Extracellular vesicles as next generation immunotherapeutics

Harnessing Exosomes: From Tumor Immune Escape to Therapeutic Innovation in Gastric Cancer Immunotherapy

Gastric cancer ranks fifth among the most prevalent cancers globally, with a dismal prognosis. In recent years, immunotherapy, particularly immune checkpoint inhibitors, has emerged as a glimmer of hope for advanced gastric cancer patients. However, not all patients can benefit from this treatment modality, as the tumor microenvironment significantly influences treatment efficacy. Exosomes, pivotal mediators of intercellular communication, exert intricate and diverse effects in shaping and regulating the tumor microenvironment. This review provides a comprehensive overview of the functional mechanisms of exosomes within the gastric cancer tumor microenvironment. It delves into their biogenesis, functions, and impact on innate and adaptive immune cells (such as dendritic cells, myeloid-derived suppressor cells, and T cells) and cancer-associated fibroblasts. Additionally, the potential applications of exosomes in gastric cancer immunotherapy are explored, including their use as biomarkers to predict responses to immune checkpoint inhibitors, and drug delivery vectors, and in the development of exosome-based vaccines and gene therapy. Notably, this review emphasizes the dual nature of exosomes: they can facilitate tumor immune escape, yet they also serve as promising targets for innovative therapeutic strategies. It also compares potential exosome-based strategies with existing immunotherapies like ICIs and emerging CAR-T cell therapies. Finally, insights into the future of exosomes in precision immunotherapy for gastric cancer are offered, presenting a forward-looking perspective on this emerging field.

Extracellular vesicle as a next-generation drug delivery platform for rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is a systemic autoimmune disorder characterized by chronic inflammation and progressive damage to connective tissue. It is driven by dysregulated cellular homeostasis, often leading to autoimmune destruction and permanent disability in severe cases. Over the past decade, various drug delivery systems have been developed to enable targeted therapies for disease prevention, reduction, or suppression. As an emerging therapeutic platform, extracellular vesicles (EVs) offer several advantages over conventional drug delivery systems, including biocompatibility and low immunogenicity. Consequently, an increasing number of studies have explored EV-based delivery systems in the treatment of RA, leveraging their natural ability to evade phagocytosis, prolong in vivo half-life, and minimize the immunogenicity of therapeutic agents. In this review, we first provide an in-depth overview of the pathogenesis of RA and the current treatment landscape. We then discuss the classification and biological properties of EVs, their potential therapeutic mechanisms, and the latest advancements in EVs as drug delivery platforms for RA therapy. We emphasize the significance of EVs as carriers in RA treatment and their potential to revolutionize therapeutic strategies. Furthermore, we examine key technological innovations and the future trajectory of EV research, focusing on the challenges and opportunities in translating these platforms into clinical practice. Our discussion aims to offer a comprehensive understanding of the current state and future prospects of EV-based therapeutics in RA.

Cancer mRNA vaccines: clinical application progress and challenges

Messenger RNA (mRNA) vaccines have emerged as one of the most promising and rapidly evolving immunotherapeutic approaches due to their ease of production, demonstrated clinical efficacy, and high safety. The coronavirus disease 2019(COVID-19) pandemic has showcased the remarkable therapeutic potential of mRNA vaccines, prompting researchers to explore their use for cancer treatment. Preclinical studies and human clinical trials have indicated their substantial clinical applicability. However, current research faces several challenges, including the complexity of tumor antigen selection, vaccine stability, and the development of resistance. This review summarizes the optimization strategies for cancer mRNA vaccines in preclinical settings, the progress of clinical trials, and the challenges encountered while analyzing various delivery vehicle types, infusion methods, and application cases across different cancer types, highlighting key factors in vaccine design. The findings demonstrate that mRNA vaccines elicit specific immune responses and exhibit favorable safety and tolerability in clinical trials. Moreover, developing personalized neoantigen vaccines offers a novel direction for cancer immunotherapy. The unique contribution of this review lies in its comprehensive overview of the latest advancements in therapeutic mRNA vaccines for cancer treatment while identifying critical areas for future research to propel the field forward.

Extracellular vesicles: a new frontier in diagnosing and treating graft-versus-host disease after allogeneic hematopoietic cell transplantation

Graft-versus-host disease (GvHD) is a prevalent complication following allogeneic hematopoietic stem cell transplantation (HSCT) and is characterized by relatively high morbidity and mortality rates. GvHD can result in extensive systemic damage in patients following allogeneic HSCT (allo-HSCT), with the skin, gastrointestinal tract, and liver frequently being the primary target organs affected. The severe manifestations of acute intestinal GvHD often indicate a poor prognosis for patients after allo-HSCT. Endoscopy and histopathological evaluation remain employed to diagnose GvHD, and auxiliary examinations exclude differential diagnoses. Currently, reliable serum biomarkers for the diagnosis and differential diagnosis of GvHD are scarce. As an essential part of standard transplant protocols, early application of immunosuppressive drugs effectively prevents GvHD. Among them, steroids represent first-line therapeutic agents, and the JAK2 inhibitor ruxolitinib represents the second-line therapeutic agent. Currently, no efficacious treatment modality exists for steroid-resistant aGvHD. Therefore, the diagnosis and treatment of GvHD still face significant medical demands. Extracellular vesicles (EVs) are nanometer to micrometer-scale biomembrane vesicles containing various bioactive components, such as proteins, nucleotides, and metabolites. Distinctive changes in serum-derived EV components occur in patients after allo-HSCT; Hence, EVs are expected to be potential biomarkers for diagnosing and treating GvHD. Furthermore, cell-free therapeutics characterized by EVs derived from mesenchymal stem cells (MSCs) have manifested remarkable therapeutic efficacy in preclinical models and preclinical trials of GvHD. Customized engineered EVs with fewer toxic and side effects for the combined treatment of GvHD hold broad prospects for clinical translation. This review article examines the potential value of translating EVs into clinical applications for the diagnosis and treatment of GvHD. It summarizes the latest advancements and prospects of engineered EVs applying GvHD.

