Interferon regulatory factor 1 priming of tumour-derived exosomes enhances the antitumour immune response

Extracellular vesicles as nature's nano carriers in cancer therapy: insights toward preclinical studies and clinical applications

Extracellular vesicles (EVs), which are secreted by various cell types, hold significant potential for cancer therapy. However, there are several challenges and difficulties that limit their application in clinical settings. This review, which integrates the work of our team and recent advancements in this research field, discusses EV-based cancer treatment strategies to guide their clinical application. The following treatment strategies are discussed: 1) leveraging the inherent properties of EVs for the development of cancer treatments; 2) modifying EVs using EV engineering methods to improve drug loading and delivery; 3) targeting key molecules in tumor-derived EV (TDE) synthesis to inhibit their production; and 4) clearing TDEs from the tumor microenvironment. Additionally, on the basis of research into EV-based vaccines and bispecific antibodies, this review elaborates on strategies to enhance antitumor immunity via EVs and discusses engineering modifications that can improve EV targeting ability and stability and the research progress of AI technology in targeted delivery of EV drugs. Although there are limited strategies for enhancing EV targeting abilities, this review provides an in-depth discussion of prior studies. Finally, this review summarizes the clinical progress on the use of EVs in cancer therapy and highlights challenges that need to be addressed.

Recent progress in cancer vaccines and nanovaccines

Vaccine science, nanotechnology, and immunotherapy are at the forefront of cancer treatment strategies, each offering significant potential for enhancing tumor-specific immunity and establishing long-lasting immune memory to prevent tumor recurrence. Despite the promise of these personalized and precision-based anti-cancer approaches, challenges such as immunosuppression, suboptimal immune activation, and T-cell exhaustion continue to hinder their effectiveness. The limited clinical success of cancer vaccines often stems from difficulties in identifying effective antigens, efficiently targeting immune cells, lymphoid organs, and the tumor microenvironment, overcoming immune evasion, enhancing immunogenicity, and avoiding lysosomal degradation. However, numerous studies have demonstrated that integrating nanotechnology with immunotherapeutic strategies in vaccine development can overcome these challenges, leading to potent antitumor immune responses and significant progress in the field. This review highlights the critical components of cancer vaccine and nanovaccine strategies for immunomodulatory antitumor therapy. It covers general vaccine strategies, types of vaccines, antigen forms, nanovaccine platforms, challenges faced, potential solutions, and key findings from preclinical and clinical studies, along with future perspectives. To fully unlock the potential of cancer vaccines and nanovaccines, precise immunological monitoring during early-phase trials is essential. This approach will help identify and address obstacles, ultimately expanding the available options for patients who are resistant to conventional cancer immunotherapies.

Extracellular vesicles-based vaccines: Emerging immunotherapies against cancer

Cancer vaccines are promising therapeutic approaches to enhance specific T-cell immunity against most solid tumors. By stimulating anti-tumor immunity, clearing minimal residual disease, and minimizing adverse effects, these vaccines target tumor cells and are effective when combined with immune checkpoint blockade or other immunotherapies. However, the development of tumor cell-based vaccines faces quality issues due to poor immunogenicity, tumor heterogeneity, a suppressive tumor immune microenvironment, and ineffective delivery methods. In contrast, extracellular vesicles (EVs), naturally released by cells, are considered the ideal drug carriers and vaccine platforms. EVs offer highly organ-specific targeting, induce broader and more effective immune responses, and demonstrate superior tissue delivery ability. The development of EV vaccines is crucial for advancing cancer immunotherapy. Compared to cell-based vaccines, EV vaccines produced under Good Manufacturing Practices (GMP) offer advantages such as high safety, ease of preservation and transport, and a wide range of sources. This review summarizes the latest research findings on EV vaccine and potential applications in this field. It also highlights novel neoantigens for the development of EV vaccines against cancer.

Interferon regulatory factor 1 mediated inhibition of Treg cell differentiation induces maternal-fetal immune imbalance in preeclampsia

The establishment and maintenance of a successful pregnancy rely heavily on maternal-fetal immune tolerance. Inflammatory and immune mechanisms during pregnancy bear a resemblance to those observed in tumor progression, with Treg cells exhibiting similar immunoregulatory functions in both contexts. Interferon regulatory factor 1 (IRF1) is implicated in modulating the immune milieu within tumors and influencing regulatory T (Treg) cell differentiation. However, the precise association between IRF1 and the onset of preeclampsia (PE) remains unclear. In our investigation, we identified trophoblasts as a significant source of IRF1 expression at the maternal-fetal interface through immunofluorescence analysis. Moreover, heightened levels of IRF1 expression were detected in both placental tissues and peripheral blood samples obtained from PE patients, concomitant with an imbalance in the Th17/Treg ratio. In the peripheral circulation, a notable inverse correlation was observed between IRF1 mRNA levels and Foxp3 mRNA, a transcription factor specific to Treg cells. IRF1 mRNA expression showed a positive association with systolic blood pressure and a negative association with serum albumin levels. Furthermore, co-culturing naïve T cells with supernatants from HTR-8/SV neo cells overexpressing IRF1 resulted in diminished differentiation of T cells into Treg cells. In summary, our study indicates elevated IRF1 expression in the peripheral blood and trophoblast cells of PE patients. Elevated IRF1 in trophoblast cells hinders the differentiation of maternal Treg cells, disrupting maternal-fetal immune tolerance and contributing to PE pathogenesis. Additionally, IRF1 expression correlates with disease severity, suggesting its potential as a novel sensitive target in PE.

Tumor Microenvironment-Derived Exosomes: A Double-Edged Sword for Advanced T Cell-Based Immunotherapy

The tumor microenvironment (TME) plays a crucial role in cancer progression and immune evasion, partially mediated by the activity of the TME-derived exosomes. These extracellular vesicles are pivotal in shaping immune responses through the transfer of proteins, lipids, and nucleic acids between cells, facilitating a complex interplay that promotes tumor growth and metastasis. This review delves into the dual roles of exosomes in the TME, highlighting both their immunosuppressive functions and their emerging therapeutic potential. Exosomes can inhibit T cell function and promote tumor immune escape by carrying immune-modulatory molecules, such as PD-L1, yet they also hold promise for cancer therapy as vehicles for delivering tumor antigens and costimulatory signals. Additionally, the review discusses the intricate crosstalk mediated by exosomes among various cell types within the TME, influencing both cancer progression and responses to immunotherapies. Moreover, this highlights current challenges and future directions. Collectively, elucidating the detailed mechanisms by which TME-derived exosomes mediate T cell function offers a promising avenue for revolutionizing cancer treatment. Understanding these interactions allows for the development of targeted therapies that manipulate exosomal pathways to enhance the immune system's response to tumors.

