Efficacy and Safety of MSC Cell Therapies for Hospitalized Patients with COVID-19: A Systematic Review and Meta-Analysis

Mesenchymal stem cell therapy for COVID-19 infection

COVID-19 emerged in December 2019 in Wuhan, China, spread worldwide rapidly, and caused millions of deaths in a short time. Many preclinical and clinical studies were performed to discover the most efficient therapy to reduce the mortality of COVID-19 patients. Among various approaches for preventing and treating COVID-19, mesenchymal stem cell (MSC) therapy can be regarded as a novel and efficient treatment for managing COVID-19 patients. In this review, we explain the pathogenesis of COVID-19 infection in humans and discuss the role of MSCs in suppressing the inflammation and cytokine storm produced by COVID-19. Then, we reviewed the clinical trial and systematic review studies that investigated the safety and efficacy of MSC therapy in the treatment of COVID-19 infection.

Development and characterization of islet-derived mesenchymal stem cells from clinical grade neonatal porcine cryopreserved islets

BACKGROUND

Porcine tissues display a great potential as donor tissues in xenotransplantation, including cell therapy. Cryopreserving clinical grade porcine tissue and using it as a source for establishing therapeutic cells should be advantageous for transportation and scheduled manufacturing of MSCs. Of note, we previously performed encapsulated porcine islet transplantation for the treatment of unstable type 1 diabetes mellitus in the clinical setting. It has been reported that co-transplantation of islets and Mesenchymal stem cells (MSCs) enhanced efficacy. We assume that co-transplantation of porcine islets and porcine islet-derived MSCs could improve the efficacy of clinical islet xenotransplantation.

METHODS

MSCs were established from fresh and cryopreserved non-clinical grade neonatal porcine islets and bone marrow (termed non-clinical grade npISLET-MSCs and npBM-MSCs, respectively), as well as from cryopreserved clinical grade neonatal porcine islets (termed clinical grade npISLET-MSCs). Subsequently, the cell proliferation rate and diameter, surface marker expression, adipogenesis, osteogenesis, and colony-forming efficiency of the MSCs were assessed.

RESULTS

Cell proliferation rate and diameter did not differ between clinical grade and non-clinical grade npISLET-MSCs. However, non-clinical grade npBM-MSCs were significantly shorter and smaller than both npISLET-MSCs (p < 0.05). MSC markers (CD29, CD44, and CD90) were strongly expressed in clinical grade npISLET-MSCs and non-clinical grade npISLET-MSCs and npBM-MSCs. The expression of MSC-negative markers CD31, CD34, and SLA-DR was low in all MSCs. Clinical grade npISLET-MSCs derived from adipose and osteoid tissues were positive for Oil Red and alkaline phosphatase staining. The results of colony-forming assay were not significantly different between clinical grade npISLET-MSCs and non-clinical grade npBM-MSCs.

CONCLUSION

The method described herein was successful in of developing clinical grade npISLET-MSCs from cryopreserved islets. Cryopreserved clinical grade porcine islets could be an excellent stable source of MSCs for cell therapy.

Relationship between oxygen partial pressure and inhibition of cell aggregation of human adipose tissue-derived mesenchymal stem cells stored in cell preservation solutions

Introduction

This study investigated the storage conditions under which cell aggregation occurs and the conditions that inhibit cell aggregation when human adipose tissue-derived mesenchymal stem cells (hADSCs) are stored in lactated Ringer's solution (LR) supplemented with 3% trehalose and 5% dextran 40 (LR-3T-5D).

Methods

We first examined the effects of storage temperature and time on the aggregation and viability of hADSCs stored in LR and LR-3T-5D. The cells were stored at 5 °C or 25 °C for various times up to 24 h. We then evaluated the effects of storage volume (250-2,000 μL), cell density (2.5-20 × 10⁵ cells/mL), and nitrogen gas replacement on aggregation, oxygen partial pressure (pO₂), and viability of hADSCs stored for 24 h at 25 °C in LR-3T-5D.

Results

When stored in LR-3T-5D, viability did not change under either condition compared with pre-storage, but the cell aggregation rate increased significantly with storage at 25 °C for 24 h (p<0.001). In LR, the aggregation rate did not change under either condition, but cell viability decreased significantly after 24 h at both 5 °C and 25 °C (p < 0.05). The cell aggregation rates and pO₂ tended to decrease with increasing solution volume and cell density. Nitrogen gas replacement significantly decreased the cell aggregation rate and pO₂ (p < 0.05). However, there were no differences in viability among cells stored under conditions of different storage volumes, densities, and nitrogen gas replacement.

Conclusions

Aggregation of cells after storage at 25 °C in LR-3T-5D may be suppressed by increasing the storage volume and cell density as well as by incorporating nitrogen replacement, which lowers the pO₂ in the solution.

