Exosomes harbor B cell targets in pancreatic adenocarcinoma and exert decoy function against complement-mediated cytotoxicity

The crosstalk within tumor microenvironment and exosomes in pancreatic cancer

Pancreatic cancer is one of the most malignant tumors with a grim prognosis. Patients develop chemoresistance that drastically decreases their survival. The chemoresistance is mainly attributed to deficient vascularization of the tumor, intratumoral heterogeneity and pathophysiological barrier due to the highly desmoplastic tumor microenvironment. The interactions of cells that constitute the tumor microenvironment change its architecture into a cancer-permissive environment and stimulate cancer development, metastasis and treatment response. The cell-cell communication in the tumor microenvironment is often mediated by exosomes that harbour a diverse repertoire of molecular cargo, such as proteins, lipids, and nucleic acid, including messenger RNAs, non-coding RNAs and DNA. Therefore, exosomes can serve as potential targets as biomarkers and improve the clinical management of pancreatic cancer to overcome chemoresistance. This review critically elucidates the role of exosomes in cell-cell communication within the tumor microenvironment and how these interactions can orchestrate chemoresistance.

Development of an innovative extracellular vesicle mimetic delivery platform for efficient miRNA delivery to tumours

Extracellular vesicles (EVs) display high degree of tissue tropism and therefore represent promising carriers for tissue-specific delivery of genes or drugs for the treatment of human diseases. However, current approaches for the loading of therapeutics into EVs have low entrapment efficiency and also do not adequately deplete endogenous EV content; thus, more effective approaches are needed. Here, we report an innovative EXtraCElluar vesicle surface Ligand-NanoParticles (EXCEL NPs), generated by transferring moieties of EVs onto the surface of synthetic nanoparticles. EXCEL NPs facilitate the efficient entrapment of therapeutics (89 % efficiency) and are completely devoid of pre-existing unwanted EV internal content. Importantly, we show that EXCEL NPs formulated using EVs derived from endothelial cells, astrocytes and macrophages retain the delivery characteristics of the original EVs. Using miRNA-146a as a model anti-cancer therapeutic, we further demonstrated successful delivery of miRNA-146a to IG10 orthotopic ovarian tumours in immune competent mice using EXCEL NPs formulated with macrophage-derived EVs. Our findings establish a new clinically translatable approach to leverage characteristics of endogenous EVs for therapeutic delivery. The versatility of the platform enables future application to different target cell types and therapeutic modalities.

Effect of Extracellular Vesicles Derived From Tumor Cells on Immune Evasion

The crosstalk between immunity and cancer in the regulation of tumor growth is considered a hallmark of cancer. Antitumor immunity refers to the innate and adaptive immune responses that regulate cancer development and proliferation. Tumor immune evasion represents a major hindrance to effective anticancer treatment. Extracellular vesicles (EVs) are nano-sized and lipid-bilayer-enclosed particles that are secreted to the extracellular space by all cell types. They are critically involved in numerous biological functions including intercellular communication. Tumor-derived extracellular vesicles (TEVs) can transport a variety of cargo to modulate immune cells in the tumor microenvironment (TME). This review provides the latest update about how tumor cells evade immune surveillance by exploiting TEVs. First, the biogenesis of EVs and the cargo-sorting machinery are discussed. Second, how tumor cells modulate immune cell differentiation, activation, and function via TEVs to evade immune surveillance is illustrated. Last but not least, the novel antitumor strategies that can reverse immune escape are summarized.

Extracellular vesicle-mediated crosstalk in tumor microenvironment dominates tumor fate

The tumor microenvironment (TME) is a complex and heterogeneous system containing various cells cooperating and competing with each other. Extracellular vesicles (EVs) differing in form and content are important intercellular communication mediators in the TME. Previous studies have focused on the cargoes within EVs rather than on the donors from which they originate and the recipient cells that exert their effects. Therefore, we provide here a detailed overview of the important roles of EVs in shaping tumor fate, highlighting their various mechanisms of intercellular dialog within the TME. We evaluate recent advances and also raise unresolved challenges to provide new ideas for clinical treatment strategies using EVs.

Exosomes as carriers to stimulate an anti-cancer immune response in immunotherapy and as predictive markers

During this era of rapid advancements in cancer immunotherapy, the application of cell-released small vesicles that activate the immune system is of considerable interest. Exosomes are cell-derived nanovesicles that show great promise for the immunological treatment of cancer because of their immunogenicity and molecular transfer capacity. Recent technological advancements have enabled the identification of functional functions that exosome cargoes perform in controlling immune responses. Exosomes are originated specifically from immune cells and tumor cells and they show unique composition patterns directly related to the immunotherapy against cancer. Exosomes can also deliver their cargo to particular cells, which can affect the phenotypic and immune-regulatory functions of those cells. Exosomes can influence the course of cancer and have therapeutic benefits by taking part in several cellular processes; as a result, they have the dual properties of activating and restraining cancer. Exosomes have tremendous potential for cancer immunotherapy; they may develop into the most powerful cancer vaccines and carriers of targeted antigens and drugs. Comprehending the potential applications of exosomes in immune therapy is significant for regulating cancer progression. This review offers an analysis of the function of exosomes in immunotherapy, specifically as carriers that function as diagnostic indicators for immunological activation and trigger an anti-cancer immune response. Moreover, it summarizes the fundamental mechanism and possible therapeutic applications of exosome-based immunotherapy for human cancer.

Extracellular vesicles-a new player in the development of urinary bladder cancer

Bladder cancer was the 10th most commonly diagnosed cancer worldwide in 2020. Extracellular vesicles (EVs) are nano-sized membranous structures secreted by all types of cells into the extracellular space. EVs can transport proteins, lipids, or nucleic acids to specific target cells. What brings more attention and potential implications is the fact that cancer cells secrete more EVs than non-malignant cells. EVs are widely studied for their role in cancer development. This publication summarizes the impact of EVs secreted by urinary bladder cancer cells on urinary bladder cancer development and metastasis. EVs isolated from urinary bladder cancer cells affect other lower-grade cancer cells or normal cells by inducing different metabolic pathways (transforming growth factor β/Smads pathway; phosphoinositide 3-kinase/Akt pathway) that promote epithelial-mesenchymal transition. The cargo carried by EVs can also induce angiogenesis, another critical element in the development of bladder cancer, and modulate the immune system response in a tumor-beneficial manner. In summary, the transfer of substances produced by tumor cells via EVs to the environment influences many stages of tumor progression. An in-depth understanding of the role EVs play in the development of urinary bladder cancer is crucial for the development of future anticancer therapies.

B cells and tertiary lymphoid structures in tumors: immunity cycle, clinical impact, and therapeutic applications

Tumorigenesis involves a multifaceted and heterogeneous interplay characterized by perturbations in individual immune surveillance. Tumor-infiltrating lymphocytes, as orchestrators of adaptive immune responses, constitute the principal component of tumor immunity. Over the past decade, the functions of tumor-specific T cells have been extensively elucidated, whereas current understanding and research regarding intratumoral B cells remain inadequate and underexplored. The delineation of B cell subsets is contingent upon distinct surface proteins and the specific transcription factors that define these subsets have yet to be fully described. Consequently, there is a pressing need for extensive and comprehensive exploration into tumor-infiltrating B cells and their cancer biology. Notably, B cells and other cellular entities assemble within the tumor milieu to establish tertiary lymphoid structures that facilitate localized immune activation and furnish novel insights for tumor research. It is of great significance to develop therapeutic strategies based on B cells, antibodies, and tertiary lymphoid structures. In this review, we address the role of B cells and tertiary lymphoid structures in tumor microenvironment, with the highlight on their spatiotemporal effect, prognostic value and therapeutic applications in tumor immunity.

