Encapsulation of human natural killer cells into novel gelatin-based polymeric hydrogel networks.

In the innate immune system, natural killer (NK) cells are effector lymphocytes which control several tumor types and microbial infections by limiting disease spread and tissue damage. With tumor cell killing abilities, with no priming or prior activation, NKs are potential anti-cancer therapies. In clinical practice, NKs are used in intravenous injections as they typically grow as suspension, similar to other blood cells. In this study, we designed a novel and effective biomaterial-based platform for NK cell delivery, which included in-situ NK cell encapsulation into three-dimensional (3D) biocompatible polymeric scaffolds for potential anti-cancer treatments. Depending on physical cross-linking between an alginate (ALG) polymer and a divalent cation, two natural polymers (gelatin (GEL) and hyaluronic acid (HA)) penetrated into pores and generated an inter-penetrating hydrogel system with improved mechanical properties and stability. After extensive characterization of hydrogels, NK cells were encapsulated inside using our in-situ gelation procedure to provide a biomimetic microenvironment. .

Satellite myoblast and mesenchymal stem cell injections decrease fatty degeneration after rotator cuff tear in rats.

Purpose: Rotator cuff (RC) tears cause fatty degeneration, aggravated by delayed treatment. Surgical repair alone cannot reverse fatty degeneration. It was aimed to test if local injections of satellite cell-derived myoblasts or satellite myoblasts (SM) from the deltoid region and mesenchymal stem cells (MSCs) from the subcutaneous abdominal fat pad would stimulate myogenesis and decrease adipogenesis in the rat model of fatty degenerated RC tear. Methods: A standardized RC tear surgery was performed on both shoulders of 24 Wistar albino rats at t = 0, and rats were followed for 8 weeks to create a chronic degeneration model. The animals were randomly divided into repair + SM and MSC (n = 12) or repair only (n = 12) groups. Transosseous repair with or without stem cell-based injection was performed on the right shoulder of all rats on week 8, with additional injections on weeks 9 and 10. The left shoulders were used as control. The animals were followed until week 14 for recovery. Results: Histological and histomorphometric analyses were performed in week 14. The repair + SM and MSC group had a significantly greater supraspinatus muscle mass than the repair only and control groups. The adipose tissue ratio was significantly lower in the repair + SM and MSC groups versus the repair only and control groups. Conclusion: Histologically, the repair + SM and MSC group had improved muscle and tendon organization. In treating chronically degenerated RC tear in a rat model, surgical repair combined with injections of SM and MSC improved fatty degeneration, tendon healing and myogenesis. Level of Evidence: Level III.

Betulin Stimulates Osteogenic Differentiation of Human Osteoblasts-Loaded Alginate-Gelatin Microbeads.

Osteoporosis, a terminal illness, has emerged as a global public health problem in recent years. The long-term use of bone anabolic drugs to treat osteoporosis causes multi-morbidity in elderly patients. Alternative therapies, such as allogenic and autogenic tissue grafts, face important issues, such as a limited source of allogenic grafts and tissue rejection in autogenic grafts. However, stem cell therapy has been shown to increase bone regeneration and decrease osteoporotic bone formation. Stem cell therapy combined with betulin (BET) supplementation might be adequate for bone remodeling and new bone tissue generation. In this study, the effect of BET on the viability and osteogenic differentiation of hFOB 1.19 cells was investigated. The cells were encapsulated in alginate-gelatin (AlGel) microbeads. In vitro tests were conducted during the 12 d of incubation. While BET showed cytotoxic activity (>1 µM) toward non-encapsulated hFOB 1.19 cells, encapsulated cells retained their functionality for up to 12 days, even at 5 µM BET. Moreover, the expression of osteogenic markers indicates an enhanced osteo-inductive effect of betulin on encapsulated hFOB 1.19, compared to the non-encapsulated cell culture. The 3D micro-environment of the AlGel microcapsules successfully protects the hFOB 1.19 cells against BET cytotoxicity, allowing BET to improve the mineralization and differentiation of osteoblast cells.

Enhancing CAR-T cells: unleashing lasting impact potential with phytohemagglutinin activation in in vivo leukemia model.

