Intranasally Administered Extracellular Vesicles from Adipose Stem Cells Have Immunomodulatory Effects in a Mouse Model of Asthma

Mesenchymal Stem Cell-Derived Extracellular Vesicle Therapy for Asthma in Murine Models: A Systematic Review and Meta-analysis

BACKGROUND

Asthma is a common disease, and among the most predominant causes of the years lived with disability. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have emerged as a promising avenue for asthma management. The objective of this study is to perform a systematic review and meta-analysis of pre-clinical studies investigating the therapeutic use of MSC-EVs in murine models of asthma.

METHODS

A systematic search of electronic databases was performed. Meta-analyses were conducted on broncho-alveolar lavage fluid (BALF) cells and cytokines, as well as airway hyper-responsiveness Penh values and histological staining scores to determine the efficacy of MSC-EVs-based therapy, comparing treated rodents with untreated ones. BALF IL-4, BALF total cells, and BALF eosinophils were chosen as the primary outcomes, while airway hyper-responsiveness Penh values, BALF cytokines excluding IL-4, and histological staining scores were chosen as secondary outcomes.

RESULTS

A total of 19 eligible studies were included in the current systematic review, with 9 assessing BALF IL-4, 11 assessing BALF total cells, and 10 assessing BALF eosinophils. Pooled Hedges' g (p-value) for each outcome was - 4.407 (< 0.001), -4.976 (< 0.001), and - 4.071 (< 0.001), showing that MSC-EVs therapy inhibits asthma pathology. Changes in secondary outcomes also indicated a reduction in inflammation, goblet cell hyperplasia, and airway hyper-responsiveness. Subgroup analyses did not reveal significant disparities between the type of rodents and administration routes, and meta-regressions were only significant for MSC-EVs source and dose in the IL-4 meta-analysis, and for administration frequency and time from the last challenge to sacrifice in the BALF total cell meta-analysis.

CONCLUSION

This review highlights the current pre-clinical evidence of MSC-EVs therapy for asthma and finds its application ameliorates multiple aspects of asthma's pathology. We further underline the importance of MSC-EVs source, dose, administration frequency, and timing on the therapeutic effect and warrant further investigation and clinical translation to assess the best treatment regimen and to gauge the efficacy of EV therapy in human asthma cases.

SCGB1C1 Plays a Critical Role in Suppression of Allergic Airway Inflammation through the Induction of Regulatory T Cell Expansion

The nanosized vesicles secreted from various cell types into the surrounding extracellular space are called extracellular vesicles (EVs). Although mesenchymal stem cell-derived EVs are known to have immunomodulatory effects in asthmatic mice, the role of identified pulmonary genes in the suppression of allergic airway inflammation remains to be elucidated. Moreover, the major genes responsible for immune regulation in allergic airway diseases have not been well documented. This study aims to evaluate the immunomodulatory effects of secretoglobin family 1C member 1 (SCGB1C1) on asthmatic mouse models. C57BL/6 mice were sensitized to ovalbumin (OVA) using intraperitoneal injection and were intranasally challenged with OVA. To evaluate the effect of SCGB1C1 on allergic airway inflammation, 5 μg/50 μL of SCGB1C1 was administrated intranasally before an OVA challenge. We evaluated airway hyperresponsiveness (AHR), total inflammatory cells, eosinophils in the bronchoalveolar lavage fluid (BALF), lung histology, serum immunoglobulin (Ig), the cytokine profiles of BALF and lung-draining lymph nodes (LLN), and the T cell populations in LLNs. The intranasal administration of SCGB1C1 significantly inhibited AHR, the presence of eosinophils in BALF, eosinophilic inflammation, goblet cell hyperplasia in the lung, and serum total and allergen-specific IgE. SCGB1C1 treatment significantly decreased the expression of interleukin (IL)-5 in the BALF and IL-4 in the LLN, but significantly increased the expression of IL-10 and transforming growth factor (TGF)-β in the BALF. Furthermore, SCGB1C1 treatment notably increased the populations of CD4+CD25+Foxp3+ regulatory T cells (Tregs) in asthmatic mice. The intranasal administration of SCGB1C1 provides a significant reduction in allergic airway inflammation and improvement of lung function through the induction of Treg expansion. Therefore, SCGB1C1 may be the major regulator responsible for suppressing allergic airway inflammation.