Oncolytic viruses alter the biogenesis of tumor extracellular vesicles and influence their immunogenicity

Extracellular vesicles (EVs) are mediators of intercellular communication in the tumor microenvironment. Tumor EVs are commonly associated with metastasis, immunosuppression or drug resistance. Viral infections usually increase EV secretion, but little is known about the effect of oncolytic viruses (OVs) on tumor EVs. Here, we investigated the impact of oncolytic vesicular stomatitis virus (VSV) and vaccinia virus on EVs secreted by human melanoma and thoracic cancer cells. We found that OV infection increases the production of EVs by tumor cells. These EVs contain proteins of viral origin, such as VSV-G, thus creating a continuum of particles sharing markers of both canonical EVs and viruses. As such, the presence of VSV-G on EVs improves the transfer of their protein content to cell types commonly found in the tumor microenvironment. A proteomic analysis also revealed that EVs-OV secreted during VSV infection are enriched in immunity-related proteins. Finally, CD8+ T cells incubated with EVs-OV from infected cells display slightly enhanced cytotoxic functions. Taken together, these data suggest that OVs enhance the communication mediated by tumor EVs, which could participate in the therapeutic efficacy of OVs. These results also provide rationale for engineering OVs to exploit EVs and disseminate therapeutic proteins within the tumor microenvironment.

Extracellular vesicle autoantibodies

Autoantibodies are immunoglobulin proteins produced by autoreactive B cells responding to self-antigens. Extracellular vesicles (EVs) are membranous structures released by almost all types of cells and extensively distributed in various biological fluids. Studies have indicated that EVs loaded with self-antigens not only play important roles in antigen presentation and autoantibody production but can also form functional immune complexes with autoantibodies (termed EV autoantibodies). While numerous papers have summarized the production and function of pathogenic autoantibodies in diseases, especially autoimmune diseases, reviews on EV autoantibodies are rare. In this review, we outline the existing knowledge about EVs, autoantibodies, and EV antigens, highlighting the formation of EV autoantibodies and their functions in autoimmune diseases and cancers. In conclusion, EV autoantibodies may be involved in the occurrence of disease(s) and also serve as potential non-invasive markers that could help in the diagnosis and/or prognosis of disease. Additional studies designed to define in more detail the molecular characteristics of EV autoantibodies and their contribution to disease are recommended.

The Nature and Nurture of Extracellular Vesicle-Mediated Signaling

In the last decade, it has become clear that extracellular vesicles (EVs) are a ubiquitous component of living systems. These small membrane-enclosed particles can confer diverse functions to the cells that release, capture, or coexist with them in an environment. We use examples across living systems to produce a conceptual framework that classifies three modes by which EVs exert functions: (a) EV release that serves a function for producing cells, (b) EV modification of the extracellular environment, and (c) EV interactions with, and alteration of, receiving cells. We provide an overview of the inherent properties of EVs (i.e., their nature) as well as factors in the environment and receiving cell (i.e., nurture) that determine whether transmission of EV cargo leads to functional cellular responses. This review broadens the context for ruminating on EV functions and highlights the emergent properties of EVs that define their role in biology and will shape their applications in medicine.

Exosomal MicroRNAs modulate the cognitive function in fasudil treated APPswe/PSEN1dE9 transgenic (APP/PS1) mice model of Alzheimer's disease

Alzheimer's disease (AD) is characterized by cognitive decline stemming from the accumulation of beta-amyloid (Aβ) plaques and the propagation of tau pathology through synapses. Exosomes, crucial mediators in neuronal development, maintenance, and intercellular communication, have gained attention in AD research. Yet, the molecular mechanisms involving exosomal miRNAs in AD remain elusive. In this study, we treated APPswe/PSEN1dE9 transgenic (APP/PS1) mice, a model for AD, with either vehicle (ADNS) or fasudil (ADF), while C57BL/6 (control) mice received vehicle (WT). Cognitive function was evaluated using the Y-maze test, and AD pathology was confirmed through immunostaining and western blot analysis of Aβ plaques and phosphorylated tau. Exosomal RNAs were extracted, sequenced, and analyzed from each mouse group. Our findings revealed that fasudil treatment improved cognitive function in AD mice, as evidenced by increased spontaneous alternation in the Y-maze test and reduced Aβ plaque load and phosphorylated tau protein expression in the hippocampus. Analysis of exosomal miRNAs identified three miRNAs (mmu-let-7i-5p, mmu-miR-19a-3p, mmu-miR-451a) common to both ADNS vs ADF and WT vs ADNS groups. Utilizing miRTarBase software, we predicted and analyzed target genes associated with these miRNAs. Gene ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of miRNA target genes indicated that mmu-miR-19a-3p and mmu-miR-451a are implicated in signal transduction, immune response, cellular communication, and nervous system pathways. Specifically, mmu-miR-19a-3p targeted genes involved in the sphingolipid signaling pathway, such as Pten and Tnf, while mmu-miR-451a targeted Nsmaf, Gnai3, and Akt3. Moreover, mmu-miR-451a targeted Myc in signaling pathways regulating the pluripotency of stem cells. In conclusion, fasudil treatment enhanced cognitive function by modulating exosomal MicroRNAs, particularly mmu-miR-451a and mmu-miR-19a-3p. These miRNAs hold promise as potential biomarkers and therapeutic targets for novel AD treatments.

Deciphering extracellular vesicles protein cargo in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) presents a significant therapeutic challenge as it is frequently diagnosed at advanced inoperable stages. Therefore, the development of a reliable screening tool for PDAC is crucial for effective prevention and treatment. Extracellular vesicles (EVs), characterized by their cup-shaped lipid bilayer structure and ubiquitous release from various cell types, offer notable advantages as an emerging liquid biopsy technique that is rapid, minimally invasive, easily sampled, and cost-effective. While EVs play a substantial role in cancer progression, EV proteins serve as direct mediators of diverse cellular behaviors and have immense potential as biomarkers for PDAC diagnosis and prognostication. This review provides an overview of EV proteins regarding PDAC diagnosis and prognostic implications as well as disease progression.