Adipose-derived, autologous mesenchymal stem cell therapy for patients with post-COVID-19 syndrome: an intermediate-size expanded access program

BACKGROUND

Evolving mutations of the novel coronavirus continue to fuel up the pandemic. The virus affects the human respiratory system along with other body systems, causing several sequelae in the survivors of the disease, presented as post-COVID-19 syndrome or long-COVID-19. This protocol utilized Hope Biosciences' autologous, adipose-derived mesenchymal stem cells (HB-adMSCs) to evaluate safety and efficacy of HB-adMSC therapy to improve signs and symptoms associated with post-COVID-19 syndrome.

METHODS

Ten eligible subjects with post-COVID-19 syndrome were enrolled in the program for a duration of 40 weeks who received 5 intravenous infusions of 2 × 108 autologous HB-adMSCs each at week 0, 2, 6, 10 and 14 with a follow-up at week 18 and end of the study at week 40. Safety assessments included incidence of adverse and serious adverse events along with the laboratory measures of hematologic, hepatic, and renal function. Efficacy was examined by quality-of-life assessments, fatigue assessments, Visual analog scale (VAS) of symptoms and monitoring of respiration and oxygen saturation rates.

RESULTS

VAS scores and Fatigue Assessment scores (FAS) showed significant improvements post-treatment (P = 0.0039, ES = 0.91) compared to baseline. Respiration rates and oxygen saturation levels that were within the normal range at the baseline remained unchanged at the end of the study (EOS). Paired comparison between baseline and EOS for short-form-36 health survey questionnaire (SF-36) scores also showed improved quality-of-life with significant improvements in individual SF-36 evaluations. Mostly mild AEs were reported during the study period with no incidence of serious AEs. Also, no detrimental effects in laboratory values were seen.

CONCLUSIONS

The results of the expanded access program indicated that treatment with autologous HB-adMSCs resulted in significant improvements in the signs and symptoms associated with post-COVID-19 syndrome as assessed by VAS and FAS scores. Additionally, improvements in the patients' quality-of-life as demonstrated using SF-36 scores that also showed significant improvements in individual scaled scores. Overall, administration of multiple infusions of autologous HB-adMSCs is safe and efficacious for improvements in the quality-of life of patients with post-COVID-19 syndrome.

TRIAL REGISTRATION

Clinical trial registration number: NCT04798066. Registered on March 15, 2021. ( https://clinicaltrials.gov/ct2/show/NCT04798066?term=hope+biosciences&cond=Post-COVID-19+Syndrome&draw=2&rank=2 ).

Short-term assays for mesenchymal stromal cell immunosuppression of T-lymphocytes

Introduction

Trauma patients are susceptible to coagulopathy and dysfunctional immune responses. Mesenchymal stromal cells (MSCs) are at the forefront of the cellular therapy revolution with profound immunomodulatory, regenerative, and therapeutic potential. Routine assays to assess immunomodulation activity examine MSC effects on proliferation of peripheral blood mononuclear cells (PBMCs) and take 3-7 days. Assays that could be done in a shorter period of time would be beneficial to allow more rapid comparison of different MSC donors. The studies presented here focused on assays for MSC suppression of mitogen-stimulated PBMC activation in time frames of 24 h or less.

Methods

Three potential assays were examined-assays of apoptosis focusing on caspase activation, assays of phosphatidyl serine externalization (PS+) on PBMCs, and measurement of tumor necrosis factor alpha (TNFα) levels using rapid ELISA methods. All assays used the same initial experimental conditions: cryopreserved PBMCs from 8 to 10 pooled donors, co-culture with and without MSCs in 96-well plates, and PBMC stimulation with mitogen for 2-72 h.

Results

Suppression of caspase activity in activated PBMCs by incubation with MSCs was not robust and was only significant at times after 24 h. Monitoring PS+ of live CD3+ or live CD4+/CD3+ mitogen-activated PBMCs was dose dependent, reproducible, robust, and evident at the earliest time point taken, 2 h, although no increase in the percentage of PS+ cells was seen with time. The ability of MSC in co-culture to suppress PBMC PS+ externalization compared favorably to two concomitant assays for MSC co-culture suppression of PBMC proliferation, at 72 h by ATP assay, or at 96 h by fluorescently labeled protein signal dilution. TNFα release by mitogen-activated PBMCs was dose dependent, reproducible, robust, and evident at the earliest time point taken, with accumulating signal over time. However, suppression levels with MSC co-culture was reliably seen only after 24 h.

