Effect of Comedications and Endotoxins on Mesenchymal Stem Cell Secretomes, Migratory and Immunomodulatory Capacity

Mesenchymal stem cells (MSCs) are becoming an increasingly popular therapeutic option among patients with a broad range of ailments to modulate immunity and induce regeneration. The majority of patients receiving these MSC therapies are on concurrent medication or have ongoing infection. In the present study, we examined the effect of immunosuppressive drugs and lipopolysaccharides (LPS)/endotoxins on the secretory profile, migration towards site of injury, and suppression of lymphocyte proliferation of bone marrow-derived MSCs (BMSCs). Generally, LPS coculture augmented the secretory capacity of BMSCs while exposure to immunosuppressive drugs resulted primarily in no change or attenuated secretion, with some cases of increased secretion, dependent on the cytokine assayed. Among the immunosuppressants evaluated, Hydrocortisone had the most widespread inhibitory effect, while LPS from E. coli O111:B4 had the most potent stimulatory effect. In addition, we also showed that Hydrocortisone or LPS from E. coli O111:B4 affected the migratory and immunosuppressive capacity of BMSCs. Following simulation with Hydrocortisone, BMSC migration was attenuated, and immunosuppressive capacity against T cell proliferation was enhanced, however, the opposite effects were seen with LPS from E. coli O111:B4. Our data suggests that the clinical outcomes of MSC-based therapy are affected by the use of immunosuppressive medication or the presence of endotoxemia in patients

IL-10 mRNA Engineered MSCs Demonstrate Enhanced Anti-Inflammation in an Acute GvHD Model

Mesenchymal stem cells (MSCs) are used in various studies to induce immunomodulatory effects in clinical conditions associated with immune dysregulation such as graft versus host disease (GvHD). However, most of these clinical trials failed to go beyond early phase 2 studies because of limited efficacy. Various methods have been assessed to increase the potency of MSCs. IL-10 is an anti-inflammatory cytokine that is known to modulate immune responses in GvHD. In this study, we evaluated the feasibility of transfecting IL-10 mRNA to enhance MSC therapeutic potential. IL-10 mRNA engineered MSCs (eMSCs-IL10) maintained high levels of IL-10 expression even after freezing and thawing. IL-10 mRNA transfection did not appear to alter MSC intrinsic characteristics. eMSCs-IL10 significantly suppressed T cell proliferation relative to naïve MSCs in vitro. In a mouse model for GvHD, eMSCs-IL10 induced a decrease in plasma level of potent pro-inflammatory cytokines and inhibited CD4+ and CD8+ T cell proliferation in the spleen. In summary, our studies demonstrate the feasibility of potentiating MSCs to enhance their immunomodulatory effects by IL-10 mRNA transfection. The use of non-viral transfection may generate a safe and potent MSC product for treatment of clinical conditions associated with immune dysregulation such as GvHD

Preliminary Report on the Effect of Mesenchymal Stem Cell Therapy in Patients with Chronic Lung Allograft Dysfunction

Background: Mesenchymal stem cell (MSC) effects can shift immune responses toward anti-inflammatory and tolerogenic phenotypes, potentially helping patients with bronchiolitis obliterans syndrome (BOS). Methods: We evaluated the effect of infusing allogeneic MSC intravenously in 9 patients with moderate BOS refractory to standard therapy who were not candidates for retransplant, dividing them into 3 dosing groups: Group 1, 1×106 MSC/kg (n=3); Group 2, 2×106 MSC/kg (n=3); and Group 3, 4×106 MSC/kg (n=3). We recorded pulmonary function tests, laboratory variables, and serum biomarkers pre- and post-MSC infusion. Results: These patients had significant decline in forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) over 1 year pre-MSC infusion (mean ± SD) FVC, 3.11±0.98 L, and FEV1 1.99+0.64 L versus FVC 2.58±1.03 and FEV1 1.61±0.52 just before infusion (P<0.05); representing a mean loss of 530 mL in FVC and 374 mL in FEV1 over 12 months. One year post-MSC infusion, mean FVC and FEV1 increased to 2.66±1.01 L and 1.63±0.55 L, respectively (changes no longer significant compared to before MSC infusion). Patients in Group 1 showed elevation of tolerance-inducing T regulatory cells and increased levels of epidermal growth factor. Tolerance-inducing Th-2 cytokines increased in Groups 1 and 2. These changes were not significantly different in these small sub-groups. Conclusion: MSC infusion appears to slow down or reverse the progressive decline in lung function in some patients with moderate BOS, possibly by inducing anti-inflammatory effects and promoting cell proliferation and angiogenesis

Glycan Node Analysis of Plasma-Derived Extracellular Vesicles

Blood plasma is a readily accessible source of extracellular vesicles (EVs), i.e., cell-secreted nanosized carriers that contain various biomolecules, including glycans. Previous studies have demonstrated that glycans play a major role in physiological and pathological processes, and certain plasma glycans have been associated with disease conditions. However, glycome studies have been limited by a lack of analytical techniques with the throughput capacity necessary to study hundreds of clinical samples. This study is the first to characterize the EV plasma glycome based on all major glycan classes. The results based on glycan node analysis revealed, as expected, that plasma-derived EVs have distinct glycan features from donor-matched whole plasma. Specifically, glycan nodes corresponding to those observed in chondroitin sulfate, dermatan sulfate, type I keratan sulfate, and type II keratan sulfate were enriched on EVs. The identification of specific differences in glycan features in plasma vs. plasma-derived EVs is relevant for understanding the physiological role of EVs and as a reference for future diagnostic studies. Additionally, the results indicate that EV glycan nodes do not substantially differ among a small set of healthy donors. These results lay the framework for the further evaluation of all EV glycan classes as diagnostic markers, therapeutic targets, and biologically active components in health and disease