Exosome-based anticancer vaccines: From Bench to bedside

Exosomes, a subset of extracellular vesicles, are released by all active cells and play a crucial role in intercellular communications. Exosomes could facilitate the transfer of various biologically active molecules, such as DNA, non-coding RNAs, and proteins, from donor to recipient cells, thereby participating in diverse biological and pathological processes. Besides, exosomes possess unique characteristics, including non-toxicity, low-immunogenicity, and stability within biological systems, rendering them highly advantageous for cancer drug development. Meanwhile, accumulating evidence suggests that exosomes originating from tumor cells and immune cells possess distinct composition profiles that play a direct role in anticancer immunotherapy. Of note, exosomes can transport their contents to specific cells, thereby exerting an impact on the phenotype and immune-regulatory functions of targeted cells. Therapeutic cancer vaccines, an emerging therapeutics of immunotherapy, could enhance antitumor immune responses by delivering a large number of tumor antigens, thereby augmenting the immune response against tumor cells. Therefore, the therapeutic rationale of cancer vaccines and exosome-based immunotherapy are almost similar to some extent, but some challenges have hindered their application in the clinical setting. Here, in this review, we first summarized the biogenesis, structure, compositions, and biological functions of exosomes. Then we described the roles of exosomes in cancer biology, particularly in tumor immunity. We also comprehensively reviewed current exosome-based anticancer vaccine development and we divided them into three types. Finally, we give some insights into clinical translation and clinical trial progress of exosome-based anticancer vaccines for future direction.

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.

A Large-Scale Meta-Analysis Reveals Positive Feedback between Macrophages and T Cells That Sensitizes Tumors to Immunotherapy

Although considerable efforts have been dedicated to identifying predictive signatures for immune checkpoint inhibitor (ICI) treatment response, current biomarkers suffer from poor generalizability and reproducibility across different studies and cancer types. The integration of large-scale multiomics studies holds great promise for discovering robust biomarkers and shedding light on the mechanisms of immune resistance. In this study, we conducted the most extensive meta-analysis involving 3,037 ICI-treated patients with genetic and/or transcriptomics profiles across 14 types of solid tumor. The comprehensive analysis uncovered both known and novel reliable signatures associated with ICI treatment outcomes. The signatures included tumor mutational burden (TMB), IFNG and PDCD1 expression, and notably, interactions between macrophages and T cells driving their activation and recruitment. Independent data from single-cell RNA sequencing and dynamic transcriptomic profiles during the ICI treatment provided further evidence that enhanced cross-talk between macrophages and T cells contributes to ICI response. A multivariable model based on eight nonredundant signatures significantly outperformed existing models in five independent validation datasets representing various cancer types. Collectively, this study discovered biomarkers predicting ICI response that highlight the contribution of immune cell networks to immunotherapy efficacy and could help guide patient treatment.

SIGNIFICANCE

Identification of robust immunogenomic connections, particularly macrophage T-cell interactions, in a large-scale pan-cancer meta-analysis and development of a predictive model for immunotherapy response that outperformed existing models could facilitate clinical decision-making.

Identification of a targetable JAK-STAT enriched androgen receptor and androgen receptor splice variant positive triple-negative breast cancer subtype

Triple-negative breast cancer (TNBC) is an aggressive subtype with no targeted therapeutics. The luminal androgen receptor (LAR) subtype constitutes 15% of TNBC and is enriched for androgen receptor (AR) and AR target genes. Here, we show that a cohort of TNBC not only expresses AR at a much higher rate (∼80%) but also expresses AR splice variants (AR-SVs) (∼20%), further subclassifying LAR-TNBC. Higher AR and AR-SV expression and corresponding aggressive phenotypes are observed predominantly in specimens obtained from African American women. LAR TNBC specimens are enriched for interferon, Janus kinase (JAK)-signal activator and transducer (STAT), and androgen signaling pathways, which are exclusive to AR-expressing epithelial cancer cells. AR- and AR-SV-expressing TNBC cell proliferation and xenograft and patient-tumor explant growth are inhibited by AR N-terminal domain-binding selective AR degrader or by a JAK inhibitor. Biochemical analysis suggests that STAT1 is an AR coactivator. Collectively, our work identifies pharmacologically targetable TNBC subtypes and identifies growth-promoting interaction between AR and JAK-STAT signaling.

Extracellular Vesicles as Delivery Systems in Disease Therapy

Extracellular vesicles (EVs)/exosomes are nanosized membrane-bound structures that are released by virtually all cells. EVs have attracted great attention in the scientific community since the discovery of their roles in cell-to-cell communication. EVs' enclosed structure protects bioactive molecules from degradation in the extracellular space and targets specific tissues according to the topography of membrane proteins. Upon absorption by recipient cells, EV cargo can modify the transcription machinery and alter the cellular functions of these cells, playing a role in disease pathogenesis. EVs have been tested as the delivery system for the mRNA COVID-19 vaccine. Recently, different therapeutic strategies have been designed to use EVs as a delivery system for microRNAs and mRNA. In this review, we will focus on the exciting and various platforms related to using EVs as delivery vehicles, mainly in gene editing using CRISPR/Cas9, cancer therapy, drug delivery, and vaccines. We will also touch upon their roles in disease pathogenesis.

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.

Hepatocellular carcinoma-derived FOXO1 inhibits tumor progression by suppressing IL-6 secretion from macrophages

Tumor heterogeneity dominates tumor biological behavior and shapes the tumor microenvironment. However, the mechanisms of tumor genetic features modulate immunity response were not clearly clarified. Tumor associated macrophages (TAMs) exert distinct immune functions in the progression of hepatocellular carcinoma (HCC) based on the inducible phenotype. FOXO family members sense changes in the extracellular or intracellular environment by activating a series of signaling pathways. FOXO1, a transcription factor that a common suppressor in hepatocellular carcinoma, correlated with a better tumor biological behavior in HCC through shaping macrophages anti-tumour response. Here, we found that human HCC tissue microarray (TMA) slides were employed to showed tumor derived FOXO1 negatively related with distribution of protumour macrophages. This phenomenon was confirmed in mouse xenograft model and in vitro. HCC-derived FOXO1 inhibits tumorigenesis not only by targeting tumor cells but also by synchronizing with re-educated macrophages. These effects may be partially dependent on FOXO1 transcriptionally modulates IRF-1/nitrio oxide (NO) axis in exerting effects in macrophages and decreasing IL-6 releasing from macrophages in tumor microenvironment indirectly. This feedback suppressed the progression of HCC by inactivation of IL-6/STAT3 in HCC. It implicates the potential role of FOXO1 in the therapeutic effects for modulating immune response by targeting macrophages.

