T cell-induced secretion of MHC class II-peptide complexes on B cell exosomes

CD83 suppresses endogenous March-I-dependent MHC class II ubiquitination, endocytosis, and degradation

MHC class II glycoproteins (MHC-II) bind peptides derived from exogenous antigens and dendritic cells (DCs) present these peptide MHC-II (pMHC-II) complexes to antigen-specific CD4 T cells during immune responses. The turnover of surface pMHC-II on antigen-presenting cells (APCs) is controlled by ubiquitin-mediated degradation of pMHC-II by the E3 ubiquitin ligase March-I. To study March-I protein expression, we have generated a mouse in which a V5 epitope-tag was knocked-in to the endogenous March-I gene, thereby allowing us to follow the fate of March-I using high-affinity anti-V5 antibodies. Quantitative analysis revealed that resting spleen DCs and B cells express only ~500 and 125 March-I molecules/cell, respectively. Endogenous March-I protein has a very short half-life in DCs and March-I mRNA, March-I protein, and MHC-II ubiquitination are rapidly terminated upon activation of both DCs and B cells. Like March-I, CD83 is a known regulator of MHC-II expression in APCs and we also show that CD83 suppresses endogenous March-I-dependent MHC-II ubiquitination, endocytosis, and degradation in mouse spleen DCs. Thus, our study reveals molecular mechanisms for both March-I- and CD83-dependent regulation of MHC-II expression in APCs.

The potential mechanisms of extracellular vesicles in transfusion-related adverse reactions: Recent advances

Blood transfusion is an irreplaceable clinical treatment. Blood components are differentiated and stored according to specific guidelines. Storage temperatures and times vary depending on the blood component, but they all release extracellular vesicles (EVs) during storage. Although blood transfusions can be life-saving, they can also cause many adverse transfusion reactions, among which the effects of EVs are of increasing interest to researchers. EVs are submicron particles that vary in size, composition, and surface biomarkers, are encapsulated by a lipid bilayer, and are not capable of self-replication. EVs released by blood cells are important contributors to pathophysiologic states through proinflammatory, coagulant, and immunosuppressive effects, which in turn promote or inhibit the associated disease phenotype. Therefore, this review explores the potential mechanisms of hematopoietic-derived EVs in transfusion-associated adverse reactions and discusses the potential of the latest proteomics tools to be applied to the analysis of EVs in the field of transfusion medicine with a view to reducing the risk of blood transfusion.

Extracellular vesicles in tumor immunity: mechanisms and novel insights

Extracellular vesicles (EVs), nanoscale vesicles secreted by cells, have attracted considerable attention in recent years due to their role in tumor immunomodulation. These vesicles facilitate intercellular communication by transporting proteins, nucleic acids, and other biologically active substances, and they exhibit a dual role in tumor development and immune evasion mechanisms. Specifically, EVs can assist tumor cells in evading immune surveillance and attack by impairing immune cell function or modulating immunosuppressive pathways, thereby promoting tumor progression and metastasis. Conversely, they can also transport and release immunomodulatory factors that stimulate the activation and regulation of the immune system, enhancing the body's capacity to combat malignant diseases. This dual functionality of EVs presents promising avenues and targets for tumor immunotherapy. By examining the biological characteristics of EVs and their influence on tumor immunity, novel therapeutic strategies can be developed to improve the efficacy and relevance of cancer treatment. This review delineates the complex role of EVs in tumor immunomodulation and explores their potential implications for cancer therapeutic approaches, aiming to establish a theoretical foundation and provide practical insights for the advancement of future EVs-based cancer immunotherapy strategies.

Exosomes as a Therapeutic Strategy in Cancer: Potential Roles as Drug Carriers and Immune Modulators

Exosome-based cancer immunotherapy is advancing quickly on the concept of artificially activating the immune system to combat cancer. They can mechanistically change the tumor microenvironment, increase immune responses, and function as efficient drug delivery vehicles because of their inherent bioactivity, low toxicity, and immunogenicity. Accurate identification of the mechanisms of action of exosomes in tumor environments, along with optimization of their isolation, purification, and characterization methods, is necessary to increase clinical applications. Exosomes can be modified through cargo loading and surface modification to enhance their therapeutic applications, either before or after the donor cells' isolation. These engineered exosomes can directly target tumor cells at the tumor site or indirectly activate innate and adaptive immune responses in the tumor microenvironment. This approach is particularly effective when combined with traditional cancer immunotherapy techniques such as vaccines, immune checkpoints, and CAR-T cells. It can improve anti-tumor responses, induce long-term immunity, and address the limitations of traditional therapies, such as poor penetration in solid tumors and immunosuppressive environments. This review aims to provide a comprehensive and detailed overview of the direct role of engineered exosomes as drug delivery systems and their immunomodulatory effects on tumors as an indirect approach to fighting cancer. Additionally, it will discuss novel immunotherapy options.

Intercellular Epigenomic Signalling via Extracellular Vesicles During B Cell Maturation

B cell maturation is crucial for effective adaptive immunity. It requires a complex signalling network to mediate antibody diversification through mutagenesis. B cells also rely on queues from other cells within the germinal centre. Recently, a novel class of intercellular signals mediated by extracellular vesicles (EVs) has emerged. Studies have shown that B cell EV-mediated signalling is involved in immune response regulation and tumorigenesis. However, the mechanistic role of B cell EVs is not yet established. We herein study the biological properties and physiological function of B cell EVs during B cell maturation. We use emerging technologies to profile B cell EV surface marker signatures at the single particle level, molecular cargo and physiological roles in B cell maturation. EV ncRNA cargo, characterised by RNA-seq, identified an EV-mediated novel non-coding RNA (ncRNA) regulatory network for B cell maturation. We show that a previously uncharacterised micro-RNA (miR-5099) in combination with a set of long ncRNA are carried within B cell EVs and could contribute to antibody diversification. The physiological role of EVs in B cell maturation is investigated using EV blockade assays and complementation studies using diverse EV sources further confirmed the physiological role and mode of action of EVs in B cell maturation.

Magnetic Iron Oxide Nanoparticles Enhance Exosome Production by Upregulating Exosome Transport and Secretion Pathways

Exosomes are cell-released nanovesicles that regulate intercellular communication by transporting a variety of bioactive molecules. They play a crucial role in various physiological and pathological processes, such as the immune response, tissue regeneration, aging, and tumor progression. There has been growing interest in controlling exosome production, which could offer valuable tools for unraveling complex cell communication networks and enabling novel therapeutic applications. Magnetic iron oxide nanoparticles (MNPs), one of the few nanomaterials approved for clinical use, have been shown to remotely modulate cellular activities such as cytoskeleton reorganization, ion channel activation, and cell polarization. In this study, we systematically investigate the effects of MNPs, acting as nanoscale force transducers, on exosome production in two distinct cell types with different responses to mechanical stimuli. Our findings reveal that magnetic force applied to intracellular MNPs induces vesicle relocation and promotes the formation of actin stress fibers. Gene expression analysis further shows that intracellular magnetic force upregulates genes related to exosome transport and secretion as well as other pathways linked to exosome biogenesis. Notably, these forces substantially enhance exosome production, particularly MNP-containing exosomes, which are accompanied by increased intercellular exchange of MNPs. In summary, our study offers valuable insights into MNP-driven exosome production and presents potential strategies for enhancing cell communication and modulating nanoparticle distribution in nanomedicine.

