Exosomes in human semen restrict HIV-1 transmission by vaginal cells and block intravaginal replication of LP-BM5 murine AIDS virus complex

Immunological defense mechanisms of ejaculates and the spread of viral infectious diseases through pig semen

This review focuses on the mechanisms of immune tolerance and antimicrobial defense in the male genital tract of the pig. Sperm cells are foreign to the immune system and, therefore, they must be protected from the immune system. The blood-testis-barrier is mediated by a physical barrier between adjacent Sertoli cells, several cell types within the testis, and interactions between immunomodulatory molecules. The blood-epididymal-barrier is composed of a physical barrier that is lined with principal cells having a network of junctional complexes in their apical lateral membrane and completed by specific transporters. The seminal plasma (SP) contains many signaling agents involved in establishing a state of immune tolerance in the female genital tract, which is essential for successful fertilization. Specific SP-proteins, however, also have pro-inflammatory capacities contributing to transient uterine inflammation, supporting the removal of foreign cells, possible pathogens, and excessive spermatozoa. While many different proteins and other substances present in semen can damage sperm cells, they may also protect them against viral infections. A delicate balance of these substances, therefore, needs to be maintained. Related to this, recent studies have shown the importance of extracellular vesicles (EVs), as they contain these substances and convey immune signals. Yet, viruses may use EVs to interact with the male genital tract and circumvent immune responses. For this reason, further research needs to explore the role of EVs in the male reproductive tract, as it might contribute to elucidating the pathogenesis of viral infections that might be transmitted via semen and to developing better vaccines.

Extracellular condensates (ECs) are endogenous modulators of HIV transcription and latency reactivation

Persistence of human immunodeficiency virus (HIV) latent reservoir is the major challenge to HIV cure because the latent reservoir is not eliminated by antiretroviral therapy (ART), and they serve as sources for viral rebound upon cessation of ART. Mechanisms regulating viral persistence are not well understood. This study used model systems of post-integration latency to explore the role of basal ganglia (BG) isolated extracellular condensates (ECs) in reprogramming HIV latent cells. We found that BG ECs from uninfected macaques (VEH) and SIV infected macaques (VEH|SIV) activate latent HIV transcription in various model systems. VEH and VEH|SIV ECs significantly increased expression of viral antigen in latently infected cells. Activation of viral transcription, antigen expression, and latency reactivation was inhibited by ECs from the brain of macaques treated with Delta-9-tetrahydrocannabinol (THC) and infected with SIV (THC|SIV). Virus produced by latently infected cells treated with VEH|SIV ECs potentiated cell-cell and cell-free HIV transmission. VEH|SIV ECs also reversed dexamethasone-mediated inhibition of HIV transcription while TNFα-mediated reactivation of latency was reversed by THC|SIV ECs. Transcriptome and secretome analyses of total RNA and supernatants from latently infected cells treated with ECs revealed significant alteration in gene expression and cytokine secretion. THC|SIV ECs increased secretion of Th2 and decreased secretion of proinflammatory cytokines. Most strikingly, while VEH/SIV ECs robustly induced HIV RNA in latently HIV-infected cells, long-term low-dose THC administration enriched ECs for anti-inflammatory cargo that significantly diminished their ability to reactivate latent HIV, an indication that ECs are endogenous host factors that may regulate HIV persistence.

Highlights

ECs isolated from SIV infected macaques (VEH|SIV ECs) is a positive regulator of LTR-dependent HIV transcription and production of infectious viral particles in vitro.ECs isolated from THC treated SIV infected macaques (THC|SIV ECs) prevents the transcription and reactivation of HIV in latently infected cells and prevents production of viral particles in vitro.ECs reprogram host transcriptome and secretome in manners that or suppress promote reactivation of latent HIV reservoir.The above highlights led to the conclusion that while VEH/SIV ECs robustly induced HIV RNA in latently HIV-infected cells, long-term low-dose THC administration enriched ECs for anti-inflammatory cargo that significantly diminished their ability to reactivate latent HIV.

Metabolic features of tumor-derived extracellular vesicles: challenges and opportunities

Tumor-derived extracellular vesicles (TDEVs) play crucial roles in intercellular communication both in the local tumor microenvironment and systemically, facilitating tumor progression and metastatic spread. They carry a variety of molecules with bioactive properties, such as nucleic acids, proteins and metabolites, that trigger different signaling processes in receptor cells and induce, among other downstream effects, metabolic reprogramming. Interestingly, the cargo of TDEVs also reflects the metabolic status of the producing cells in a time- and context-dependent manner, providing information on the functionality and state of those cells. For these reasons, together with their ability to be detected in diverse biofluids, there is increasing interest in the study of TDEVs, particularly their metabolic cargo, as diagnostic and prognostic tools in cancer management. This review presents a compilation of metabolism-related molecules (enzymes and metabolites) described in cancer extracellular vesicles (EVs) with potential use as cancer biomarkers, and discusses the challenges arising in this rapidly evolving field.

Lipidomic and Proteomic Insights from Extracellular Vesicles in Postmortem Dorsolateral Prefrontal Cortex Reveal Substance Use Disorder-Induced Brain Changes

Substance use disorder (SUD) significantly increases the risk of neurotoxicity, inflammation, oxidative stress, and impaired neuroplasticity. The activation of inflammatory pathways by substances may lead to glial activation and chronic neuroinflammation, potentially mediated by the release of extracellular particles (EPs), such as extracellular condensates (ECs) and extracellular vesicles (EVs). These particles, which reflect the physiological, pathophysiological, and metabolic states of their cells of origin, might carry molecular signatures indicative of SUD. In particular, our study investigated neuroinflammatory signatures in SUD by isolating EVs from the dorsolateral prefrontal cortex (dlPFC) Brodmann's area 9 (BA9) in postmortem subjects. We isolated BA9-derived EVs from postmortem brain tissues of eight individuals (controls: n=4, SUD: n=4). The EVs were analyzed for physical properties (concentration, size, zeta potential, morphology) and subjected to integrative multi-omics analysis to profile the lipidomic and proteomic characteristics. We assessed the interactions and bioactivity of EVs by evaluating their uptake by glial cells. We further assessed the effects of EVs on complement mRNA expression in glial cells as well as their effects on microglial migration. No significant differences in EV concentration, size, zeta potential, or surface markers were observed between SUD and control groups. However, lipidomic analysis revealed significant enrichment of glycerophosphoinositol bisphosphate (PIP2) in SUD EVs. Proteomic analysis indicates downregulation of SERPINB12, ACYP2, CAMK1D, DSC1, and FLNB, and upregulation of C4A, C3, and ALB in SUD EVs. Gene ontology and protein-protein interactome analyses highlight functions such as cell motility, focal adhesion, and acute phase response signaling that is associated with the identified proteins. Both control and SUD EVs increased C3 and C4 mRNA expression in microglia, but only SUD EVs upregulated these genes in astrocytes. SUD EVs also significantly enhanced microglial migration in a wound healing assay.This study successfully isolated EVs from postmortem brains and used a multi-omics approach to identify EV-associated lipids and proteins in SUD. Elevated C3 and C4 in SUD EVs and the distinct effects of EVs on glial cells suggest a crucial role in acute phase response signaling and neuroinflammation.

From stem cells to extracellular vesicles: a new horizon in tissue engineering and regenerative medicine

In the fields of tissue engineering and regenerative medicine, extracellular vesicles (EVs) have become viable therapeutic tools. EVs produced from stem cells promote tissue healing by regulating the immune system, enhancing cell proliferation and aiding remodeling processes. Recently, EV has gained significant attention from researchers due to its ability to treat various diseases. Unlike stem cells, stem cell-derived EVs show lower immunogenicity, are less able to overcome biological barriers, and have a higher safety profile. This makes the use of EVs derived from cell-free stem cells a promising alternative to whole-cell therapy. This review focuses on the biogenesis, isolation, and characterization of EVs and highlights their therapeutic potential for bone fracture healing, wound healing, and neuronal tissue repair and treatment of kidney and intestinal diseases. Additionally, this review discusses the potential of EVs for the treatment of cancer, COVID-19, and HIV. In summary, the use of EVs derived from stem cells offers a new horizon for applications in tissue engineering and regenerative medicine.

Cytotoxic and viricidal effects of human semen on mumps virus-infected lymphocytes: In vitro studies

Viruses in human semen may be sexually transmitted via free and cell-mediated viral infection. The potential effects of semen on the infection and sexual transmission of most viruses in semen remain largely unclear. The present study elucidated the inhibitory effects of human seminal plasma (SP) on Jurkat cell (JC)-mediated mumps virus (MuV) infection. We demonstrated that MuV efficiently infected JCs and that the JCs infected by MuV (JC-MuV) mediated MuV infection of HeLa cells. Remarkably, SP was highly cytotoxic to JCs and inhibited JC-MuV infection of HeLa cells. The cytotoxic factor possessed a molecular weight of less than 3 kDa, whereas that of the viricidal factor was over 100 kDa. The cooperation of cytotoxic and viricidal factors was required for the SP inhibition of JC-MuV infection, and prostatic fluid (PF) was responsible for both the cytotoxic and viricidal effects of SP. The cytotoxic effects we observed were resistant to the treatment of PF with boiling water, proteinase K, RNase A, and DNase I. Our results provide novel insights into the antiviral properties of SP, which may limit cell-mediated sexual viral transmission.