Extracellular vesicles as next generation immunotherapeutics

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

Sea Cucumber Derived Triterpenoid Glycoside Frondoside A: A Potential Anti-Bladder Cancer Drug

Bladder cancer is a highly recurrent disease and a common cause of cancer-related deaths worldwide. Despite recent developments in diagnosis and therapy, the clinical outcome of bladder cancer remains poor; therefore, novel anti-bladder cancer drugs are urgently needed. Natural bioactive substances extracted from marine organisms such as sea cucumbers, scallops, and sea urchins are believed to have anti-cancer activity with high effectiveness and less toxicity. Frondoside A is a triterpenoid glycoside isolated from sea cucumber, Cucumaria frondosa. It has been demonstrated that Frondoside A exhibits anti-proliferative, anti-invasive, anti-angiogenic, anti-cancer, and potent immunomodulatory effects. In addition, CpG oligodeoxynucleotide (CpG-ODN) has also been shown to have potent anti-cancer effects in various tumors models, such as liver cancer, breast cancer, and bladder cancer. However, very few studies have investigated the effectiveness of Frondoside A against bladder cancer alone or in combination with CpG-ODN. In this study, we first investigated the individual effects of both Frondoside A and CpG-ODN and subsequently studied their combined effects on human bladder cancer cell viability, migration, apoptosis, and cell cycle in vitro, and on tumor growth in nude mice using human bladder cancer cell line UM-UC-3. To interrogate possible synergistic effects, combinations of different concentrations of the two drugs were used. Our data showed that Frondoside A decreased the viability of bladder cancer cells UM-UC-3 in a concentration-dependent manner, and its inhibitory effect on cell viability (2.5 μM) was superior to EPI (10 μM). We also showed that Frondoside A inhibited UM-UC-3 cell migration, affected the distribution of cell cycle and induced cell apoptosis in concentration-dependent manners, which effectively increased the sub-G1 (apoptotic) cell fraction. In addition, we also demonstrated that immunomodulator CpG-ODN could synergistically potentiate the inhibitory effects of Frondoside A on the proliferation and migration of human bladder cancer cell line UM-UC-3. In in vivo experiments, Frondoside A (800 μg/kg/day i.p. for 14 days) alone and in combination with CpG-ODN (1 mg/kg/dose i.p.) significantly decreased the growth of UM-UC-3 tumor xenografts, without any significant toxic side-effects; however, the chemotherapeutic agent EPI caused weight loss in nude mice. Taken together, these findings indicated that Frondoside A in combination with CpG-ODN is a promising therapeutic strategy for bladder cancer.

Tumor-Derived Extracellular Vesicles in Cancer Immunoediting and Their Potential as Oncoimmunotherapeutics

The tumor microenvironment (TME) within and around a tumor is a complex interacting mixture of tumor cells with various stromal cells, including endothelial cells, fibroblasts, and immune cells. In the early steps of tumor formation, the local microenvironment tends to oppose carcinogenesis, while with cancer progression, the microenvironment skews into a protumoral TME and the tumor influences stromal cells to provide tumor-supporting functions. The creation and development of cancer are dependent on escape from immune recognition predominantly by influencing stromal cells, particularly immune cells, to suppress antitumor immunity. This overall process is generally called immunoediting and has been categorized into three phases; elimination, equilibrium, and escape. Interaction of tumor cells with stromal cells in the TME is mediated generally by cell-to-cell contact, cytokines, growth factors, and extracellular vesicles (EVs). The least well studied are EVs (especially exosomes), which are nanoparticle-sized bilayer membrane vesicles released by many cell types that participate in cell/cell communication. EVs carry various proteins, nucleic acids, lipids, and small molecules that influence cells that ingest the EVs. Tumor-derived extracellular vesicles (TEVs) play a significant role in every stage of immunoediting, and their cargoes change from immune-activating in the early stages of immunoediting into immunosuppressing in the escape phase. In addition, their cargos change with different treatments or stress conditions and can be influenced to be more immune stimulatory against cancer. This review focuses on the emerging understanding of how TEVs affect the differentiation and effector functions of stromal cells and their role in immunoediting, from the early stages of immunoediting to immune escape. Consideration of how TEVs can be therapeutically utilized includes different treatments that can modify TEV to support cancer immunotherapy.

Extracellular Vesicle Mimetics: Preparation from Top-Down Approaches and Biological Functions

Extracellular vesicles (EVs) have attracted attention as delivery vehicles due to their structure, composition, and unique properties in regeneration and immunomodulation. However, difficulties during production and isolation processes of EVs limit their large-scale clinical applications. EV mimetics (EVMs), prepared via top-down strategies that improve the yield of nanoparticles while retaining biological properties similar to those of EVs have been used to address these limitations. Herein, the preparation of EVMs is reviewed and their characteristics in terms of structure, composition, targeting ability, cellular uptake mechanism, and immunogenicity, as well as their strengths, limitations, and future clinical application prospects as EV alternatives are summarized.

Extracellular vesicles deliver sodium iodide symporter protein and promote cancer cell radioiodine therapy

Extracellular vesicles (EVs) are a promising carrier for various cargos with antitumor effects, but their capacity to transfer the ability to transport radioiodine for cancer theranostics remains unexplored. Herein, we tested the hypothesis that EVs can be loaded with the sodium iodide symporter (NIS) protein and efficiently deliver the payload to recipient cancer cells to facilitate radioiodine uptake. The results revealed that donor cells either transduced with an adenoviral vector for transient expression or engineered for stable overexpression secreted EVs that contained substantial amounts of NIS protein but not NIS mRNA. Huh7 liver cancer cells treated with EVs secreted from each of the donor cell types showed significantly increased plasma membrane NIS protein, indicating efficient payload delivery. Furthermore, intact function of the delivered NIS protein was confirmed by significantly increased radioiodine transport in recipient cancer cells that peaked at 48 h. Importantly, NIS protein delivered by EVs significantly enhanced the antitumor effects of ¹³¹I radiotherapy. These results reveal that EVs are a promising vehicle to deliver NIS protein to cancer cells in sufficient amounts for radioiodine-based theranostics.

The therapeutic potential of exosomes derived from different cell sources in liver diseases

Exosomes are small nanovesicles with a size of approximately 40-120 nm that are secreted from cells. They are involved in the regulation of cell homeostasis and mediate intercellular communication. In addition, they carry proteins, nucleic acids, and lipids that regulate the biological activity of receptor cells. Recent studies have shown that exosomes perform important functions in liver diseases. This review will focus on liver diseases (drug-induced liver injury, hepatic ischemia-reperfusion injury, liver fibrosis, acute liver failure, and hepatocellular carcinoma) and summarize the therapeutic potential of exosomes from different cell sources in liver disease.