Light-activated photosensitizer/quercetin co-loaded extracellular vesicles for precise oral squamous cell carcinoma therapy

Oral squamous cell carcinoma (OSCC) is the most common subtype of head and neck malignancies, characterized by a five-year survival rate that remains persistently below 50%, indicative of limited progress in therapeutic interventions. There is an urgent imperative to develop innovative therapeutic strategies, warranting the investigation of advanced treatment modalities. Nanocarriers offer a promising avenue by significantly enhancing drug properties and pharmacokinetics. Extracellular vesicles (EVs) are naturally occurring nanocarriers produced by cells and have become a focal point in drug delivery research. Quercetin, one of the most abundant dietary flavonoids, exhibits potent anticancer effects. However, its pharmaceutical application is hampered by poor water solubility, instability under physiological conditions, and low bioavailability. To overcome these obstacles, we propose using bio-derived EVs as carriers to co-encapsulate quercetin with the photosensitizer chlorin e6. This strategy leverages the intrinsic targeting capabilities of EVs for precise drug delivery to tumors, along with light-activated drug release, enabling rapid quercetin release under near-infrared light, effectively inhibiting cellular proliferation and inducing apoptosis in tumor cells. In vivo studies demonstrated that drug-loaded EVs exhibited robust tumor-targeting efficacy, resulting in effective and selective tumor ablation upon photoactivation in mice bearing subcutaneous MOC2 tumors.

MiR-124 Delivered by Extracellular Vesicles from Mesenchymal Stem Cell Exerts Neuroprotective Effects by Stabilizing the p62-Keap1-Nrf2 Pathway after Spinal Cord Injury in Rats

Spinal cord injury (SCI) can cause irreversible trauma to nervous tissue, leading to permanent damage to the patient's motor and sensory functions. Extracellular vesicles derived from mesenchymal stem cells (MSC-EVs) can simulate most of the functions of MSCs and are considered an ideal treatment option for SCI. However, the potential mechanism of MSC-EVs treatment for SCI still needs to be explored. We cultured neurons in vitro to investigate the effect of miR-124 on the p62-Keap1-Nrf2 pathway. Besides, MSC-EVs containing miR-124 were injected into a rat spinal cord injury model to observe their neural repair effect. The accumulation of p62 can be reversed by miR-124, which promotes autophagy and alleviates oxidative stress, thereby exerting neuroprotective effects. Rats who received injection of MSC-EVs overexpressing miR-124 after surgery showed higher BBB scores, lower levels of cell apoptosis, and better spinal cord tissue morphology. Our results indicated that miR-124 can stabilize the p62-Keap1-Nrf2 loop, thereby promoting autophagy and alleviating oxidative stress to exert neuroprotective effects. Our research proposes a novel potential target for treating SCI.

Mesenchymal stem cell-derived extracellular vesicles in periodontal bone repair

Periodontitis is a chronic inflammatory disease that destroys tooth-supporting structures and poses significant public health challenges due to its high prevalence and links to systemic health conditions. Traditional treatments are effective in reducing the inflammatory response and improving the clinical symptoms of periodontitis. However, these methods are challenging to achieve an ideal treatment effect in alveolar bone repair. Mesenchymal stem cells (MSCs) represent a potential alternative for the treatment of periodontal bone defects due to their self-renewal and differentiation capabilities. Recent research indicates that MSCs exert their effects primarily through paracrine mechanisms. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) serve as pivotal mediators in intercellular communication, transferring microRNAs (miRNAs), messenger RNAs (mRNAs), proteins, and cytokines to recipient cells, thereby emulating the therapeutic effects of MSCs. In periodontitis, MSC-EVs play a pivotal role in immunomodulation and bone remodeling, thereby facilitating periodontal bone repair. As a cell-free therapy, MSC-EVs demonstrate considerable clinical potential due to their specialized membrane structure, minimal immunogenicity, low toxicity, high biocompatibility, and nanoscale size. This review indicates that MSC-EVs represent a promising approach for periodontitis treatment, with the potential to overcome the limitations of traditional therapies and offer a more effective solution for bone repair in periodontal disease. In this review, we introduce MSC-EVs, emphasizing their mechanisms and clinical applications in periodontal bone repair. It synthesizes recent advances, existing challenges, and future prospects to present up-to-date information and novel techniques for periodontal regeneration and to guide the improvement of MSC-EV therapy in clinical practice.

Drug Delivery System for Cancer Immunotherapy: Potential Roles, Challenge and Recent Advances

Immunotherapy has emerged as a pivotal advancement in oncological therapeutics, representing a paradigm shift from conventional treatment modalities including surgery, radiotherapy, and chemotherapy. This innovative approach demonstrates considerable clinical potential through its capacity to enhance systemic anti-tumor responses via active or passive immunomodulation. Compared to traditional therapies, immunotherapy offers distinct advantages such as broad applicability, rapid therapeutic onset, and reduced adverse effects. However, critical challenges persist in clinical implementation, particularly concerning treatment safety and efficacy optimization. Current limitations, including drug off-target effects and biological delivery barriers, frequently result in suboptimal therapeutic outcomes and severe complications such as autoimmune disorders and nonspecific inflammation. Recently advancements in drug delivery systems (DDS) present transformative solutions to these challenges. Sophisticated DDS platforms enable precise spatiotemporal delivery of tumor antigens, immunotherapeutic agents, and immunostimulatory molecules, thereby achieving targeted modulation of diverse immune cell populations. This technological innovation not only enhances therapeutic efficacy but also significantly mitigates adverse reactions, while facilitating synergistic combinations with conventional cancer treatments. In this review, we outline the application of new drug delivery platforms in major malignancies (including but not limited to melanoma, non-small cell lung cancer, hormone receptor-positive breast cancer, and hepatocellular carcinoma). We further propose evidence-based optimization strategies for next-generation delivery platforms, aiming to bridge the gap between preclinical development and clinical implementation in cancer immunotherapy.