Mechanisms of extracellular vesicle uptake and implications for the design of cancer therapeutics

The translation of pre-clinical anti-cancer therapies to regulatory approval has been promising, but slower than hoped. While innovative and effective treatments continue to achieve or seek approval, setbacks are often attributed to a lack of efficacy, failure to achieve clinical endpoints, and dose-limiting toxicities. Successful efforts have been characterized by the development of therapeutics designed to specifically deliver optimal and effective dosing to tumour cells while minimizing off-target toxicity. Much effort has been devoted to the rational design and application of synthetic nanoparticles to serve as targeted therapeutic delivery vehicles. Several challenges to the successful application of this modality as delivery vehicles include the induction of a protracted immune response that results in their rapid systemic clearance, manufacturing cost, lack of stability, and their biocompatibility. Extracellular vesicles (EVs) are a heterogeneous class of endogenous biologically produced lipid bilayer nanoparticles that mediate intercellular communication by carrying bioactive macromolecules capable of modifying cellular phenotypes to local and distant cells. By genetic, chemical, or metabolic methods, extracellular vesicles (EVs) can be engineered to display targeting moieties on their surface while transporting specific cargo to modulate pathological processes following uptake by target cell populations. This review will survey the types of EVs, their composition and cargoes, strategies employed to increase their targeting, uptake, and cargo release, and their potential as targeted anti-cancer therapeutic delivery vehicles.

Formin-like 1β phosphorylation at S1086 is necessary for secretory polarized traffic of exosomes at the immune synapse in Jurkat T lymphocytes

We analyzed here how formin-like 1 β (FMNL1β), an actin cytoskeleton-regulatory protein, regulates microtubule-organizing center (MTOC) and multivesicular bodies (MVB) polarization and exosome secretion at an immune synapse (IS) model in a phosphorylation-dependent manner. IS formation was associated with transient recruitment of FMNL1β to the IS, which was independent of protein kinase C δ (PKCδ). Simultaneous RNA interference of all FMNL1 isoforms prevented MTOC/MVB polarization and exosome secretion, which were restored by FMNL1βWT expression. However, expression of the non-phosphorylatable mutant FMNL1βS1086A did not restore neither MTOC/MVB polarization nor exosome secretion to control levels, supporting the crucial role of S1086 phosphorylation in MTOC/MVB polarization and exosome secretion. In contrast, the phosphomimetic mutant, FMNL1βS1086D, restored MTOC/MVB polarization and exosome secretion. Conversely, FMNL1βS1086D mutant did not recover the deficient MTOC/MVB polarization occurring in PKCδ-interfered clones, indicating that S1086 FMNL1β phosphorylation alone is not sufficient for MTOC/MVB polarization and exosome secretion. FMNL1 interference inhibited the depletion of F-actin at the central region of the immune synapse (cIS), which is necessary for MTOC/MVB polarization. FMNL1βWT and FMNL1βS1086D, but not FMNL1βS1086A expression, restored F-actin depletion at the cIS. Thus, actin cytoskeleton reorganization at the IS underlies the effects of all these FMNL1β variants on polarized secretory traffic. FMNL1 was found in the IS made by primary T lymphocytes, both in T cell receptor (TCR) and chimeric antigen receptor (CAR)-evoked synapses. Taken together, these results point out a crucial role of S1086 phosphorylation in FMNL1β activation, leading to cortical actin reorganization and subsequent control of MTOC/MVB polarization and exosome secretion.

Exosome-based nanoparticles and cancer immunotherapy

Over the past decades, cancer immunotherapy has encountered challenges such as immunogenicity, inefficiency, and cytotoxicity. Consequently, exosome-based cancer immunotherapy has gained rapid traction as a promising alternative. Exosomes, a type of extracellular vesicles (EVs) ranging from 50 to 150 nm, are self-originating and exhibit fewer side effects compared to traditional therapies. Exosome-based immunotherapy encompasses three significant areas: cancer vaccination, co-inhibitory checkpoints, and adoptive T-cell therapy. Each of these fields leverages the inherent advantages of exosomes, demonstrating substantial potential for individualized tumor therapy and precision medicine. This review aims to elucidate the reasons behind the promise of exosome-based nanoparticles as cancer therapies by examining their characteristics and summarizing the latest research advancements in cancer immunotherapy.

Chimeric antigen receptor (CAR) T-cell therapy: Harnessing extracellular vesicles for enhanced efficacy

A cutting-edge approach in cell-based immunotherapy for combating resistant cancer involves genetically engineered chimeric antigen receptor T (CAR-T) lymphocytes. In recent years, these therapies have demonstrated effectiveness, leading to their commercialization and clinical application against certain types of cancer. However, CAR-T therapy faces limitations, such as the immunosuppressive tumour microenvironment (TME) that can render CAR-T cells ineffective, and the adverse side effects of the therapy, including cytokine release syndrome (CRS). Extracellular vesicles (EVs) are a diverse group of membrane-bound particles released into the extracellular environment by virtually all cell types. They are essential for intercellular communication, transferring cargoes such as proteins, lipids, various types of RNAs, and DNA fragments to target cells, traversing biological barriers both locally and systemically. EVs play roles in numerous physiological processes, with those from both immune and non-immune cells capable of modulating the immune system through activation or suppression. Leveraging this capability of EVs to enhance CAR-T cell therapy could represent a significant advancement in overcoming its current limitations. This review examines the current landscape of CAR-T cell immunotherapy and explores the potential role of EVs in augmenting its therapeutic efficacy.

Harnessing exosomes as cancer biomarkers in clinical oncology

Exosomes are extracellular vesicles well known for facilitating cell-to-cell communication by distributing essential macromolecules like proteins, DNA, mRNA, lipids, and miRNA. These vesicles are abundant in fluids distributed throughout the body, including urine, blood, saliva, and even bile. They are important diagnostic tools for breast, lung, gastrointestinal cancers, etc. However, their application as cancer biomarkers has not yet been implemented in most parts of the world. In this review, we discuss how OMICs profiling of exosomes can be practiced by substituting traditional imaging or biopsy methods for cancer detection. Previous methods like extensive imaging and biopsy used for screening were expensive, mostly invasive, and could not easily provide early detection for various types of cancer. Exosomal biomarkers can be utilized for routine screening by simply collecting body fluids from the individual. We anticipate that the use of exosomes will be brought to light by the success of clinical trials investigating their potential to enhance cancer detection and treatment in the upcoming years.

B cells secrete functional antigen-specific IgG antibodies on extracellular vesicles

B cells and the antibodies they produce are critical in host defense against pathogens and contribute to various immune-mediated diseases. B cells responding to activating signals in vitro release extracellular vesicles (EV) that carry surface antibodies, yet B cell production of EVs that express antibodies and their function in vivo is incompletely understood. Using transgenic mice expressing the Cre recombinase in B cells switching to IgG1 to induce expression of fusion proteins between emerald green fluorescent protein (emGFP) and the EV tetraspanin CD63 as a model, we identify emGFP expression in B cells responding to foreign antigen in vivo and characterize the emGFP+ EVs they release. Our data suggests that emGFP+ germinal center B cells undergoing immunoglobulin class switching to express IgG and their progeny memory B cells and plasma cells, also emGFP+, are sources of circulating antigen-specific IgG+ EVs. Furthermore, using a mouse model of influenza virus infection, we find that IgG+ EVs specific for the influenza hemagglutinin antigen protect against virus infection. In addition, crossing the B cell Cre driver EV reporter mice onto the Nba2 lupus-prone strain revealed increased circulating emGFP+ EVs that expressed surface IgG against nuclear antigens linked to autoimmunity. These data identify EVs loaded with antibodies as a novel route for antibody secretion in B cells that contribute to adaptive immune responses, with important implications for different functions of IgG+ EVs in infection and autoimmunity.