The systematic role of pancreatic cancer exosomes: distant communication, liquid biopsy and future therapy

Pancreatic cancer remains one of the most lethal diseases worldwide. Cancer-derived exosomes, benefiting from the protective role of the lipid membrane, exhibit remarkable stability in the circulatory system. These exosomes, released by tumor microenvironment, contain various biomolecules such as proteins, RNAs, and lipids that plays a pivotal role in mediating distant communication between the local pancreatic tumor and other organs or tissues. They facilitate the transfer of oncogenic factors to distant sites, contributing to the compromised body immune system, distant metastasis, diabetes, cachexia, and promoting a microenvironment conducive to tumor growth and metastasis in pancreatic cancer patients. Beyond their intrinsic roles, circulating exosomes in peripheral blood can be detected to facilitate accurate liquid biopsy. This approach offers a novel and promising method for the diagnosis and management of pancreatic cancer. Consequently, circulating exosomes are not only crucial mediators of systemic cell-cell communication during pancreatic cancer progression but also hold great potential as precise tools for pancreatic cancer management and treatment. Exosome-based liquid biopsy and therapy represent promising advancements in the diagnosis and treatment of pancreatic cancer. Exosomes can serve as drug delivery vehicles, enhancing the targeting and efficacy of anticancer treatments, modulating the immune system, and facilitating gene editing to suppress tumor growth. Ongoing research focuses on biomarker identification, drug delivery systems, and clinical trials to validate the safety and efficacy of exosome-based therapies, offering new possibilities for early diagnosis and precision treatment in pancreatic cancer. Leveraging the therapeutic potential of exosomes, including their ability to deliver targeted drugs and modulate immune responses, opens new avenues for innovative treatment strategies.

Th2 cell extracellular vesicles promote eosinophil survival through the cytokine cargo IL-3 and prolong airway eosinophilia

Background

Extracellular vesicles (EVs) mediate intercellular communication during immune responses. EVs are abundant in respiratory biofluids, and the composition of EVs in the lung changes during inflammation.

Objective

We aimed to quantify the contribution of T cells to airway EVs in allergic lung inflammation and ascertain their function during a type 2 inflammatory response.

Methods

Genetic membrane tagging was combined with single vesicle flow cytometry to quantify T cell EVs in the airways of mice challenged with ovalbumin or house dust mite. EVs were purified from T helper type 2 (Th2) cell cultures and their functions on eosinophils assessed by flow cytometry and RNA sequencing. Th2 cell EVs were instilled into the lungs of mice to determine effects on lung eosinophilia. Finally, the function of an EV protein cargo was tested using inhibitors and blocking antibodies.

Results

T cell EVs are increased in the airways of mice with induced allergic inflammation. EVs secreted by Th2 cells inhibit apoptosis and induce activating pathways in eosinophils in vitro. This effect depends on re-stimulation through the T cell receptor. Th2 cell EVs prolong eosinophilia in vivo during allergic airway inflammation. Th2 cell EVs carry a potent form of the cytokine IL-3 on their surfaces, which inhibits apoptosis by activating Jak1/2-dependent pro-survival programs in eosinophils.

Conclusion

Th2 cell EVs promote eosinophil survival and prolong eosinophilia during allergic airway inflammation. This function depends on the EV cargo IL-3, supporting a role for EVs as vehicles of cytokine-based communication in lung inflammation.

Key Messages

T cells secrete extracellular vesicles in the airway during allergic lung inflammation.Th2 cell extracellular vesicles inhibit eosinophil apoptosis and prolong airway eosinophilia during allergic lung inflammation.IL-3 carried on Th2 cell EVs is a functional cargo, supporting a role for cytokine-carrying EVs as drivers of type 2 inflammation.

Capsule summary

This study supports that T cell extracellular vesicles may be important drivers of eosinophilic inflammation through the cytokine cargo IL-3, offering new insights into pro-inflammatory signaling in the allergic lung of patients with asthma.

Unbiasedly decoding the tumor microenvironment with single-cell multiomics analysis in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with a poor prognosis and limited therapeutic options. Research on the tumor microenvironment (TME) of PDAC has propelled the development of immunotherapeutic and targeted therapeutic strategies with a promising future. The emergence of single-cell sequencing and mass spectrometry technologies, coupled with spatial omics, has collectively revealed the heterogeneity of the TME from a multiomics perspective, outlined the development trajectories of cell lineages, and revealed important functions of previously underrated myeloid cells and tumor stroma cells. Concurrently, these findings necessitated more refined annotations of biological functions at the cell cluster or single-cell level. Precise identification of all cell clusters is urgently needed to determine whether they have been investigated adequately and to identify target cell clusters with antitumor potential, design compatible treatment strategies, and determine treatment resistance. Here, we summarize recent research on the PDAC TME at the single-cell multiomics level, with an unbiased focus on the functions and potential classification bases of every cellular component within the TME, and look forward to the prospects of integrating single-cell multiomics data and retrospectively reusing bulk sequencing data, hoping to provide new insights into the PDAC TME.

Exosomal mediators in sepsis and inflammatory organ injury: unraveling the role of exosomes in intercellular crosstalk and organ dysfunction

Sepsis, a severe systemic inflammatory response to infection, remains a leading cause of morbidity and mortality worldwide. Exosomes, as mediators of intercellular communication, play a pivotal role in the pathogenesis of sepsis through modulating immune responses, metabolic reprogramming, coagulopathy, and organ dysfunction. This review highlights the emerging significance of exosomes in these processes. Initially, it provides an in-depth insight into exosome biogenesis and characterization, laying the groundwork for understanding their diverse and intricate functions. Subsequently, it explores the regulatory roles of exosomes in various immune cells such as neutrophils, macrophages, dendritic cells, T cells, and B cells. This analysis elucidates how exosomes are pivotal in modulating immune responses, thus contributing to the complexity of sepsis pathophysiology. Additionally, this review delves into the role of exosomes in the regulation of metabolism and subsequent organ dysfunction in sepsis. It also establishes a connection between exosomes and the coagulation cascade, which affects endothelial integrity and promotes thrombogenesis in sepsis. Moreover, the review discusses the dual role of exosomes in the progression and resolution of sepsis, exploring their complex involvement in inflammation and healing processes. Furthermore, it underscores their potential as biomarkers and therapeutic targets. Understanding these mechanisms presents new opportunities for novel interventions to mitigate the severe outcomes of sepsis, emphasizing the therapeutic promise of exosome research in critical care settings.

Exosome-based delivery strategies for tumor therapy: an update on modification, loading, and clinical application

Malignancy is a major public health problem and among the leading lethal diseases worldwide. Although the current tumor treatment methods have therapeutic effect to a certain extent, they still have some shortcomings such as poor water solubility, short half-life, local and systemic toxicity. Therefore, how to deliver therapeutic agent so as to realize safe and effective anti-tumor therapy become a problem urgently to be solved in this field. As a medium of information exchange and material transport between cells, exosomes are considered to be a promising drug delivery carrier due to their nano-size, good biocompatibility, natural targeting, and easy modification. In this review, we summarize recent advances in the isolation, identification, drug loading, and modification of exosomes as drug carriers for tumor therapy alongside their application in tumor therapy. Basic knowledge of exosomes, such as their biogenesis, sources, and characterization methods, is also introduced herein. In addition, challenges related to the use of exosomes as drug delivery vehicles are discussed, along with future trends. This review provides a scientific basis for the application of exosome delivery systems in oncological therapy.