Exosomal circular RNAs in tumor microenvironment: An emphasis on signaling pathways and clinical opportunities

Exosomes can regulate the malignant progression of tumors by carrying a variety of genetic information and transmitting it to target cells. Recent studies indicate that exosomal circular RNAs (circRNAs) regulate multiple biological processes in carcinogenesis, such as tumor growth, metastasis, epithelial-mesenchymal transition, drug resistance, autophagy, metabolism, angiogenesis, and immune escape. In the tumor microenvironment (TME), exosomal circRNAs can be transferred among tumor cells, endothelial cells, cancer-associated fibroblasts, immune cells, and microbiota, affecting tumor initiation and progression. Due to the high stability and widespread presence of exosomal circRNAs, they hold promise as biomarkers for tumor diagnosis and prognosis prediction in blood and urine. In addition, designing nanoparticles targeting exosomal circRNAs and utilizing exosomal circRNAs derived from immune cells or stem cells provide new strategies for cancer therapy. In this review, we examined the crucial role of exosomal circRNAs in regulating tumor-related signaling pathways and summarized the transmission of exosomal circRNAs between various types of cells and their impact on the TME. Finally, our review highlights the potential of exosomal circRNAs as diagnostic and prognostic prediction biomarkers, as well as suggesting new strategies for clinical therapy.

CD81-guided heterologous EVs present heterogeneous interactions with breast cancer cells

BACKGROUND

Extracellular vesicles (EVs) are cell-secreted particles conceived as natural vehicles for intercellular communication. The capacity to entrap heterogeneous molecular cargoes and target specific cell populations through EV functionalization promises advancements in biomedical applications. However, the efficiency of the obtained EVs, the contribution of cell-exposed receptors to EV interactions, and the predictability of functional cargo release with potential sharing of high molecular weight recombinant mRNAs are crucial for advancing heterologous EVs in targeted therapy applications.

METHODS

In this work, we selected the popular EV marker CD81 as a transmembrane guide for fusion proteins with a C-terminal GFP reporter encompassing or not Trastuzumab light chains targeting the HER2 receptor. We performed high-content imaging analyses to track EV-cell interactions, including isogenic breast cancer cells with manipulated HER2 expression. We validated the functional cargo delivery of recombinant EVs carrying doxorubicin upon EV-donor cell treatment. Then, we performed an in vivo study using JIMT-1 cells commonly used as HER2-refractory, trastuzumab-resistant model to detect a more than 2000 nt length recombinant mRNA in engrafted tumors.

RESULTS

Fusion proteins participated in vesicular trafficking dynamics and accumulated on secreted EVs according to their expression levels in HEK293T cells. Despite the presence of GFP, secreted EV populations retained a HER2 receptor-binding capacity and were used to track EV-cell interactions. In time-frames where the global EV distribution did not change between HER2-positive (SK-BR-3) or -negative (MDA-MB-231) breast cancer cell lines, the HER2 exposure in isogenic cells remarkably affected the tropism of heterologous EVs, demonstrating the specificity of antiHER2 EVs representing about 20% of secreted bulk vesicles. The specific interaction strongly correlated with improved cell-killing activity of doxorubicin-EVs in MDA-MB-231 ectopically expressing HER2 and reduced toxicity in SK-BR-3 with a knocked-out HER2 receptor, overcoming the effects of the free drug. Interestingly, the fusion protein-corresponding transcripts present as full-length mRNAs in recombinant EVs could reach orthotopic breast tumors in JIMT-1-xenografted mice, improving our sensitivity in detecting penetrant cargoes in tissue biopsies.

CONCLUSIONS

This study highlights the quantitative aspects underlying the creation of a platform for secreted heterologous EVs and shows the limits of single receptor-ligand interactions behind EV-cell engagement mechanisms, which now become the pivotal step to predict functional tropism and design new generations of EV-based nanovehicles.

Engineered extracellular vesicles enable high-efficient delivery of intracellular therapeutic proteins

Developing an intracellular delivery system is of key importance in the expansion of protein-based therapeutics acting on cytosolic or nuclear targets. Recently, extracellular vesicles (EVs) have been exploited as next-generation delivery modalities due to their natural role in intercellular communication and biocompatibility. However, fusion of protein of interest to a scaffold represents a widely used strategy for cargo enrichment in EVs, which could compromise the stability and functionality of cargo. Herein, we report intracellular delivery via EV-based approach (IDEA) that efficiently packages and delivers native proteins both in vitro and in vivo without the use of a scaffold. As a proof-of-concept, we applied the IDEA to deliver cyclic GMP-AMP synthase (cGAS), an innate immune sensor. The results showed that cGAS-carrying EVs activated interferon signaling and elicited enhanced antitumor immunity in multiple syngeneic tumor models. Combining cGAS EVs with immune checkpoint inhibition further synergistically boosted antitumor efficacy in vivo. Mechanistically, scRNA-seq demonstrated that cGAS EVs mediated significant remodeling of intratumoral microenvironment, revealing a pivotal role of infiltrating neutrophils in the antitumor immune milieu. Collectively, IDEA, as a universal and facile strategy, can be applied to expand and advance the development of protein-based therapeutics.

Extracellular vesicles

Cells, pathogens, and other systems release extracellular vesicles (EVs). The particles promote intercellular communication and contain proteins, lipids, RNA and DNA. Initially considered to be cellular waste in the twentieth century, EVs were becoming recognized for their function in biological communication and control. EVs are divided into many subtypes: exosomes, microvesicles, and apoptotic bodies. Exosomes form in the late endosome/multivesicular body and are released when the compartments fuse with the plasma membrane. Microvesicles are generated by direct budding of the plasma membrane, whereas apoptotic bodies are formed after cellular apoptosis. The new guideline for EVs that describes alternate nomenclature for EVs. The particles modulate the immune response by affecting both innate and adaptive immunity, and their specific the structure allows them to be used as biomarkers to diagnose a variety of diseases. EVs have a wide range of applications, for example, delivery systems for medications and genetic therapies because of their ability to convey specific cellular material. In anti-tumor therapy, EVs deliver therapeutic chemicals to tumor cells. The EVs promote transplant compatibility and reduce organ rejection. Host-parasite interactions, therapeutic and diagnostic for cancer, cardiovascular disease, cardiac tissue regeneration, and the treatment of neurological diseases such as Alzheimer's and Parkinson's. The study of EVs keeps on expanding, revealing new functions and beneficial options. EVs have the potential to change drug delivery, diagnostics, and specific therapeutics, creating a new frontier in biomedical.