Therapeutic potential of mesenchymal stem cell-derived exosomes for allergic airway inflammation

Due to their immunomodulatory capacities, mesenchymal stem cells (MSCs) have been extensively used as therapeutic approaches in cell-based therapy for various inflammatory diseases. Several lines of studies have shown that the most beneficial effects of MSCs are associated with MSC-derived exosomes. Exosomes are nanoscale extracellular vesicles that contain important biomolecules such as RNA, microRNAs (miRNAs), DNA, growth factors, enzymes, chemokines, and cytokines that regulate immune cell functions and parenchymal cell survival. Recently, exosomes, especially MSC-derived exosomes, have been shown to have protective effects in allergic airway inflammation. This review focused on the immune-regulatory potential of MSC-derived exosomes as nanoscale delivery systems in the treatment of allergic airway inflammation.

Sublingual prophylactic administration of OVA-loaded MSC-derived exosomes to prevent allergic sensitization

AIM

This study evaluated the immunomodulatory and delivery potential of adipose tissue-isolated MSC-derived exosomes as a prophylactic regimen through a sublingual route in the ovalbumin (OVA)-induced allergic asthma murine model.

MATERIAL AND METHODS

Balb/c mice received 10 μg/dose of OVA-enriched MSC-derived exosomes as a prophylactic regimen in six doses during three weeks, and then OVA sensitization was conducted through intraperitoneal and aerosol administration of allergen. The total cells and eosinophils counted in nasal lavage fluid (NALF) and lung tissues were assessed for histopathological analysis. In addition, the secretion of IFN-γ, IL-4, and TGF-β by spleen cells and serum OVA-specific IgE levels were measured via ELISA.

RESULTS

Significant reduction in the IgE levels and IL-4 production, along with elevated TGF-β levels, were observed. Also, limited cellular infiltrations and perivascular and peribronchiolar inflammation in the lung tissues and normal total numbers of cells and eosinophils in the NALF were reported.

CONCLUSION

Prophylactic regimen using OVA-enriched MSC-derived exosomes modulated immune responses and inhibited allergic OVA sensitization.

Immune response modulation by allergen loaded into mesenchymal stem cell-derived exosomes as an effective carrier through sublingual immunotherapy

BACKGROUND

Allergen-specific sublingual immunotherapy (SLIT) was considered an interesting needle-free alternative for subcutaneous immunotherapy (SCIT). Mesenchymal stem cell (MSC)-derived exosomes were introduced as potent nanoscale delivery systems with immunomodulatory potentials. The current study investigated the therapeutic efficacy of SLIT using ovalbumin (OVA)-enriched MSC-derived exosomes formulation in a murine model of allergic asthma.

MATERIAL AND METHODS

MSCs were harvested from mice adipose tissues. Then, exosomes were isolated, and OVA-loaded exosomes were prepared. Following sensitization, Balb/c mice received therapeutic formulation (10 μg/dose OVA-containing MSC-derived exosomes) twice a week for two months. Serum OVA-specific IgE levels as well as IFN-γ, IL-4, and TGF-β secretions by cultured splenocytes were measured by ELISA. Also, lung tissue underwent histopathologic analysis, and the numbers of inflammatory cells and eosinophils in nasopharyngeal lavage fluid (NALF) were examined.

RESULTS

SLIT using OVA-enriched exosomes significantly reduced IgE levels and IL-4 production, while the secretion of IFN-γ and TGF-β were significantly elevated. Also, a decrease was observed in the numbers of total cells and eosinophils in the NALF, and lower levels of perivascular and peribronchiolar inflammation and cellular infiltrations were observed in the lung tissue.

CONCLUSION

SLIT using OVA-loaded exosomes improved immunomodulatory responses and efficiently alleviated allergic inflammation.

Immunomodulatory Effects of Mesenchymal Stem Cell-Derived Extracellular Vesicles in Allergic Airway Disease

Mesenchymal stem cells (MSCs) have been reported as promising candidates for the treatment of various diseases, especially allergic diseases, as they have the capacity to differentiate into various cells. However, MSCs itself have several limitations such as creating a risk of aneuploidy, difficulty in handling them, immune rejection, and tumorigenicity, so interest in the extracellular vesicles (EVs) released from MSCs are increasing, and many studies have been reported. Previous studies have shown that extracellular vesicles (EVs) produced by MSCs are as effective as the MSCs themselves in suppression of allergic airway inflammation through the suppression of Th2 cytokine production and the induction of regulatory T cells (Treg) expansion. EVs are one of the substances secreted by paracrine induction from MSCs, and because it exerts its effect by delivering contents such as mRNA, microRNA, and proteins to the receptor cell, it can reduce the problems or risks related to stem cell therapy. This article reviews the immunomodulatory properties of MSCs-derived EVs and their therapeutic implications for allergic airway disease.