Immune evasion on the nanoscale: Small extracellular vesicles in pancreatic ductal adenocarcinoma immunity

Pancreatic ductal adenocarcinoma (PDAC) is a type of cancer alarmingly expanding in our modern societies that is still proving to be very challenging to counteract. This disease constitutes a quintessential example of the multiple interactions existing between the tumour and its surrounding microenvironment. In particular, PDAC is characterized by a very immunosuppressive environment that favours cancer growth and makes this cancer type very resistant to immunotherapy. The primary tumour releases many factors that influence both the microenvironment and the immune landscape. Extracellular vesicles (EVs), recently identified as indispensable entities ensuring cell-to-cell communication in both physiological and pathological processes, seem to play a pivotal function in ensuring the delivery of these factors to the tumour-surrounding tissues. In this review, we summarize the present understanding on the crosstalk among tumour cells and the cellular immune microenvironment emphasizing the pro-malignant role played by extracellular vesicles. We also discuss how a greater knowledge of the roles of EVs in tumour immune escape could be translated into clinical applications.

Extracellular vesicle-encapsulated miR-10a-5p derived from MDSCs restrains germinal center B cells in experimental Sjögren's syndrome

Primary Sjögren's syndrome (pSS) is a progressive systemic autoimmune disease characterized by chronic inflammation of the exocrine glands, resulting in damage to the salivary and lacrimal glands. Our group and other researchers have reported that myeloid-derived suppressor cell-derived extracellular vesicles (MDSC-EVs) could attenuate the progression of autoimmune disease by impairing T-cell function. However, the effect of MDSC-EVs on B-cell function and the underlying mechanism remains largely unknown. In this study, we found that MDSC-EVs significantly attenuated the progression of experimental Sjögren's syndrome (ESS). Moreover, treatment with MDSC-EVs via intravenous injection markedly reduced the percentage of germinal center (GC) B cells in ESS mice. In vitro, MDSC-EVs could directly suppress the generation of GC B cells and the expression of B cell lymphoma 6 (Bcl-6) in B cells under GC B-cell-polarizing conditions. Mechanistically, miR-10a-5p carried by MDSC-EVs regulated the differentiation of GC B cells by targeting Bcl-6, and inhibition of miR-10a-5p in MDSC-EVs significantly reversed the effect of MDSC-EVs involved in alleviating the development of ESS. Taken together, our findings demonstrated that miR-10a-5p carried by MDSC-EVs inhibited the generation of B cells by targeting Bcl-6 and eventually alleviated the progression of ESS, which may provide novel therapeutic targets for the treatment of pSS.

B cell extracellular vesicles contain monomeric IgM that binds antigen and enters target cells

The production and release of small phospholipid membrane vesicles, or extracellular vesicles (EVs), is a trait of most prokaryotic and eukaryotic cells. EVs display heterogeneity in content, size, biogenesis, activity, and function. B cells uniquely express immunoglobulin and produce EVs; however, the relationship between these entities has not been clarified. Here, we used several methodologies to isolate large (11,000 × g) and small (110,000 × g) EVs and evaluate their IgM content, characteristics and activity. We found that B cells from multiple cell lines and primary B cells produce EVs that display monomeric IgM on the surface and contain encapsulated monomeric IgM, which is independent of secreted pentameric IgM. Our data indicate EV IgM can bind antigen specifically, and EV IgM can be incorporated intracellularly into secondary cells. These results suggest immunological activities different from secreted pentameric IgM that may constitute a separate and distinct antibody distribution system.

Screening of Exosome-Derived Proteins and Their Potential as Biomarkers in Diagnostic and Prognostic for Pancreatic Cancer

In the oncological area, pancreatic cancer is one of the most lethal diseases, with 5-year survival rising just 10% in high-development countries. This disease is genetically characterized by KRAS as a driven mutation followed by SMAD4, CDKN2, and TP53-associated mutations. In clinical aspects, pancreatic cancer presents unspecific clinical symptoms with the absence of screening and early plasmatic biomarker, being that CA19-9 is the unique plasmatic biomarker having specificity and sensitivity limitations. We analyzed the plasmatic exosome proteomic profile of 23 patients with pancreatic cancer and 10 healthy controls by using Nanoscale liquid chromatography coupled to tandem mass spectrometry (NanoLC-MS/MS). The pancreatic cancer patients were subdivided into IPMN and PDAC. Our findings show 33, 34, and 7 differentially expressed proteins when comparing the IPMN vs. control, PDAC-No treatment vs. control, and PDAC-No treatment vs. IPMN groups, highlighting proteins of the complement system and coagulation, such as C3, APOB, and SERPINA. Additionally, PDAC with no treatment showed 11 differentially expressed proteins when compared to Folfirinox neoadjuvant therapy or Gemcitabine adjuvant therapy. So here, we found plasmatic exosome-derived differentially expressed proteins among cancer patients (IPMN, PDAC) when comparing with healthy controls, which could represent alternative biomarkers for diagnostic and prognostic evaluation, supporting further scientific and clinical studies on pancreatic cancer.

Recent progress in exosome research: isolation, characterization and clinical applications

Exosomes, a kind of nano-vesicles released by various cell types, carry a variety of "cargos" including proteins, RNAs, DNAs and lipids. There is substantial evidence that exosomes are involved in intercellular communication by exchanging "cargos" among cells and play important roles in cancer development. Because of the different expressions of "cargos" carried by exosomes in biological fluids under physiological and pathological conditions, exosomes have the potential as a minimally invasive method of liquid biopsy for cancer diagnosis and prognosis. In addition, due to their good biocompatibility, safety, biodistribution and low immunogenicity, exosomes also have potential applications in the development of promising cancer treatment methods. In this review, we summarize the recent progress in the isolation and characterization techniques of exosomes. Moreover, we review the biological functions of exosomes in regulating tumor metastasis, drug resistance and immune regulation during cancer development and outline the applications of exosomes in cancer therapy.

Three-dimensional-cultured MSC-derived exosome with hydrogel for cerebral ischemia repair

Microglia-mediated neuroinflammatory response, one of the most essential pathological processes of cerebral ischemia-reperfusion (I/R) injury, is acknowledged as the main factors leading to poor prognosis of cerebral ischemia. Exosome derived from mesenchymal stem cell (MSC-Exo) exhibits neuroprotective functions by reducing cerebral ischemia-induced neuroinflammatory response and promoting angiogenesis. However, MSC-Exo has disadvantages such as insufficient targeting capability and low production, which limits their clinical applications. Here, we fabricated gelatin methacryloyl (GelMA) hydrogel for three-dimensional (3D) culture of MSCs. It is indicated that 3D environment could simulate the biological niches of MSCs, thereby significantly increasing the cell stemness of MSCs and improving the yield of MSCs-derived exosomes (3D-Exo). In this study, we utilized the modified Longa method to induce middle cerebral artery occlusion (MCAO) model. Additionally, in vitro and in vivo studies were conducted to interrogate the mechanism of the stronger neuroprotective effect of 3D-Exo. Furthermore, the administration of 3D-Exo in MCAO model could promote neovascularization in infarct region and result in a significant suppression of inflammatory response. This study proposed an exosome-based targeting delivery system for cerebral ischemia and provided a promising strategy for efficient and large-scale production of MSC-Exo.