Exosomes derived from olive flounders infected with Streptococcus parauberis: Proteomic analysis, immunomodulation, and disease resistance capacity

Multidrug-resistant Streptococcus parauberis causes high fish mortality in aquaculture, necessitating an urgent need for innovative control strategies. This study aimed to develop an immunizing agent against S. parauberis using exosomes isolated from the plasma of olive flounders infected experimentally with S. parauberis (Sp-Exo). Initially, we tested the in vitro immunomodulatory effect of Sp-Exo in murine macrophage RAW264.7 cells and compared it to that of exosomes isolated from naïve fish (PBS-Exo-treated). Notably, Sp-Exo treatment significantly (p < 0.05) upregulated pro-and anti-inflammatory cytokines (Il1β, Tnfα, and Il10), antimicrobial peptide, defensin isoforms (Def-rs2 and Def-ps1), and antiviral (Ifnβ1 and Isg15) genes. In vivo studies in larval and adult zebrafish revealed similar patterns of immunomodulation. Furthermore, larval and adult zebrafish exhibited significantly (p < 0.05) enhanced resistance to S. parauberis infection following treatment with Sp-Exo compared to that with PBS-Exo. Proteomic analysis using isobaric tags for relative and absolute quantitation (iTRAQ) approach revealed the presence of 77 upregulated and 94 downregulated differentially expressed proteins (DEPs) in Sp-Exo, with 22 and 37 significantly (p < 0.05) upregulated and downregulated DEPs, respectively. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Search Tool for the Retrieval of Interacting Genes/Proteins analyses revealed that these genes are associated with key pathways, such as innate immune responses, complement system, acute phase responses, phospholipid efflux, and chylomicron remodeling. In conclusion, Sp-Exo demonstrated superior immunomodulatory activity and significant resistance against S. parauberis infection relative to that on treatment with PBS-Exo. Proteomic analysis further verified that most DEPs in Sp-Exo were associated with immune induction or modulation. These findings highlight the potential of Sp-Exo as a promising vaccine candidate against S. parauberis and other bacterial infections in olive flounder.

Review of exosomes and their potential for veterinary medicine

Small extracellular vesicles called exosomes are released by almost all cell types and play a crucial role in both healthy and pathological circumstances. Exosomes, found in biological fluids (including plasma, urine, milk, semen, saliva, abdominal fluid and cervical vaginal fluid) and ranging in size from 50 to 150 nm, are critical for intercellular communication. Analysis of exosomal cargos, including micro RNAs (miRNAs), proteins and lipids, has been proposed as valuable diagnostic and prognostic biomarkers of disease. Exosomes can also be used as novel, cell-free, treatment strategies. In this review, we discuss the role, significance and application of exosomes and their cargos in diseases of animals.

Exosomes multifunctional roles in HIV-1: insight into the immune regulation, vaccine development and current progress in delivery system

Human Immunodeficiency Virus (HIV-1) is known to establish a persistent latent infection. The use of combination antiretroviral therapy (cART) can effectively reduce the viral load, but the treatment can be costly and may lead to the development of drug resistance and life-shortening side effects. It is important to develop an ideal and safer in vivo target therapy that will effectively block viral replication and expression in the body. Exosomes have recently emerged as a promising drug delivery vehicle due to their low immunogenicity, nanoscale size (30-150nm), high biocompatibility, and stability in the targeted area. Exosomes, which are genetically produced by different types of cells such as dendritic cells, neurons, T and B cells, epithelial cells, tumor cells, and mast cells, are designed for efficient delivery to targeted cells. In this article, we review and highlight recent developments in the strategy and application of exosome-based HIV-1 vaccines. We also discuss the use of exosome-based antigen delivery systems in vaccine development. HIV-1 antigen can be loaded into exosomes, and this modified cargo can be delivered to target cells or tissues through different loading approaches. This review also discusses the immunological prospects of exosomes and their role as biomarkers in disease progression. However, there are significant administrative and technological obstacles that need to be overcome to fully harness the potential of exosome drug delivery systems.

Biological function of Extracellular Vesicles (EVs): a review of the field

Extracellular vesicles (EVs) theranostic potential is under intense investigation. There is a wealth of information highlighting the role that EVs and the secretome play in disease and how these are being utilized for clinical trials and novel therapeutic possibilities. However, understanding of the physiological and pathological roles of EVs remain incomplete. The challenge lies in reaching a consensus concerning standardized quality-controlled isolation, storage, and sample preparation parameters. Interest in circulating EV cargo as diagnostic and prognostic biomarkers is steadily growing. Though promising, various limitations need to be addressed before there can be successful, full-scale therapeutic use of approved EVs. These limitations include obtaining or manufacturing from the appropriate medium (e.g., from bodily fluid or cell culture), loading and isolating EVs, stability, and storage, standardization of processing, and determining potency. This review highlights specific topics, including circulation of abnormal EVs contribute to human disease and the theranostic potential of EVs. Theranostics is defined as a combination of the word's therapeutics and diagnostics and describes how a specific medicine or technique can function as both. Key findings include, (1) EVs and the secretome are future theranostics which will be utilized as both biomarkers for diagnosis and as therapeutics, (2) basic and translational research supports clinical trials utilizing EVs/secretome, and (3) additional investigation is required to fully unmask the theranostic potential of EVs/secretome in specific diseases and injuries.

Altered Proteomic Profile of Exosomes Secreted from Vero Cells Infected with Porcine Epidemic Diarrhea Virus

Porcine epidemic diarrhea virus (PEDV) infection causes severe diarrhea in pigs and can be fatal in newborn piglets. Exosomes are extracellular vesicles secreted by cells that transfer biologically active proteins, lipids, and RNA to neighboring or distant cells. Herein, the morphology, particle size, and secretion of exosomes derived from a control and PEDV-infected group are examined, followed by a proteomic analysis of the exosomes. The results show that the exosomes secreted from the Vero cells had a typical cup-shaped structure. The average particle size of the exosomes from the PEDV-infected group was 112.4 nm, whereas that from the control group was 150.8 nm. The exosome density analysis and characteristic protein determination revealed that the content of exosomes in the PEDV-infected group was significantly higher than that in the control group. The quantitative proteomics assays revealed 544 differentially expressed proteins (DEPs) in the PEDV-infected group's exosomes compared with those in the controls, with 236 upregulated and 308 downregulated proteins. The DEPs were closely associated with cellular regulatory pathways, such as the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)-protein kinase B (Akt) signaling pathway, extracellular matrix-receptor interaction, focal adhesion, and cytoskeletal regulation. These findings provide the basis for further investigation of the pathogenic mechanisms of PEDV and the discovery of novel antiviral targets.

Extracellular Vesicles and Infection: From Hijacked Machinery to Therapeutic Tools

Extracellular vesicles (EVs) comprise a broad range of secreted cell-derived membrane vesicles. Beyond their more well-characterized role in cell communication, in recent years, EVs have also been shown to play important roles during infection. Viruses can hijack the biogenesis of exosomes (which are small EVs) to promote viral spreading. Additionally, these exosomes are also important mediators in inflammation and immune responses during both bacterial and viral infections. This review summarizes these mechanisms while also describing the impact of bacterial EVs in regulating immune responses. Finally, the review also focuses on the potential and challenges of using EVs, in particular, to tackle infectious diseases.

Selective pharmacological inhibition alters human carcinoma lung cell-derived extracellular vesicle formation

Exosomes also termed small extracellular vesicles (sEVs) are important mediators of intercellular communication in many physiological and pathological processes such as protein clearance, immunity, infections, signaling, and cancer. Elevated circulating levels of exosomes have been linked to some viral infections, aggressive cancer, and neurodegenerative diseases. Some pharmacological compounds have been demonstrated to effectively inhibit exosome production pathways. There are very few studies on exosome inhibition and how they influence pathophysiological conditions.

Methods

In the current study, we examined how inhibition of extracellular vesicle release and/or uptake would impact the exosome formation pathway. Using a constellation of improved EV experimental approaches, we evaluated the concentration-based cytotoxicity effects of pharmacological agents (ketoconazole, climbazole, and heparin) on Human Lung Carcinoma (A549) cell viability. We investigated the effect of inhibitor dosages on exosome production and release. Analysis of exosome inhibition includes quantitative analysis and total protein expression of exosome release after pharmacological inhibition; we examined exosome protein level after inhibition.