Advancements in melanoma immunotherapy: the emergence of Extracellular Vesicle Vaccines

Malignant melanoma represents a particularly aggressive type of skin cancer, originating from the pathological transformation of melanocytes. While conventional interventions such as surgical resection, chemotherapy, and radiation therapy are available, their non-specificity and collateral damage to normal cells has shifted the focus towards immunotherapy as a notable approach. Extracellular vesicles (EVs) are naturally occurring transporters, and are capable of delivering tumor-specific antigens and directly engaging in the immune response. Multiple types of EVs have emerged as promising platforms for melanoma vaccination. The effectiveness of EV-based melanoma vaccines manifests their ability to potentiate the immune response, particularly by activating dendritic cells (DCs) and CD8+ T lymphocytes, through engineering a synergy of antigen presentation and targeted delivery. Here, this review mainly focuses on the construction strategies for EV vaccines from various sources, their effects, and immunological mechanisms in treating melanoma, as well as the shortcomings and future perspectives in this field. These findings will provide novel insights into the innovative exploitation of EV-based vaccines for melanoma immune therapy.

Cell-cell communication: new insights and clinical implications

Multicellular organisms are composed of diverse cell types that must coordinate their behaviors through communication. Cell-cell communication (CCC) is essential for growth, development, differentiation, tissue and organ formation, maintenance, and physiological regulation. Cells communicate through direct contact or at a distance using ligand-receptor interactions. So cellular communication encompasses two essential processes: cell signal conduction for generation and intercellular transmission of signals, and cell signal transduction for reception and procession of signals. Deciphering intercellular communication networks is critical for understanding cell differentiation, development, and metabolism. First, we comprehensively review the historical milestones in CCC studies, followed by a detailed description of the mechanisms of signal molecule transmission and the importance of the main signaling pathways they mediate in maintaining biological functions. Then we systematically introduce a series of human diseases caused by abnormalities in cell communication and their progress in clinical applications. Finally, we summarize various methods for monitoring cell interactions, including cell imaging, proximity-based chemical labeling, mechanical force analysis, downstream analysis strategies, and single-cell technologies. These methods aim to illustrate how biological functions depend on these interactions and the complexity of their regulatory signaling pathways to regulate crucial physiological processes, including tissue homeostasis, cell development, and immune responses in diseases. In addition, this review enhances our understanding of the biological processes that occur after cell-cell binding, highlighting its application in discovering new therapeutic targets and biomarkers related to precision medicine. This collective understanding provides a foundation for developing new targeted drugs and personalized treatments.

Immunogenicity of Extracellular Vesicles

Extracellular vesicles (EVs) are promising next-generation therapeutics and drug delivery systems due to demonstrated safety and efficacy in preclinical models and early-stage clinical trials. There is an urgent need to address the immunogenicity of EVs (beyond the apparent lack of immunotoxicity) to advance clinical development. To date, few studies have assessed unintended immunological recognition of EVs. An in-depth understanding of EV-induced immunogenicity and clearance is necessary to develop effective therapeutic strategies, including approaches to mitigate immunological recognition when undesired. This article summarizes various factors involved in the potential immunogenicity of EVs and strategies to reduce immunological recognition for improved therapeutic benefit.

Components, Formulations, Deliveries, and Combinations of Tumor Vaccines

Tumor vaccines, an important part of immunotherapy, prevent cancer or kill existing tumor cells by activating or restoring the body's own immune system. Currently, various formulations of tumor vaccines have been developed, including cell vaccines, tumor cell membrane vaccines, tumor DNA vaccines, tumor mRNA vaccines, tumor polypeptide vaccines, virus-vectored tumor vaccines, and tumor-in-situ vaccines. There are also multiple delivery systems for tumor vaccines, such as liposomes, cell membrane vesicles, viruses, exosomes, and emulsions. In addition, to decrease the risk of tumor immune escape and immune tolerance that may exist with a single tumor vaccine, combination therapy of tumor vaccines with radiotherapy, chemotherapy, immune checkpoint inhibitors, cytokines, CAR-T therapy, or photoimmunotherapy is an effective strategy. Given the critical role of tumor vaccines in immunotherapy, here, we look back to the history of tumor vaccines, and we discuss the antigens, adjuvants, formulations, delivery systems, mechanisms, combination therapy, and future directions of tumor vaccines.

The Discovery of Extracellular Vesicles and Their Emergence as a Next-Generation Therapy

From their humble discovery as cellular debris to cementing their natural capacity to transfer functional molecules between cells, the long-winded journey of extracellular vesicles (EVs) now stands at the precipice as a next-generation cell-free therapeutic tool to revolutionize modern-day medicine. This perspective provides a snapshot of the discovery of EVs to their emergence as a vibrant field of biology and the renaissance they usher in the field of biomedical sciences as therapeutic agents for cardiovascular pathologies. Rapid development of bioengineered EVs is providing innovative opportunities to overcome biological challenges of natural EVs such as potency, cargo loading and enhanced secretion, targeting and circulation half-life, localized and sustained delivery strategies, approaches to enhance systemic circulation, uptake and lysosomal escape, and logistical hurdles encompassing scalability, cost, and time. A multidisciplinary collaboration beyond the field of biology now extends to chemistry, physics, biomaterials, and nanotechnology, allowing rapid development of designer therapeutic EVs that are now entering late-stage human clinical trials.

Role of aptamer technology in extracellular vesicle biology and therapeutic applications

Extracellular vesicles (EVs) are cell-derived nanosized membrane-bound vesicles that are important intercellular signalling regulators in local cell-to-cell and distant cell-to-tissue communication. Their inherent capacity to transverse cell membranes and transfer complex bioactive cargo reflective of their cell source, as well as their ability to be modified through various engineering and modification strategies, have attracted significant therapeutic interest. Molecular bioengineering strategies are providing a new frontier for EV-based therapy, including novel mRNA vaccines, antigen cross-presentation and immunotherapy, organ delivery and repair, and cancer immune surveillance and targeted therapeutics. The revolution of EVs, their diversity as biocarriers and their potential to contribute to intercellular communication, is well understood and appreciated but is ultimately dependent on the development of methods and techniques for their isolation, characterization and enhanced targeting. As single-stranded oligonucleotides, aptamers, also known as chemical antibodies, offer significant biological, chemical, economic, and therapeutic advantages in terms of their size, selectivity, versatility, and multifunctional programming. Their integration into the field of EVs has been contributing to the development of isolation, detection, and analysis pipelines associated with bioengineering strategies for nano-meets-molecular biology, thus translating their use for therapeutic and diagnostic utility.