CAR-T cell-derived exosomes: a new perspective for cancer therapy

Chimeric antigen receptor (CAR)-T cell adoptive immunotherapy is a promising cancer treatment that uses genetically engineered T cells to attack tumors. However, this therapy can have some adverse effects. CAR-T cell-derived exosomes are a potential alternative to CAR-T cells that may overcome some limitations. Exosomes are small vesicles released by cells and can carry a variety of molecules, including proteins, RNA, and DNA. They play an important role in intercellular communication and can be used to deliver therapeutic agents to cancer cells. The application of CAR-T cell-derived exosomes could make CAR-T cell therapy more clinically controllable and effective. Exosomes are cell-free, which means that they are less likely to cause adverse reactions than CAR-T cells. The combination of CAR-T cells and exosomes may be a more effective way to treat cancer than either therapy alone. Exosomes can deliver therapeutic agents to cancer cells where CAR-T cells cannot reach. The appropriate application of both cellular and exosomal platforms could make CAR-T cell therapy a more practicable treatment for cancer. This combination therapy could offer a safe and effective way to treat a variety of cancers.

Engineered dendritic cells-derived exosomes harboring HIV-1 Nefmut-Tat fusion protein and heat shock protein 70: A promising HIV-1 safe vaccine candidate

Antigen presenting cells (APCs)-derived exosomes are nano-vesicles that can induce antigen-specific T cell responses, and possess therapeutic effects in clinical settings. Moreover, dendritic cells (DCs)-based vaccines have been developed to combat human immunodeficiency virus-1 (HIV-1) infection in preclinical and clinical trials. We investigated the immunostimulatory effects (B- and T-cells activities) of DCs- and exosomes-based vaccine constructs harboring HIV-1 Nefmut-Tat fusion protein as an antigen candidate and heat shock protein 70 (Hsp70) as an adjuvant in mice. The modified DCs and engineered exosomes harboring Nefmut-Tat protein or Hsp70 were prepared using lentiviral vectors compared to electroporation, characterized and evaluated by in vitro and in vivo immunological tests. Our data indicated that the engineered exosomes induced high levels of total IgG, IgG2a, IFN-γ, TNF-α and Granzyme B. Moreover, co-injection of exosomes harboring Hsp70 could significantly increase the secretion of antibodies, cytokines and Granzyme B. The highest levels of IFN-γ and TNF-α were observed in exosomes harboring Nefmut-Tat combined with exosomes harboring Hsp70 (Exo-Nefmut-Tat + Exo-Hsp70) regimen after single-cycle replicable (SCR) HIV-1 exposure. Generally, Exo-Nefmut-Tat + Exo-Hsp70 regimen can be considered as a promising safe vaccine candidate due to high T-cells (Th1 and CTL) activity and its maintenance against SCR HIV-1 exposure.

Exosome-like Systems: From Therapies to Vaccination for Cancer Treatment and Prevention-Exploring the State of the Art

Cancer remains one of the main causes of death in the world due to its increasing incidence and treatment difficulties. Although significant progress has been made in this field, innovative approaches are needed to reduce tumor incidence, progression, and spread. In particular, the development of cancer vaccines is currently ongoing as both a preventive and therapeutic strategy. This concept is not new, but few vaccines have been approved in oncology. Antigen-based vaccination emerges as a promising strategy, leveraging specific tumor antigens to activate the immune system response. However, challenges persist in finding suitable delivery systems and antigen preparation methods. Exosomes (EXs) are highly heterogeneous bilayer vesicles that carry several molecule types in the extracellular space. The peculiarity is that they may be released from different cells and may be able to induce direct or indirect stimulation of the immune system. In particular, EX-based vaccines may cause an anti-tumor immune attack or produce memory cells recognizing cancer antigens and inhibiting disease development. This review delves into EX composition, biogenesis, and immune-modulating properties, exploring their role as a tool for prevention and therapy in solid tumors. Finally, we describe future research directions to optimize vaccine efficacy and realize the full potential of EX-based cancer immunotherapy.

Endolysosomal vesicles at the center of B cell activation

The endolysosomal system specializes in degrading cellular components and is crucial to maintaining homeostasis and adapting rapidly to metabolic and environmental cues. Cells of the immune system exploit this network to process antigens or promote cell death by secreting lysosome-related vesicles. In B lymphocytes, lysosomes are harnessed to facilitate the extraction of antigens and to promote their processing into peptides for presentation to T cells, critical steps to mount protective high-affinity antibody responses. Intriguingly, lysosomal vesicles are now considered important signaling units within cells and also display secretory functions by releasing their content to the extracellular space. In this review, we focus on how B cells use pathways involved in the intracellular trafficking, secretion, and function of endolysosomes to promote adaptive immune responses. A basic understanding of such mechanisms poses an interesting frontier for the development of therapeutic strategies in the context of cancer and autoimmune diseases.

The incorporation of extracellular vesicle markers varies among vesicles with distinct surface charges

Extracellular vesicles (EVs) are important mediators of intercellular communication. However, the methods available for distinguishing the heterogeneity of secreted EVs and isolating and purifying them are limited. This study introduced a HiBiT-tag to detect various EV markers, including CD63, CD9, Epidermal Growth Factor Receptor (EGFR), Flotilin1, and Syndecan-1, and investigated whether these marker-containing vesicles were capable of binding to differently charged column carriers. Four column carriers, Diethylaminoethyl (DEAE), Capto Adhere, Blue and Heparin, showed affinity for CD63 containing EVs, but their elution patterns varied. Furthermore, we observed that the elution patterns of the EV markers differed among vesicles with distinct surface charges when a DEAE column was used. This suggests that the incorporation of EV markers varied between these vesicles. The markers showed different subcellular localizations, indicating that the site of vesicle formation may contribute to the production of vesicles with varying charges and marker incorporation. These findings may have implications for the development of methods to purify homogeneous EVs, which could be useful in EV-mediated drug delivery systems.

Exosome-Mediated Impact on Systemic Metabolism

Exosomes are small extracellular vesicles that carry lipids, proteins, and microRNAs (miRNAs). They are released by all cell types and can be found not only in circulation but in many biological fluids. Exosomes are essential for interorgan communication because they can transfer their contents from donor to recipient cells, modulating cellular functions. The miRNA content of exosomes is responsible for most of their biological effects, and changes in exosomal miRNA levels can contribute to the progression or regression of metabolic diseases. As exosomal miRNAs are selectively sorted and packaged into exosomes, they can be useful as biomarkers for diagnosing diseases. The field of exosomes and metabolism is expanding rapidly, and researchers are consistently making new discoveries in this area. As a result, exosomes have great potential for a next-generation drug delivery platform for metabolic diseases.