Chimeric antigen receptor T (CAR-T) cell therapy holds great promise as an innovative immunotherapeutic approach for cancer treatment. To optimize the production and application of CAR-T cells, we evaluated the in vivo stability and efficacy capacities of CAR-T cells developed under different conditions. In this study, CAR-T cells were activated using Phytohemagglutinin (PHA) or anti-CD3&anti-CD28 and were compared in an in vivo CD19+B-cell cancer model in mouse groups. Our results demonstrated that CAR-T cells activated with PHA exhibited higher stability and anti-cancer efficacy compared to those activated with anti-CD3&anti-CD28. Specifically, CAR19BB-T cells activated with PHA exhibited continuous proliferation and long-term persistence without compromising their anti-cancer efficacy. Kaplan-Meier survival analysis revealed prolonged overall survival in the CAR-T cell-treated groups compared to the only tumor group. Furthermore, specific LTR-targeted RT-PCR analysis confirmed the presence of CAR-T cells in the treated groups, with significantly higher levels observed in the CAR19BB-T (PHA) group compared to other groups. Histopathological analysis of spleen, kidney, and liver tissue sections indicated reduced inflammation and improved tissue integrity in the CAR-T cell-treated groups. Our findings highlight the potential benefits of using PHA as a co-stimulatory method for CAR-T cell production, offering a promising strategy to enhance their stability and persistence. These results provide valuable insights for the development of more effective and enduring immunotherapeutic approaches for cancer treatment. CAR-T cells activated with PHA may offer a compelling therapeutic option for advancing cancer immunotherapy in clinical applications.

Suprachoroidal spheroidal mesenchymal stem cell implantation in retinitis pigmentosa: clinical results of 6 months follow-up.

PURPOSE: This prospective clinical case series aimed to evaluate the effect of suprachoroidal implantation of mesenchymal stem cells (MSCs) in the form of spheroids as a stem cell therapy for retinitis pigmentosa (RP) patients with relatively good visual acuity. METHODS: Fifteen eyes of 15 patients with RP who received suprachoroidal implantation of MSCs in the form of spheroids were included. Best-corrected visual acuity (BCVA), 10-2 and 30-2 visual field examination and multifocal electroretinography (mfERG) recordings were recorded at baseline, postoperative 1st, 3rd and 6th months during follow-up. RESULTS: Baseline median BCVA of RP patients was 1.30 (1.00-2.00) logMAR. BCVA has improved to 1.00 (0.50-1.30), 0.80 (0.40-1.30) and 0.80 (0.40-1.30) at the postoperative 1st, 3rd and 6th months, respectively. The improvements from baseline to the 3rd and 6th months were statistically significant (p = 0.03 and p < 0.001, respectively). In the 30-2 VF test, median MD was significantly improved at the 6th month compared to baseline (p = 0.030). In the 10-2 VF test, the median MD value was significantly different at the 6th month compared to the baseline (p = 0.043). The PSD value of the 10-2 VF test was significantly different at the 6th month compared to the 3rd month (p = 0.043). The amplitudes of P1 waves in < 2°, 5°-10° and 10°-15° rings improved significantly at the postoperative 6th month (p = 0.014, p = 0.018 and p = 0.017, respectively). There was also a statistically significant improvement in implicit times of P1 waves in 10°-15° ring at the postoperative 6th month (p = 0.004). CONCLUSION: Suprachoroidal implantation of MSCs in the form of spheroids as a stem cell therapy for RP patients with relatively good visual acuity has an improving effect on BCVA, VF and mfERG recordings during the 6-month follow-up period. Spheroidal MSCs with enhanced effects may be more successful in preventing apoptosis and improving retinal tissue healing in RP patients.