Proteomic profiling of small extracellular vesicles derived from mouse pancreatic cancer and stellate cells: Role in pancreatic cancer

Small extracellular vesicles (sEVs) are cell-derived vesicles evolving as important elements involved in all stages of cancers. sEVs bear unique protein signatures that may serve as biomarkers. Pancreatic cancer (PC) records a very poor survival rate owing to its late diagnosis and several cancer cell-derived proteins have been reported as candidate biomarkers. However, given the pivotal role played by stellate cells (PSCs, which produce the collagenous stroma in PC), it is essential to also assess PSC-sEV cargo in biomarker discovery. Thus, this study aimed to isolate and characterise sEVs from mouse PC cells and PSCs cultured alone or as co-cultures and performed proteomic profiling and pathway analysis. Proteomics confirmed the enrichment of specific markers in the sEVs compared to their cells of origin as well as the proteins that are known to express in each of the culture types. Most importantly, for the first time it was revealed that PSC-sEVs are enriched in proteins (including G6PI, PGAM1, ENO1, ENO3, and LDHA) that mediate pathways related to development of diabetes, such as glucose metabolism and gluconeogenesis revealing a potential role of PSCs in pancreatic cancer-related diabetes (PCRD). PCRD is now considered a harbinger of PC and further research will enable to identify the role of these components in PCRD and may develop as novel candidate biomarkers of PC.

HB-EGF-loaded nanovesicles enhance trophectodermal spheroid attachment and invasion

The ability of trophectodermal cells (outer layer of the embryo) to attach to the endometrial cells and subsequently invade the underlying matrix are critical stages of embryo implantation during successful pregnancy establishment. Extracellular vesicles (EVs) have been implicated in embryo-maternal crosstalk, capable of reprogramming endometrial cells towards a pro-implantation signature and phenotype. However, challenges associated with EV yield and direct loading of biomolecules limit their therapeutic potential. We have previously established generation of cell-derived nanovesicles (NVs) from human trophectodermal cells (hTSCs) and their capacity to reprogram endometrial cells to enhance adhesion and blastocyst outgrowth. Here, we employed a rapid NV loading strategy to encapsulate potent implantation molecules such as HB-EGF (NVHBEGF). We show these loaded NVs elicit EGFR-mediated effects in recipient endometrial cells, activating kinase phosphorylation sites that modulate their activity (AKT S124/129, MAPK1 T185/Y187), and downstream signalling pathways and processes (AKT signal transduction, GTPase activity). Importantly, they enhanced target cell attachment and invasion. The phosphoproteomics and proteomics approach highlight NVHBEGF-mediated short-term signalling patterns and long-term reprogramming capabilities on endometrial cells which functionally enhance trophectodermal-endometrial interactions. This proof-of-concept study demonstrates feasibility in enhancing the functional potency of NVs in the context of embryo implantation.

Rapid and in-depth proteomic profiling of small extracellular vesicles for ultralow samples

The integration of robust single-pot, solid-phase-enhanced sample preparation with powerful liquid chromatography-tandem mass spectrometry (LC-MS/MS) is routinely used to define the extracellular vesicle (EV) proteome landscape and underlying biology. However, EV proteome studies are often limited by sample availability, requiring upscaling cell cultures or larger volumes of biofluids to generate sufficient materials. Here, we have refined data independent acquisition (DIA)-based MS analysis of EV proteome by optimizing both protein enzymatic digestion and chromatography gradient length (ranging from 15 to 44 min). Our short 15 min gradient length can reproducibly quantify 1168 (from as little as 500 pg of EV peptides) to 3882 proteins groups (from 50 ng peptides), including robust quantification of 22 core EV marker proteins. Compared to data-dependent acquisition, DIA achieved significantly greater EV proteome coverage and quantification of low abundant protein species. Moreover, we have achieved optimal magnetic bead-based sample preparation tailored to low quantities of EVs (0.5 to 1 µg protein) to obtain sufficient peptides for MS quantification of 1908-2340 protein groups. We demonstrate the power and robustness of our pipeline in obtaining sufficient EV proteomes granularity of different cell sources to ascertain known EV biology. This underscores the capacity of our optimised workflow to capture precise and comprehensive proteome of EVs, especially from ultra-low sample quantities (sub-nanogram), an important challenge in the field where obtaining in-depth proteome information is essential.

Rapid generation of functional nanovesicles from human trophectodermal cells for embryo attachment and outgrowth

Extracellular vesicles (EVs) are important mediators of embryo attachment and outgrowth critical for successful implantation. While EVs have garnered immense interest in their therapeutic potential in assisted reproductive technology by improving implantation success, their large-scale generation remains a major challenge. Here, we report a rapid and scalable production of nanovesicles (NVs) directly from human trophectoderm cells (hTSCs) via serial mechanical extrusion of cells; these NVs can be generated in approximately 6 h with a 20-fold higher yield than EVs isolated from culture medium of the same number of cells. NVs display similar biophysical traits (morphologically intact, spherical, 90-130 nm) to EVs, and are laden with hallmark players of implantation that include cell-matrix adhesion and extracellular matrix organisation proteins (ITGA2/V, ITGB1, MFGE8) and antioxidative regulators (PRDX1, SOD2). Functionally, NVs are readily taken up by low-receptive endometrial HEC1A cells and reprogram their proteome towards a receptive phenotype that support hTSC spheroid attachment. Moreover, a single dose treatment with NVs significantly enhanced adhesion and spreading of mouse embryo trophoblast on fibronectin matrix. Thus, we demonstrate the functional potential of NVs in enhancing embryo implantation and highlight their rapid and scalable generation, amenable to clinical utility.

Extracellular vesicles derived from immune cells: Role in tumor therapy

Extracellular vesicles (EVs), which have a lipid nano-sized structure, are known to contain the active components of parental cells and play a crucial role in intercellular communication. The progression and metastasis of tumors are influenced by EVs derived from immune cells, which can simultaneously stimulate and suppress immune responses. In the past few decades, there has been a considerable focus on EVs due to their potential in various areas such as the development of vaccines, delivering drugs, making engineered modifications, and serving as biomarkers for diagnosis and prognosis. This review focuses on the substance information present in EVs derived from innate and adaptive immune cells, their effects on the immune system, and their applications in cancer treatment. While there are still challenges to overcome, it is important to explore the composition of immune cells released vesicles and their potential therapeutic role in tumor therapy. The review also highlights the current limitations and future prospects in utilizing EVs for treatment purposes.