Mesenchymal Stem Cell-Derived Extracellular Vesicles and Their Therapeutic Use in Central Nervous System Demyelinating Disorders

Autoimmune demyelinating diseases-including multiple sclerosis, neuromyelitis optica spectrum disorder, anti-myelin oligodendrocyte glycoprotein-associated disease, acute disseminated encephalomyelitis, and glial fibrillary acidic protein (GFAP)-associated meningoencephalomyelitis-are a heterogeneous group of diseases even though their common pathology is characterized by neuroinflammation, loss of myelin, and reactive astrogliosis. The lack of safe pharmacological therapies has purported the notion that cell-based treatments could be introduced to cure these patients. Among stem cells, mesenchymal stem cells (MSCs), obtained from various sources, are considered to be the ones with more interesting features in the context of demyelinating disorders, given that their secretome is fully equipped with an array of anti-inflammatory and neuroprotective molecules, such as mRNAs, miRNAs, lipids, and proteins with multiple functions. In this review, we discuss the potential of cell-free therapeutics utilizing MSC secretome-derived extracellular vesicles-and in particular exosomes-in the treatment of autoimmune demyelinating diseases, and provide an outlook for studies of their future applications.

Coronavirus Porcine Deltacoronavirus Upregulates MHC Class I Expression through RIG-I/IRF1-Mediated NLRC5 Induction

Major histocompatibility complex class I (MHC-I) and MHC-II molecules, mainly being responsible for the processing and presentation of intracellular or extracellular antigen, respectively, are critical for antiviral immunity. Here, we reported that porcine deltacoronavirus (PDCoV) with the zoonotic potential and potential spillover from pigs to humans, upregulated the expressions of porcine MHC-I (swine leukocyte antigen class I, SLA-I) molecules and SLA-I antigen presentation associated genes instead of porcine MHC-II (SLA-II) molecules both in primary porcine enteroids and swine testicular (ST) cells at the late stage of infection, and this finding was verified in vivo. Moreover, the induction of SLA-I molecules by PDCoV infection was mediated through enhancing the expression of NOD-like receptor (NLR) family caspase recruitment domain-containing 5 (NLRC5). Mechanistic studies demonstrated that PDCoV infection robustly elevated retinoic acid-inducible gene I (RIG-I) expression, and further initiated the downstream type I interferon beta (IFN-β) production, which led to the upregulation of NLRC5 and SLA-I genes. Likewise, interferon regulatory factor 1 (IRF1) elicited by PDCoV infection directly activated the promoter activity of NLRC5, resulting in an increased expression of NLRC5 and SLA-I upregulation. Taken together, our findings advance our understanding of how PDCoV manipulates MHC molecules, and knowledge that could help inform the development of therapies and vaccines against PDCoV. IMPORTANCE MHC-I molecules play a crucial role in antiviral immunity by presenting intracellular antigens to CD8⁺T lymphocytes and eliminating virus-infected cells by natural killer cells' "missing-self recognition." However, the manipulation of MHC molecules by coronaviruses remains poorly understood. Here, we demonstrated that PDCoV, a zoonotic potential coronavirus efficiently infecting cells from broad species, greatly increased the expressions of porcine MHC-I (SLA-I) molecules and MHC-I antigen presentation associated genes but not porcine MHC-II (SLA-II) molecules both in vitro and in vivo. Mechanistically, the upregulation of MHC-I molecules by PDCoV infection required the master transactivator of MHC-I, NLRC5, which was mediated not only by RIG-I-initiated type I IFN signaling pathway but also by IRF1 induced by PDCoV as it could activate NLRC5 promoter activity. These results provide significant insights into the modification of the MHC class I pathway and may provide a potential therapeutic intervention for PDCoV.

Exosomes for Regulation of Immune Responses and Immunotherapy

Exosomes are membrane-enveloped nanosized (30–150 nm) extracellular vesicles of endosomal origin produced by almost all cell types and encompass a multitude of functioning biomolecules. Exosomes have been considered crucial players of cell-to-cell communication in physiological and pathological conditions. Accumulating evidence suggests that exosomes can modulate the immune system by delivering a plethora of signals that can either stimulate or suppress immune responses, which have potential applications as immunotherapies for cancer and autoimmune diseases. Here, we discuss the current knowledge about the active biomolecular components of exosomes that contribute to exosomal function in modulating different immune cells and also how these immune cell-derived exosomes play critical roles in immune responses. We further discuss the translational potential of engineered exosomes as immunotherapeutic agents with their advantages over conventional nanocarriers for drug delivery and ongoing clinical trials.

Overexpression of OASL upregulates TET1 to induce aberrant activation of CD4+ T cells in systemic sclerosis via IRF1 signaling

Background

Systemic sclerosis (SSc), an autoimmune disease with unknown etiology and pathogenesis, is characterized by abnormal autoimmunity, vascular dysfunction, and progressive fibrosis of skin and organs. Studies have shown that a key factor in the pathogenesis of SSc is aberrant activation of CD4⁺ T cells. Our previous studies have shown that a global hypomethylation state of CD4⁺ T cells is closely related to aberrant activation. However, the exact mechanism of hypomethylation in CD4+T cells is not yet clear.

Methods

Illumina HiSeq 2500 Platform was used to screen differentially expressed genes and explore the role of OASL, TET1, and IRF1 in the abnormal activation of CD4+T cells in SSc. Finally, double luciferase reporter gene experiments were used to analyze the interaction between IRF1 and TET1.

Results

OASL overexpression could upregulate TET1 to increase the hydroxymethylation levels of CD4+ T cells and induce high expression of functional proteins (CD40L and CD70), thus promoting CD4+T cell aberrant activation. Moreover, OASL upregulated TET1 via IRF1 signaling activation, and a double luciferase reporter gene experiment revealed that IRF1 can bind to the TET1 promoter region to regulate its expression.

Conclusions

OASL participates in the regulation of abnormal hypomethylation of CD4+ T cells in SSc, which implies a pivotal role for IFN signaling in the pathogenesis of SSc. Regulating DNA methylation and IFN signaling may serve as therapeutic treatments in SSc.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02741-w.

Exosomes: Biological Pharmaceutical Nanovectors for Theranostics

Exosomes are natural cell-derived nanovesicles of endocytic origin that enable cellular crosstalk by transferring encapsulated molecular cargos across biological barriers, thereby holding significantly complex implications in the etiology and progression of diverse disease states. Consequently, the development of exosomes-based nano-theranostic strategies has received immense consideration for advancing therapeutic interventions and disease prognosis. Their favorable biopharmaceutical properties make exosomes a unique nanoparticulate carrier for pharmaceutical drug delivery. This review provides an update on the contemporary strategies utilizing exosomes for theranostic applications in nanomedicine. In addition, we provide a synopsis of exosomal features and insights into strategic modifications that control in vivo biodistribution. We further discuss their opportunities, merits and pitfalls for cell/tissue targeted drug delivery in personalized nanotherapy.