Functional and Clinical Proteomic Exploration of Pancreatic Cancer

Pancreatic cancer, most cases being pancreatic ductal adenocarcinoma (PDAC), is one of the most lethal cancers with a median survival time of less than 6 months. Therapeutic options are very limited for PDAC patients, and surgery is still the most effective treatment, making improvements in early diagnosis critical. One typical characteristic of PDAC is the desmoplastic reaction of its stroma microenvironment, which actively interacts with cancer cells to orchestrate key components in tumorigenesis, metastasis, and chemoresistance. Global exploration of cancer-stroma crosstalk is essential to decipher PDAC biology and design intervention strategies. Over the past decade, the dramatic improvement of proteomics technologies has enabled profiling of proteins, post-translational modifications (PTMs), and their protein complexes at unprecedented sensitivity and dimensionality. Here, starting with our current understanding of PDAC characteristics, including precursor lesions, progression models, tumor microenvironment, and therapeutic advancements, we describe how proteomics contributes to the functional and clinical exploration of PDAC, providing insights into PDAC carcinogenesis, progression, and chemoresistance. We summarize recent achievements enabled by proteomics to systematically investigate PTMs-mediated intracellular signaling in PDAC, cancer-stroma interactions, and potential therapeutic targets revealed by these functional studies. We also highlight proteomic profiling of clinical tissue and plasma samples to discover and verify useful biomarkers that can aid early detection and molecular classification of patients. In addition, we introduce spatial proteomic technology and its applications in PDAC for deconvolving tumor heterogeneity. Finally, we discuss future prospects of applying new proteomic technologies in comprehensively understanding PDAC heterogeneity and intercellular signaling networks. Importantly, we expect advances in clinical functional proteomics for exploring mechanisms of cancer biology directly by high-sensitivity functional proteomic approaches starting from clinical samples.

Mechanisms of obesity- and diabetes mellitus-related pancreatic carcinogenesis: a comprehensive and systematic review

Research on obesity- and diabetes mellitus (DM)-related carcinogenesis has expanded exponentially since these two diseases were recognized as important risk factors for cancers. The growing interest in this area is prominently actuated by the increasing obesity and DM prevalence, which is partially responsible for the slight but constant increase in pancreatic cancer (PC) occurrence. PC is a highly lethal malignancy characterized by its insidious symptoms, delayed diagnosis, and devastating prognosis. The intricate process of obesity and DM promoting pancreatic carcinogenesis involves their local impact on the pancreas and concurrent whole-body systemic changes that are suitable for cancer initiation. The main mechanisms involved in this process include the excessive accumulation of various nutrients and metabolites promoting carcinogenesis directly while also aggravating mutagenic and carcinogenic metabolic disorders by affecting multiple pathways. Detrimental alterations in gastrointestinal and sex hormone levels and microbiome dysfunction further compromise immunometabolic regulation and contribute to the establishment of an immunosuppressive tumor microenvironment (TME) for carcinogenesis, which can be exacerbated by several crucial pathophysiological processes and TME components, such as autophagy, endoplasmic reticulum stress, oxidative stress, epithelial-mesenchymal transition, and exosome secretion. This review provides a comprehensive and critical analysis of the immunometabolic mechanisms of obesity- and DM-related pancreatic carcinogenesis and dissects how metabolic disorders impair anticancer immunity and influence pathophysiological processes to favor cancer initiation.

Exosomes as natural nanocarrier-based drug delivery system: recent insights and future perspectives

Exosomes are nanosized (size ~ 30-150 nm) natural vesicular structures released from cells by physiological processes or pathological circumstances. Exosomes are growing in popularity as a result of their many benefits over conventional nanovehicles, including their ability to escape homing in the liver or metabolic destruction and their lack of undesired accumulation before reaching their intended targets. Various therapeutic molecules, including nucleic acids, have been incorporated into exosomes by different techniques, many of which have shown satisfactory performance in various diseases. Surface-modified exosomes are a potentially effective strategy, and it increases the circulation time and produces the specific drug target vehicle. In this comprehensive review, we describe composition exosomes biogenesis and the role of exosomes in intercellular signaling and cell-cell communications, immune responses, cellular homeostasis, autophagy, and infectious diseases. In addition, we discuss the role of exosomes as diagnostic markers, and their therapeutic and clinical implications. Furthermore, we addressed the challenges and outstanding developments in exosome research and discuss future perspectives. In addition to the current status of exosomes as a therapeutic carrier, the lacuna in the clinical development lifecycles along with the possible strategies to fill the lacuna have been addressed.

Theranostic extracellular vesicles: a concise review of current imaging technologies and labeling strategies

Extracellular vesicles (EVs), or exosomes, are naturally occurring nano- and micro-sized membrane vesicles playing an essential role in cell-to-cell communication. There is a recent increasing interest in harnessing the therapeutic potential of these natural nanoparticles to develop cell-free regenerative medicine and manufacture highly biocompatible and targeted drug and gene delivery vectors, amongst other applications. In the context of developing novel and effective EV-based therapy, imaging tools are of paramount importance as they can be used to not only elucidate the underlying mechanisms but also provide the basis for optimization and clinical translation. In this review, recent efforts and knowledge advances on EV-based therapies have been briefly introduced, followed by an outline of currently available labeling strategies by which EVs can be conjugated with various imaging agents and/or therapeutic drugs and genes. A comprehensive review of prevailing EV imaging technologies is then presented along with examples and applications, with emphasis on imaging probes and agents, corresponding labeling methods, and the pros and cons of each imaging modality. Finally, the potential of theranostic EVs as a powerful new weapon in the arsenal of regenerative medicine and nanomedicine is summarized and envisioned.

Interactions between Platelets and Tumor Microenvironment Components in Ovarian Cancer and Their Implications for Treatment and Clinical Outcomes

Platelets, the primary operatives of hemostasis that contribute to blood coagulation and wound healing after blood vessel injury, are also involved in pathological conditions, including cancer. Malignancy-associated thrombosis is common in ovarian cancer patients and is associated with poor clinical outcomes. Platelets extravasate into the tumor microenvironment in ovarian cancer and interact with cancer cells and non-cancerous elements. Ovarian cancer cells also activate platelets. The communication between activated platelets, cancer cells, and the tumor microenvironment is via various platelet membrane proteins or mediators released through degranulation or the secretion of microvesicles from platelets. These interactions trigger signaling cascades in tumors that promote ovarian cancer progression, metastasis, and neoangiogenesis. This review discusses how interactions between platelets, cancer cells, cancer stem cells, stromal cells, and the extracellular matrix in the tumor microenvironment influence ovarian cancer progression. It also presents novel potential therapeutic approaches toward this gynecological cancer.

The Roles of Exosomal Proteins: Classification, Function, and Applications

Exosome, a subpopulation of extracellular vesicles, plays diverse roles in various biological processes. As one of the most abundant components of exosomes, exosomal proteins have been revealed to participate in the development of many diseases, such as carcinoma, sarcoma, melanoma, neurological disorders, immune responses, cardiovascular diseases, and infection. Thus, understanding the functions and mechanisms of exosomal proteins potentially assists clinical diagnosis and targeted delivery of therapies. However, current knowledge about the function and application of exosomal proteins is still limited. In this review, we summarize the classification of exosomal proteins, and the roles of exosomal proteins in exosome biogenesis and disease development, as well as in the clinical applications.