In Vitro FVIII-Encoding Transgenic Mesenchymal Stem Cells Maintain Successful Coagulation in FVIII-Deficient Plasma Mimicking Hemophilia A

Objective: Hemophilia A is an X-linked recessive bleeding disorder caused by a deficiency of plasma coagulation factor VIII (FVIII), and it accounts for about 80%-85% of all cases of hemophilia. Plasma-derived therapies or recombinant FVIII concentrates are used to prevent and treat the bleeding symptoms along with FVIII-mimicking antibodies. Recently, the European Medicines Agency granted conditional marketing approval for the first gene therapy for hemophilia A. The aim of this study was to determine the effectiveness of coagulation in correcting FVIII deficiency with FVIII-secreting transgenic mesenchymal stem cells (MSCs). Materials and Methods: A lentiviral vector encoding a B domain-deleted FVIII cDNA sequence with CD45R0 truncated (CD45R0t) surface marker was designed to develop a transgenic FVIII-expressing primary cell line by transducing MSCs. The efficacy and functionality of the FVIII secreted from the MSCs was assessed with anti-FVIII ELISA, CD45R0t flow cytometry, FVIII western blot, and mixing test analysis in vitro. Results: The findings of this study showed that the transgenic MSCs maintained persistent FVIII secretion. There was no significant difference in FVIII secretion over time, suggesting stable FVIII expression from the MSCs. The functionality of the FVIII protein secreted in the MSC supernatant was demonstrated by applying a mixing test in coagulation analysis. In the mixing test analysis, FVIII-deficient human plasma products were mixed with either a saline control or FVIII-secreted MSC supernatant. The mean FVIII level of the saline control group was 0.41±0.03 IU/dL, whereas the mean level was 25.41±33.38 IU/dL in the FVIII-secreting MSC supernatant mixed group (p<0.01). The mean activated partial thromboplastin time (aPTT) of the saline control group was 92.69±11.38 s, while in the FVIII-secreting MSC supernatant mixed group, the mean aPTT level decreased to 38.60±13.38 s (p<0.001). Conclusion: The findings of this in vitro study suggest that the new method presented here is promising as a possible treatment for hemophilia A. Accordingly, a study of FVIII-secreting transgenic MSCs will next be initiated in a FVIII-knockout animal model.

Lentiviral Micro-dystrophin Gene Treatment into Late-stage mdx Mice for Duchenne Muscular Dystrophy Disease.

AIM: Duchenne Muscular Dystrophy (DMD) results in a deficiency of dystrophin expression in patient muscle fibers, leading to progressive muscle degeneration. Treatment of DMD has undertaken current transformation with the advancement of novel gene therapy and molecular biology techniques, which are secure, well-tolerated, and effective therapeutic approaches. INTRODUCTION: DMD gene therapies have mainly focused on young DMD patients as in vivo animal model trials have been performed in 0-1-month DMD mice. However, it has not yet been answered how micro-dystrophin encoding lentiviral treatment affects Dystrophin expression and DMD symptoms in 10-month mdx mice. METHODS: We planned to integrate the micro-Dystrophin gene sequence into the muscle cells by viral transfer, using micro-Dystrophin-encoding lentivirus to reduce the dystrophic pathology in late-stage dmd mice. The histopathological and physiological-functional regeneration activities of the lentiviralmicro- Dystrophin gene therapy methods were compared, along with changes in temporal Dystrophin expression and their functionality, toxicity, and gene expression level. RESULTS: Here, we showed that the micro-dystrophin transgene transfers intramuscularly and intraperitoneally in late-stage dmd-mdx-4cv mice restored dystrophin expression in the skeletal and cardiac muscle (p <0.001). Furthermore, motor performance analysis, including hanging and tracking tests, improved statistically significantly after the treatment (p <0.05). CONCLUSION: Consequently, this study suggests that patients in the late stages of muscular dystrophy can benefit from lentiviral micro-dystrophin gene therapies to present an improvement in dystrophic muscle pathology.

Preparation of Cell-Loaded Microbeads as Stable and Injectable Delivery Platforms for Tissue Engineering.

Cell transplants in therapeutic studies do not preserve their long-term function inside the donor body. In mesenchymal stem cell (MSC) transplants, transplanted cells disperse through the body and are prone to degradation by immune cells after the transplant process. Various strategies, such as usage of the immunosuppressive drugs to eliminate allograft rejection, are designed to increase the efficiency of cell therapy. Another strategy is the construction of biomimetic encapsulates using polymeric materials, which isolate stem cells and protect them from environmental effects. In this study, fibroblasts (L929) and MSCs were investigated for their improved viability and functionality once encapsulated inside the alginate microbeads under in vitro conditions for up to 12 days of incubation. Thus, uniform and injectable (<200 µm) cell-loaded microbeads were constructed by the electrostatically assisted spraying technique. Results showed that both L929 and MSCs cells continue their metabolic activity inside the microbeads during the incubation periods. Glucose consumption and lactic acid production levels of both cell lines were consistently observed. The released cell number on day 12 was found to be increased compared to day 0. Protein expression levels of both groups increased every day with the expected doubling rate. Hence, this strategy with a simple yet clever design to encapsulate either MSCs or L929 cells might outstand as a potential cell delivery platform for cell therapy-based tissue engineering.