Discussion

Takeaways from these studies are as follows: (1) while early measures of PBMC activation is evident at 2-6 h, immunosuppression was only reliably detected at 24 h; (2) PS externalization at 24 h is a surrogate assay for MSC immunomodulation; and (3) rapid ELISA assay detection of TNFα release by PBMCs is a robust and sensitive assay for MSC immunomodulation at 24 h.

Rationale for combined therapies in severe-to-critical COVID-19 patients

An unprecedented global social and economic impact as well as a significant number of fatalities have been brought on by the coronavirus disease 2019 (COVID-19), produced by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Acute SARS-CoV-2 infection can, in certain situations, cause immunological abnormalities, leading to an anomalous innate and adaptive immune response. While most patients only experience mild symptoms and recover without the need for mechanical ventilation, a substantial percentage of those who are affected develop severe respiratory illness, which can be fatal. The absence of effective therapies when disease progresses to a very severe condition coupled with the incomplete understanding of COVID-19's pathogenesis triggers the need to develop innovative therapeutic approaches for patients at high risk of mortality. As a result, we investigate the potential contribution of promising combinatorial cell therapy to prevent death in critical patients.

Dissecting the Interrelationship between COVID-19 and Diabetes Mellitus

COVID-19 disease, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to enormous morbidity and mortality worldwide. After gaining entry into the human host, the virus initially infects the upper and lower respiratory tract, subsequently invading multiple organs, including the pancreas. While on one hand, diabetes mellitus (DM) is a significant risk factor for severe COVID-19 infection and associated death, recent reports have shown the onset of DM in COVID-19-recovered patients. SARS-CoV-2 infiltrates the pancreatic islets and activates stress response and inflammatory signaling pathways, impairs glucose metabolism, and consequently leads to their death. Indeed, the pancreatic autopsy samples of COVID-19 patients reveal the presence of SARS-CoV-2 particles in β-cells. The current review describes how the virus enters the host cells and activates an immunological response. Further, it takes a closer look into the interrelationship between COVID-19 and DM with the aim to provide mechanistic insights into the process by which SARS-CoV-2 infects the pancreas and mediates dysfunction and death of endocrine islets. The effects of known anti-diabetic interventions for COVID-19 management are also discussed. The application of mesenchymal stem cells (MSCs) as a future therapy for pancreatic β-cells damage to reverse COVID-19-induced DM is also emphasized.

Systematic review and meta-analysis of cell therapy for COVID-19: global clinical trial landscape, published safety/efficacy outcomes, cell product manufacturing and clinical delivery

During the pandemic of severe respiratory distress syndrome coronavirus 2 (SARS-CoV2), many novel therapeutic modalities to treat Coronavirus 2019 induced disease (COVID-19) were explored. This study summarizes 195 clinical trials of advanced cell therapies targeting COVID-19 that were registered over the two years between January 2020 to December 2021. In addition, this work also analyzed the cell manufacturing and clinical delivery experience of 26 trials that published their outcomes by July 2022. Our demographic analysis found the highest number of cell therapy trials for COVID-19 was in United States, China, and Iran (N=53, 43, and 19, respectively), with the highest number per capita in Israel, Spain, Iran, Australia, and Sweden (N=0.641, 0.232, 0,223, 0.194, and 0.192 trials per million inhabitants). The leading cell types were multipotent mesenchymal stromal/stem cells (MSCs), natural killer (NK) cells, and mononuclear cells (MNCs), accounting for 72%, 9%, and 6% of the studies, respectively. There were 24 published clinical trials that reported on infusions of MSCs. A pooled analysis of these MSC studies found that MSCs provide a relative risk reduction for all-cause COVID-19 mortality of RR=0.63 (95% CI 0.46 to 0.85). This result corroborates previously published smaller meta-analyses, which suggested that MSC therapy demonstrated a clinical benefit for COVID-19 patients. The sources of the MSCs used in these studies and their manufacturing and clinical delivery methods were remarkably heterogeneous, with some predominance of perinatal tissue-derived products. Our results highlight the important role that cell therapy products may play as an adjunct therapy in the management of COVID-19 and its related complications, as well as the importance of controlling key manufacturing parameters to ensure comparability between studies. Thus, we support ongoing calls for a global registry of clinical studies with MSC products that could better link cell product manufacturing and delivery methods to clinical outcomes. Although advanced cell therapies may provide an important adjunct treatment for patients affected by COVID-19 in the near future, preventing pathology through vaccination still remains the best protection to date. We conducted a systematic review and meta-analysis of advanced cell therapy clinical trials as potential novel treatment for COVID-19 (resulting from SARS-CoV-2 coronavirus infection), including analysis of the global clinical trial landscape, published safety/efficacy outcomes (RR/OR), and details on cell product manufacturing and clinical delivery. This study had a 2-year observation interval from start of January 2020 to end of December 2021, including a follow-up period until end of July to identify published outcomes, which covers the most vivid period of clinical trial activity, and is also the longest observation period studied until today. In total, we identified 195 registered advanced cell therapy studies for COVID-19, employing 204 individual cell products. Leading registered trial activity was attributed to the USA, China, and Iran. Through the end of July 2022, 26 clinical trials were published, with 24 out of 26 articles employing intravenous infusions (IV) of mesenchymal stromal/stem cell (MSC) products. Most of the published trials were attributed to China and Iran. The cumulative results from the 24 published studies employing infusions of MSCs indicated an improved survival (RR=0.63 with 95% Confidence Interval 0.46 to 0.85). Our study is the most comprehensive systematic review and meta-analysis on cell therapy trials for COVID-19 conducted to date, clearly identifying the USA, China, and Iran as leading advanced cell therapy trial countries for COVID-19, with further strong contributions from Israel, Spain, Australia and Sweden. Although advanced cell therapies may provide an important adjunct treatment for patients affected by COVID-19 in the future, preventing pathology through vaccination remains the best protection.