Results

Selective inhibition of exosomes altered particle sizes, and heparin significantly reduced the total exosomes released. Climbazole and heparin undermined membrane-bound tetraspanin CD63 expression and significantly disrupted ALIX protein (p ≤ 0.0001) and TSG101 (p ≤ 0.001). Azoles and heparin also disrupt transmembrane trafficking by modulating Ras binding protein (p ≤ 0.001).

Conclusion

These findings revealed that pharmacological inhibition of exosomes regulates the endocytic pathway and expression of endosomal sorting complex required for transport mediators, suggesting climbazole and heparin as effective inhibitors of exosome synthesis.

Engineered extracellular vesicles (EVs): Promising diagnostic/therapeutic tools for pediatric high-grade glioma

Diffuse intrinsic pontine glioma (DIPG) is a highly malignant brain tumor that mainly occurs in children with extremely low overall survival. Traditional therapeutic strategies, such as surgical resection and chemotherapy, are not feasible mostly due to the special location and highly diffused features. Radiotherapy turns out to be the standard treatment method but with limited benefits of overall survival. A broad search for novel and targeted therapies is in the progress of both preclinical investigations and clinical trials. Extracellular vesicles (EVs) emerged as a promising diagnostic and therapeutic candidate due to their distinct biocompatibility, excellent cargo-loading-delivery capacity, high biological barrier penetration efficiency, and ease of modification. The utilization of EVs in various diseases as biomarker diagnoses or therapeutic agents is revolutionizing modern medical research and practice. In this review, we will briefly talk about the research development of DIPG, and present a detailed description of EVs in medical applications, with a discussion on the application of engineered peptides on EVs. The possibility of applying EVs as a diagnostic tool and drug delivery system in DIPG is also discussed.

Exosome-derived Small RNAs in mouse Sertoli cells inhibit spermatogonial apoptosis

Spermatogenesis is a highly complicated biological process that occurs in the epithelium of the seminiferous tubules. It is regulated by a complex network of endocrine and paracrine factors. Sertoli cells (SCs) play a key role in spermatogenesis due to their production of trophic, differentiation, and immune-modulating factors. However, many of the molecular pathways of SC action remain controversial and unclear. Recently, many studies have focused on exosomes as an important mechanism of intercellular communication. We found that the exosomes derived from mouse SCs inhibited the apoptosis of primary spermatogonia. A total of 1016 miRNAs in SCs and 556 miRNAs in exosomes were detected using miRNA high-throughput sequencing. A total of 294 miRNAs were differentially expressed between SCs and exosomes. Furthermore, 19 tsRNA families appeared in SCs, while 6 tsRNA families appeared in exosomes. A total of 57 and 1 miRNAs (RPM >4) and 14 and 1 tsRNAs were exclusively expressed in SCs and exosomes, respectively. MiR-10b is one of the top ten exosomes with a relatively large enrichment of miRNA. Overexpression of miR-10b downregulates the expression of the target KLF4 to reduce spermatogonial apoptosis in primary spermatogonia or the C18-4 cell line.

Exosome and virus infection

Exosomes are messengers of intercellular communication in monolayer vesicles derived from cells. It affects the pathophysiological process of the body in various diseases, such as tumors, inflammation, and infection. It has been confirmed that exosomes are similar to viruses in biogenesis, and exosome cargo is widely involved in many viruses’ replication, transmission, and infection. Simultaneously, virus-associated exosomes can promote immune escape and activate the antiviral immune response of the body, which bidirectionally modulates the immune response. This review focuses on the role of exosomes in HIV, HBV, HCV, and SARS-CoV-2 infection and explores the prospects of exosome development. These insights may be translated into therapeutic measures for viral infections and reduce the disease burden.

Plant-Derived Exosome-like Nanoparticles for Biomedical Applications and Regenerative Therapy

Plant-derived exosome-like nanoparticles (PDENs) comprise various bioactive biomolecules. As an alternative cell-free therapeutic approach, they have the potential to deliver nano-bioactive compounds to the human body, and thus lead to various anti-inflammatory, antioxidant, and anti-tumor benefits. Moreover, it is known that Indonesia is one of the herbal centers of the world, with an abundance of unexplored sources of PDENs. This encouraged further research in biomedical science to develop natural richness in plants as a source for human welfare. This study aims to verify the potential of PDENs for biomedical purposes, especially for regenerative therapy applications, by collecting and analyzing data from the latest relevant research and developments.

SIV Infection Regulates Compartmentalization of Circulating Blood Plasma miRNAs within Extracellular Vesicles (EVs) and Extracellular Condensates (ECs) and Decreases EV-Associated miRNA-128

Background: This is Manuscript 1 of a two-part Manuscript of the same series. Here, we present findings from our first set of studies on the abundance and compartmentalization of blood plasma extracellular microRNAs (exmiRNAs) into extracellular particles, including blood plasma extracellular vesicles (EVs) and extracellular condensates (ECs) in the setting of untreated HIV/SIV infection. The goals of the study presented in this Manuscript 1 are to (i) assess the abundance and compartmentalization of exmiRNAs in EVs versus ECs in the healthy uninfected state, and (ii) evaluate how SIV infection may affect exmiRNA abundance and compartmentalization in these particles. Considerable effort has been devoted to studying the epigenetic control of viral infection, particularly in understanding the role of exmiRNAs as key regulators of viral pathogenesis. MicroRNA (miRNAs) are small (~20-22 nts) non-coding RNAs that regulate cellular processes through targeted mRNA degradation and/or repression of protein translation. Originally associated with the cellular microenvironment, circulating miRNAs are now known to be present in various extracellular environments, including blood serum and plasma. While in circulation, miRNAs are protected from degradation by ribonucleases through their association with lipid and protein carriers, such as lipoproteins and other extracellular particles-EVs and ECs. Functionally, miRNAs play important roles in diverse biological processes and diseases (cell proliferation, differentiation, apoptosis, stress responses, inflammation, cardiovascular diseases, cancer, aging, neurological diseases, and HIV/SIV pathogenesis). While lipoproteins and EV-associated exmiRNAs have been characterized and linked to various disease processes, the association of exmiRNAs with ECs is yet to be made. Likewise, the effect of SIV infection on the abundance and compartmentalization of exmiRNAs within extracellular particles is unclear. Literature in the EV field has suggested that most circulating miRNAs may not be associated with EVs. However, a systematic analysis of the carriers of exmiRNAs has not been conducted due to the inefficient separation of EVs from other extracellular particles, including ECs. Methods: Paired EVs and ECs were separated from EDTA blood plasma of SIV-uninfected male Indian rhesus macaques (RMs, n = 15). Additionally, paired EVs and ECs were isolated from EDTA blood plasma of combination anti-retroviral therapy (cART) naïve SIV-infected (SIV+, n = 3) RMs at two time points (1- and 5-months post infection, 1 MPI and 5 MPI). Separation of EVs and ECs was achieved with PPLC, a state-of-the-art, innovative technology equipped with gradient agarose bead sizes and a fast fraction collector that allows high-resolution separation and retrieval of preparative quantities of sub-populations of extracellular particles. Global miRNA profiles of the paired EVs and ECs were determined with RealSeq Biosciences (Santa Cruz, CA) custom sequencing platform by conducting small RNA (sRNA)-seq. The sRNA-seq data were analyzed using various bioinformatic tools. Validation of key exmiRNAs was performed using specific TaqMan microRNA stem-loop RT-qPCR assays. Results: We showed that exmiRNAs in blood plasma are not restricted to any type of extracellular particles but are associated with lipid-based carriers-EVs and non-lipid-based carriers-ECs, with a significant (~30%) proportion of the exmiRNAs being associated with ECs. In the blood plasma of uninfected RMs, a total of 315 miRNAs were associated with EVs, while 410 miRNAs were associated with ECs. A comparison of detectable miRNAs within paired EVs and ECs revealed 19 and 114 common miRNAs, respectively, detected in all 15 RMs. Let-7a-5p, Let-7c-5p, miR-26a-5p, miR-191-5p, and let-7f-5p were among the top 5 detectable miRNAs associated with EVs in that order. In ECs, miR-16-5p, miR-451, miR-191-5p, miR-27a-3p, and miR-27b-3p, in that order, were the top detectable miRNAs in ECs. miRNA-target enrichment analysis of the top 10 detected common EV and EC miRNAs identified MYC and TNPO1 as top target genes, respectively. Functional enrichment analysis of top EV- and EC-associated miRNAs identified common and distinct gene-network signatures associated with various biological and disease processes. Top EV-associated miRNAs were implicated in cytokine-cytokine receptor interactions, Th17 cell differentiation, IL-17 signaling, inflammatory bowel disease, and glioma. On the other hand, top EC-associated miRNAs were implicated in lipid and atherosclerosis, Th1 and Th2 cell differentiation, Th17 cell differentiation, and glioma. Interestingly, infection of RMs with SIV revealed that the brain-enriched miR-128-3p was longitudinally and significantly downregulated in EVs, but not ECs. This SIV-mediated decrease in miR-128-3p counts was validated by specific TaqMan microRNA stem-loop RT-qPCR assay. Remarkably, the observed SIV-mediated decrease in miR-128-3p levels in EVs from RMs agrees with publicly available EV miRNAome data by Kaddour et al., 2021, which showed that miR-128-3p levels were significantly lower in semen-derived EVs from HIV-infected men who used or did not use cocaine compared to HIV-uninfected individuals. These findings confirmed our previously reported finding and suggested that miR-128 may be a target of HIV/SIV. Conclusions: In the present study, we used sRNA sequencing to provide a holistic understanding of the repertoire of circulating exmiRNAs and their association with extracellular particles, such as EVs and ECs. Our data also showed that SIV infection altered the profile of the miRNAome of EVs and revealed that miR-128-3p may be a potential target of HIV/SIV. The significant decrease in miR-128-3p in HIV-infected humans and in SIV-infected RMs may indicate disease progression. Our study has important implications for the development of biomarker approaches for various types of cancer, cardiovascular diseases, organ injury, and HIV based on the capture and analysis of circulating exmiRNAs.