Biomembrane-based nanostructures for cancer targeting and therapy: From synthetic liposomes to natural biomembranes and membrane-vesicles

The translational success of liposomes in chemotherapeutics has already demonstrated the great potential of biomembrane-based nanostructure in effective drug delivery. Meanwhile, increasing efforts are being dedicated to the application of naturally derived lipid membranes, including cellular membranes and extracellular vesicles in anti-cancer therapies. While synthetic liposomes support superior multifunctional flexibility, natural biomembrane materials possess interesting biomimetic properties and can also be further engineered for intelligent design. Despite being remarkably different from each other in production and composition, the phospholipid bilayer structure in common allows liposomes, cell membrane-derived nanomaterials, and extracellular vesicles to be modified, functionalized, and exploited in many similar manners against challenges posed by tumor-targeted drug delivery. This review will summarize the recent advancements in engineering the membrane-derived nanostructures with "intelligent" modules to respond, regulate, and target tumor cells and the microenvironment to fight against malignancy. We will also discuss perspectives of combining engineered functionalities with naturally occurring activity for enhanced cancer therapy.

Tumor-Derived Extracellular Vesicles: Their Role in Immune Cells and Immunotherapy

Nowadays, tumor has been the serious threat to human health and life. To further explore the mechanism of tumor genesis and development is necessarily for developing the effective treatment strategy. Extracellular vesicles are the vesicles secreted by almost all types of cells, and they play an important part in intercellular communication by transporting their cargoes. Immune cells are the vital components of the human defense system, which defense against infection and tumor through cytotoxicity, immune surveillance, and clearance. However, via release tumor-derived extracellular vesicles, tumor could induce immune cells dysfunction to facilitate its proliferation and metastasis. Studies have shown that tumor-derived extracellular vesicles play dual role on immune cells by their specific cargoes. Here, we reviewed the effects of tumor-derived extracellular vesicles on immune cells in recent years and also summarized their research progress in the tumor immunotherapy and diagnosis.

Long-Residence Pneumonia Vaccine Developed Using PEG-Grafted Hybrid Nanovesicles from Cell Membrane Fusion of Mycoplasma and IFN-γ-Primed Macrophages

CD8⁺ T cell responses play a critical regulatory role in protection against mycoplasma infection-related respiratory diseases. Nanovesicles derived from cell membranes have been shown to induce CD8⁺ T cell responses. Moreover, the short residence time of mycoplasma membrane-related vaccines in local lymph nodes limits the efficacy of current mycoplasma vaccines. Here, a long-residence pneumonia vaccine is developed using nanovesicles prepared by cell membrane fusion of Mycoplasma hyopneumoniae and interferon-γ (IFN-γ   )-primed macrophages, which are grafted with polyethylene glycol to increase residence time in the lymph nodes. Upregulation of intercellular adhesion molecule-1 (ICAM-1) on the membrane of IFN-γ-primed macrophages increases the targeting of the hybrid nanovesicle vaccine to the local lymph nodes, with increased CD8⁺ T cell activation. A mechanistic study reveals that CD8⁺ T cell activation is achieved via a pathway involving upregulation of C-C motif chemokine ligand 2/3 expression by E26 transformation-specific sequences, followed by increased immune-stimulatory activity of dendritic cells. In vivo, prophylactic testing reveals that the hybrid nanovesicle vaccine triggers a long-term immune response, as evidenced by a memory CD8⁺ T cell response against mycoplasma infection. The current study provides a new design strategy for mycoplasma vaccines that involves a hybrid method using biological sources and artificial modification.

Exosome-Based Vaccines: History, Current State, and Clinical Trials

Extracellular vesicles (EVs) are released by most cell types as part of an intracellular communication system in crucial processes such as inflammation, cell proliferation, and immune response. However, EVs have also been implicated in the pathogenesis of several diseases, such as cancer and numerous infectious diseases. An important feature of EVs is their ability to deliver a wide range of molecules to nearby targets or over long distances, which allows the mediation of different biological functions. This delivery mechanism can be utilized for the development of therapeutic strategies, such as vaccination. Here, we have highlighted several studies from a historical perspective, with respect to current investigations on EV-based vaccines. For example, vaccines based on exosomes derived from dendritic cells proved to be simpler in terms of management and cost-effectiveness than dendritic cell vaccines. Recent evidence suggests that EVs derived from cancer cells can be leveraged for therapeutics to induce strong anti-tumor immune responses. Moreover, EV-based vaccines have shown exciting and promising results against different types of infectious diseases. We have also summarized the results obtained from completed clinical trials conducted on the usage of exosome-based vaccines in the treatment of cancer, and more recently, coronavirus disease.

IRF1 regulates the progression of colorectal cancer via interferon‑induced proteins

Radiation is one of the main methods for the treatment of colorectal cancer (CRC) before or after surgery. However, radiotherapy tolerance of patients with CRC is often a major concern. Interferon regulatory factor 1 (IRF1) is a member of the IRF family and is involved in the development of multiple diseases, including tumors. The present study investigated the role of IRF1 in the development and radiation sensitivity of CRC. Immunohistochemistry was performed to examine the expression levels of IRF1 in tissue samples from patients with CRC, as well as in nude mice. MTT, 5‑ethynyl‑20‑deoxyuridine, colony formation, cell cycle alteration and apoptosis assays were performed in CRC cell lines. Western blotting and immunofluorescence were used to detect the expression levels of a series of proteins. RNA sequencing was applied to identify genes whose expression was upregulated by IRF1 overexpression. Xenograft nude mouse models and hematoxylin and eosin staining were used to validate the present findings in vivo. It was revealed that the expression levels of IRF1 were significantly lower in CRC tissues than in adjacent tissues. IRF1 upregulation inhibited cell proliferation and colony formation, caused G1 cell arrest, promoted cell apoptosis, and enhanced the sensitivity of CRC cells to X‑ray irradiation. The role of IRF1 in promoting the radiosensitivity of CRC was further demonstrated in nude mice with CRC xenografts. In addition, RNA sequencing revealed that overexpression of IRF1 in CRC cells significantly increased the expression levels of interferon‑induced protein family members interferon α inducible protein 6, interferon induced transmembrane protein 1 and interferon induced protein 35 (fold change >2.0). In summary, the present study demonstrated that the upregulation of IRF1 inhibited the progression and promoted the radiosensitivity of CRC, likely by regulating interferon‑induced proteins.