Extracellular vesicles mediated gastric cancer immune response: tumor cell death or immune escape?

Gastric cancer (GC) is a major global health issue, being the fifth most prevalent cancer and the third highest contributor to cancer-related deaths. Although treatment strategies for GC have diversified, the prognosis for advanced GC remains poor. Hence, there is a critical need to explore new directions for GC treatment to enhance diagnosis, treatment, and patient prognosis. Extracellular vesicles (EVs) have emerged as key players in tumor development and progression. Different sources of EVs carry different molecules, resulting in distinct biological functions. For instance, tumor-derived EVs can promote tumor cell proliferation, alter the tumor microenvironment and immune response, while EVs derived from immune cells carry molecules that regulate immune function and possess tumor-killing capabilities. Numerous studies have demonstrated the crucial role of EVs in the development, immune escape, and immune microenvironment remodeling in GC. In this review, we discuss the role of GC-derived EVs in immune microenvironment remodeling and EVs derived from immune cells in GC development. Furthermore, we provide an overview of the potential uses of EVs in immunotherapy for GC.

Role of Exosomes in Cancer and Aptamer-Modified Exosomes as a Promising Platform for Cancer Targeted Therapy

Exosomes are increasingly recognized as important mediators of intercellular communication in cancer biology. Exosomes can be derived from cancer cells as well as cellular components in tumor microenvironment. After secretion, the exosomes carrying a wide range of bioactive cargos can be ingested by local or distant recipient cells. The released cargos act through a variety of mechanisms to elicit multiple biological effects and impact most if not all hallmarks of cancer. Moreover, owing to their excellent biocompatibility and capability of being easily engineered or modified, exosomes are currently exploited as a promising platform for cancer targeted therapy. In this review, we first summarize the current knowledge of roles of exosomes in risk and etiology, initiation and progression of cancer, as well as their underlying molecular mechanisms. The aptamer-modified exosome as a promising platform for cancer targeted therapy is then briefly introduced. We also discuss the future directions for emerging roles of exosome in tumor biology and perspective of aptamer-modified exosomes in cancer therapy.

Melanoma extracellular vesicles inhibit tumor growth and metastasis by stimulating CD8 T cells

Tumor cell-derived extracellular vesicles (EVs) play a crucial role in mediating immune responses by carrying and presenting tumor antigens. Here, we suggested that melanoma EVs triggered cytotoxic CD8 T cell-mediated inhibition of tumor growth and metastasis. Our results indicated that immunization of mice with melanoma EVs inhibited melanoma growth and metastasis while increasing CD8 T cells and serum interferon γ (IFN-γ) in vivo. In vitro experiments showed that melanoma EV stimulates dendritic cells (DCs) maturation, and mature dendritic cells induce T lymphocyte activation. Thus, tumor cell-derived EVs can generate anti-tumor immunity in a prophylactic setting and may be potential candidates for cell-free tumor vaccines.

Advances of machine learning-assisted small extracellular vesicles detection strategy

Detection of extracellular vesicles (EVs), particularly small EVs (sEVs), is of great significance in exploring their physiological characteristics and clinical applications. The heterogeneity of sEVs plays a crucial role in distinguishing different types of cells and diseases. Machine learning, with its exceptional data processing capabilities, offers a solution to overcome the limitations of conventional detection methods for accurately classifying sEV subtypes and sources. Principal component analysis, linear discriminant analysis, partial least squares discriminant analysis, XGBoost, support vector machine, k-nearest neighbor, and deep learning, along with some combined methods such as principal component-linear discriminant analysis, have been successfully applied in the detection and identification of sEVs. This review focuses on machine learning-assisted detection strategies for cell identification and disease prediction via sEVs, and summarizes the integration of these strategies with surface-enhanced Raman scattering, electrochemistry, inductively coupled plasma mass spectrometry and fluorescence. The performance of different machine learning-based detection strategies is compared, and the advantages and limitations of various machine learning models are also evaluated. Finally, we discuss the merits and limitations of the current approaches and briefly outline the perspective of potential research directions in the field of sEV analysis based on machine learning.

Dendritic cell vaccination strategy for the treatment of acute myeloid leukemia: a systematic review

BACKGROUND AIMS

Acute myeloid leukemia (AML) is classified as a hematologic malignancy characterized by the proliferation of immature blood cells within the bone marrow (BM), resulting in an aberrant and unregulated cellular growth. The primary therapeutic modalities for AML include chemotherapy and hematopoietic stem cell transplantation. However, it is important to note that these treatments are accompanied by important adverse effects and mortality rates. Therefore, the need for more effective treatment options seems necessary, and dendritic cell (DC) vaccine therapy can be one of these options. In this study, we aim to investigate the effectiveness of DC vaccination therapy for the management of AML.

METHODS

PubMed, Scopus, ProQuest, Web of Science, and Google Scholar databases were searched for this systematic review. The articles were evaluated based on the inclusion criteria of this study and initially compared in terms of titles or abstracts. Finally, the articles related to the topic of this review were obtained in full text. The complete remission and partial remission, survival, correlative immune assays, and health-related metrics were used to evaluate this cellular immunotherapy effectiveness. The quality of the studies was assessed independently using the Cochrane risk-of-bias tools. The compiled data were input into a standard Excel spreadsheet. Each domain was evaluated as having either a "low risk," "high risk," or "unclear risk" of bias.

RESULTS

Among the 3986 studies that were determined, a total of 11 correlated trials were selected for inclusion in this systematic review. DC vaccine therapy was effective in inducing complete and partial remission, and stabilization of the disease. Additionally, it was discovered that the treatment strengthened the immune system as seen by increased levels of CD4+ and CD8+ T cells, Th1 cytokines, WT1-specific T cells, and activated NK cells.

CONCLUSION

We conducted a systematic review that supports the use of DC vaccine therapy as an effective treatment for AML. The therapy demonstrated potentials in achieving remission, enhancing the immune system function, and increasing overall survival. However, more studies are required to improve the methods of preparing and delivering the DC vaccine, and to confirm its long-term safety and effectiveness.