CAR-T Cells with Phytohemagglutinin (PHA) Provide Anti-Cancer Capacity with Better Proliferation, Rejuvenated Effector Memory, and Reduced Exhausted T Cell Frequencies.

The development of genetic modification techniques has led to a new era in cancer treatments that have been limited to conventional treatments such as chemotherapy. intensive efforts are being performed to develop cancer-targeted therapies to avoid the elimination of non-cancerous cells. One of the most promising approaches is genetically modified CAR-T cell therapy. The high central memory T cell (Tcm) and stem cell-like memory T cell (Tscm) ratios in the CAR-T cell population increase the effectiveness of immunotherapy. Therefore, it is important to increase the populations of CAR-expressing Tcm and Tscm cells to ensure that CAR-T cells remain long-term and have cytotoxic (anti-tumor) efficacy. In this study, we aimed to improve CAR-T cell therapy's time-dependent efficacy and stability, increasing the survival time and reducing the probability of cancer cell growth. To increase the sub-population of Tcm and Tscm in CAR-T cells, we investigated the production of a long-term stable and efficient cytotoxic CAR-T cell by modifications in the cell activation-dependent production using Phytohemagglutinin (PHA). PHA, a lectin that binds to the membranes of T cells and increases metabolic activity and cell division, is studied to increase the Tcm and Tscm population. Although it is known that PHA significantly increases Tcm cells, B-lymphocyte antigen CD19-specific CAR-T cell expansion, its anti-cancer and memory capacity has not yet been tested compared with aCD3/aCD28-amplified CAR-T cells. Two different types of CARs (aCD19 scFv CD8-(CD28 or 4-1BB)-CD3z-EGFRt)-expressing T cells were generated and their immunogenic phenotype, exhausted phenotype, Tcm-Tscm populations, and cytotoxic activities were determined in this study. The proportion of T cell memory phenotype in the CAR-T cell populations generated by PHA was observed to be higher than that of aCD3/aCD28-amplified CAR-T cells with similar and higher proliferation capacity. Here, we show that PHA provides long-term and efficient CAR-T cell production, suggesting a potential alternative to aCD3/aCD28-amplified CAR-T cells.

microRNA 1307 Is a Potential Target for SARS-CoV-2 Infection: An in Vitro Model.

microRNAs (miRs) are proposed as critical molecular targets in SARS-CoV-2 infection. Our recent in silico studies identified seven SARS-CoV-2 specific miR-like sequences, which are highly conserved with humans, including miR-1307-3p, with critical roles in COVID-19. In this current study, Vero cells were infected with SARS-CoV-2, and miR expression profiles were thereafter confirmed by qRT-PCR. miR-1307-3p was the most highly expressed miR in the infected cells; we, therefore, transiently inhibited its expression in both infected and uninfected cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) cell proliferation assay assessed cell viability following SARS-CoV-2 infection, identifying that miR-1307 expression is inversely correlated with cell viability. Lastly, changes in miR-1307-dependent pathways were analyzed through a detailed miRNOME and associated in silico analysis. In addition to our previously identified miRs, including miR-1307-3p, the upregulation of miR-193a-5p, miR-5100, and miR-23a-5p and downregulation of miR-130b-5p, miR34a-5p, miR-505-3p, miR181a-2-3p, miR-1271-5p, miR-598-3p, miR-34c-3p, and miR-129-5p were also established in Vero cells related to general lung disease-related genes following SARS-CoV-2 infection. Targeted anti-miR-1307-3p treatment rescued cell viability in infection when compared to SARS CoV-2 mediated cell cytotoxicity only. We furthermore identified by in silico analysis that miR-1307-3p is conserved in all SARS-CoV-2 sequences/strains, except in the BA.2 variant, possibly contributing to the lower disease severity of this variant, which warrants further investigation. Small RNA seq analysis was next used to evaluate alterations in the miRNOME, following miR-1307-3p manipulation, identifying critical pathobiological pathways linked to SARS-CoV-2 infection-mediated upregulation of this miR. On the basis of our findings, miRNAs like miR-1307-3p play a critical role in SARS-CoV-2 infection, including via effects on disease progression and severity.