Extracellular Vesicles in Flaviviridae Pathogenesis: Their Roles in Viral Transmission, Immune Evasion, and Inflammation

The members of the Flaviviridae family are becoming an emerging threat for public health, causing an increasing number of infections each year and requiring effective treatment. The consequences of these infections can be severe and include liver inflammation with subsequent carcinogenesis, endothelial damage with hemorrhage, neuroinflammation, and, in some cases, death. The mechanisms of Flaviviridae pathogenesis are being actively investigated, but there are still many gaps in their understanding. Extracellular vesicles may play important roles in these mechanisms, and, therefore, this topic deserves detailed research. Recent data have revealed the involvement of extracellular vesicles in steps of Flaviviridae pathogenesis such as transmission, immune evasion, and inflammation, which is critical for disease establishment. This review covers recent papers on the roles of extracellular vesicles in the pathogenesis of Flaviviridae and includes examples of clinical applications of the accumulated data.

Recent Progress in Prompt Molecular Detection of Exosomes Using CRISPR/Cas and Microfluidic-Assisted Approaches Toward Smart Cancer Diagnosis and Analysis

Exosomes are essential indicators of molecular mechanisms involved in interacting with cancer cells and the tumor environment. As nanostructures based on lipids and nucleic acids, exosomes provide a communication pathway for information transfer by transporting biomolecules from the target cell to other cells. Importantly, these extracellular vesicles are released into the bloodstream by the most invasive cells, i. e., cancer cells; in this way, they could be considered a promising specific biomarker for cancer diagnosis. In this matter, CRISPR-Cas systems and microfluidic approaches could be considered practical tools for cancer diagnosis and understanding cancer biology. CRISPR-Cas systems, as a genome editing approach, provide a way to inactivate or even remove a target gene from the cell without affecting intracellular mechanisms. These practical systems provide vital information about the factors involved in cancer development that could lead to more effective cancer treatment. Meanwhile, microfluidic approaches can also significantly benefit cancer research due to their proper sensitivity, high throughput, low material consumption, low cost, and advanced spatial and temporal control. Thereby, employing CRISPR-Cas- and microfluidics-based approaches toward exosome monitoring could be considered a valuable source of information for cancer therapy and diagnosis. This review assesses the recent progress in these promising diagnosis approaches toward accurate cancer therapy and in-depth study of cancer cell behavior.

Haematopoietic cell-derived exosomes in cancer development and therapeutics: From basic science to clinical practice

BACKGROUND

The tumour microenvironment (TME) is a specialised niche involving intercellular communication among cancer cells and various host cells. Among the host cells, the quantity and quality of immune cells within the TME play essential roles in cancer development and management. The immunologically suppressive, so-called 'cold' TME established by a series of tumour-host interactions, including generating immunosuppressive cytokines and recruiting regulatory host immune cells, is associated with resistance to therapies and worse clinical outcomes.

MAIN BODY

Various therapeutic approaches have been used to target the cold TME, including immune checkpoint blockade therapy and adoptive T-cell transfer. A promising, less explored therapeutic strategy involves targeting TME-associated exosomes. Exosomes are nanometer-sized, extracellular vesicles that transfer material from donor to recipient cells. These particles can reprogram the recipient cells and modulate the TME. In particular, exosomes from haematopoietic cells are known to promote or suppress cancer progression under specific conditions. Understanding the effects of haematopoietic cell-secreted exosomes may foster the development of therapeutic exosomes (tExos) for personalised cancer treatment. However, the development of exosome-based therapies has unique challenges, including scalable production, purification, storage and delivery of exosomes and controlling batch variations. Clinical trials are being conducted to verify the safety, feasibility, availability and efficacy of tExos.

CONCLUSION

This review summarises our understanding of how haematopoietic cell-secreted exosomes regulate the TME and antitumour immunity and highlights present challenges and solutions for haematopoietic cell-derived exosome-based therapies.

Trick-or-Trap: Extracellular Vesicles and Viral Transmission

Extracellular vesicles (EVs) are lipid membrane-enclosed particles produced by most cells, playing important roles in various biological processes. They have been shown to be involved in antiviral mechanisms such as transporting antiviral molecules, transmitting viral resistance, and participating in antigen presentation. While viral transmission was traditionally thought to occur through independent viral particles, the process of viral infection is complex, with multiple barriers and challenges that viruses must overcome for successful infection. As a result, viruses exploit the intercellular communication pathways of EVs to facilitate cluster transmission, increasing their chances of infecting target cells. Viral vesicle transmission offers two significant advantages. Firstly, it enables the collective transmission of viral genomes, increasing the chances of infection and promoting interactions between viruses in subsequent generations. Secondly, the use of vesicles as vehicles for viral transmission provides protection to viral particles against environmental factors, while also expanding the cell tropism allowing viruses to reach cells in a receptor-independent manner. Understanding the role of EVs in viral transmission is crucial for comprehending virus evolution and developing innovative antiviral strategies, therapeutic interventions, and vaccine approaches.

The proteome and phosphoproteome of circulating extracellular vesicle-enriched preparations are associated with characteristic clinical features in type 1 diabetes

Introduction

There are no validated clinical or laboratory biomarkers to identify and differentiate endotypes of type 1 diabetes (T1D) or the risk of progression to chronic complications. Extracellular vesicles (EVs) have been studied as biomarkers in several different disease states but have not been well studied in T1D.

Methods

As the initial step towards circulating biomarker identification in T1D, this pilot study aimed to provide an initial characterization of the proteomic and phosphoproteomic landscape of circulating EV-enriched preparations in participants with established T1D (N=10) and healthy normal volunteers (Controls) (N=7) (NCT03379792) carefully matched by age, race/ethnicity, sex, and BMI. EV-enriched preparations were obtained using EVtrap® technology. Proteins were identified and quantified by LC-MS analysis. Differential abundance and coexpression network (WGCNA), and pathway enrichment analyses were implemented.

Results

The detected proteins and phosphoproteins were enriched (75%) in exosomal proteins cataloged in the ExoCarta database. A total of 181 proteins and 8 phosphoproteins were differentially abundant in participants with T1D compared to controls, including some well-known EVproteins (i.e., CD63, RAB14, BSG, LAMP2, and EZR). Enrichment analyses of differentially abundant proteins and phosphoproteins of EV-enriched preparations identified associations with neutrophil, platelet, and immune response functions, as well as prion protein aggregation. Downregulated proteins were involved in MHC class II signaling and the regulation of monocyte differentiation. Potential key roles in T1D for C1q, plasminogen, IL6ST, CD40, HLA-DQB1, HLA-DRB1, CD74, NUCB1, and SAP, are highlighted. Remarkably, WGCNA uncovered two protein modules significantly associated with pancreas size, which may be implicated in the pathogenesis of T1D. Similarly, these modules showed significant enrichment for membrane compartments, processes associated with inflammation and the immune response, and regulation of viral processes, among others.

Discussion

This study demonstrates the potential of proteomic and phosphoproteomic signatures of EV-enriched preparations to provide insight into the pathobiology of T1D. The WGCNA analysis could be a powerful tool to discriminate signatures associated with different pathobiological components of the disease.

An update on stem cell and stem cell-derived extracellular vesicle-based therapy in the management of Alzheimer's disease

Globally, neurological diseases pose a major burden to healthcare professionals in terms of the management and prevention of the disorder. Among neurological diseases, Alzheimer's disease (AD) accounts for 50%-70% of dementia and is the fifth leading cause of mortality worldwide. AD is a progressive, degenerative neurological disease, with the loss of neurons and synapses in the cerebral cortex and subcortical regions. The management of AD remains a debate among physicians as no standard and specific "disease-modifying" modality is available. The concept of 'Regenerative Medicine' is aimed at regenerating the degenerated neural tissues to reverse the pathology in AD. Genetically modified engineered stem cells modify the course of AD after transplantation into the brain. Extracellular vesicles (EVs) are an emerging new approach in cell communication that involves the transfer of cellular materials from parental cells to recipient cells, resulting in changes at the molecular and signaling levels in the recipient cells. EVs are a type of vesicle that can be transported between cells. Many have proposed that EVs produced from mesenchymal stem cells (MSCs) may have therapeutic promise in the treatment of AD. The biology of AD, as well as the potential applications of stem cells and their derived EVs-based therapy, were explored in this paper.