Exosomal circRNAs: Novel biomarkers and therapeutic targets for urinary tumors

Exosomal circRNAs have emerged as promising biomarkers and therapeutic targets for urinary tumors. In this review, we explored the intricate role of exosomal circRNAs in urological cancers, focusing on their biological functions, dysregulation in tumors, and potential clinical applications. The review delves into the mechanisms by which exosomal circRNAs contribute to tumor progression and highlights their diagnostic and therapeutic implications. By synthesizing current research findings, we present a compelling case for the significance of exosomal circRNAs in the context of urinary tumors. Furthermore, the review discusses the challenges and opportunities associated with utilizing exosomal circRNAs as diagnostic tools and targeted therapeutic agents. There is a need for further research to elucidate the specific mechanisms of exosomal circRNA secretion and delivery, as well as to enhance the detection methods for clinical translational applications. Overall, this comprehensive review underscores the pivotal role of exosomal circRNAs in urinary tumors and underscores their potential as valuable biomarkers and therapeutic tools in the management of urological cancers.

Exosome-mediated communication between gastric cancer cells and macrophages: implications for tumor microenvironment

Gastric cancer (GC) is a malignant neoplasm originating from the epithelial cells of the gastric mucosa. The pathogenesis of GC is intricately linked to the tumor microenvironment within which the cancer cells reside. Tumor-associated macrophages (TAMs) primarily differentiate from peripheral blood monocytes and can be broadly categorized into M1 and M2 subtypes. M2-type TAMs have been shown to promote tumor growth, tissue remodeling, and angiogenesis. Furthermore, they can actively suppress acquired immunity, leading to a poorer prognosis and reduced tolerance to chemotherapy. Exosomes, which contain a myriad of biologically active molecules including lipids, proteins, mRNA, and noncoding RNAs, have emerged as key mediators of communication between tumor cells and TAMs. The exchange of these molecules via exosomes can markedly influence the tumor microenvironment and consequently impact tumor progression. Recent studies have elucidated a correlation between TAMs and various clinicopathological parameters of GC, such as tumor size, differentiation, infiltration depth, lymph node metastasis, and TNM staging, highlighting the pivotal role of TAMs in GC development and metastasis. In this review, we aim to comprehensively examine the bidirectional communication between GC cells and TAMs, the implications of alterations in the tumor microenvironment on immune escape, invasion, and metastasis in GC, targeted therapeutic approaches for GC, and the efficacy of potential GC drug resistance strategies.

Nutrient availability regulates the secretion and function of immune cell-derived extracellular vesicles through metabolic rewiring

Extracellular vesicle (EV)-based immunotherapeutics have emerged as promising strategy for treating diseases, and thus, a better understanding of the factors that regulate EV secretion and function can provide insights into developing advanced therapies. Here, we report that nutrient availability, even changes in individual nutrient components, may affect EV biogenesis and composition of immune cells [e.g., macrophages (Mφs)]. As a proof of concept, EVs from M1-Mφ under glutamine-depleted conditions (EVGLN-) had higher yields, functional compositions, and immunostimulatory potential than EVs from conventional GLN-present medium (EVGLN+). Mechanistically, the systemic metabolic rewiring (e.g., altered energy and redox metabolism) induced by GLN depletion resulted in up-regulated pathways related to EV biogenesis/cargo sorting (e.g., ESCRT) and immunostimulatory molecule production (e.g., NF-κB and STAT) in Mφs. This study highlights the importance of nutrient status in EV secretion and function, and optimizing metabolic states and/or integrating them with other engineering methods may advance the development of EV therapeutics.

Diverse drug delivery systems for the enhancement of cancer immunotherapy: an overview

Despite the clear benefits demonstrated by immunotherapy, there is still an inevitable off-target effect resulting in serious adverse immune reactions. In recent years, the research and development of Drug Delivery System (DDS) has received increased prominence. In decades of development, DDS has demonstrated the ability to deliver drugs in a precisely targeted manner to mitigate side effects and has the advantages of flexible control of drug release, improved pharmacokinetics, and drug distribution. Therefore, we consider that combining cancer immunotherapy with DDS can enhance the anti-tumor ability. In this paper, we provide an overview of the latest drug delivery strategies in cancer immunotherapy and briefly introduce the characteristics of DDS based on nano-carriers (liposomes, polymer nano-micelles, mesoporous silica, extracellular vesicles, etc.) and coupling technology (ADCs, PDCs and targeted protein degradation). Our aim is to show readers a variety of drug delivery platforms under different immune mechanisms, and analyze their advantages and limitations, to provide more superior and accurate targeting strategies for cancer immunotherapy.

Prostate cancer-derived small extracellular vesicle proteins: the hope in diagnosis, prognosis, and therapeutics

Current diagnostic tools for prostate cancer (PCa) diagnosis and risk stratification are insufficient. The hidden onset and poor efficacy of traditional therapies against metastatic PCa make this disease a heavy burden in global men's health. Prostate cancer-derived extracellular vesicles (PCDEVs) have garnered attention in recent years due to their important role in communications in tumor microenvironment. Recent advancements have demonstrated PCDEVs proteins play an important role in PCa invasion, progression, metastasis, therapeutic resistance, and immune escape. In this review, we briefly discuss the applications of sEV proteins in PCa diagnosis and prognosis in liquid biopsy, focus on the roles of the PCa-derived small EVs (sEVs) proteins in tumor microenvironment associated with cancer progression, and explore the therapeutic potential of sEV proteins applied for future metastatic PCa therapy.

Identification of antigens in the Trichinella spiralis extracellular vesicles for serological detection of early stage infection in swine

BACKGROUND

Several studies have reported the roles of Trichinella spiralis extracellular vesicles in immune regulation and pathogen diagnosis. Currently, the T. spiralis muscle larvae excretory/secretory product (Ts-ML-ES) is the antigen recommended by the International Commission on Trichinellosis (ICT) for serological diagnosis of trichinellosis. However, it can only be used to detect middle and late stages of infections, and cross-reactions with other parasite detections occur. Therefore, there is a need to identify antigens for specific detection of early stage trichinellosis.