Factors Affecting the Population of Mesenchymal Stem Cells in Adipose-Derived Stromal Vascular Fraction

Background: Recently, the adipose tissue-derived stromal vascular fraction has become the most popular source for obtaining mesenchymal stem cells because it is less expensive and is easier to perform than bone marrow concentrate harvesting. However, no study has investigated the factors affecting the mesenchymal stem cell population in adipose tissue derived stromal vascular fraction. Understanding the interaction of patient factors with the mesenchymal stem cell count and cell viability in adipose tissue-derived stromal vascular fraction could provide crucial information for surgeons to improve patient selection and outcomes. Aims: To evaluate the factors affecting the mesenchymal stem cell count, total cell count, and cell viability in adipose tissue-derived stromal vascular fraction. Study Design: Retrospective cross-sectional study. Methods: This study retrospectively reviewed the medical records of 30 patients who underwent liposuction to harvest adipose tissue-derived stromal vascular fraction at our stem cell center. Operative variables, such as lipoaspirate amount and donor areas from the stromal vascular fraction harvesting site, included the entire abdomen and lower abdomen. We recorded the mesenchymal stem cell population, cell viability, and cell count of stromal vascular fraction, and we analyzed the results to determine statistical significance. Results: The factors that were found to be significantly related are as follows; between cell number and age (p=0.001) and amount of lipoaspirate (p<0.001); between cell viability and body mass index (p=0.005) and hypertension (p=0.047); and between coronary artery disease and mesenchymal stem cell counts (p = 0.028). Conclusion: The relationship of patient factors (age, body mass index, hypertension, and coronary artery disease) with cell viability and mesenchymal stem cell counts may be important for clinical applications. However, the effect of medications on these relationships should be investigated in larger studies.

The effects of thymoquinone on pancreatic cancer and immune cells.

OBJECTIVES: Black cumin is widely used as a spice and as a traditional treatment. The active ingredient in black cumin seeds is thymoquinone. Thymoquinone has shown anticancer effects in some cancers. We planned to investigate its anticancer effect on pancreatic cancer cell lines. METHODS: Thymoquinone chemical component in various doses was prepared and inoculated on pancreatic cancer cell culture, healthy mesenchymal stem cells, and peripheral blood mononuclear cell culture. IC50 values were calculated by absorbance data and measuring cell viability by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide staining of cells incubated with thymoquinone at 24, 48, and 72 h. RESULTS: There was dose-related cytotoxicity. Maximal cytotoxicity was observed at 24 h and 100 µM thymoquinone concentrations in pancreatic cancer cell culture and mesenchymal stem cells. Any concentration of thymoquinone was not cytotoxic to peripheral blood mononuclear cell. Thymoquinone even caused proliferation at a concentration of 6.25 µM. CONCLUSIONS: Since the cytotoxic concentration of thymoquinone on pancreatic cancer cell culture and mesenchymal stem cells is the same, it is not appropriate to use thymoquinone to achieve cytotoxicity in pancreatic cancer. However, since thymoquinone provides proliferation in peripheral blood mononuclear cell at a noncytotoxic dose, it may have an immune activator effect. Therefore, in vivo studies are needed to investigate the effect of thymoquinone on the immune system.

The Therapeutic Significance of Mesenchymal Stem Cells in COVID-19 Acute Pulmonary Respiratory Disease.