Extracellular Vesicles as Therapeutic Resources in the Clinical Environment

The native role of extracellular vesicles (EVs) in mediating the transfer of biomolecules between cells has raised the possibility to use them as therapeutic vehicles. The development of therapies based on EVs is now expanding rapidly; here we will describe the current knowledge on different key points regarding the use of EVs in a clinical setting. These points are related to cell sources of EVs, isolation, storage, and delivery methods, as well as modifications to the releasing cells for improved production of EVs. Finally, we will depict the application of EVs therapies in clinical trials, considering the impact of the COVID-19 pandemic on the development of these therapies, pointing out that although it is a promising therapy for human diseases, we are still in the initial phase of its application to patients.

Protein-Coding Region Derived Small RNA in Exosomes from Influenza A Virus-Infected Cells

Exosomes may function as multifactorial mediators of cell-to-cell communication, playing crucial roles in both physiological and pathological processes. Exosomes released from virus-infected cells may contain RNA and proteins facilitating infection spread. The purpose of our study was to analyze how the small RNA content of exosomes is affected by infection with the influenza A virus (IAV). Exosomes were isolated by ultracentrifugation after hemadsorption of virions and their small RNA content was identified using high-throughput sequencing. As compared to mock-infected controls, 856 RNA transcripts were significantly differentially expressed in exosomes from IAV-infected cells, including fragments of 458 protein-coding (pcRNA), 336 small, 28 long intergenic non-coding RNA transcripts, and 33 pseudogene transcripts. Upregulated pcRNA species corresponded mainly to proteins associated with translation and antiviral response, and the most upregulated among them were RSAD2, CCDC141 and IFIT2. Downregulated pcRNA species corresponded to proteins associated with the cell cycle and DNA packaging. Analysis of differentially expressed pseudogenes showed that in most cases, an increase in the transcription level of pseudogenes was correlated with an increase in their parental genes. Although the role of exosome RNA in IAV infection remains undefined, the biological processes identified based on the corresponding proteins may indicate the roles of some of its parts in IAV replication.

Blood plasma derived extracellular vesicles (BEVs): particle purification liquid chromatography (PPLC) and proteomic analysis reveals BEVs as a potential minimally invasive tool for predicting response to breast cancer treatment

PURPOSE

Circulating blood plasma derived extracellular vesicles (BEVs) containing proteins hold promise for their use as minimally invasive biomarkers for predicting response to cancer therapy. The main goal of this study was to establish the efficiency and utility of the particle purification liquid chromatography (PPLC) BEV isolation method and evaluate the role of BEVs in predicting breast cancer (BC) patient response to neoadjuvant chemotherapy (NAC).

METHODS

PPLC isolation was used to separate BEVs from non-EV contaminants and characterize BEVs from 17 BC patients scheduled to receive NAC. Using LC-MS/MS, we compared the proteome of PPLC-isolated BEVs from patients (n = 7) that achieved a pathological complete response (pCR) after NAC (responders [R]) to patients (n = 10) who did not achieve pCR (non-responders [NR]). Luminal MCF7 and basaloid MDA-MB-231 BC cells were treated with isolated BEVs and evaluated for metabolic activity by MTT assay.

RESULTS

NR had elevated BEV concentrations and negative zeta potential (ζ-potential) prior to receipt of NAC. Eight proteins were enriched in BEVs of NR. GP1BA (CD42b), PECAM-1 (CD31), CAPN1, HSPB1 (HSP27), and ANXA5 were validated using western blot. MTT assay revealed BEVs from R and NR patients increased metabolic activity of MCF7 and MDA-MB-231 BC cells and the magnitude was highest in MCF7s treated with NR BEVs.

CONCLUSION

PPLC-based EV isolation provides a preanalytical separation process for BEVs devoid of most contaminants. Our findings suggest that PPLC-isolated BEVs and the five associated proteins may be established as predictors of chemoresistance, and thus serve to identify NR to spare them the toxic effects of NAC.

Chronic delta-9-tetrahydrocannabinol (THC) treatment counteracts SIV-induced modulation of proinflammatory microRNA cargo in basal ganglia-derived extracellular vesicles

BACKGROUND

Early invasion of the central nervous system (CNS) by human immunodeficiency virus (HIV) (Gray et al. in Brain Pathol 6:1-15, 1996; An et al. in Ann Neurol 40:611-6172, 1996), results in neuroinflammation, potentially through extracellular vesicles (EVs) and their micro RNAs (miRNA) cargoes (Sharma et al. in FASEB J 32:5174-5185, 2018; Hu et al. in Cell Death Dis 3:e381, 2012). Although the basal ganglia (BG) is a major target and reservoir of HIV in the CNS (Chaganti et al. in Aids 33:1843-1852, 2019; Mintzopoulos et al. in Magn Reson Med 81:2896-2904, 2019), whether BG produces EVs and the effect of HIV and/or the phytocannabinoid-delta-9-tetrahydrocannabinol (THC) on BG-EVs and HIV neuropathogenesis remain unknown.

METHODS

We used the simian immunodeficiency virus (SIV) model of HIV and THC treatment in rhesus macaques (Molina et al. in AIDS Res Hum Retroviruses 27:585-592, 2011) to demonstrate for the first time that BG contains EVs (BG-EVs), and that BG-EVs cargo and function are modulated by SIV and THC. We also used primary astrocytes from the brains of wild type (WT) and CX3CR1+/GFP mice to investigate the significance of BG-EVs in CNS cells.

RESULTS

Significant changes in BG-EV-associated miRNA specific to SIV infection and THC treatment were observed. BG-EVs from SIV-infected rhesus macaques (SIV EVs) contained 11 significantly downregulated miRNAs. Remarkably, intervention with THC led to significant upregulation of 37 miRNAs in BG-EVs (SIV-THC EVs). Most of these miRNAs are predicted to regulate pathways related to inflammation/immune regulation, TLR signaling, Neurotrophin TRK receptor signaling, and cell death/response. BG-EVs activated WT and CX3CR1+/GFP astrocytes and altered the expression of CD40, TNFα, MMP-2, and MMP-2 gene products in primary mouse astrocytes in an EV and CX3CR1 dependent manners.

CONCLUSIONS

Our findings reveal a role for BG-EVs as a vehicle with potential to disseminate HIV- and THC-induced changes within the CNS.

Multifunctional role of exosomes in viral diseases: From transmission to diagnosis and therapy

Efforts to discover antiviral drugs and diagnostic platforms have intensified to an unprecedented level since the outbreak of COVID-19. Nano-sized endosomal vesicles called exosomes have gained considerable attention from researchers due to their role in intracellular communication to regulate the biological activity of target cells through cargo proteins, nucleic acids, and lipids. According to recent studies, exosomes play a vital role in viral diseases including covid-19, with their interaction with the host immune system opening the door to effective antiviral treatments. Utilizing the intrinsic nature of exosomes, it is imperative to elucidate how exosomes exert their effect on the immune system or boost viral infectivity. Exosome biogenesis machinery is hijacked by viruses to initiate replication, spread infection, and evade the immune response. Exosomes, however, also participate in protective mechanisms by triggering the innate immune system. Besides that, exosomes released from the cells can carry a robust amount of information about the diseased state, serving as a potential biomarker for detecting viral diseases. This review describes how exosomes increase virus infectivity, act as immunomodulators, and function as a potential drug delivery carrier and diagnostic biomarker for diseases caused by HIV, Hepatitis, Ebola, and Epstein-Barr viruses. Furthermore, the review analyzes various applications of exosomes within the context of COVID-19, including its management.