Interferon regulatory factor 1(IRF-1) activates anti-tumor immunity via CXCL10/CXCR3 axis in hepatocellular carcinoma (HCC)

Interferon regulatory factor 1 (IRF-1) is a tumor suppressor gene in cancer biology with anti-proliferative and pro-apoptotic effect on cancer cells, however mechanisms of IRF-1 regulating tumor microenvironment (TME) in hepatocellular carcinoma (HCC) remain only partially characterized. Here, we investigated that IRF-1 regulates C-X-C motif chemokine 10 (CXCL10) and chemokine receptor 3 (CXCR3) to activate anti-tumor immunity in HCC. We found that IRF-1 mRNA expression was positively correlated with CXCL10 and CXCR3 through qRT-PCR assay in HCC tumors and in analysis of the TCGA database. IRF-1 response elements were identified in the CXCL10 promoter region, and ChIP-qPCR confirmed IRF-1 binding to promote CXCL10 transcription. IRF-2 is a competitive antagonist for IRF-1 mediated transcriptional effects, and overexpression of IRF-2 decreased basal and IFN-γ induced CXCL10 expression. Although IRF-1 upregulated CXCR3 expression in HCC cells, it inhibited proliferation and exerted pro-apoptotic effects, which overcome proliferation partly mediated by activating the CXCL10/CXCR3 autocrine axis. In vitro and in vivo studies showed that IRF-1 increased CD8⁺ T cells, NK and NKT cells migration, and activated IFN-γ secretion in NK and NKT cells to induce tumor apoptosis through the CXCL10/CXCR3 paracrine axis. Conversely, this effect was markedly abrogated in HCC tumor bearing mice deficient in CXCR3. Therefore, the IRF-1/CXCL10/CXCR3 axis contributes to the anti-tumor microenvironment in HCC.

Injection site vaccinology of a recombinant vaccinia-based vector reveals diverse innate immune signatures

Poxvirus systems have been extensively used as vaccine vectors. Herein a RNA-Seq analysis of intramuscular injection sites provided detailed insights into host innate immune responses, as well as expression of vector and recombinant immunogen genes, after vaccination with a new multiplication defective, vaccinia-based vector, Sementis Copenhagen Vector. Chikungunya and Zika virus immunogen mRNA and protein expression was associated with necrosing skeletal muscle cells surrounded by mixed cellular infiltrates. The multiple adjuvant signatures at 12 hours post-vaccination were dominated by TLR3, 4 and 9, STING, MAVS, PKR and the inflammasome. Th1 cytokine signatures were dominated by IFNγ, TNF and IL1β, and chemokine signatures by CCL5 and CXCL12. Multiple signatures associated with dendritic cell stimulation were evident. By day seven, vaccine transcripts were absent, and cell death, neutrophil, macrophage and inflammation annotations had abated. No compelling arthritis signatures were identified. Such injection site vaccinology approaches should inform refinements in poxvirus-based vector design.

Poxvirus vector systems have been widely developed for vaccine applications. Despite considerable progress, so far only one recombinant poxvirus vectored vaccine has to date been licensed for human use, with ongoing efforts seeking to enhance immunogenicity whilst minimizing reactogenicity. The latter two characteristics are often determined by early post-vaccination events at the injection site. We therefore undertook an injection site vaccinology approach to analyzing gene expression at the vaccination site after intramuscular inoculation with a recombinant, multiplication defective, vaccinia-based vaccine. This provided detailed insights into inter alia expression of vector-encoded immunoregulatory genes, as well as host innate and adaptive immune responses. We propose that such injection site vaccinology can inform rational vaccine vector design, and we discuss how the information and approach elucidated herein might be used to improve immunogenicity and limit reactogenicity of poxvirus-based vaccine vector systems.

Exosomes in Immune Regulation

Exosomes, small extracellular vesicles mediate intercellular communication by transferring their cargo including DNA, RNA, proteins and lipids from cell to cell. Notably, in the immune system, they have protective functions. However in cancer, exosomes acquire new, immunosuppressive properties that cause the dysregulation of immune cells and immune escape of tumor cells supporting cancer progression and metastasis. Therefore, current investigations focus on the regulation of exosome levels for immunotherapeutic interventions. In this review, we discuss the role of exosomes in immunomodulation of lymphoid and myeloid cells, and their use as immune stimulatory agents to elicit specific cytotoxic responses against the tumor.

Interferon Regulatory Factor-1 (IRF1) activates autophagy to promote liver ischemia/reperfusion injury by inhibiting β-catenin in mice

Autophagy is an important factor in liver ischemia-reperfusion injury. In the current study we investigate the function of interferon regulatory factor-1 (IRF1) in regulating autophagy to promote hepatic ischemia reperfusion injury (IR). The high expression of IRF1 during hepatic IR exhibited increased liver damage and was associated with activation of autophagy shown by Western blot markers, as well as immunofluorescent staining for autophagosomes. These effects were diminished by IRF1 deficiency in IRF1 knock out (KO) mice. Moreover, the autophagy inhibitor 3-MA decreased IR-induced liver necrosis and markedly abrogated the rise in liver injury tests (AST/ALT). β-catenin expression decreased during liver IR and was increased in the IRF1 KO mice. Immunoprecipitation assay showed the binding between IRF1 and β-catenin. Overexpression of IRF1 induced autophagy and also inhibited the expression of β-catenin. β-catenin inhibitor increased autophagy while β-catenin agonist suppressed autophagy in primary mouse hepatocytes. These results indicate that IRF1 induced autophagy aggravates hepatic IR injury in part by inhibiting β-catenin and suggests that targeting IRF1 may be an effective strategy in reducing hepatic IR injury.

Tre2-Bub2-Cdc16 Family Proteins Based Nomogram Serve as a Promising Prognosis Predicting Model for Melanoma

Tre2-Bub2-Cdc16 (TBC) proteins are conserved in eukaryotic organisms and function as negative feedback dominating the GAPs for Rab GTPases, while the function of TBC proteins in melanoma remains unclear. In this study, we observed the differential expression of 33 TBC genes in TCGA datasets classified by clinical features. Seven prognostic-associated TBC genes were identified by LASSO Cox regression analysis. Mutation analysis revealed distinctive frequency alteration in the seven prognostic-associated TBCs between cases with high and low scores. High-risk score and cluster 1 based on LASSO Cox regression and consensus clustering analysis were relevant to clinical features and unfavorable prognosis. GSVA analysis showed that prognostic-associated TBCs were related to metabolism and protein transport signaling pathway. Correlation analysis indicated the relationship between the prognostic-associated TBCs with RAB family members, invasion-related genes and immune cells. The prognostic nomogram model was well established to predict survival in melanoma. What's more, interference of one of the seven TBC proteins TBC1D7 was confirmed to inhibit the proliferation, migration and invasion of melanoma cells in vitro. In summary, we preliminarily investigated the impact of TBCs on melanoma through multiple bioinformatics analysis and experimental validation, which is helpful for clarifying the mechanism of melanoma and the development of anti-tumor drugs.