The coronavirus disease 2019 pandemic caused by severe acute respiratory syndrome-related coronavirus-2 continues its effects around the world with its new variants. Coronavirus disease 2019 infection may continue with a post-coronavirus disease period, which is characterized by high morbidity apart from the acute and subacute phases. Host immune response quality and inflammasome-induced uncontrollable inflammatory response take a role together in the pathogenesis of severe acute respiratory syndrome-related corona- virus-2 infection. Therefore, treatment of severe acute respiratory syndrome-related coronavirus-2 infection should basically include 3 measures: Viral replication, inflammation, and tissue damage control. Today, there is no effective therapy to control these points. At this point, preclinical studies have shown that mesenchymal stem cells can control inflammatory reactions and lung damage through both immune regulation and inflammasome control. Subsequently, controlled clinical studies on severe acute respiratory syndrome-related coronavirus-2 infection confirm their ability, indicating that mesenchymal stem cells may be a safe treatment option while reducing severe acute respiratory syndrome-related coronavirus-2-related morbidity and mortality. On the other hand, post-coronavirus syndrome is as important as acute coronavirus syndrome, it is a picture that can cause morbidity and mortality. Mesenchymal stem cell application can prevent the development of post-coronavirus syndrome through the mechanism of an inflammasome. However, there is no study that analyzes the effects of current treatments using mesenchymal stem cells in the post-coronavirus disease period, and that tests the use of mesenchymal stem cells when post-coronavirus syndrome develops. In this respect, studies that test the efficacy of mesenchymal stem cells in the post-coronavirus disease period are certainly needed.

The effects of thymoquinone on pancreatic cancer and immune cells

SUMMARY OBJECTIVES: Black cumin is widely used as a spice and as a traditional treatment. The active ingredient in black cumin seeds is thymoquinone. Thymoquinone has shown anticancer effects in some cancers. We planned to investigate its anticancer effect on pancreatic cancer cell lines. METHODS: Thymoquinone chemical component in various doses was prepared and inoculated on pancreatic cancer cell culture, healthy mesenchymal stem cells, and peripheral blood mononuclear cell culture. IC50 values were calculated by absorbance data and measuring cell viability by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide staining of cells incubated with thymoquinone at 24, 48, and 72 h. RESULTS: There was dose-related cytotoxicity. Maximal cytotoxicity was observed at 24 h and 100 μM thymoquinone concentrations in pancreatic cancer cell culture and mesenchymal stem cells. Any concentration of thymoquinone was not cytotoxic to peripheral blood mononuclear cell. Thymoquinone even caused proliferation at a concentration of 6.25 μM. CONCLUSIONS: Since the cytotoxic concentration of thymoquinone on pancreatic cancer cell culture and mesenchymal stem cells is the same, it is not appropriate to use thymoquinone to achieve cytotoxicity in pancreatic cancer. However, since thymoquinone provides proliferation in peripheral blood mononuclear cell at a noncytotoxic dose, it may have an immune activator effect. Therefore, in vivo studies are needed to investigate the effect of thymoquinone on the immune system.

Factors affecting cell viability and the yield of adipose-derived stromal vascular fraction.

The stromal vascular fraction (SVF) is isolated from adipose tissue and has tremendous regenerative potential for proliferation and differentiation. This study aimed to investigate the factors affecting the cell yield and viability of the SVF to improve the outcomes of its clinical applications and enhance its clinical usage. We performed a retrospective analysis with 121 patients who underwent liposuction to harvest adipose-derived SVF. We recorded patient demographic and clinical characteristics, including age, sex, body mass index (BMI), blood type, medical comorbidities, and smoking and alcohol consumption. As for operative variables, we noted the amount of lipoaspirate and the donor areas, including the lower and entire abdomen. The viability and the cell count of SVF were documented. Sex was a statistically significant factor for viability rate (p < 0.015) and cell count (p < 0.009). Men had higher viability, while women had higher cell counts. We found a statistically significant difference in the presence of hypertension (p = 0.024) and alcohol consumption (p = 0.024). There was a statistically significant relationship between cell count and age (p < 0.001), BMI (p = 0.006), and amount of lipoaspirate (p < 0.001). Sex had significant associations with cell count and viability, while age, BMI, and lipoaspirate amount were significantly associated with cell count. Hypertension and alcohol consumption significantly affected cell count, which is the first such report of this association. Surgeons could apply this knowledge to patient selection for optimal treatment outcomes. Additionally, understanding these factors can help manage patient expectations.