Exosome: The “Off-the-Shelf” Cellular Nanocomponent as a Potential Pathogenic Agent, a Disease Biomarker, and Neurotherapeutics

Exosomes are nanosized “off-the-shelf” lipid vesicles released by almost all cell types and play a significant role in cell–cell communication. Exosomes have already been proven to carry cell-specific cargos of proteins, lipids, miRNA, and noncoding RNA (ribonucleic acid). These vesicles can be selectively taken up by the neighboring cell and can regulate cellular functions. Herein, we have discussed three different roles of exosomes in neuroscience. First, we have discussed how exosomes play the role of a pathogenic agent as a part of cell–cell communication and transmit pathogens such as amyloid-beta (Aβ), further helping in the propagation of neurodegenerative and other neurological diseases. In the next section, the review talks about the role of exosomes in biomarker discovery in neurological disorders. Toward the end, we have reviewed how exosomes can be harnessed and engineered for therapeutic purposes in different brain diseases. This review is based on the current knowledge generated in this field and our comprehension of this domain.

Impact of Storage Conditions on EV Integrity/Surface Markers and Cargos

Extracellular vesicles (EVs) are small biological particles released into biofluids by every cell. Based on their size, they are classified into small EVs (<100 nm or <200 nm) and medium or large EVs (>200 nm). In recent years, EVs have garnered interest for their potential medical applications, including disease diagnosis, cell-based biotherapies, targeted drug delivery systems, and others. Currently, the long-term and short-term storage temperatures for biofluids and EVs are −80 °C and 4 °C, respectively. The storage capacity of EVs can depend on their number, size, function, temperature, duration, and freeze−thaw cycles. While these parameters are increasingly studied, the effects of preservation and storage conditions of EVs on their integrity remain to be understood. Knowledge gaps in these areas may ultimately impede the widespread applicability of EVs. Therefore, this review summarizes the current knowledge on the effect of storage conditions on EVs and their stability and critically explores prospective ways for improving long-term storage conditions to ensure EV stability.

Mesenchymal Stromal/Stem Cells-Derived Exosomes as an Antimicrobial Weapon for Orodental Infections

The oral cavity as the second most various microbial community in the body contains a broad spectrum of microorganisms which are known as the oral microbiome. The oral microbiome includes different types of microbes such as bacteria, fungi, viruses, and protozoa. Numerous factors can affect the equilibrium of the oral microbiome community which can eventually lead to orodental infectious diseases. Periodontitis, dental caries, oral leukoplakia, oral squamous cell carcinoma are some multifactorial infectious diseases in the oral cavity. In defending against infection, the immune system has an essential role. Depending on the speed and specificity of the reaction, immunity is divided into two different types which are named the innate and the adaptive responses but also there is much interaction between them. In these responses, different types of immune cells are present and recent evidence demonstrates that these cell types both within the innate and adaptive immune systems are capable of secreting some extracellular vesicles named exosomes which are involved in the response to infection. Exosomes are 30-150 nm lipid bilayer vesicles that consist of variant molecules, including proteins, lipids, and genetic materials and they have been associated with cell-to-cell communications. However, some kinds of exosomes can be effective on the pathogenicity of various microorganisms and promoting infections, and some other ones have antimicrobial and anti-infective functions in microbial diseases. These discrepancies in performance are due to the origin of the exosome. Exosomes can modulate the innate and specific immune responses of host cells by participating in antigen presentation for activation of immune cells and stimulating the release of inflammatory factors and the expression of immune molecules. Also, mesenchymal stromal/stem cells (MSCs)-derived exosomes participate in immunomodulation by different mechanisms. Ease of expansion and immunotherapeutic capabilities of MSCs, develop their applications in hundreds of clinical trials. Recently, it has been shown that cell-free therapies, like exosome therapies, by having more advantages than previous treatment methods are emerging as a promising strategy for the treatment of several diseases, in particular inflammatory conditions. In orodental infectious disease, exosomes can also play an important role by modulating immunoinflammatory responses. Therefore, MSCs-derived exosomes may have potential therapeutic effects to be a choice for controlling and treatment of orodental infectious diseases.

Extracellular Vesicles as a New Promising Therapy in HIV Infection

Combination antiretroviral therapy (cART) effectively blocks HIV replication but cannot completely eliminate HIV from the body mainly due to establishment of a viral reservoir. To date, clinical strategies designed to replace cART for life and alternatively to eliminate the HIV reservoir have failed. The reduced expression of viral antigens in the latently infected cells is one of the main reasons behind the failure of the strategies to purge the HIV reservoir. This situation has forced the scientific community to search alternative therapeutic strategies to control HIV infection. In this regard, recent findings have pointed out extracellular vesicles as therapeutic agents with enormous potential to control HIV infection. This review focuses on their role as pro-viral and anti-viral factors, as well as their potential therapeutic applications.

Semen Extracellular Vesicles Mediate Vertical Transmission of Subgroup J Avian Leukosis Virus

Subgroup J avian leukosis virus (ALV-J) is a highly oncogenic retrovirus that has been devastating the global poultry industry since the late 1990s. The major infection model of ALV-J is vertical transmission, which is responsible for the congenital infection of progeny from generation to generation. Increasing evidence has suggested that extracellular vesicles (EVs) derived from virus-infected cells or biological fluids have been thought to be vehicles of transmission for viruses. However, the role of EVs in infection and transmission of ALV-J remains obscure. In the present study, semen extracellular vesicles (SE) were isolated and purified from ALV-J-infected rooster seminal plasma (SE-ALV-J), which was shown to contain ALV-J genomic RNA and partial viral proteins, as determined by RNA sequencing, reverse transcription-quantitative PCR and Western blotting. Furthermore, SE-ALV-J was proved to be able to transmit ALV-J infection to host cells and establish productive infection. More importantly, artificial insemination experiments showed that SE-ALV-J transmitted ALV-J infection to SPF hens, and subsequently mediated vertical transmission of ALV-J from the SPF hens to the progeny chicks. Taken together, the results of the present study suggested that ALV-J utilized host semen extracellular vesicles as a novel means for vertical transmission, enhancing our understanding on mechanisms underlying ALV-J transmission.

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SE-ALV-J- contains ALV-J genomic RNA and partial viral proteins.

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SE-ALV-J could transmit ALV-J infection to host cells and establish productive infection.

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SE-ALV-J mediates vertical transmission of ALV-J in animal model.

HIV-infection and cocaine use regulate semen extracellular vesicles proteome and miRNAome in a manner that mediates strategic monocyte haptotaxis governed by miR-128 network

BACKGROUND

Extracellular vesicles (EVs) are regulators of cell-cell interactions and mediators of horizontal transfer of bioactive molecules between cells. EV-mediated cell-cell interactions play roles in physiological and pathophysiological processes, which maybe modulated by exposure to pathogens and cocaine use. However, the effect of pathogens and cocaine use on EV composition and function are not fully understood.

RESULTS

Here, we used systems biology and multi-omics analysis to show that HIV infection (HIV +) and cocaine (COC) use (COC +) promote the release of semen-derived EVs (SEV) with dysregulated extracellular proteome (exProtein), miRNAome (exmiR), and exmiR networks. Integrating SEV proteome and miRNAome revealed a significant decrease in the enrichment of disease-associated, brain-enriched, and HIV-associated miR-128-3p (miR-128) in HIV + COC + SEV with a concomitant increase in miR-128 targets-PEAK1 and RND3/RhoE. Using two-dimensional-substrate single cell haptotaxis, we observed that in the presence of HIV + COC + SEV, contact guidance provided by the extracellular matrix (ECM, collagen type 1) network facilitated far-ranging haptotactic cues that guided monocytes over longer distances. Functionalizing SEV with a miR-128 mimic revealed that the strategic changes in monocyte haptotaxis are in large part the result of SEV-associated miR-128.

CONCLUSIONS

We propose that compositionally and functionally distinct HIV + COC + and HIV-COC- SEVs and their exmiR networks may provide cells relevant but divergent haptotactic guidance in the absence of chemotactic cues, under both physiological and pathophysiological conditions.

Stalling SARS-CoV2 infection with stem cells: can regenerating perinatal tissue mesenchymal stem cells offer a multi-tiered therapeutic approach to COVID-19?