Roles of IFN-γ in tumor progression and regression: a review

BACKGROUND

Interferon-γ (IFN-γ) plays a key role in activation of cellular immunity and subsequently, stimulation of antitumor immune-response. Based on its cytostatic, pro-apoptotic and antiproliferative functions, IFN-γ is considered potentially useful for adjuvant immunotherapy for different types of cancer. Moreover, it IFN-γ may inhibit angiogenesis in tumor tissue, induce regulatory T-cell apoptosis, and/or stimulate the activity of M1 proinflammatory macrophages to overcome tumor progression. However, the current understanding of the roles of IFN-γ in the tumor microenvironment (TME) may be misleading in terms of its clinical application.

MAIN BODY

Some researchers believe it has anti-tumorigenic properties, while others suggest that it contributes to tumor growth and progression. In our recent work, we have shown that concentration of IFN-γ in the TME determines its function. Further, it was reported that tumors treated with low-dose IFN-γ acquired metastatic properties while those infused with high dose led to tumor regression. Pro-tumorigenic role may be described through IFN-γ signaling insensitivity, downregulation of major histocompatibility complexes, upregulation of indoleamine 2,3-dioxygenase, and checkpoint inhibitors such as programmed cell death ligand 1.

CONCLUSION

Significant research efforts are required to decipher IFN-γ-dependent pro- and anti-tumorigenic effects. This review discusses the current knowledge concerning the roles of IFN-γ in the TME as a part of the complex immune response to cancer and highlights the importance of identifying IFN-γ responsive patients to improve their sensitivity to immuno-therapies.

Interferon regulatory factor 1 (IRF-1) and IRF-2 regulate PD-L1 expression in hepatocellular carcinoma (HCC) cells

The objective response rate of immune checkpoint blockade (ICB) in hepatocellular carcinoma (HCC) with anti PD-L1/PD-1 therapy is low. Discovering the signaling pathways regulating PD-L1 might help to improve ICB response rates. Here, we investigate transcription factors IRF-1 and IRF-2 signaling pathways regulating PD-L1 in HCC cells. In vivo studies show that IRF-1 and PD-L1 mRNA expression in human HCC tumors are significantly repressed compared with noncancerous background liver. IRF-1, IRF-2, and PD-L1 mRNA expression correlated positively in HCC tumors. Increased IRF-1 mRNA expression was observed in patients with well-differentiated or early stage HCC tumors. In vitro studies show that IFN-γ induces PD-L1 mRNA and protein expression through upregulation of IRF-1 in mouse and human HCC cells. IRF-1, IRF-2, and PD-L1 mRNA expression is upregulated in murine HCC by co-culture with effector T cells from spleen cells incubated with anti-CD3/CD28 antibodies. IRF-2 over-expression down-regulates IFN-γ induced PD-L1 promoter activity and protein levels in a dose-dependent manner. We identify two IRF-1 response elements (IRE1/IRE2) in the upstream 5'-flanking region of the CD274 (PD-L1) gene promoter. Site-directed mutagenesis shows both IRE1 and IRE2 are functional in transfection promoter assays. IRF-1 traditionally functions as tumor suppressor gene. However, these novel findings show a complex role for IRF-1 which upregulates PD-L1 in the inflammatory tumor microenvironment. IRF-1 antagonizes IRF-2 for binding to the IRE promoter element in PD-L1 which gives new insight to the regulation of PD-L1/PD-1 pathways in HCC ICB therapy.

Cardiovascular morbidities of obstructive sleep apnea and the role of circulating extracellular vesicles

Obstructive sleep apnea (OSA) is characterized by recurrent upper airway collapse during sleep resulting in impaired blood gas exchange, namely intermittent hypoxia (IH) and hypercapnia, fragmented sleep (SF), increased oxidative stress and systemic inflammation. Among a myriad of potential associated morbidities, OSA has been particularly implicated as mechanistically contributing to the prevalence and severity of cardiovascular diseases (CVD). However, the benefits of continuous positive airway pressure (CPAP), which is generally employed in OSA treatment, to either prevent or improve CVD outcomes remain unconvincing, suggesting that the pathophysiological mechanisms underlying the incremental CVD risk associated with OSA are not clearly understood. One of the challenges in development of non-invasive diagnostic assays is the ability to identify clinically and mechanistically relevant biomarkers. Circulating extracellular vesicles (EVs) and their cargos reflect underlying changes in cellular homeostasis and can provide insights into how cells and systems cope with physiological perturbations by virtue of the identity and abundance of miRNAs, mRNAs, proteins, and lipids that are packaged in the EVs under normal as well as diseased states, such as OSA. EVs can not only provide unique insights into coordinated cellular responses at the organ or systemic level, but can also serve as reporters of the effects of OSA in CVD, either by their properties enabling regeneration and repair of injured vascular cells or by damaging them. Here, we highlight recent progress in the pathological CVD consequences of OSA, and explore the putative roles of EVs in OSA-associated CVD, along with emerging diagnostic and therapeutic opportunities.

The reviews of this paper are available via the supplemental material section.

Exosomes: From garbage bins to translational medicine

Exosomes are lipid bilayer-enclosed vesicles of endosomal origin, which initially considered as garbage bins to dispose unwanted cellular components, but they are now emerged as an intercellular communication system involved in several physiological and pathological conditions. With the increasing understanding that the healthy patients release exosomes with distinct proteins and RNAs, exosomes have been exploited as biomarkers for disease diagnosis and prognosis. Owing to the intrinsic immunomodulatory in a tumor microenvironment, exosomes have also been vaccinated into patients against malignant diseases. Moreover, the nano-metered exosomes are relatively stable in extracellular fluids. Thus they appear attractive in delivering "cargo" to destined cells with enhanced efficiency. In this review, we outline the current knowledge in exosomal biogenesis and isolation. Furthermore, the biological activities of exosomes are also discussed with a focus on their potentials to be employed in translational medicine, especially as biomarkers, vaccines and therapeutic delivery system.

Perspectives in HPV Secondary Screening and Personalized Therapy Basing on Our Understanding of HPV-Related Carcinogenesis Pathways

As cervical cancer is one of the most common malignancies in women worldwide even with present screening methods, the incidence in most developed countries is not decreasing for the last 15-20 years. A shift has been observed in the age of diagnosis in favour of younger women, and treatment of already developed cervical cancer is a challenge for surgeons. It is imperative to find new diagnostic methods for accurately pointing out patients at high risk of developing malignant disease and developing personalized treatment. Since cervical cancer is almost exclusively associated with HPV infection, understanding changes happening in an infected cell may prove invaluable for search of such methods, but it may also prove helpful in the diagnosis and treatment of other anogenital and nasopharyngeal region cancers. This review follows HPV-related changes in infected cell biology to point what potential markers and targets for therapy are in option when dealing with HPV-related diseases.