Preliminary Report of the Academic CAR-T (ISIKOK-19) Cell Clinical Trial in Turkey: Characterization of Product and Outcomes of Clinical Application

Objective: Chimeric antigen receptor T (CAR-T) cell therapies have already made an impact on the treatment of B-cell malignancies. Although CAR-T cell therapies are promising, there are concerns about commercial products regarding their affordability and sustainability. In this preliminary study, the results of the first production and clinical data of an academic CAR-T cell (ISIKOK-19) trial in Turkey are presented. Materials and Methods: A pilot clinical trial (NCT04206943) designed to assess the safety and feasibility of ISIKOK-19 T-cell therapy for patients with relapsed and refractory CD19+ tumors was conducted and participating patients received ISIKOK-19 infusions between October 2019 and July 2021. The production data of the first 8 patients and the clinical outcome of 7 patients who received ISIKOK-19 cell infusions are presented in this study. Results: Nine patients were enrolled in the trial [5 with acute lymphoblastic leukemia (ALL) and 4 with non-Hodgkin lymphoma (NHL)], but only 7 patients could receive treatment. Two of the 3 participating ALL patients and 3 of the 4 NHL patients had complete/partial response (overall response rate: 72%). Four patients (57%) had CAR-T-related toxicities (cytokine release syndrome, CAR-T-related encephalopathy syndrome, and pancytopenia). Two patients were unresponsive and had progressive disease following CAR-T therapy. Two patients with partial response had progressive disease during follow-up. Conclusion: Production efficacy and fulfillment of the criteria of quality control were satisfactory for academic production. Response rates and toxicity profiles were also acceptable for this heavily pretreated/refractory patient group. ISIKOK-19 cells appear to be a safe, economical, and efficient treatment option for CD19+ tumors. However, the findings of this study need to be supported by the currently ongoing ISIKOK-19 clinical trial.

Safety and Efficacy of Co-transplantation of Hematopoietic Stem Cells Combined With Human Umbilical Cord-Derived Mesenchymal Stem Cells in Children With Severe Aplastic Anemia: A Single-Center Experience.

OBJECTIVES: The mostimportant problems thatlimitthe effectiveness of allogeneic hematopoietic stem cell transplantation in patients with severe aplastic anemia are graft failure and graft-versus-host disease. Mesenchymal stem cells can support normal hematopoiesis and prevent graft-versus-host disease. We aimed to analyze the effects of combined transplant of human umbilical cord-derived mesenchymal stem cells and matched donor allogeneic hematopoietic stem cells in children with severe aplastic anemia. MATERIALS AND METHODS: We retrospectively examined 15 pediatric patients with severe aplastic anemia who received fludarabine-based reduced intensity conditioning regimen and intravenously infused human umbilical cord-derived mesenchymal stem cells at a dose of 1 × 106/kg recipient body weight within 12 to 18 hours before hematopoietic stem cells infusion. We evaluated the engraftment rate, the frequency and severity of graft-versus-host disease, and the overall survival rate. RESULTS: No patients had adverse events related to intravenously human umbilical cord-derived mesenchymal stem cells infusion. All patients achieved successful engraftment and sustained donor chimerism. The median time for neutrophil and platelet engraftment was 14 and 25 days,respectively. The frequency was 20% for grade III/IV acute graftversus- host disease and 15.3% for chronic graftversus-host disease. Patients were followed-up for a median of 33 months (range, 2-89 months). The 5-year overall survival rate was 80%. CONCLUSIONS: Combined transplant of matched donor hematopoietic stem cells with human umbilical cord-derived mesenchymal stem cells is safe in pediatric patients with severe aplastic anemia. The achievement of engraftment in all of our patients and the acceptable frequency of acute and chronic graft-versus-host disease and survival rate are encouraging.

Mutational landscape of SARS-CoV-2 genome in Turkey and impact of mutations on spike protein structure.