The emergence of COVID-19 has created a major health crisis across the globe. Invasion of SARS-CoV-2 into the lungs causes acute respiratory distress syndrome (ARDS) that result in the damage of lung alveolar epithelial cells. Currently, there is no standard treatment available to treat the disease and the resultant lung scarring is irreversible even after recovery. This has prompted researchers across the globe to focus on developing new therapeutics and vaccines for the treatment and prevention of COVID-19. Mesenchymal stem cells (MSCs) have emerged as an efficient drug screening platform and MSC-derived organoids has found applications in disease modeling and drug discovery. Perinatal tissue derived MSC based cell therapies have been explored in the treatment of various disease conditions including ARDS because of their enhanced regenerative and immunomodulatory properties. The multi-utility properties of MSCs have been described in this review wherein we discuss the potential use of MSC-derived lung organoids in screening of novel therapeutic compounds for COVID-19 and also in disease modeling to better understand the pathogenesis of the disease. This article also summarizes the rationale behind the development of MSC-based cell- and cell-free therapies and vaccines for COVID-19 with a focus on the current progress in this area. With the pandemic raging, an important necessity is to develop novel treatment strategies which will not only alleviate the disease symptoms but also avoid any off-target effects which could further increase post infection sequelae. Naturally occurring mesenchymal stem cells could be the magic bullet which fulfil these criteria.

A comprehensive study to delineate the role of an extracellular vesicle-associated microRNA-29a in chronic methamphetamine use disorder

Extracellular vesicles (EVs), which express a repertoire of cargo molecules (cf. proteins, microRNA, lipids, etc.), have been garnering a prominent role in the modulation of several cellular processes. Here, using both non-human primate and rodent model systems, we provide evidence that brain-derived EV (BDE) miRNA, miR-29a-3p (mir-29a), is significantly increased during chronic methamphetamine (MA) exposure. Further, miR-29a levels show significant increase both with drug-seeking and reinstatement in a rat MA self-administration model. We also show that EV-associated miR-29a is enriched in EV pool comprising of small EVs and exomeres and further plays a critical role in MA-induced inflammation and synaptodendritic damage. Furthermore, treatment with the anti-inflammatory drug ibudilast (AV411), which is known to reduce MA relapse, decreased the expression of miR-29a and subsequently attenuated inflammation and rescued synaptodendritic injury. Finally, using plasma from MUD subjects, we provide translational evidence that EV-miR29a could potentially serve as a biomarker to detect neuronal damage in humans diagnosed with MA use disorder (MUD). In summary, our work suggests that EV-associated miR-29a-3p plays a crucial role in MUD and might be used as a potential blood-based biomarker for detecting chronic inflammation and synaptic damage.

Extracellular Vesicles Regulated by Viruses and Antiviral Strategies

Extracellular vesicles (EVs), consisting of exosomes, micro-vesicles, and other vesicles, mainly originate from the multi-vesicular body (MVB) pathway or plasma membrane. EVs are increasingly recognized as a tool to mediate the intercellular communication and are closely related to human health. Viral infection is associated with various diseases, including respiratory diseases, neurological diseases, and cancers. Accumulating studies have shown that viruses could modulate their infection ability and pathogenicity through regulating the component and function of EVs. Non-coding RNA (ncRNA) molecules are often targets of viruses and also serve as the main functional cargo of virus-related EVs, which have an important role in the epigenetic regulation of target cells. In this review, we summarize the research progress of EVs under the regulation of viruses, highlighting the content alteration and function of virus-regulated EVs, emphasizing their isolation methods in the context of virus infection, and potential antiviral strategies based on their use. This review would promote the understanding of the viral pathogenesis and the development of antiviral research.

Exosomes as Intercellular Messengers in Hypertension

People living with hypertension have a higher risk of developing heart diseases, and hypertension remains a top cause of mortality. In hypertension, some detrimental changes occur in the arterial wall, which include physiological and biochemical changes. Furthermore, this disease is characterized by turbulent blood flow, increased fluid shear stress, remodeling of the blood vessels, and endothelial dysfunction. As a complex disease, hypertension is thought to be caused by an array of factors, its etiology consisting of both environmental and genetic factors. The Mosaic Theory of hypertension states that many factors, including genetics, environment, adaptive, neural, mechanical, and hormonal perturbations are intertwined, leading to increases in blood pressure. Long-term efforts by several investigators have provided invaluable insight into the physiological mechanisms responsible for the pathogenesis of hypertension, and these include increased activity of the sympathetic nervous system, overactivation of the renin-angiotensin-aldosterone system (RAAS), dysfunction of the vascular endothelium, impaired platelet function, thrombogenesis, vascular smooth muscle and cardiac hypertrophy, and altered angiogenesis. Exosomes are extracellular vesicles released by all cells and carry nucleic acids, proteins, lipids, and metabolites into the extracellular environment. They play a role in intercellular communication and are involved in the pathophysiology of diseases. Since the discovery of exosomes in the 1980s, numerous studies have been carried out to understand the biogenesis, composition, and function of exosomes. In this review, we will discuss the role of exosomes as intercellular messengers in hypertension.

New insights into exosome mediated tumor-immune escape: Clinical perspectives and therapeutic strategies

Recent advances in extracellular vesicle biology have uncovered a substantial role in maintaining cell homeostasis in health and disease conditions by mediating intercellular communication, thus catching the scientific community's attention worldwide. Extracellular microvesicles, some called exosomes, functionally transfer biomolecules such as proteins and non-coding RNAs from one cell to another, influencing the local environment's biology. Although numerous advancements have been made in treating cancer patients with immune therapy, controlling the disease remains a challenge in the clinic due to tumor-driven interference with the immune response and inability of immune cells to clear cancer cells from the body. The present review article discusses the recent findings and knowledge gaps related to the role of exosomes derived from tumors and the tumor microenvironment cells in tumor escape from immunosurveillance. Further, we highlight examples where exosomal non-coding RNAs influence immune cells' response within the tumor microenvironment and favor tumor growth and progression. Therefore, exosomes can be used as a therapeutic target for the treatment of human cancers.

A Comprehensive Insight into the Role of Exosomes in Viral Infection: Dual Faces Bearing Different Functions

Extracellular vesicles (EVs) subtype, exosome is an extracellular nano-vesicle that sheds from cells’ surface and originates as intraluminal vesicles during endocytosis. Firstly, it was thought to be a way for the cell to get rid of unwanted materials as it loaded selectively with a variety of cellular molecules, including RNAs, proteins, and lipids. However, it has been found to play a crucial role in several biological processes such as immune modulation, cellular communication, and their role as vehicles to transport biologically active molecules. The latest discoveries have revealed that many viruses export their viral elements within cellular factors using exosomes. Hijacking the exosomal pathway by viruses influences downstream processes such as viral propagation and cellular immunity and modulates the cellular microenvironment. In this manuscript, we reviewed exosomes biogenesis and their role in the immune response to viral infection. In addition, we provided a summary of how some pathogenic viruses hijacked this normal physiological process. Viral components are harbored in exosomes and the role of these exosomes in viral infection is discussed. Understanding the nature of exosomes and their role in viral infections is fundamental for future development for them to be used as a vaccine or as a non-classical therapeutic strategy to control several viral infections.

Exosomes in HIV infection

PURPOSE OF REVIEW

The exosomes play a critical role in HIV infection, which constitute a pathway to release intracellular material and exchange material and information between cells. Exosomes have become a hotspot in the field of AIDS research. This review introduces the formation process of HIV particles and exosomes, and summarizes the role of exosomes in the progression of HIV disease from multiple aspects.

RECENT FINDINGS

Many components of the exosomes involved in HIV transfer and replication affect the occurrence, development, and outcome of AIDS, and are closely related to HIV infection. Exosomes can have a dual impact on HIV infection, and play an important role in activating the latent reservoir of HIV and affecting the chronic inflammation of HIV. The biological information carried by exosomes is also of great significance for the prediction of HIV disease.

SUMMARY

The present review summarizes the role of exosomes in HIV disease progression in various aspects in order to further understand the underlying mechanism affecting the infection and providing a new idea for the clinical diagnosis and treatment of AIDS.

Preserving extracellular vesicles for biomedical applications: consideration of storage stability before and after isolation

Extracellular vesicles (EVs) are nanovesicles released by various cell types. EVs are known for cell-to-cell communications and have potent biological activities. Despite great progress in recent years for studies exploring the potentials of EVs for early disease detection, therapeutic application and drug delivery, determination of the favorable storage conditions of EVs has been challenging. The understanding of the impact of storage conditions on EVs before and after isolation is still limited. Storage may change the size, number, contents, functions, and behaviors of EVs. Here, we summarized current studies about the stability of EVs in different conditions, focusing on temperatures, durations, and freezing and thawing cycles. -80 °C seems to remain the most favorable condition for storage of biofluids and isolated EVs, while isolated EVs may be stored at 4 °C shortly. Lyophilization is promising for storage of EV products. Challenges remain in the understanding of storage-mediated change in EVs and in the development of advanced preservation techniques of EVs.