Context-specific regulation of extracellular vesicle biogenesis and cargo selection

To coordinate, adapt and respond to biological signals, cells convey specific messages to other cells. An important aspect of cell-cell communication involves secretion of molecules into the extracellular space. How these molecules are selected for secretion has been a fundamental question in the membrane trafficking field for decades. Recently, extracellular vesicles (EVs) have been recognized as key players in intercellular communication, carrying not only membrane proteins and lipids but also RNAs, cytosolic proteins and other signalling molecules to recipient cells. To communicate the right message, it is essential to sort cargoes into EVs in a regulated and context-specific manner. In recent years, a wealth of lipidomic, proteomic and RNA sequencing studies have revealed that EV cargo composition differs depending upon the donor cell type, metabolic cues and disease states. Analyses of distinct cargo 'fingerprints' have uncovered mechanistic linkages between the activation of specific molecular pathways and cargo sorting. In addition, cell biology studies are beginning to reveal novel biogenesis mechanisms regulated by cellular context. Here, we review context-specific mechanisms of EV biogenesis and cargo sorting, focusing on how cell signalling and cell state influence which cellular components are ultimately targeted to EVs.

Revolutionizing anti-tumor therapy: unleashing the potential of B cell-derived exosomes

B cells occupy a vital role in the functioning of the immune system, working in tandem with T cells to either suppress or promote tumor growth within the tumor microenvironment(TME). In addition to direct cell-to-cell communication, B cells and other cells release exosomes, small membrane vesicles ranging in size from 30-150 nm, that facilitate intercellular signaling. Exosome research is an important development in cancer research, as they have been shown to carry various molecules such as major histocompatibility complex(MHC) molecules and integrins, which regulate the TME. Given the close association between TME and cancer development, targeting substances within the TME has emerged as a promising strategy for cancer therapy. This review aims to present a comprehensive overview of the contributions made by B cells and exosomes to the tumor microenvironment (TME). Additionally, we delve into the potential role of B cell-derived exosomes in the progression of cancer.

Extracellular vesicles as next generation immunotherapeutics

Extracellular vesicles (EVs) function as a mode of intercellular communication and molecular transfer to elicit diverse biological/functional response. Accumulating evidence has highlighted that EVs from immune, tumour, stromal cells and even bacteria and parasites mediate the communication of various immune cell types to dynamically regulate host immune response. EVs have an innate capacity to evade recognition, transport and transfer functional components to target cells, with subsequent removal by the immune system, where the immunological activities of EVs impact immunoregulation including modulation of antigen presentation and cross-dressing, immune activation, immune suppression, and immune surveillance, impacting the tumour immune microenvironment. In this review, we outline the recent progress of EVs in immunorecognition and therapeutic intervention in cancer, including vaccine and targeted drug delivery and summarise their utility towards clinical translation. We highlight the strategies where EVs (natural and engineered) are being employed as a therapeutic approach for immunogenicity, tumoricidal function, and vaccine development, termed immuno-EVs. With seminal studies providing significant progress in the sequential development of engineered EVs as therapeutic anti-tumour platforms, we now require direct assessment to tune and improve the efficacy of resulting immune responses - essential in their translation into the clinic. We believe such a review could strengthen our understanding of the progress in EV immunobiology and facilitate advances in engineering EVs for the development of novel EV-based immunotherapeutics as a platform for cancer treatment.

The role of extracellular vesicles in cancer

Intercellular communication is a key feature of cancer progression and metastasis. Extracellular vesicles (EVs) are generated by all cells, including cancer cells, and recent studies have identified EVs as key mediators of cell-cell communication via packaging and transfer of bioactive constituents to impact the biology and function of cancer cells and cells of the tumor microenvironment. Here, we review recent advances in understanding the functional contribution of EVs to cancer progression and metastasis, as cancer biomarkers, and the development of cancer therapeutics.

Extracellular Vesicles in Breast Cancer: From Biology and Function to Clinical Diagnosis and Therapeutic Management

Breast cancer (BC) is the first worldwide most frequent cancer in both sexes and the most commonly diagnosed in females. Although BC mortality has been thoroughly declining over the past decades, there are still considerable differences between women diagnosed with early BC and when metastatic BC is diagnosed. BC treatment choice is widely dependent on precise histological and molecular characterization. However, recurrence or distant metastasis still occurs even with the most recent efficient therapies. Thus, a better understanding of the different factors underlying tumor escape is mainly mandatory. Among the leading candidates is the continuous interplay between tumor cells and their microenvironment, where extracellular vesicles play a significant role. Among extracellular vesicles, smaller ones, also called exosomes, can carry biomolecules, such as lipids, proteins, and nucleic acids, and generate signal transmission through an intercellular transfer of their content. This mechanism allows tumor cells to recruit and modify the adjacent and systemic microenvironment to support further invasion and dissemination. By reciprocity, stromal cells can also use exosomes to profoundly modify tumor cell behavior. This review intends to cover the most recent literature on the role of extracellular vesicle production in normal and cancerous breast tissues. Specific attention is paid to the use of extracellular vesicles for early BC diagnosis, follow-up, and prognosis because exosomes are actually under the spotlight of researchers as a high-potential source of liquid biopsies. Extracellular vesicles in BC treatment as new targets for therapy or efficient nanovectors to drive drug delivery are also summarized.

Dendritic cell-derived exosomes: A new horizon in personalized cancer immunotherapy?

Dendritic cells (DCs) release nanometer-sized membrane vesicles known as dexosomes, containing different molecules, particularly proteins, for presenting antigens, i.e., major histocompatibility complex (MHC)-I/II and CD86. Dexosomes can, directly and indirectly, stimulate antigen-reactive CD8⁺ and CD4⁺ T cell responses. Antigen-loaded dexosomes can lead to the development of potent anti-tumoral immune responses. Notably, developing dexosome-based cell-free vaccines could serve as a new vaccination platform in the era of immunotherapy for various cancers. Furthermore, combining dexosomes vaccination strategies with other treatment approaches can considerably increase tumor-specific T cell responses. Herein, we aimed to review how dexosomes interact with immune cells, e.g., CD4⁺ and CD8⁺ T cells and natural killer (NK) cells. Besides, we discussed the limitations of this approach and suggested potential strategies to improve its effectiveness for affected patients.