Pancreatic Cancer in Chronic Pancreatitis: Pathogenesis and Diagnostic Approach

Chronic pancreatitis is one of the main risk factors for pancreatic cancer, but it is a rare event. Inflammation and oncogenes work hand in hand as key promoters of this disease. Tobacco is another co-factor. During alcoholic chronic pancreatitis, the cumulative risk of cancer is estimated at 4% after 15 to 20 years. This cumulative risk is higher in hereditary pancreatitis: 19 and 12% in the case of PRSS1 and SPINK1 mutations, respectively, at an age of 60 years. The diagnosis is difficult due to: (i) clinical symptoms of cancer shared with those of chronic pancreatitis; (ii) the parenchymal and ductal remodeling of chronic pancreatitis rendering imaging analysis difficult; and (iii) differential diagnoses, such as pseudo-tumorous chronic pancreatitis and paraduodenal pancreatitis. Nevertheless, the occurrence of cancer during chronic pancreatitis must be suspected in the case of back pain, weight loss, unbalanced diabetes, and jaundice, despite alcohol withdrawal. Imaging must be systematically reviewed. Endoscopic ultrasound-guided fine-needle biopsy can contribute by targeting suspicious tissue areas with the help of molecular biology (search for KRAS, TP53, CDKN2A, DPC4 mutations). Short-term follow-up of patients is necessary at the clinical and paraclinical levels to try to diagnose cancer at a surgically curable stage. Pancreatic surgery is sometimes necessary if there is any doubt.

Tumor-Derived Extracellular Vesicles: Multifunctional Entities in the Tumor Microenvironment

Tumor cells release extracellular vesicles (EVs) that can function as mediators of intercellular communication in the tumor microenvironment. EVs contain a host of bioactive cargo, including membrane, cytosolic, and nuclear proteins, in addition to noncoding RNAs, other RNA types, and double-stranded DNA fragments. These shed vesicles may deposit paracrine information and can also be taken up by stromal cells, causing the recipient cells to undergo phenotypic changes that profoundly impact diverse facets of cancer progression. For example, this unique form of cellular cross talk helps condition the premetastatic niche, facilitates evasion of the immune response, and promotes invasive and metastatic activity. These findings, coupled with those demonstrating that the number and content of EVs produced by tumors can vary depending on their tumor of origin, disease stage, or response to therapy, have raised the exciting possibility that EVs can be used for risk stratification, diagnostic, and even prognostic purposes. We summarize recent developments and the current knowledge of EV cargoes, their impact on disease progression, and implementation of EV-based liquid biopsies as tumor biomarkers.

Exosomes: A potential tool for immunotherapy of ovarian cancer

Ovarian cancer is a malignant tumor of the female reproductive system, with a very poor prognosis and high mortality rates. Chemotherapy and radiotherapy are the most common treatments for ovarian cancer, with unsatisfactory results. Exosomes are a subpopulation of extracellular vesicles, which have a diameter of approximately 30-100 nm and are secreted by many different types of cells in various body fluids. Exosomes are highly stable and are effective carriers of immunotherapeutic drugs. Recent studies have shown that exosomes are involved in various cellular responses in the tumor microenvironment, influencing the development and therapeutic efficacy of ovarian cancer, and exhibiting dual roles in inhibiting and promoting tumor development. Exosomes also contain a variety of genes related to ovarian cancer immunotherapy that could be potential biomarkers for ovarian cancer diagnosis and prognosis. Undoubtedly, exosomes have great therapeutic potential in the field of ovarian cancer immunotherapy. However, translation of this idea to the clinic has not occurred. Therefore, it is important to understand how exosomes could be used in ovarian cancer immunotherapy to regulate tumor progression. In this review, we summarize the biomarkers of exosomes in different body fluids related to immunotherapy in ovarian cancer and the potential mechanisms by which exosomes influence immunotherapeutic response. We also discuss the prospects for clinical application of exosome-based immunotherapy in ovarian cancer.

Small Extracellular Vesicles as a New Class of Medicines

Extracellular vesicles (EVs) are nanovesicles that are naturally released from cells in a lipid bilayer-bound form. A subset population with a size of 200 nm, small EVs (sEVs), is enticing in many ways. Initially perceived as mere waste receptacles, sEVs have revealed other biological functions, such as cell-to-cell signal transduction and communication. Besides their notable biological functions, sEVs have profound advantages as future drug modalities: (i) excellent biocompatibility, (ii) high stability, and (iii) the potential to carry undruggable macromolecules as cargo. Indeed, many biopharmaceutical companies are utilizing sEVs, not only as diagnostic biomarkers but as therapeutic drugs. However, as all inchoate fields are challenging, there are limitations and hindrances in the clinical translation of sEV therapeutics. In this review, we summarize different types of sEV therapeutics, future improvements, and current strategies in large-scale production.

A New Potential Therapeutic Target for Cancer in Ubiquitin-Like Proteins-UBL3

Ubiquitin-like proteins (Ubls) are involved in a variety of biological processes through the modification of proteins. Dysregulation of Ubl modifications is associated with various diseases, especially cancer. Ubiquitin-like protein 3 (UBL3), a type of Ubl, was revealed to be a key factor in the process of small extracellular vesicle (sEV) protein sorting and major histocompatibility complex class II ubiquitination. A variety of sEV proteins that affects cancer properties has been found to interact with UBL3. An increasing number of studies has implied that UBL3 expression affects cancer cell growth and cancer prognosis. In this review, we provide an overview of the relationship between various Ubls and cancers. We mainly introduce UBL3 and its functions and summarize the current findings of UBL3 and examine its potential as a therapeutic target in cancers.

Role of exosomes in tumour growth, chemoresistance and immunity: state-of-the-art

Cancer is one of the most lethal diseases, and limited available treatment options contribute to its high mortality rate. Exosomes are considered membrane-bound nanovesicles that include different molecules such as lipids, proteins, and nucleic acids. Virtually most cells could release exosomes via exocytosis in physiological and pathological conditions. Tumour-derived exosomes (TDEs) play essential roles in tumorigenesis, proliferation, progression, metastasis, immune escape, and chemoresistance by transferring functional biological cargos, triggering different autocrine, and paracrine signalling cascades. Due to their antigen-presenting properties, exosomes are widely used as biomarkers and drug carriers and have a prominent role in cancer immunotherapy. They offer various advantages in carrier systems (e.g. in chemotherapy, siRNA, and miRNA), delivery of diagnostic agents owing to their stability, loading of hydrophobic and hydrophilic agents, and drug targeting. Novel exosomes-based carriers can be generated as intelligent systems using various sources and crosslinking chemistry extracellular vesicles (EVs). Exosomes studded with targeting ligands, including peptides, can impart in targeted delivery of cargos to tumour cells. In this review, we comprehensively summarised the important role of tumour-derived exosomes in dictating cancer pathogenesis and resistance to therapy. We have therefore, investigated in further detail the pivotal role of tumour-derived exosomes in targeting various cancer cells and their applications, and prospects in cancer therapy and diagnosis. Additionally, we have implicated the potential utility and significance of tumour exosomes-based nanoparticles as an efficient and novel therapeutic carrier and their applications in treating advanced cancers.