Immunomodulatory extracellular vesicles: an alternative to cell therapy for COVID-19

Introduction: SARS-CoV-2 induces a cytokine storm and can cause inflammation, fibrosis and apoptosis in the lungs, leading to acute respiratory distress syndrome (ARDS). ARDS is the leading cause of mortality and morbidity the associated to COVID-19, and the cytokine storm is a prominent etiological factor. Mesenchymal stem cell-derived extracellular vesicles are an alternative therapy for the management of inflammatory and autoimmune conditions due to their immunosuppressive properties. The immunomodulatory and tissue regeneration capabilities of extracellular vesicles may support their application as a prospective therapy for COVID-19.Areas Covered: We explored the clinical evidence on extracellular vesicles as antiviral agents and in mitigating ARDS, and their therapeutic potential in COVID-19.Expert Opinion: Clinical trials using extracellular vesicles are registered against COVID-19 associated complications, with some evidence of safety and efficacy. Extracellular vesicles present an alternative potential for cell therapy for COVID-19 management, but further preclinical and clinical investigations are needed.

The CD8+ T Cell Noncytotoxic Antiviral Responses

The CD8+ T cell noncytotoxic antiviral response (CNAR) was discovered during studies of asymptomatic HIV-infected subjects more than 30 years ago. In contrast to CD8+ T cell cytotoxic lymphocyte (CTL) activity, CNAR suppresses HIV replication without target cell killing. This activity has characteristics of innate immunity: it acts on all retroviruses and thus is neither epitope specific nor HLA restricted. The HIV-associated CNAR does not affect other virus families. It is mediated, at least in part, by a CD8+ T cell antiviral factor (CAF) that blocks HIV transcription. A variety of assays used to measure CNAR/CAF and the effects on other retrovirus infections are described. Notably, CD8+ T cell noncytotoxic antiviral responses have now been observed with other virus families but are mediated by different cytokines. Characterizing the protein structure of CAF has been challenging despite many biologic, immunologic, and molecular studies. It represents a low-abundance protein that may be identified by future next-generation sequencing approaches. Since CNAR/CAF is a natural noncytotoxic activity, it could provide promising strategies for HIV/AIDS therapy, cure, and prevention.

Conditioned medium derived from seminal extracellular vesicles-exposed endometrial stromal cells induces inflammatory cytokine secretion by macrophages

OBJECTIVE

Seminal plasma (SP) contains large numbers of sub-cellular structures called extracellular vesicles (EV) which have been postulated to have immunological functions due to their bioactive contents including proteins and small non-coding RNAs. Although the response of endometrial cells to seminal EV (SEV) is recently being elucidated, the impact of these signaling vesicles on stroma-immune crosstalk is still unknown. Herein, we aimed to investigate the effect of conditioned medium (CM) derived from SEV-exposed endometrial stromal cells (eSC) on cytokine secretion by macrophages.

STUDY DESIGN

SEV were isolated from SP samples of healthy donors and characterized by common methods needed for EV characterization, including size determination by dynamic light scattering (DLS), transmission electron microscopy (TEM), and western blot analysis of EV markers. Endometrial biopsies were obtained from healthy individuals and eSC were isolated and characterized. EV internalization assay was performed by labeling the SEV with PKH67 green fluorescent dye. Then, the eSC were exposed to SEV and the CM was collected. Finally, the CM from SEV-exposed eSC was added to the macrophage culture and the level of inflammatory (interleukin (IL)-1α and IL-6) and anti-inflammatory (IL-10) cytokines were measured in the culture supernatant of macrophages.

RESULTS

The results demonstrated that the CM derived from SEV-exposed eSC induce IL-1α and IL-6 secretion by the macrophages, while the secretion of IL-10 was reduced.

CONCLUSION

Our results support the idea that the stroma-immune interaction is affected by SEV. This effect may be a part of immunoregulatory function of SP inside upper female genital tract and have an obvious impact during peri-implantation period.

Characterization of an Antiviral Component in Human Seminal Plasma

Numerous types of viruses have been found in human semen, which raises concerns about the sexual transmission of these viruses. The overall effect of semen on viral infection and transmission have yet to be fully investigated. In the present study, we aimed at the effect of seminal plasma (SP) on viral infection by focusing on the mumps viral (MuV) infection of HeLa cells. MuV efficiently infected HeLa cells in vitro. MuV infection was strongly inhibited by the pre-treatment of viruses with SP. SP inhibited MuV infection through the impairment of the virus's attachment to cells. The antiviral activity of SP was resistant to the treatment of SP with boiling water, Proteinase K, RNase A, and DNase I, suggesting that the antiviral factor would not be proteins and nucleic acids. PNGase or PLA2 treatments did not abrogate the antiviral effect of SP against MuV. Further, we showed that the prostatic fluid (PF) showed similar inhibition as SP, whereas the epididymal fluid and seminal vesicle extract did not inhibit MuV infection. Both SP and PF also inhibited MuV infection of other cell types, including another human cervical carcinoma cell line C33a, mouse primary epididymal epithelial cells, and Sertoli cell line 15P1. Moreover, this inhibitory effect was not specific to MuV, as the herpes simplex virus 1, dengue virus 2, and adenovirus 5 infections were also inhibited by SP and PF. Our findings suggest that SP contains a prostate-derived pan-antiviral factor that may limit the sexual transmission of various viruses.

Nanotechnology for virus treatment

The continued emergence of novel viruses poses a significant threat to global health. Uncontrolled outbreaks can result in pandemics that have the potential to overburden our healthcare and economic systems. While vaccination is a conventional modality that can be employed to promote herd immunity, antiviral vaccines can only be applied prophylactically and do little to help patients who have already contracted viral infections. During the early stages of a disease outbreak when vaccines are unavailable, therapeutic antiviral drugs can be used as a stopgap solution. However, these treatments do not always work against emerging viral strains and can be accompanied by adverse effects that sometimes outweigh the benefits. Nanotechnology has the potential to overcome many of the challenges facing current antiviral therapies. For example, nanodelivery vehicles can be employed to drastically improve the pharmacokinetic profile of antiviral drugs while reducing their systemic toxicity. Other unique nanomaterials can be leveraged for their virucidal or virus-neutralizing properties. In this review, we discuss recent developments in antiviral nanotherapeutics and provide a perspective on the application of nanotechnology to the SARS-CoV-2 outbreak and future virus pandemics.

Intercellular Communication by Vascular Endothelial Cell-Derived Extracellular Vesicles and Their MicroRNAs in Respiratory Diseases

Respiratory diseases and their comorbidities, such as cardiovascular disease and muscle atrophy, have been increasing in the world. Extracellular vesicles (EVs), which include exosomes and microvesicles, are released from almost all cell types and play crucial roles in intercellular communication, both in the regulation of homeostasis and the pathogenesis of various diseases. Exosomes are of endosomal origin and range in size from 50 to 150 nm in diameter, while microvesicles are generated by the direct outward budding of the plasma membrane in size ranges of 100-2,000 nm in diameter. EVs can contain various proteins, metabolites, and nucleic acids, such as mRNA, non-coding RNA species, and DNA fragments. In addition, these nucleic acids in EVs can be functional in recipient cells through EV cargo. The endothelium is a distributed organ of considerable biological importance, and disrupted endothelial function is involved in the pathogenesis of respiratory diseases such as chronic obstructive pulmonary disease, pulmonary hypertension, and acute respiratory distress syndrome. Endothelial cell-derived EVs (EC-EVs) play crucial roles in both physiological and pathological conditions by traveling to distant sites through systemic circulation. This review summarizes the pathological roles of vascular microRNAs contained in EC-EVs in respiratory diseases, mainly focusing on chronic obstructive pulmonary disease, pulmonary hypertension, and acute respiratory distress syndrome. Furthermore, this review discusses the potential clinical usefulness of EC-EVs as therapeutic agents in respiratory diseases.

The versatile role of exosomes in human retroviral infections: from immunopathogenesis to clinical application

Eukaryotic cells produce extracellular vesicles (EVs) mediating intercellular communication. These vesicles encompass many bio-molecules such as proteins, nucleic acids, and lipids that are transported between cells and regulate pathophysiological actions in the recipient cell. Exosomes originate from multivesicular bodies inside cells and microvesicles shed from the plasma membrane and participate in various pathological conditions. Retroviruses such as Human Immunodeficiency Virus -type 1 (HIV-1) and Human T-cell leukemia virus (HTLV)-1 engage exosomes for spreading and infection. Exosomes from virus-infected cells transfer viral components such as miRNAs and proteins that promote infection and inflammation. Additionally, these exosomes deliver virus receptors to target cells that make them susceptible to virus entry. HIV-1 infected cells release exosomes that contribute to the pathogenesis including neurological disorders and malignancy. Exosomes can also potentially carry out as a modern approach for the development of HIV-1 and HTLV-1 vaccines. Furthermore, as exosomes are present in most biological fluids, they hold the supreme capacity for clinical usage in the early diagnosis and prognosis of viral infection and associated diseases. Our current knowledge of exosomes' role from virus-infected cells may provide an avenue for efficient retroviruses associated with disease prevention. However, the exact mechanism involved in retroviruses infection/ inflammation remains elusive and related exosomes research will shed light on the mechanisms of pathogenesis.