Extracellular vesicles are conduits for E. coli heat-labile enterotoxin (LT) and the B-subunits of LT and cholera toxin in immune cell-to-cell communication

Several pathogens excrete their toxins either directly into the host or through extracellular vesicles. Enterotoxigenic E. coli is capable of secreting heat-labile toxin LT in extracellular vesicles (EVs) which are delivered to mammalian cells. LT and its B-subunit, LTB, and their structurally and functionally related toxin from Vibrio cholerae, CT and CTB, are potent immunogens and adjuvants. However, despite their reported remarkable effects on immune cells, the mechanisms by which they mediate their immunological properties are still unclear. We show that B cells incubated with LT or LTB secreted EVs in the cell culture medium. However, compared to unstimulated cells, EVs and their internal protein content were significantly reduced in recipient B cells. Analysis of protein markers of the vesicles secreted by B cells were found to be enriched in exosomes of endosomal origin. B cells incubated with FITC-CTB secreted CTB in EVs which were taken up by recipient B and T cells. FITC-CTB transfected into exosomes from mouse dendritic cells were also taken up by recipient B cells. Moreover, B cells incubated with FITC-CTB secreted CTB in EVs which increased the number of recipient B cells expressing higher levels of CD25 and CD86. These results suggest that EVs from B cells are conduits for the enterotoxins, and play an important role in the enterotoxins immune cell-to-cell communication. This is the first report which looked at EVs as a mean to deliver these proteins from and to immune cells.

Extracellular vesicles as a novel approach for breast cancer therapeutics

Breast cancer (BC) still lacks effective management approaches to control metastatic and therapy-resistant disease. Extracellular vesicles (EVs), with a diameter of 50-1000 nm, are secreted by all types of living cells, are protected by a lipid bilayer and encapsulate biological cargos including RNAs, proteins and lipids. They play an important role in intercellular communications and are significantly associated with pathological conditions. Accumulating evidence indicates that cancer cells secrete EVs and communicate with neighboring cells within the tumor microenvironment (TME), which plays an important role in BC metastasis, immune escape and chemoresistance, thus providing a new therapeutic window. EVs can stimulate angiogenesis and extracellular matrix remodeling, establish premetastatic niches, inhibit immune response and promote cancer metastasis. Recent advances have demonstrated that EVs are a potential therapeutic target or carrier and have emerged as promising strategies for BC treatment. In this review, we summarize the role of EVs in BC metastasis, chemoresistance and immune escape, which provides the foundation for developing novel therapeutic approaches. We also focus on current EV-based drug delivery strategies in BC and EV cargo-targeted BC therapy and discuss the limitations and future perspectives of EV-based drug delivery in BC.

Exosomes: The Role in Tumor Tolerance and the Potential Strategy for Tumor Therapy

Drug and radiotherapy resistance is the primary cause of treatment failure and poor prognosis in patients with tumors. Exosomes are extracellular vesicles loaded with substances such as nucleic acids, lipids, and proteins that transmit information between cells. Studies have found that exosomes are involved in tumor therapy resistance through drug efflux, promotion of drug resistance phenotypes, delivery of drug-resistance-related molecules, and regulation of anti-tumor immune responses. Based on their low immunogenicity and high biocompatibility, exosomes have been shown to reduce tumor therapy resistance by loading nucleic acids, proteins, and drugs inside xosomes or expressing tumor-specific antigens, target peptides, and monoclonal antibodies on their phospholipid bimolecular membranes. Consequently, future research on genetically engineered exosomes is expected to eliminate resistance to tumor treatment, improving the overall prognosis of patients with tumors.

Exosomes Derived from Immune Cells: The New Role of Tumor Immune Microenvironment and Tumor Therapy

Exosomes are small vesicles secreted by living cells, with a typical lipid bilayer structure. They carry a variety of proteins, lipids, RNA and other important information, play an important role in the transmission of substances and information between cells, and gradually become a marker for early diagnosis of many diseases and an important tool in drug delivery system. Immune cells are an important part of tumor microenvironment, and they can affect tumor progression by secreting a variety of immunoreactive substances. This review focuses on the effects of various immune cell-derived exosomes on tumor cells, different immune cells and other stromal cells in tumor microenvironment. Exosomes derived from different immune cells can not only reshape a pro-inflammatory microenvironment to inhibit tumor progression, but also promote tumor progression by inhibiting the killing effect of NK cells, CD8⁺T cells and other cells or promoting tumor cells and immunosuppressive immune cells. In addition, we also discussed that some exosomes derived from immune cells (such as DC, M1 macrophages and neutrophils) play a tumor inhibitory role after being engineered.

Extracellular signals regulate the biogenesis of extracellular vesicles

Extracellular vesicles (EVs) are naturally released membrane vesicles that act as carriers of proteins and RNAs for intercellular communication. With various biomolecules and specific ligands, EV has represented a novel form of information transfer, which possesses extremely outstanding efficiency and specificity compared to the classical signal transduction. In addition, EV has extended the concept of signal transduction to intercellular aspect by working as the collection of extracellular information. Therefore, the functions of EVs have been extensively characterized and EVs exhibit an exciting prospect for clinical applications. However, the biogenesis of EVs and, in particular, the regulation of this process by extracellular signals, which are essential to conduct further studies and support optimal utility, remain unclear. Here, we review the current understanding of the biogenesis of EVs, focus on the regulation of this process by extracellular signals and discuss their therapeutic value.

Engineered Extracellular Vesicles in Treatment of Type 1 Diabetes Mellitus: A Prospective Review

Insulin replacement is an available treatment for autoimmune type 1 diabetes mellitus (T1DM). There are multiple limitations in the treatment of autoimmune diseases such as T1DM by immunosuppression using drugs and chemicals. The advent of extracellular vesicle (EV)-based therapies for the treatment of various diseases has attracted much attention to the field of bio-nanomedicine. Tolerogenic nanoparticles can induce immune tolerance, especially in autoimmune diseases. EVs can deliver cargo to specific cells without restrictions. Accordingly, EVs can be used to deliver tolerogenic nanoparticles, including iron oxide-peptide-major histocompatibility complex, polyethylene glycol-silver-2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester, and carboxylated poly (lactic-co-glycolic acid) nanoparticles coupled with or encapsulating an antigen, to effectively treat autoimmune T1DM. The present work highlights the advances in exosome-based delivery of tolerogenic nanoparticles for the treatment of autoimmune T1DM.

Immunomodulatory effects of extracellular vesicles in glioblastoma

Glioblastoma (GB) is a type of brain cancer that can be considered aggressive. Glioblastoma treatment has significant challenges due to the immune privilege site of the brain and the presentation of an immunosuppressive tumor microenvironment. Extracellular vesicles (EVs) are cell-secreted nanosized vesicles that engage in intercellular communication via delivery of cargo that may cause downstream effects such as tumor progression and recipient cell modulation. Although the roles of extracellular vesicles in cancer progression are well documented, their immunomodulatory effects are less defined. Herein, we focus on glioblastoma and explain the immunomodulatory effects of extracellular vesicles secreted by both tumor and immune cells in detail. The tumor to immune cells, immune cells to the tumor, and intra-immune cells extracellular vesicles crosstalks are involved in various immunomodulatory effects. This includes the promotion of immunosuppressive phenotypes, apoptosis, and inactivation of immune cell subtypes, which affects the central nervous system and peripheral immune system response, aiding in its survival and progression in the brain.

Potential Application of Exosomes in Vaccine Development and Delivery

Exosomes are cell-derived components composed of proteins, lipid, genetic information, cytokines, and growth factors. They play a vital role in immune modulation, cell-cell communication, and response to inflammation. Immune modulation has downstream effects on the regeneration of damaged tissue, promoting survival and repair of damaged resident cells, and promoting the tumor microenvironment via growth factors, antigens, and signaling molecules. On top of carrying biological messengers like mRNAs, miRNAs, fragmented DNA, disease antigens, and proteins, exosomes modulate internal cell environments that promote downstream cell signaling pathways to facilitate different disease progression and induce anti-tumoral effects. In this review, we have summarized how vaccines modulate our immune response in the context of cancer and infectious diseases and the potential of exosomes as vaccine delivery vehicles. Both pre-clinical and clinical studies show that exosomes play a decisive role in processes like angiogenesis, prognosis, tumor growth metastasis, stromal cell activation, intercellular communication, maintaining cellular and systematic homeostasis, and antigen-specific T- and B cell responses. This critical review summarizes the advancement of exosome based vaccine development and delivery, and this comprehensive review can be used as a valuable reference for the broader delivery science community.