METHODS

Extracellular vesicles of T. spiralis muscle larvae (Ts-ML-EVs) were isolated by ultracentrifugation and characterized by transmission electron microscopy, nanoparticle tracking analysis, flow cytometry and western blot. Ts-ML-EVs protein profiles were analyzed by LC-MS/MS proteomics for identification of potential antigens (Ts-TTPA). Ts-TTPA were cloned into pMAL-c5X vector and expressed as recombinant proteins for evaluation of potential as detected antigens by western blot and ELISA.

RESULTS

Isolated Ts-ML-EVs were round or elliptic (with diameters between 110.1 and 307.6 nm), showing a bilayer membrane structure. The specific surface markers on the Ts-ML-EVs were CD81, CD63, enolase and the 14-3-3 protein. A total of 53 proteins were identified by LC-MS/MS, including a variety of molecules that have been reported as potential detection and vaccine candidates. The cDNA of Ts-TTPA selected in this study has a total length of 1152 bp, encoding 384 amino acids with a molecular weight of 44.19 kDa. It contains a trypsin domain and can be recognized by anti-His antibody. It reacted with swine sera infected with 10,000 T. spiralis at 15, 25, 35 and 60 days post-infection (dpi). At 10 μg/ml, this antigen could detect T. spiralis antibodies from the swine sera at 13 dpi. There were no cross-reactions with the swine sera infected with other parasites including Clonorchis sinensis, Toxoplasma gondii, Taenia suis, Ascaris suis and Trichuris suis.

CONCLUSIONS

This study identifies potential early stage detection antigens and more thoroughly characterizes a serine protease domain-containing protein. Extracellular vesicle proteins may be explored as effective antigens for the early stage detection of trichinellosis.

Targeting of tumor cells by custom antigen transfer: a novel approach for immunotherapy of cancer

In the early stages of carcinogenesis, the transformed cells become "invisible" to the immune system. From this moment on, the evolution of the tumor depends essentially on the genotype of the primitive cancer cells and their subsequent genetic drift. The role of the immune system in blocking tumor progression from the earliest stages is largely underestimated because by the time tumors are clinically detectable, the immune system has already completely failed its task. Therefore, a clinical treatment capable of restoring the natural anti-tumor role of the immune system could prove to be the "ultimate weapon" against cancer. Herein, we propose a novel therapeutic approach for the treatment of solid cancer that exploits the capability of activated monocytes to transfer major histocompatibility complex I (MHC-I) molecules bound to antigenic peptides to cancer cells using microvesicles as cargo, making tumor cells target of a "natural" CD8+ T lymphocyte cytotoxic response.

Dendritic Cell Vaccines: A Shift from Conventional Approach to New Generations

In the emerging era of cancer immunotherapy, immune checkpoint blockades (ICBs) and adoptive cell transfer therapies (ACTs) have gained significant attention. However, their therapeutic efficacies are limited due to the presence of cold type tumors, immunosuppressive tumor microenvironment, and immune-related side effects. On the other hand, dendritic cell (DC)-based vaccines have been suggested as a new cancer immunotherapy regimen that can address the limitations encountered by ICBs and ACTs. Despite the success of the first generation of DC-based vaccines, represented by the first FDA-approved DC-based therapeutic cancer vaccine Provenge, several challenges remain unsolved. Therefore, new DC vaccine strategies have been actively investigated. This review addresses the limitations of the currently most adopted classical DC vaccine and evaluates new generations of DC vaccines in detail, including biomaterial-based, immunogenic cell death-inducing, mRNA-pulsed, DC small extracellular vesicle (sEV)-based, and tumor sEV-based DC vaccines. These innovative DC vaccines are envisioned to provide a significant breakthrough in cancer immunotherapy landscape and are expected to be supported by further preclinical and clinical studies.

Role of Exosomes in the Pathogenesis and Theranostic of Alzheimer's Disease and Parkinson's Disease

Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common neurodegenerative diseases (NDDs) threatening the lives of millions of people worldwide, including especially elderly people. Currently, due to the lack of a timely diagnosis and proper intervention strategy, AD and PD largely remain incurable. Innovative diagnosis and therapy are highly desired. Exosomes are small vesicles that are present in various bodily fluids, which contain proteins, nucleic acids, and active biomolecules, and which play a crucial role especially in intercellular communication. In recent years, the role of exosomes in the pathogenesis, early diagnosis, and treatment of diseases has attracted ascending attention. However, the exact role of exosomes in the pathogenesis and theragnostic of AD and PD has not been fully illustrated. In the present review, we first introduce the biogenesis, components, uptake, and function of exosomes. Then we elaborate on the involvement of exosomes in the pathogenesis of AD and PD. Moreover, the application of exosomes in the diagnosis and therapeutics of AD and PD is also summarized and discussed. Additionally, exosomes serving as drug carriers to deliver medications to the central nervous system are specifically addressed. The potential role of exosomes in AD and PD is explored, discussing their applications in diagnosis and treatment, as well as their current limitations. Given the limitation in the application of exosomes, we also propose future perspectives for better utilizing exosomes in NDDs. Hopefully, it would pave ways for expanding the biological applications of exosomes in fundamental research as well as theranostics of NDDs.

Extracellular vesicles and their cells of origin: Open issues in autoimmune diseases

The conventional therapeutic approaches to treat autoimmune diseases through suppressing the immune system, such as steroidal and non-steroidal anti-inflammatory drugs, are not adequately practical. Moreover, these regimens are associated with considerable complications. Designing tolerogenic therapeutic strategies based on stem cells, immune cells, and their extracellular vesicles (EVs) seems to open a promising path to managing autoimmune diseases' vast burden. Mesenchymal stem/stromal cells (MSCs), dendritic cells, and regulatory T cells (Tregs) are the main cell types applied to restore a tolerogenic immune status; MSCs play a more beneficial role due to their amenable properties and extensive cross-talks with different immune cells. With existing concerns about the employment of cells, new cell-free therapeutic paradigms, such as EV-based therapies, are gaining attention in this field. Additionally, EVs' unique properties have made them to be known as smart immunomodulators and are considered as a potential substitute for cell therapy. This review provides an overview of the advantages and disadvantages of cell-based and EV-based methods for treating autoimmune diseases. The study also presents an outlook on the future of EVs to be implemented in clinics for autoimmune patients.