Clinical application prospects and transformation value of dental follicle stem cells in oral and neurological diseases

Since dental pulp stem cells (DPSCs) were first reported, six types of dental SCs (DSCs) have been isolated and identified. DSCs originating from the craniofacial neural crest exhibit dental-like tissue differentiation potential and neuro-ectodermal features. As a member of DSCs, dental follicle SCs (DFSCs) are the only cell type obtained at the early developing stage of the tooth prior to eruption. Dental follicle tissue has the distinct advantage of large tissue volume compared with other dental tissues, which is a prerequisite for obtaining a sufficient number of cells to meet the needs of clinical applications. Furthermore, DFSCs exhibit a significantly higher cell proliferation rate, higher colony-formation capacity, and more primitive and better anti-inflammatory effects than other DSCs. In this respect, DFSCs have the potential to be of great clinical significance and translational value in oral and neurological diseases, with natural advantages based on their origin. Lastly, cryopreservation preserves the biological properties of DFSCs and enables them to be used as off-shelf products for clinical applications. This review summarizes and comments on the properties, application potential, and clinical transformation value of DFSCs, thereby inspiring novel perspectives in the future treatment of oral and neurological diseases.

Efficacy of umbilical cord mesenchymal stromal cells for COVID-19: A systematic review and meta-analysis

Objectives

A major challenge for COVID-19 therapy is dysregulated immune response associated with the disease. Umbilical cord mesenchymal stromal cells (UC-MSCs) may be a promising candidate for COVID-19 treatment owing to their immunomodulatory and anti-inflammatory functions. Therefore, this study aimed to evaluate the effectiveness of UC-MSCs inpatients with COVID-19.

Method

Medline, Embase, PubMed, Cochrane Library, and Web of Science databases were searched to collect clinical trials concerning UC-MSCs for the treatment of COVID-19. After literature screening, quality assessment, and data extraction, a systematic review and meta-analysis of the included study were performed.

Results

This systematic review and meta-analysis were prospectively registered on PROSPERO, and the registration number is CRD42022304061. After screening, 10 studies involving 293 patients with COVID-19 were eventually included. Our meta-analysis results showed that UC-MSCs can reduce mortality (relative risk [RR] =0.60, 95% confidence interval [CI]: [0.38, 0.95], P=0.03) in COVID-19 patients. No significant correlation was observed between adverse events and UC-MSC treatment (RR=0.85, 95% CI: [0.65, 1.10], P=0.22; RR=1.00, 95%CI: [0.64, 1.58], P=1.00). In addition, treatment with UC-MSCs was found to suppress inflammation and improve pulmonary symptoms.

Conclusions

UC-MSCs hold promise as a safe and effective treatment for COVID-19.

Systematic Review Registartion

PROSPERO, identifier CRD42022304061.

Universal or Personalized Mesenchymal Stem Cell Therapies: Impact of Age, Sex, and Biological Source

Mesenchymal stem/stromal cells (MSCs) hold great promise for the treatment of autoimmune conditions given their immunomodulatory properties. Based on the low immunogenicity of MSCs, it is tempting to consider the expansion of MSCs from a “universal donor” in culture prior to their allogeneic applications for immediate care. This raises the critical question of the criteria we should use to select the best “universal donor”. It is also imperative we compare the “universal” approach with a “personalized” one for clinical value. In addition to the call for MHC-matching, recent studies suggest that factors including age, sex, and biological sources of MSCs can have significant impact on therapy outcome. Here, we will review findings from these studies, which shed light on the variables that can guide the important choice of “universal” or “personalized” MSC therapy for autoimmune diseases.