Engineered Tumor-Derived Extracellular Vesicles: Potentials in Cancer Immunotherapy

Exosomes are nano vesicles from the larger family named Extracellular Vesicle (EV)s which are released by various cells including tumor cells, mast cells, dendritic cells, B lymphocytes, neurons, adipocytes, endothelial cells, and epithelial cells. They are considerable messengers that can exchange proteins and genetic materials between the cells. Within the past decade, Tumor derived exosomes (TEX) have been emerged as important mediators in cancer initiation, progression and metastasis as well as host immune suppression and drug resistance. Although tumor derived exosomes consist of tumor antigens and several Heat Shock Proteins such as HSP70 and HSP90 to stimulate immune response against tumor cells, they contain inhibitory molecules like Fas ligand (Fas-L), Transforming Growth Factor Beta (TGF-β) and Prostaglandin E2 (PGE2) leading to decrease the cytotoxicity and establish immunosuppressive tumor microenvironment (TME). To bypass this problem and enhance immune response, some macromolecules such as miRNAs, HSPs and activatory ligands have been recognized as potent immune inducers that could be used as anti-tumor agents to construct a nano sized tumor vaccine. Here, we discussed emerging engineered exosomes as a novel therapeutic strategy and considered the associated challenges.

IRF1 association with tumor immune microenvironment and use as a diagnostic biomarker for colorectal cancer recurrence

Colorectal cancer (CRC) is considered to be one of the most lethal cancer types globally, and its recurrence is a major treatment challenge. Identifying the factors involved when determining the risk of CRC recurrence is required to improve personalized therapy for patients with CRC. Based on the GSE39582 dataset, the present study demonstrated that a higher ratio of M1 macrophages and activated memory CD4+ T cells indicated a better recurrence-free survival (RFS) time for CRC, using CIBERSORT and Pearson's correlation analysis. Through weighted correlation network analysis (WGCNA), an immune-associated module was identified that was significantly positively correlated with the ratio of M1 macrophages and activated memory CD4+ T cells. In this module, using WGCNA and a protein-protein interaction network, interferon regulatory factor 1 (IRF1), chemokine ligand 5, ubiquitin/ISG15-conjugating enzyme E2 L6, guanylate binding protein 1 and interleukin 2 receptor subunit beta were identified as hub genes. Among these genes, univariate Cox and multivariate Cox analysis revealed that IRF1 may be a potential diagnostic biomarker for RFS in patients with CRC. This was further validated using The Cancer Genome Atlas data. Gene set enrichment analysis demonstrated that IRF1 influenced the genes and pathways that are associated with immune cell recruitment and activation. Additionally, the DNA methylation of cg27587780 and cg15375424 CpG sites in the IRF1 gene region was indicated to be negatively correlated with IRF1 mRNA expression and positively correlated with the recurrence of CRC. Collectively, the results of the present study demonstrated that IRF1 may be a potential diagnostic biomarker for RFS in patients with CRC.

Exosomes and their role in tumorigenesis and anticancer drug resistance

Exosomes are a class of extracellular vesicles ranging in size from 40 to 100 nm, which are secreted by both cancer cells and multiple stromal cells in the tumor microenvironment. Following their secretion, exosomes partake in endocrine, paracrine and autocrine signaling. Internalization of exosomes by tumor cells influences several cellular pathways which alter cancer cell physiology. Tumor-derived exosomes secreted by cancer or stromal cells can also confer anticancer drug-resistant traits upon cancer cells. These exosomes promote chemoresistance by transferring their cargo which includes nucleic acids, proteins, and metabolites to cancer cells or act as a decoy for immunotherapeutic targets. Depletion of exosomes can reverse some of the detrimental effects on tumor metabolism and restore drug sensitivity to chemotherapeutic treatment. Herein we discuss various approaches that have been developed to deplete exosomes for therapeutic purposes. The natural composition, low immunogenicity and cytotoxicity of exosomes, along with their ability to specifically target tumor cells, render them an appealing platform for drug delivery. The ability of exosomes to mediate autocrine and paracrine signaling in target cells, along with their natural structure and low immunogenicity render them an attractive vehicle for the delivery of anticancer drugs to tumors.

Roles of exosomes in liver metastases: Novel diagnosis and treatment choices

Tumors tend to metastasize to the liver. Premetastatic niche formation is a vital step in liver metastasis. Tumor-derived exosomes can influence premetastatic niche formation from three aspects: vascular leakiness and angiogenesis, recruitment of nonresident cells, and changes in local resident cells. Exosomes from other tissues, such as mesenchymal stem cell-derived exosomes and engineered exosomes, also have therapeutic potential, but further research on these exosomes is required. Based on the mechanism of premetastatic niche formation, we summarize the therapeutic and diagnostic potential of exosomes in inhibiting liver metastases in this review in an attempt to provide new avenues for the prevention and treatment of liver metastases.

Possibility of Exosome-Based Therapeutics and Challenges in Production of Exosomes Eligible for Therapeutic Application

Exosomes are cell-derived vesicles with a diameter 30-120 nm. Exosomes contain endogenous proteins and nucleic acids; delivery of these molecules to exosome-recipient cells causes biological effects. Exosomes derived from some types of cells such as mesenchymal stem cells and dendritic cells have therapeutic potential and may be biocompatible and efficient agents against various disorders such as organ injury. However, there are many challenges for the development of exosome-based therapeutics. In particular, producing exosomal formulations is the major barrier for therapeutic application because of their heterogeneity and low productivity. Development and optimization of producing methods, including methods for isolation and storage of exosome formulations, are required for realizing exosome-based therapeutics. In addition, improvement of therapeutic potential and delivery efficiency of exosomes are important for their therapeutic application. In this review, we summarize current knowledge about therapeutic application of exosomes and discuss some challenges in their successful use.

A Challenge to Aging Society by microRNA in Extracellular Vesicles: microRNA in Extracellular Vesicles as Promising Biomarkers and Novel Therapeutic Targets in Multiple Myeloma

Multiple myeloma (MM) is a malignancy of terminally differentiated plasma cells and is the second most common hematological cancer. MM frequently occurs in the elderly population with the median age as the middle sixties. Over the last 10 years, the prognosis of MM has been dramatically improved by new therapeutic drugs; however, MM is still incurable. The pathogenesis of MM is still unclear, thus greater understanding of the molecular mechanisms of MM malignancy is desirable. Recently, microRNAs (miRNAs) were shown to modulate the expression of genes critical for MM pathogenesis. In addition, miRNAs are secreted via extracellular vesicles (EVs), which are released from various cell types including MM cells, and these miRNAs are involved in multiple types of cell-cell interactions, which lead to the malignancy of MM. In this review, we summarize the current knowledge regarding the role of miRNA secretion via EVs and of EVs themselves in MM development. We also discuss the potential clinical applications of EVs as promising biomarkers and new therapeutic targets for improving the outcome of MM, resulting in a brighter future for aging societies.