"Liquid biopsy" - extracellular vesicles as potential novel players towards precision medicine in asthma

Extracellular vesicles (EVs) have emerged as vital mediators in intracellular communication in the lung microenvironment. Environmental exposure to various triggers (e.g., viruses, allergens) stimulates the EV-mediated cascade of pro-inflammatory responses that play a key role in the asthma pathomechanism. This complex EV-mediated crosstalk in the asthmatic lung microenvironment occurs between different cell types, including airway epithelial cells and immune cells. The cargo composition of EVs mirrors hereby the type and activation status of the parent cell. Therefore, EVs collected in a noninvasive way (e.g., in nasal lavage, serum) could inform on the disease status as a "liquid biopsy", which is particularly important in the pediatric population. As a heterogeneous disease, asthma with its distinct endotypes and phenotypes requires more investigation to develop novel diagnostics and personalized case management. Filling these knowledge gaps may be facilitated by further EV research. Here, we summarize the contribution of EVs in the lung microenvironment as potential novel players towards precision medicine in the development of asthma. Although rapidly evolving, the EV field is still in its infancy. However, it is expected that a better understanding of the role of EVs in the asthma pathomechanism will open up new horizons for precision medicine diagnostic and therapeutic solutions.

Mesenchymal Stem Cell-Derived Secretome: A Potential Therapeutic Option for Autoimmune and Immune-Mediated Inflammatory Diseases

Immune-mediated inflammatory diseases (IMIDs) encompass several entities such as "classic" autoimmune disorders or immune-mediated diseases with autoinflammatory characteristics. Adult stem cells including mesenchymal stem cells (MSCs) are by far the most commonly used type in clinical practice. However, due to the possible side effects of MSC-based treatments, there is an increase in interest in the MSC-secretome (containing large extracellular vesicles, microvesicles, and exosomes) as an alternative therapeutic option in IMIDs. A wide spectrum of MSC-secretome-related biological activities has been proven thus far including anti-inflammatory, anti-apoptotic, and immunomodulatory properties. In comparison with MSCs, the secretome is less immunogenic but exerts similar biological actions, so it can be considered as an ideal cell-free therapeutic alternative. Additionally, since the composition of the MSC-secretome can be engineered, for a future perspective, it could also be viewed as part of a potential delivery system within nanomedicine, allowing us to specifically target dysfunctional cells or tissues. Although many encouraging results from pre-clinical studies have recently been obtained that strongly support the application of the MSC-secretome in IMIDs, human studies with MSC-secretome administration are still in their infancy. This article reviews the immunomodulatory effects of the MSC-secretome in IMIDs and provides insight into the interpretation of its beneficial biological actions.

Chronic obstructive pulmonary disease and asthma: mesenchymal stem cells and their extracellular vesicles as potential therapeutic tools

Chronic lung diseases, such as chronic obstructive pulmonary disease (COPD) and asthma, are one of the most frequent causes of morbidity and mortality in the global. COPD is characterized by progressive loss of lung function through inflammation, apoptosis, and oxidative stress caused by chronic exposure to harmful environmental pollutants. Airway inflammation and epithelial remodeling are also two main characteristics of asthma. In spite of extensive efforts from researchers, there is still a great need for novel therapeutic approaches for treatment of these conditions. Accumulating evidence suggests the potential role of mesenchymal stem cells (MSCs) in treatment of many lung injuries due to their beneficial features including immunomodulation and tissue regeneration. Besides, the therapeutic advantages of MSCs are chiefly related to their paracrine functions such as releasing extracellular vesicles (EVs). EVs comprising exosomes and microvesicles are heterogeneous bilayer membrane structures loaded with various lipids, nucleic acids and proteins. Due to their lower immunogenicity, tumorigenicity, and easier management, EVs have appeared as favorable alternatives to stem cell therapies. Therefore, in this review, we provided an overview on the current understanding of the importance of MSCs and MSC-derived EVs from different sources reported in preclinical and clinical COPD and asthmatic models.