M1 Microglia-derived Exosomes Promote Activation of Resting Microglia and Amplifies Proangiogenic Effects through Irf1/miR-155-5p/Socs1 Axis in the Retina

Activation of microglia plays a key role in the development of neovascular retinal diseases. Therefore, it is essential to reveal its pathophysiological and molecular mechanisms to interfere with disease progression. Here a publicly available single-cell RNA sequencing dataset is used to identify that intercellular communications from M1 microglia toward M0 microglia are increased in the retinal angiogenesis model via exosomes. Moreover, the results both in vitro and in vivo demonstrate that M1 microglia-derived exosomes promote the activation and enhance the proangiogenic ability of resting microglia. Based on miRNA sequencing of exosomes combined with gene interference, further results show that activated microglia-derived exosomes promoted microglial activation by transmitting polarized signals to M0 microglia via miR-155-5p. Subsequently, miR-155-5p suppresses Socs1 and activates the NFκB pathway, which ultimately causes the inflammatory cascade and amplifies the proangiogenic effect. In addition, upregulated Irf1 drives the expression of miR-155-5p in activated microglia, thus leading to an increase in the tendency of miR-155-5p to be encapsulated by exosomes. Thus, this study elucidates the critical role of intercellular communication among various types of microglia in the complex retinal microenvironment during angiogenesis, and contributes to the novel, targeted, and potential therapeutic strategies for clinical retinal neovascularization.

Extracellular Vesicles and Their Roles in the Tumor Immune Microenvironment

Tumor cells actively incorporate molecules (e.g., proteins, lipids, RNA) into particles named extracellular vesicles (EVs). Several groups have demonstrated that EVs can be transferred to target (recipient) cells, making EVs an important means of intercellular communication. Indeed, EVs are able to modulate the functions of target cells by reprogramming signaling pathways. In a cancer context, EVs promote the formation of a supportive tumor microenvironment (TME) and (pre)metastatic niches. Recent studies have revealed that immune cells, tumor cells and their secretome, including EVs, promote changes in the TME and immunosuppressive functions of immune cells (e.g., natural killer, dendritic cells, T and B cells, monocytes, macrophages) that allow tumor cells to establish and propagate. Despite the growing knowledge on EVs and on their roles in cancer and as modulators of the immune response/escape, the translation into clinical practice remains in its early stages, hence requiring improved translational research in the EVs field. Here, we comprehensively review the current knowledge and most recent research on the roles of EVs in tumor immune evasion and immunosuppression in both solid tumors and hematological malignancies. We also highlight the clinical utility of EV-mediated immunosuppression targeting and EV-engineering. Importantly, we discuss the controversial role of EVs in cancer biology, current limitations and future perspectives to further the EV knowledge into clinical practice.

Functions and clinical applications of exosomes in pancreatic cancer

Pancreatic cancer (PC) is one of the most malignant tumors and has an abysmal prognosis, with a 5-year survival rate of only 11%. At present, the main clinical dilemmas in PC are the lack of biomarkers and the unsatisfactory therapeutic effects. The treatments for and outcomes of PC have improved, but remain unsatisfactory. Exosomes are nanosized extracellular vesicles, and an increasing number of studies have found that exosomes play an essential role in tumor pathology. In this review, we describe the process of exosome biogenesis, as well as exosome extraction methods and identification strategies, and we then explain in detail the roles and mechanisms of exosomes in invasion, metastasis, chemoresistance and immunosuppression in PC. Finally, we summarize the clinical applications of exosomes. Our observations indicate that exosomes represent a novel direction in the clinical treatment of PC.

Phenotype and Neuronal Cytotoxic Function of Glioblastoma Extracellular Vesicles

Glioblastoma (GBM) is the most aggressive and lethal form of brain tumor. Extracellular vesicles (EVs) released by tumor cells play a critical role in cellular communication in the tumor microenvironment promoting tumor progression and invasion. We hypothesized that GBM EVs possess unique characteristics which exert effects on endogenous CNS cells including neurons, producing dose-dependent neuronal cytotoxicity. We purified EVs from the plasma of 20 GBM patients, 20 meningioma patients, and 21 healthy controls, and characterized EV phenotypes by electron microscopy, nanoparticle tracking analysis, protein concentration, and proteomics. We evaluated GBM EV functions by determining their cytotoxicity in primary neurons and the neuroblastoma cell line SH-SY5Y. In addition, we determined levels of IgG antibodies in the plasma in GBM (n = 82), MMA (n = 83), and controls (non-tumor CNS disorders and healthy donors, n = 50) with capture ELISA. We discovered that GBM plasma EVs are smaller in size and had no relationship between size and concentration. Importantly, GBM EVs purified from both plasma and tumor cell lines produced IgG-mediated, complement-dependent apoptosis and necrosis in primary human neurons, mouse brain slices, and neuroblastoma cells. The unique phenotype of GBM EVs may contribute to its neuronal cytotoxicity, providing insight into its role in tumor pathogenesis.

Cancer-derived small extracellular vesicles: emerging biomarkers and therapies for pancreatic ductal adenocarcinoma diagnosis/prognosis and treatment

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal cancers worldwide with high mortality, which is mainly due to the lack of reliable biomarkers for PDAC diagnosis/prognosis in the early stages and effective therapeutic strategies for the treatment. Cancer-derived small extracellular vesicles (sEVs), which carry various messages and signal biomolecules (e.g. RNAs, DNAs, proteins, lipids, and glycans) to constitute the key features (e.g. genetic and phenotypic status) of cancer cells, are regarded as highly competitive non-invasive biomarkers for PDAC diagnosis/prognosis. Additionally, new insights on the biogenesis and molecular functions of cancer-derived sEVs pave the way for novel therapeutic strategies based on cancer-derived sEVs for PDAC treatment such as inhibition of the formation or secretion of cancer-derived sEVs, using cancer-derived sEVs as drug carriers and for immunotherapy. This review provides a comprehensive overview of the most recent scientific and clinical research on the discovery and involvement of key molecules in cancer-derived sEVs for PDAC diagnosis/prognosis and strategies using cancer-derived sEVs for PDAC treatment. The current limitations and emerging trends toward clinical application of cancer-derived sEVs in PDAC diagnosis/prognosis and treatment have also been discussed.

Culprits of PDAC resistance to gemcitabine and immune checkpoint inhibitor: Tumour microenvironment components

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive and lethal cancer with a dismal five-year survival rate of 11%. Despite remarkable advancements in cancer therapeutics, PDAC patients rarely benefit from it due to insurmountable treatment resistance. Notably, PDAC is pathologically characterized by an extensive desmoplastic reaction and an extremely immunosuppressive tumour microenvironment (TME). The PDAC TME consists of cell components (e.g., tumour, immune and stromal cells) and noncellular components (e.g., extracellular matrix), exhibiting high complexity and their interplay resulting in resistance to chemotherapeutics and immune checkpoint inhibitors. In our review, we shed light on how crosstalk of complex environmental components modulates PDAC drug resistance, and we summarize related clinical trials. Moreover, we extend our discussion on TME exploration and exosome analysis, providing new insights into clinical applications, including personalized medicine, disease monitoring and drug carriers.