Foot-and-mouth disease virus degrades Rab27a to suppress the exosome-mediated antiviral immune response

Foot-and-mouth disease (FMD) is a highly contagious infection caused by foot-and-mouth disease virus (FMDV). Exosomes are extracellular vesicles that mediate antiviral immune responses in host cells and could be used by pathogens to evade host cell immune responses. Whether FMDV affects exosome secretion or whether exosomes derived from FMDV-infected cells mediate host cell antiviral immune responses is not yet clarified. In this study, the exosomes were identified and extracted from FMDV-infected PK-15 cells, and it was found that FMDV inhibits exosome secretion. Further investigation revealed that FMDV suppresses exosomes by degrading Rab27a via the autophagy-lysosome pathway. Also, microRNA (miRNA) differential analysis was performed in exosomes, which revealed that miRNA-136 was highly differentially expressed in exosomes and may be the key miRNA that inhibits the proliferation of FMDV. In summary, these results showed that host cells take advantage of exosomes to mediate their antiviral immune response, while FMDV evades exosome-mediated immune responses by degrading the exosome molecular switch, Rab27a.

Extracellular Vesicles in the Pathogenesis of Viral Infections in Humans

Most cells can release extracellular vesicles (EVs), membrane vesicles containing various proteins, nucleic acids, enzymes, and signaling molecules. The exchange of EVs between cells facilitates intercellular communication, amplification of cellular responses, immune response modulation, and perhaps alterations in viral pathogenicity. EVs serve a dual role in inhibiting or enhancing viral infection and pathogenesis. This review examines the current literature on EVs to explore the complex role of EVs in the enhancement, inhibition, and potential use as a nanotherapeutic against clinically relevant viruses, focusing on neurotropic viruses: Zika virus (ZIKV) and human immunodeficiency virus (HIV). Overall, this review's scope will elaborate on EV-based mechanisms, which impact viral pathogenicity, facilitate viral spread, and modulate antiviral immune responses.

Circulating exosomal microRNAs as emerging non-invasive clinical biomarkers in heart failure: Mega bio-roles of a nano bio-particle

Exosomes are nano-sized extracellular vesicles containing a cell-specific biologically active cargo of proteins and genetic materials. Exosomes are constitutively released from almost all cell-types and affect neighboring or distant cells through a complex intercellular exchange of the genetic information and/or regulation of certain gene expressions that change the function and behavior of recipient cells. Those released into body fluids are the major mediators of intercellular communications. The success of the biological functions of exosomes is highly mediated by the effective transfer of microRNAs (miRs). Exosomes secreted by a damaged or diseased heart can exhibit alterations in the miRs' profile that may reflect the cellular origin and (patho)physiological state, as a "signature" or "fingerprint" of the donor cell. It has been shown that the transportation of cardiac-specific miRs in exosomes can be rapidly detected and measured, holding great potential as biomarkers in heart diseases. Currently, the search for new biomarkers of heart diseases remains a large and increasing enterprise. Notably, circulating exosomal miRs (Exo-miRs) have successfully gained huge interests for their diagnostic and prognostic potentials. The present review highlights circulating Exo-miRs explored for diagnosis/prognosis and outcome prediction in patients with heart failure (HF). To this end, we explain the feasibility of exosomes as clinical biomarkers, discuss the priority of circulating Exo-miRs over non-exosomal ones as a biomarker, and then outline reported circulating Exo-miRs having the biomarker function in HF patients, together with their mechanism of action. In conclusion, circulating Exo-miRs represent emerging diagnostic (Exo-miR-92b-5p, Exo-miR-146a, Exo-miR-181c, and Exo-miR-495) and prognostic (Exo-miR-192, Exo-miR-194, Exo-miR-34a, Exo-miR-425, Exo-miR-744) biomarkers for HF.

Long-Term Low-Dose Delta-9-Tetrahydrocannbinol (THC) Administration to Simian Immunodeficiency Virus (SIV) Infected Rhesus Macaques Stimulates the Release of Bioactive Blood Extracellular Vesicles (EVs) that Induce Divergent Structural Adaptations and Signaling Cues

Blood extracellular vesicles (BEVs) carry bioactive cargo (proteins, genetic materials, lipids, licit, and illicit drugs) that regulate diverse functions in target cells. The cannabinoid drug delta-9-tetrahydrocannabinol (THC) is FDA approved for the treatment of anorexia and weight loss in people living with HIV. However, the effect of THC on BEV characteristics in the setting of HIV/SIV infection needs to be determined. Here, we used the SIV-infected rhesus macaque model of AIDS to evaluate the longitudinal effects of THC (THC/SIV) or vehicle (VEH/SIV) treatment in HIV/SIV infection on the properties of BEVs. While BEV concentrations increased longitudinally (pre-SIV (0), 30, and 150 days post-SIV infection (DPI)) in VEH/SIV macaques, the opposite trend was observed with THC/SIV macaques. SIV infection altered BEV membrane properties and cargo composition late in infection, since i) the electrostatic surface properties (zeta potential, ζ potential) showed that RM BEVs carried negative surface charge, but at 150 DPI, SIV infection significantly changed BEV ζ potential; ii) BEVs from the VEH/SIV group altered tetraspanin CD9 and CD81 levels compared to the THC/SIV group. Furthermore, VEH/SIV and THC/SIV BEVs mediated divergent changes in monocyte gene expression, morphometrics, signaling, and function. These include altered tetraspanin and integrin β1 expression; altered levels and distribution of polymerized actin, FAK/pY397 FAK, pERK1/2, cleaved caspase 3, proapoptotic Bid and truncated tBid; and altered adhesion of monocytes to collagen I. These data indicate that HIV/SIV infection and THC treatment result in the release of bioactive BEVs with potential to induce distinct structural adaptations and signaling cues to instruct divergent cellular responses to infection.

Electrostatic Surface Properties of Blood and Semen Extracellular Vesicles: Implications of Sialylation and HIV-Induced Changes on EV Internalization

Although extracellular vesicle (EV) surface electrostatic properties (measured as zeta potential, ζ-potential) have been reported by many investigators, the biophysical implications of charge and EV origin remains uncertain. Here, we compared the ζ-potential of human blood EVs (BEVs) and semen EVs (SEVs) from 26 donors that were HIV-infected (HIV+, n = 13) or HIV uninfected (HIV-, n = 13). We found that, compared to BEVs that bear neutral surface charge, SEVs were significantly more negatively charged, even when BEVs and SEVs were from the same individual. Comparison of BEVs and SEVs from HIV- and HIV+ groups revealed subtle HIV-induced alteration in the ζ-potential of EVs, with the effect being more significant in SEVs (∆ζ-potential = -8.82 mV, p-value = 0.0062) than BEVs (∆ζ-potential = -1.4 mV, p-value = 0.0462). These observations were validated by differences in the isoelectric point (IEP) of EVs, which was in the order of HIV + SEV ≤ HIV-SEV ≪ HIV + BEV ≤ HIV-BEV. Functionally, the rate and efficiency of SEV internalization by the human cervical epithelial cell line, primary peripheral blood lymphocytes, and primary blood-derived monocytes were significantly higher than those of BEVs. Mechanistically, removal of sialic acids from the surface of EVs using neuraminidase treatment significantly decreased SEV's surface charge, concomitant with a substantial reduction in SEV's internalization. The neuraminidase effect was independent of HIV infection and insignificant for BEVs. Finally, these results were corroborated by enrichment of glycoproteins in SEVs versus BEVs. Taken together, these findings uncover fundamental tissue-specific differences in surface electrostatic properties of EVs and highlight the critical role of surface charge in EV/target cell interactions.

Potent Restriction of Sexual Zika Virus Infection by the Lipid Fraction of Extracellular Vesicles in Semen

Sexual Zika virus (ZIKV) transmission from men to women occurs less frequently than the often-detected high viral loads in semen would suggest, but worries that this transmission route predisposes to fetal damage in pregnant women remain. To better understand sexual ZIKV pathogenesis, we studied the permissiveness of the human female genital tract to infection and the effect of semen on this process. ZIKV replicates in vaginal tissues and primary epithelial cells from the vagina, ectocervix, and endocervix and induces an innate immune response, but also continues to replicate without cytopathic effect. Infection of genital cells and tissues is strongly inhibited by extracellular vesicles (EV) in semen at physiological vesicle-to-virus ratios. Liposomes with the same composition as semen EVs also impair infection, indicating that the EV’s lipid fraction, rather than their protein or RNA cargo, is responsible for this anti-viral effect. Thus, EVs in semen potently restrict ZIKV transmission, but the virus propagates well once infection in the recipient mucosa has been established.