The Coronavirus Disease 2019 (COVID-19) was declared a pandemic in March 2020 by the World Health Organization (WHO). As of May 25th, 2021 there were 2.059.941 SARS-COV2 genome sequences that have been submitted to the GISAID database, with numerous variations. Here, we aim to analyze the SARS-CoV-2 genome data submitted to the GISAID database from Turkey and to determine the variant and clade distributions by the end of May 2021, in accordance with their appearance timeline. We compared these findings to USA, Europe, and Asia data as well. We have also evaluated the effects of spike protein variations, detected in a group of genome sequences of 13 patients who applied to our clinic, by using 3D modeling algorithms. For this purpose, we analyzed 4607 SARS-CoV-2 genome sequences submitted by different lab centers from Turkey to the GISAID database between March 2020 and May 2021. Described mutations were also introduced in silico to the spike protein structure to analyze their isolated impacts on the protein structure. The most abundant clade was GR followed by G, GH, and GRY and we did not detect any V clade. The most common variant was B.1, followed by B.1.1, and the UK variant, B.1.1.7. Our results clearly show a concordance between the variant distributions, the number of cases, and the timelines of different variant accumulations in Turkey. The 3D simulations indicate an increase in the surface hydrophilicity of the reference spike protein and the detected mutations. There was less surface hydrophilicity increase in the Asp614Gly mutation, which exhibits a more compact conformation around the ACE-2 receptor binding domain region, rendering the structure in a "down" conformation. Our genomic findings can help to model vaccination programs and protein modeling may lead to different approaches for COVID-19 treatment strategies.

Co-transplantation of mesenchymal stromal cell and haploidentical hematopoietic stem cell with TCR αß depletion in children with primary immunodeficiency syndromes.

BACKGROUND: Haploidentical HSCT is a good option for children with PIDs lacking an HLA-matched donor. Co-transplantation of MSCs during haploidentical HSCT in patients with PIDs may enhance engraftment, decrease the risk of GVHD, and ensure stable donor chimerism. METHODS: Twenty-seven pediatric patients (median age, 1.4 years; range, .3-10.9) with PIDs undergoing thirty haploidentical HSCT with TCR αß depletion and co-transplantation of MSCs were enrolled to study. Most patients (73.3%) received myeloablative conditioning consisting of treosulfan or busulfan, fludarabine, and thiotepa. The median duration of follow-up was 14.3 months (range, 1-69 months). RESULTS: Acute GVHD occurred in 7 patients (grade I-II n = 5, grade III-IV n = 2). Chronic GVHD was observed in only one patient. Twenty-one patients (70.2%) had 100% donor chimerism in all cell lines including T-cell and B-cell lineages. Primary graft failure was observed in 7 patients (25.9%). The cumulative incidences of TRM were 20% at day 100, and 26.7% at one year and five years. Probabilities of OS were 80% at day 100, and 71.9% at 1 year and 5 years. Infants transplanted younger than 6 months of age had the highest 5-year survival rate (85.7%). CONCLUSION: We conclude that use of TCR αß depleted haploidentical transplantation with MSCs may ensure a rapid engraftment rate, low incidence of significant acute and chronic GVHD, and acceptable post-transplantation morbidity, especially in patients diagnosed with SCID and may be considered in children with PIDs. In younger patients (≤6 months), survival is comparable between HLA-matched graft and CD3+ TCRαß depleted HLA-mismatched graft recipients.

Gamma-irradiated SARS-CoV-2 vaccine candidate, OZG-38.61.3, confers protection from SARS-CoV-2 challenge in human ACEII-transgenic mice.

The SARS-CoV-2 virus caused the most severe pandemic around the world, and vaccine development for urgent use became a crucial issue. Inactivated virus formulated vaccines such as Hepatitis A and smallpox proved to be reliable approaches for immunization for prolonged periods. In this study, a gamma-irradiated inactivated virus vaccine does not require an extra purification process, unlike the chemically inactivated vaccines. Hence, the novelty of our vaccine candidate (OZG-38.61.3) is that it is a non-adjuvant added, gamma-irradiated, and intradermally applied inactive viral vaccine. Efficiency and safety dose (either 1013 or 1014 viral RNA copy per dose) of OZG-38.61.3 was initially determined in BALB/c mice. This was followed by testing the immunogenicity and protective efficacy of the vaccine. Human ACE2-encoding transgenic mice were immunized and then infected with the SARS-CoV-2 virus for the challenge test. This study shows that vaccinated mice have lowered SARS-CoV-2 viral RNA copy numbers both in oropharyngeal specimens and in the histological analysis of the lung tissues along with humoral and cellular immune responses, including the neutralizing antibodies similar to those shown in BALB/c mice without substantial toxicity. Subsequently, plans are being made for the commencement of Phase 1 clinical trial of the OZG-38.61.3 vaccine for the COVID-19 pandemic.