The complement system as a regulator of tumor-promoting activities mediated by myeloid-derived suppressor cells

Tumor progression relies on the interaction between tumor cells and their surrounding tumor microenvironment (TME), which also influences therapeutic responses. The complement system, an essential part of innate immunity, has been traditionally considered an effector arm against tumors. However, established tumors co-opt complement-mediated immune responses in the TME to support chronic inflammation, activate cancer-related signaling pathways and hamper antitumor immune responses. In this context, myeloid-derived suppressor cells (MDSCs), a heterogeneous population of myeloid progenitors with immunosuppressive functions, are recognized as major mediators of tumor-associated complement activities. This review focuses on the impact of complement activation within the TME, with a special emphasis on MDSC functions and the involvement of the C5a/C5aR1 axis. We also discuss the translation of these findings into therapeutic advances based on complement inhibition.

IgG+ Extracellular Vesicles Measure Therapeutic Response in Advanced Pancreatic Cancer

(1) Background: Pancreatic ductal adenocarcinoma (PDAC) is expected to be the second-leading cause of cancer deaths by 2030. Imaging techniques are the standard for monitoring the therapy response in PDAC, but these techniques have considerable limits, including delayed disease progression detection and difficulty in distinguishing benign from malignant lesions. Extracellular vesicle (EV) liquid biopsy is an emerging diagnosis modality. Nonetheless, the majority of research for EV-based diagnosis relies on point analyses of EVs at specified times, while longitudinal EV population studies before and during therapeutic interventions remain largely unexplored. (2) Methods: We analyzed plasma EV protein composition at diagnosis and throughout PDAC therapy. (3) Results: We found that IgG is linked with the diagnosis of PDAC and the patient’s response to therapy, and that the IgG+ EV population increases with disease progression and reduces with treatment response. Importantly, this covers PDAC patients devoid of the standard PDAC seric marker CA19.9 expression. We also observed that IgG is bound to EVs via the tumor antigen MAGE B1, and that this is independent of the patient’s inflammatory condition and IgG seric levels. (4) Conclusions: We here propose that a population analysis of IgG+ EVs in PDAC plasma represents a novel method to supplement the monitoring of the PDAC treatment response.

Extracellular vesicle-mediated immunoregulation in cancer

Extracellular vesicles (EVs) have emerged as immunomodulatory regulators during tumor progression. These small vesicles encapsulate a variety of molecules, including DNA, RNA, and proteins. When EVs come in contact with recipient cells, the EVs transmit various physiological characteristics; for example, proteins on the surface of EVs act as ligands. Immune checkpoint blockade targeting cytotoxic T-lymphocyte-associated antigen 4 (CTLA4), programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) has shown promise in a subset of cancer patients. PD-L1 on EVs acts as a key immunomodulator. Suppression of EV secretion enhances the efficacy of immunotherapy using immune checkpoint blockade antibodies. In addition to immune checkpoint blockade therapy, chimeric antigen receptor T (CAR-T) cell therapy has also been used to successfully eliminate cancer cells. Interestingly, CAR-T-cell-derived EVs express CAR on their surface. Compared with CAR-T cells, CAR-expressing EVs do not express PD1, so their antitumor effect cannot be weakened. In this review, we describe the current understanding of EVs in cancer immunity and summarize their crucial roles in immunomodulation.

A Comprehensive Search of Non-Canonical Proteins in Non-Small Cell Lung Cancer and Their Impact on the Immune Response

There is substantial interest in mining neoantigens for cancer applications. Non-canonical proteins resulting from frameshift mutations have been identified as neoantigens in cancer. We investigated the landscape of non-canonical proteins in non-small cell lung cancer (NSCLC) and their induced immune response in the form of autoantibodies. A database of cryptoproteins was computationally constructed and comprised all alternate open reading frames (altORFs) and ORFs identified in pseudogenes, noncoding RNAs, and untranslated regions of mRNAs that did not align with known canonical proteins. Proteomic profiles of seventeen lung adenocarcinoma (LUAD) cell lines were searched to evaluate the occurrence of cryptoproteins. To assess the immunogenicity, immunoglobulin (Ig)-bound cryptoproteins in plasmas were profiled by mass spectrometry. The specimen set consisted of plasmas from 30 newly diagnosed NSCLC cases, pre-diagnostic plasmas from 51 NSCLC cases, and 102 control plasmas. An analysis of LUAD cell lines identified 420 cryptoproteins. Plasma Ig-bound analyses revealed 90 cryptoproteins uniquely found in cases and 14 cryptoproteins that had a fold-change >2 compared to controls. In pre-diagnostic samples, 17 Ig-bound cryptoproteins yielded an odds ratio ≥2. Eight Ig-bound cryptoproteins were elevated in both pre-diagnostic and newly diagnosed cases compared to controls. Cryptoproteins represent a class of neoantigens that induce an autoantibody response in NSCLC.

Selective isolation of extracellular vesicles from minimally processed human plasma as a translational strategy for liquid biopsies

Background

Intercellular communication is mediated by extracellular vesicles (EVs), as they enclose selectively packaged biomolecules that can be horizontally transferred from donor to recipient cells. Because all cells constantly generate and recycle EVs, they provide accurate timed snapshots of individual pathophysiological status. Since blood plasma circulates through the whole body, it is often the biofluid of choice for biomarker detection in EVs. Blood collection is easy and minimally invasive, yet reproducible procedures to obtain pure EV samples from circulating biofluids are still lacking. Here, we addressed central aspects of EV immunoaffinity isolation from simple and complex matrices, such as plasma.

Methods

Cell-generated EV spike-in models were isolated and purified by size-exclusion chromatography, stained with cellular dyes and characterized by nano flow cytometry. Fluorescently-labelled spike-in EVs emerged as reliable, high-throughput and easily measurable readouts, which were employed to optimize our EV immunoprecipitation strategy and evaluate its performance. Plasma-derived EVs were captured and detected using this straightforward protocol, sequentially combining isolation and staining of specific surface markers, such as CD9 or CD41. Multiplexed digital transcript detection data was generated using the Nanostring nCounter platform and evaluated through a dedicated bioinformatics pipeline.

Results

Beads with covalently-conjugated antibodies on their surface outperformed streptavidin-conjugated beads, coated with biotinylated antibodies, in EV immunoprecipitation. Fluorescent EV spike recovery evidenced that target EV subpopulations can be efficiently retrieved from plasma, and that their enrichment is dependent not only on complex matrix composition, but also on the EV surface phenotype. Finally, mRNA profiling experiments proved that distinct EV subpopulations can be captured by directly targeting different surface markers. Furthermore, EVs isolated with anti-CD61 beads enclosed mRNA expression patterns that might be associated to early-stage lung cancer, in contrast with EVs captured through CD9, CD63 or CD81. The differential clinical value carried within each distinct EV subset highlights the advantages of selective isolation.

Conclusions

This EV isolation protocol facilitated the extraction of clinically useful information from plasma. Compatible with common downstream analytics, it is a readily implementable research tool, tailored to provide a truly translational solution in routine clinical workflows, fostering the inclusion of EVs in novel liquid biopsy settings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40364-022-00404-1.