Targeting Endocytosis and Cell Communications in the Tumor Immune Microenvironment

The existence of multiple endocytic pathways is well known, and their exact biological effects in tumors have been intensively investigated. Endocytosis can affect the connection between tumor cells and determine the fate of tumor cells. Many relationships between endocytosis and tumor cells have been elucidated, but the mechanism of endocytosis between different types of cells in tumors needs to be explored in greater depth. Endocytic receptors sense the environment and are induced by specific ligands to trigger communication between tumor and immune cells. Crosstalk in the tumor microenvironment can occur through direct contact between cell adhesion molecules or indirectly through exosomes. So a better understanding of the endocytic pathways that control cell adhesion molecules and function is expected to lead to new candidates for cancer treatment. In additional, tumor-derived exosomes may changes immune cell function, which may be a key role for tumors to evade immune detection and response. The overall understanding of exosomes through endocytosis is also expected to bring new candidates for therapeutic regulation of tumor immune microenvironment. In this case, endocytic pathways coordinate cell adhesion molecules and exosomes and can be used as targets in the tumor immune microenvironment for cancer treatment.

Understanding the extracellular vesicle surface for clinical molecular biology

Extracellular vesicles (EVs) are lipid-membrane enclosed nanoparticles that play significant roles in health and disease. EVs are abundant in body fluids and carry an array of molecules (proteins, lipids, nucleic acids and glycans) that reflect the identity and activity of their cell-of-origin. While the advent of high throughput omics technologies has allowed in-depth characterisation of EV compositions, how these molecular species are spatially distributed within EV structures is not well appreciated. This is particularly true of the EV surface where a plethora of molecules are reported to be both integral and peripherally associated to the EV membrane. This coronal layer or 'atmosphere' that surrounds the EV membrane contributes to a large, highly interactive and dynamic surface area that is responsible for facilitating EV interactions with the extracellular environment. The EV coronal layer harbours surface molecules that reflect the identity of parent cells, which is likely a highly valuable property in the context of diagnostic liquid biopsies. In this review, we describe the current understanding of the mechanical, electrostatic and molecular properties of the EV surface that offer significant biomarker potential and contribute to a highly dynamic interactome.

The roles of small extracellular vesicles in cancer and immune regulation and translational potential in cancer therapy

Extracellular vesicles (EVs) facilitate the extracellular transfer of proteins, lipids, and nucleic acids and mediate intercellular communication among multiple cells in the tumour environment. Small extracellular vesicles (sEVs) are defined as EVs range in diameter from approximately 50 to 150 nm. Tumour-derived sEVs (TDsEVs) and immune cell-derived sEVs have significant immunological activities and participate in cancer progression and immune responses. Cancer-specific molecules have been identified on TDsEVs and can function as biomarkers for cancer diagnosis and prognosis, as well as allergens for TDsEVs-based vaccination. Various monocytes, including but not limited to dendritic cells (DCs), B cells, T cells, natural killer (NK) cells, macrophages, and myeloid-derived suppressor cells (MDSCs), secrete sEVs that regulate immune responses in the complex immune network with either protumour or antitumour effects. After engineered modification, sEVs from immune cells and other donor cells can provide improved targeting and biological effects. Combined with their naïve characteristics, these engineered sEVs hold great potential as drug carriers. When used in a variety of cancer therapies, they can adjunctly enhance the safety and antitumor efficacy of multiple therapeutics. In summary, both naïve sEVs in the tumour environment and engineered sEVs with effector cargoes are regarded as showing promising potential for use in cancer diagnostics and therapeutics.

Exosomes carrying immune checkpoints, a promising therapeutic approach in cancer treatment

Exosomes are a subgroup of extracellular vesicles generated by distinct cells. Tumor-derived extracellular vesicles convey immunological checkpoint molecules. TEXs as critical mediators in tumor development, metastasis, and immune escape have recently become the focus of scientific research. Exosomes are involved in the regulation of the immune system. Exosomes interact with target cells in the tumor microenvironment, changing their function based on the cargo they contain. Exosomal immune checkpoints might be exploited to track tumor immune evasion, treatment response, and patient prognosis while enhancing tumor cell proliferation and spread. This review focuses on tumor-derived exosomes, their immunosuppressive effects in mice models, and their role in cancer immunotherapy. Exosomes are being studied as possible cancer vaccines, with numerous uses in tumor immunotherapy. Exosomes can carry chemotherapeutics, siRNA, and monoclonal antibodies. Exosomes produced by macrophages might be used to treat cancer. These and other clinical consequences provide new doors for cancer treatment.

Multimodal Repair of Spinal Cord Injury With Mesenchymal Stem Cells

Spinal cord injury (SCI) is a result of a devastating injury to the central nervous system. Currently, there is no effective treatment available for these patients. The possible use of mesenchymal stem cell (MSC)-based treatment for SCI has been the focus of extensive investigations and is increasingly moving from the bench to bedside. Both experimental observations and clinical studies have shown the safety and efficacy of MSCs in managing SCI. However, the exact mechanism by which MSCs contribute to the repair of the injured spinal cord remains to be elucidated. In this review, we aim to summarize current research findings about the role of MSCs in improving complex pathology after SCI. MSCs exert a multimodal repair mechanism targeting multiple events in the secondary injury cascade. Our recent results showing the perineurium-like differentiation of surviving MSCs in the injured spinal cord may further the understanding of the fate of transplanted MSCs. These findings provide fundamental support for the clinical use of MSCs in SCI patients. Under experimental conditions, combining novel physical, chemical, and biological approaches led to significant improvements in the therapeutic efficacy of MSCs. These findings hold promise for the future of cell-based clinical treatment of SCI.

Extracellular RNAs from immune cells under obesity-a narrative review

BACKGROUND AND OBJECTIVE

Obesity affects hundreds of millions of people worldwide and is characterized by chronic inflammation and insulin resistance, leading to Type II diabetes and atherosclerotic cardiovascular disease. Extracellular RNAs (exRNAs) are among the components which effect immune actions under obese conditions, and technological advances in recent years have rapidly increased our understanding of their roles and functions. Here we review essential background information on exRNAs and vesicles as well as the impact of immune-derived exRNAs in obesity-related disease. We also offer perspectives on clinical applications of exRNAs and future research directions.

METHODS

We searched PubMed for articles relevant to immune-derived exRNAs in obesity. Articles written in English and published prior to May 25, 2022 were included.

KEY CONTENT AND FINDINGS

We report findings on the roles of immune-derived exRNAs which are important in obesity-related disease. We also highlight several exRNAs derived from other cell lineages which act on immune cells in metabolic disease.

CONCLUSIONS

ExRNAs produced by immune cells have profound local and systemic effects under obese conditions and can impact metabolic disease phenotypes. Immune-derived exRNAs represent an important target for future research and therapy.

