have shown, stem cells proliferation and differentiation could be regulated by microRNAs (miRNAs). How miRNAs regulate CSC behavior is an interesting area of research that can help us study and control the function of these cells in vitro; an achievement that may be beneficial for patients with cardiovascular diseases. The secretome of stem and progenitor cells has been studied and it has been determined that exosomes are the main source of their secretion which are very small vesicles at the nanoscale and originate from endosomes, which are secreted into the extracellular space and act as key signaling organelles in intercellular communication. Mesenchymal stem cells, cardiac-derived progenitor cells, embryonic stem cells, induced pluripotent stem cells (iPSCs), and iPSC-derived cardiomyocytes release exosomes that have been shown to have cardioprotective, immunomodulatory, and reparative effects. Herein, we summarize the regulation roles of miRNAs and exosomes in cardiac stem cells.

Contribution of natural killer cells in innate immunity against colorectal cancer.

Natural killer cells are members of the innate immune system and promote cytotoxic activity against tumor or infected cells independently from MHC recognition. NK cells are modulated by the expression of activator/inhibitory receptors. The ratio of this activator/inhibitory receptors is responsible for the cytotoxic activity of NK cells toward the target cells. Owing to the potent anti-tumor properties of NK cells, they are considered as interesting approach in tumor treatment. Colorectal cancer (CRC) is the second most common cause of death in the world and the incidence is about 2 million new cases per year. Metastatic CRC is accompanied by a poor prognosis with less than three years of overall survival. Chemotherapy and surgery are the most adopted treatments. Besides, targeted therapy and immune checkpoint blockade are novel approach to CRC treatment. In these patients, circulating NK cells are a prognostic marker. The main target of CRC immune cell therapy is to improve the tumor cell's recognition and elimination by immune cells. Adaptive NK cell therapy is the milestone to achieve the purpose. Allogeneic NK cell therapy has been widely investigated within clinical trials. In this review, we focus on the NK related approaches including CAR NK cells, cell-based vaccines, monoclonal antibodies and immunomodulatory drugs against CRC tumoral cells.

Adaptive NK Cell Therapy Modulated by Anti-PD-1 Antibody in Gastric Cancer Model.

Recently, adaptive NK cell therapy has become a promising treatment but has limited efficacy as a monotherapy. The identification of immune checkpoint inhibitor (ICI) molecules has opened a new horizon of immunotherapy. Herein, we aimed to demonstrate the cytotoxic effects of a polytherapy consisting of ex vivo expanded IL-2-activated NK cells combined with human anti-PD-1 antibody as an important checkpoint molecule in a xenograft gastric cancer mouse model. EBV-LCL cell is used as a feeder to promote NK cell proliferation with a purity of 93.4%. Mice (NOG, female, 6-8 weeks old) with xenograft gastric tumors were treated with PBS, ex vivo IL-2-activated NK cells, IL-2-activated NK cell along with human anti-PD-1 (Nivolumab), and IL-2-activated pretreated NK cells with anti-PD-1 antibody. The cytotoxicity of ex vivo expanded NK cells against MKN-45 cells was assessed by a lactate dehydrogenase (LDH) assay. Tumor volume was evaluated for morphometric properties, and tumor-infiltrating NK cells were assessed by immunohistochemistry (IHC) and quantified by flow cytometry. Pathologic responses were considered by H and E staining. Ex vivo LDH evaluation showed the cytotoxic potential of treated NK cells against gastric cancer cell line. We indicated that the adoptive transfer of ex vivo IL-2-activated NK cells combined with anti-PD-1 resulted in tumor growth inhibition in a xenograft gastric cancer model. Mitotic count was significantly decreased (*p < 0.05), and the tumor was associated with improved infiltration of NK cells in the NK-anti-PD-1 pretreated group (*p < 0.05). In conclusion, the combination approach of activated NK cells and anti-PD-1 therapy results in tumor growth inhibition, accompanied by tumor immune cell infiltration in the gastric tumor model.

Cell therapy in patients with COVID-19 using Wharton's jelly mesenchymal stem cells: a phase 1 clinical trial.

BACKGROUND: Mesenchymal stem cells (MSCs) have received particular attention because of their ability to modulate the immune system and inhibit inflammation caused by cytokine storms due to SARS-CoV-2. New alternative therapies may reduce mortality rates in patients with COVID19. This study aimed to assess the safety and efficacy of injecting intravenous Wharton's jelly-derived MSCs in patients with COVID-19 as a treatment. METHODS: In this study, five patients with severe COVID-19 were treated with Wharton's jelly-derived mesenchymal stem cells (150 × 106 cells per injection). These patients were subject to three intravenous injections 3 days apart, and monitoring was done on days 0, 3, 6, and 14 in routine tests, inflammatory cytokines, and flow cytometry of CD4 and CD8 markers. A lung CT scan was performed on base and days 14 and 28. In addition, IgM and IgG antibodies against SARS-CoV-2 were measured before and after treatment. RESULTS: The results showed that IL-10 and SDF-1 increased after cell therapy, but VEGF, TGF-ß, IFN-γ, IL-6, and TNFα decreased. Routine hematology tests, myocardial enzyme tests, biochemical tests, and inflammation tests were performed for all patients before and after cell therapy on base and days 3, 6, and 14, which indicated the improvement of test results over time. COVID-19 antibody tests rose in 14 days after WJ-MSC injection. The total score of zonal involvement in both lungs was improved. CONCLUSIONS: In patients, the trend of tests was generally improving, and we experienced a reduction in inflammation. No serious complications were observed in patients except the headache in one of them, which was resolved without medication. In this study, we found that patients with severe COVID-19 in the inflammatory phase respond better to cell therapy. More extensive clinical trials should be performed in this regard. TRIAL REGISTRATION: IRCT, IRCT20190717044241N2 . Registered April 22, 2020.

The role of mesenchymal stromal cells in immune modulation of COVID-19: focus on cytokine storm.

The outbreak of coronavirus disease 2019 (COVID-19) pandemic is quickly spreading all over the world. This virus, which is called SARS-CoV-2, has infected tens of thousands of people. Based on symptoms, the pathogenesis of acute respiratory illness is responsible for highly homogenous coronaviruses as well as other pathogens. Evidence suggests that high inflammation rates, oxidation, and overwhelming immune response probably contribute to pathology of COVID-19. COVID-19 causes cytokine storm, which subsequently leads to acute respiratory distress syndrome (ARDS), often ending up in the death of patients. Mesenchymal stem cells (MSCs) are multipotential stem cells that are recognized via self-renewal capacity, generation of clonal populations, and multilineage differentiation. MSCs are present in nearly all tissues of the body, playing an essential role in repair and generation of tissues. Furthermore, MSCs have broad immunoregulatory properties through the interaction of immune cells in both innate and adaptive immune systems, leading to immunosuppression of many effector activities. MSCs can reduce the cytokine storm produced by coronavirus infection. In a number of studies, the administration of these cells has been beneficial for COVID-19 patients. Also, MSCs may be able to improve pulmonary fibrosis and lung function. In this review, we will review the newest research findings regarding MSC-based immunomodulation in patients with COVID-19.