Extracellular Vesicles Derived from Allergen Immunotherapy-Treated Mice Suppressed IL-5 Production from Group 2 Innate Lymphoid Cells

Extracellular vesicles and the lung: from disease pathogenesis to biomarkers and treatments

Nanosized extracellular vesicles (EVs) are released by all cells to convey cell-to-cell communication. EVs, including exosomes and microvesicles, carry an array of bioactive molecules, such as proteins and RNAs, encapsulated by a membrane lipid bilayer. Epithelial cells, endothelial cells, and various immune cells in the lung contribute to the pool of EVs in the lung microenvironment and carry molecules reflecting their cellular origin. EVs can maintain lung health by regulating immune responses, inducing tissue repair, and maintaining lung homeostasis. They can be detected in lung tissues and biofluids such as bronchoalveolar lavage fluid and blood, offering information about disease processes, and can function as disease biomarkers. Here, we discuss the role of EVs in lung homeostasis and pulmonary diseases such as asthma, chronic obstructive pulmonary disease, cystic fibrosis, pulmonary fibrosis, and lung injury. The mechanistic involvement of EVs in pathogenesis and their potential as disease biomarkers are discussed. Finally, the pulmonary field benefits from EVs as clinical therapeutics in severe pulmonary inflammatory disease, as EVs from mesenchymal stem cells attenuate severe respiratory inflammation in multiple clinical trials. Further, EVs can be engineered to carry therapeutic molecules for enhanced and broadened therapeutic opportunities, such as the anti-inflammatory molecule CD24. Finally, we discuss the emerging opportunity of using different types of EVs for treating severe respiratory conditions.

Plasma extracellular vesicles regulate the Functions of Th2 and ILC2 cells via miRNA-150-5p in patients with allergic rhinitis

Allergic rhinitis (AR), a chronic airway inflammation, has witnessed a rising prevalence in recent decades. Recent research indicates that various EVs are released into plasma in allergic airway inflammation, correlating with impaired airway function and severe inflammation. However, the contribution of plasma EVs to AR pathogenesis remains incompletely understood. We isolated plasma EVs using differential ultracentrifugation or size exclusion chromatography (SEC) and obtained differential microRNA (miRNA) expression profiles through miRNA sequencing. Peripheral blood mononuclear cells (PBMCs) were exposed to plasma EVs and miRNA mimics and inhibitors to assess the effect of plasma EVs and the underlying mechanisms. We found that EVs from HC and AR patients exhibited comparable characteristics in terms of concentration, structure, and EV marker expression. AR-EVs significantly enhanced Th2 cell levels and promoted ILC2 differentiation and IL-13+ ILC2 levels compared to HC-EVs. Both HC-EVs and AR-EVs were efficiently internalized by CD4+ T cells and ILCs. miRNA sequencing of AR-EVs revealed unique miRNA signatures implicated in diverse biological processes, among which miR-150-5p, miR-144-3p, miR-10a-5p, and miR-10b-5p were identified as pivotal contributors to AR-EVs' effects on CD4+ T cells and ILC2s. MiR-150-5p exhibited the most pronounced impact on cell differentiation and was confirmed to be upregulated in AR-EVs by PCR. In total, our study demonstrated that plasma EVs from patients with AR exhibited a pronounced capacity to significantly enhance the differentiation of Th2 cells and ILC2, which was correlated with an elevated expression of miR-150-5p within AR-EVs. These findings contribute to the advancement of our comprehension of EVs in the pathogenesis of AR and hold the potential to unveil novel therapeutic targets for the treatment of AR.

Extracellular vesicles: Messengers of allergic immune responses and novel therapeutic strategy

Extracellular vesicles (EVs) are nanosized particles released by nearly every cell type across all kingdoms of life. As a result, EVs are ubiquitously present in various human body fluids. Composed of a lipid bilayer, EVs encapsulate proteins, nucleic acids, and metabolites, thus playing a crucial role in immunity, for example, by enabling intercellular communication. More recently, there has been increasing evidence that EVs can also act as key regulators of allergic immune responses. Their ability to facilitate cell-to-cell contact and to transport a variety of different biomolecules enables active modulation of both innate and adaptive immune processes associated with allergic reactions. A comprehensive understanding of the intricate mechanisms underlying the interactions among allergens, immune cells, and EVs is imperative to develop innovative strategies for controlling allergic responses. This review highlights the recent roles of host cell- and bacteria-derived EVs in allergic diseases, presenting experimental and clinical evidence that underscores their significance. Additionally, the therapeutic potential of EVs in allergy management is outlined, along with the challenges associated with targeted delivery and cargo stability for clinical use. Optimization of EV composition and targeting strategies holds promise for advancing translational applications and establishing EVs as biomarkers or safe therapeutics for assessing allergic reactions. For these reasons, EVs represent a promising avenue for advancing both our understanding and management of allergic immune processes.

Circulating extracellular particles from severe COVID-19 patients show altered profiling and innate lymphoid cell-modulating ability

Introduction

Extracellular vesicles (EVs) and particles (EPs) represent reliable biomarkers for disease detection. Their role in the inflammatory microenvironment of severe COVID-19 patients is not well determined. Here, we characterized the immunophenotype, the lipidomic cargo and the functional activity of circulating EPs from severe COVID-19 patients (Co-19-EPs) and healthy controls (HC-EPs) correlating the data with the clinical parameters including the partial pressure of oxygen to fraction of inspired oxygen ratio (PaO2/FiO2) and the sequential organ failure assessment (SOFA) score.

Methods

Peripheral blood (PB) was collected from COVID-19 patients (n=10) and HC (n=10). EPs were purified from platelet-poor plasma by size exclusion chromatography (SEC) and ultrafiltration. Plasma cytokines and EPs were characterized by multiplex bead-based assay. Quantitative lipidomic profiling of EPs was performed by liquid chromatography/mass spectrometry combined with quadrupole time-of-flight (LC/MS Q-TOF). Innate lymphoid cells (ILC) were characterized by flow cytometry after co-cultures with HC-EPs or Co-19-EPs.

Results

We observed that EPs from severe COVID-19 patients: 1) display an altered surface signature as assessed by multiplex protein analysis; 2) are characterized by distinct lipidomic profiling; 3) show correlations between lipidomic profiling and disease aggressiveness scores; 4) fail to dampen type 2 innate lymphoid cells (ILC2) cytokine secretion. As a consequence, ILC2 from severe COVID-19 patients show a more activated phenotype due to the presence of Co-19-EPs.

Discussion

In summary, these data highlight that abnormal circulating EPs promote ILC2-driven inflammatory signals in severe COVID-19 patients and support further exploration to unravel the role of EPs (and EVs) in COVID-19 pathogenesis.