Role of exosomes in lung cancer: A comprehensive insight from immunomodulation to theragnostic applications

Exosomes are 30 to 150 nm-diameter lipid bilayer-enclosed extracellular vesicles that enable cell-to-cell communication through secretion and uptake. The exosomal cargoes contain RNA, lipids, proteins, and metabolites which can be delivered to recipient cells in vivo. In a healthy lung, exosomes facilitate interaction between adaptive and innate immunity and help maintain normal lung physiology. However, tumor-derived exosomes in lung cancer (LC) can, on the other hand, restrict immune cell proliferation, cause apoptosis in activated CD8+ T effector cells, reduce natural killer cell activity, obstruct monocyte differentiation, and promote proliferation of myeloid-derived suppressor and regulatory T cells. In addition, exosomes in the tumor microenvironment may also play a critical role in cancer progression and the development of drug resistance. In this review, we aim to comprehensively examine the current updates on the role of exosomes in lung carcinogenesis and their potential application as a diagnostic, prognostic, and therapeutic tool in lung cancer.

Recent progress of dendritic cell-derived exosomes (Dex) as an anti-cancer nanovaccine

Although cancer vaccines such as dendritic cell (DC) vaccines and peptide vaccines have become appealing and attractive anticancer immunotherapy options in recent decades, some obstacles have hindered their successful application in the clinical setting. The difficulties associated with the high cost of DC preparation, storage of DC vaccines, tumor-mediated immunosuppressive environment, identification of specific tumor antigens, and high degradation of antigen peptides in vivo limit the clinical application and affect the outcomes of these cancer vaccines. Recently, nanocarriers have been considered as a new approach for vaccine delivery. As biogenic nanocarriers, exosomes are small membrane vesicles secreted by cells that carry various proteins, RNAs, and lipids. More importantly, DC-derived exosomes (Dex) express tumor antigens, MHC molecules, and co-stimulatory molecules on their surface, which trigger the release of antigen-specific CD4⁺ and CD8⁺ T cells. With their membrane structure, Dex can avoid high degradation while ensuring favorable biocompatibility and biosafety in vivo. In addition, Dex can be stored in vitro for a longer period, which facilitates a significant reduction in production costs. Furthermore, they have shown better antitumor efficacy in preclinical studies compared with DC vaccines owing to their higher immunogenicity and stronger resistance to immunosuppressive effects. However, the clinical efficacy of Dex vaccines remains limited. In this review, we aimed to evaluate the efficacy of Dex as an anticancer nanovaccine.

Exosomes: Biogenesis, targeting, characterisation and their potential as 'Plug & Play' vaccine platforms

Exosomes are typically characterized as spherical extracellular vesicles less than 150 nm in diameter that have been released into the extracellular environment via fusion of multivesicular bodies (MVBs) to the plasma membrane. Exosomes play a key role in cell-cell communication, vary widely in their composition and potential cargo, and are reportedly involved in processes as diverse as angiogenesis, apoptosis, antigen presentation, inflammation, receptor-mediated endocytosis, cell proliferation, and differentiation, and cell-signaling. Exosomes can also act as biomarkers of health and disease and have enormous potential use as therapeutic agents. Despite this, the understanding of how exosome biogenesis can be utilized to generate exosomes carrying specific targets for particular therapeutic uses, their manufacture, detailed analytical characterization, and methods of application are yet to be fully harnessed. In this review, we describe the current understanding of these areas of exosome biology from a biotechnology and bioprocessing aspect, but also highlight the challenges that remain to be overcome to fully harness the power of exosomes as therapeutic agents, with a particular focus on their use and application as vaccine platforms. This article is protected by copyright. All rights reserved.

Proteomic profiling of serum small extracellular vesicles reveals immune signatures of children with pneumonia

BACKGROUND

Pneumonia is the leading cause of death in young children globally. However, the underlying pathological mechanism of pediatric pneumonia remains unclear. In infection disease contexts, small extracellular vesicles (sEVs) have been shown to be a useful source of markers for pathogenesis and immune response. We hypothesized that functional molecules such as protein harbored by sEVs would provide mechanistic insights into the immune response in children with pneumonia.

METHODS

We isolated sEVs from serum collected from children with and without pneumonia, performed proteomic analysis of the sEVs with label-free mass spectrometry, and then conducted functional enrichment analysis of proteomic data.

RESULTS

We identified fifteen differentially expressed proteins and ten unique proteins in children with pneumonia as compared to healthy children. In the pneumonia group, immune-related processes and pathways were positively enriched as upregulated proteins were involved in neutrophil activation, complement regulation, defense against bacteria, humoral immune response and regulation of immune effector processes However, pathways associated with tissue development and extracellular matrix remodeling were negatively enriched, as downregulated proteins were linked to extracellular matrix structure and cell adhesions.

CONCLUSIONS

Our findings provided insights into host responses to pathogen infection, which has contributed to understanding the pathogenesis of children with pneumonia. Furthermore, our studies suggested that serum sEVs proteins could be considered a potential source of biomarkers for diagnosing pediatric pneumonia.

Research Progress in the Application of Exosomes in Immunotherapy

Exosomes are nanoscale extracellular vesicles (EVs), which are present in all body fluids tested. They are secreted by a variety of cells including macrophages, dendritic cells, mast cells, granulocytes, lymphocytes, and tumor cells. Exosomes secreted by different cells have different biological components and functional characteristics and play an important role in many pathophysiological activities. Recent studies have revealed that exosomes can regulate the occurrence and development of inflammatory immune diseases and tumors by transmitting their unique proteins, lipids, and nucleic acids as signaling molecules to other cells. Exosomes serve as a novel class of diagnostic biomarkers and drug delivery systems with promising applications in immunotherapy, particularly because breakthroughs in nanotechnology have led to the development and exploration of engineered exosomes for immunotargeted therapies. Therefore, here we review the progress being made on the application of exosomes in immunotherapy and its multiple regulatory mechanisms and explore the potential application of exosomes in immunotherapy in the future.

Extracellular vesicles as natural therapeutic agents and innate drug delivery systems for cancer treatment: Recent advances, current obstacles, and challenges for clinical translation

As cancer poses a significant threat to the well-being of humans on a global scale, many researchers have embarked on the search for effective anticancer therapeutic agents. In recent years, many drugs have been shown to have extraordinary anticancer effects. However, in a lot of cases the treatment is accompanied by undesirable side effects due to some intrinsic properties linked to the therapeutic agents, such as poor targeting selectivity and short half-life in the circulation. In this regard, extracellular vesicles (EVs), a diverse family of natural cell-derived vesicles, steal the show as potential anticancer immunotherapy or delivery vectors of anticancer agents since they are an innate mechanism of intercellular communication. Here, we describe some of the most hotly-debated issues regarding the use of EVs as anticancer therapeutics. First, we review the biology of EVs providing the most up-to-date definition of EVs as well as highlighting their circulation kinetics and homing properties. Next, we share our views on popular methods reported for EV isolation, characterization, and functional analysis. Pioneering and innovative reports along with emerging challenges in the field of EV imaging and EV drug loading strategies are then discussed. Finally, we examine in detail the therapeutic application of EVs in cancer treatment, including their role in cancer immunotherapy and as natural delivery systems for anticancer agents including natural compounds such as paclitaxel and doxorubicin. We consider standardised protocols and proper analytical approaches to be crucial in improving the reproducibility and rigor in EV research and ensuring the successful translation of EVs as anticancer therapeutics.