Cell culture-derived extracellular vesicles: Considerations for reporting cell culturing parameters.

Cell culture-conditioned medium (CCM) is a valuable source of extracellular vesicles (EVs) for basic scientific, therapeutic and diagnostic applications. Cell culturing parameters affect the biochemical composition, release and possibly the function of CCM-derived EVs (CCM-EV). The CCM-EV task force of the Rigor and Standardization Subcommittee of the International Society for Extracellular Vesicles aims to identify relevant cell culturing parameters, describe their effects based on current knowledge, recommend reporting parameters and identify outstanding questions.

Extracellular vesicles and co-isolated endogenous retroviruses from murine cancer cells differentially affect dendritic cells.

Cells secrete extracellular vesicles (EVs) and non-vesicular extracellular (nano)particles (NVEPs or ENPs) that may play a role in intercellular communication. Tumor-derived EVs have been proposed to induce immune priming of antigen presenting cells or to be immuno-suppressive agents. We suspect that such disparate functions are due to variable compositions in EV subtypes and ENPs.

Detection of the interactions of tumour derived extracellular vesicles with immune cells is dependent on EV-labelling methods.

Cell-cell communication within the complex tumour microenvironment is critical to cancer progression. Tumor-derived extracellular vesicles (TD-EVs) are key players in this process. They can interact with immune cells and modulate their activity, either suppressing or activating the immune system.

Homosalate boosts the release of tumour-derived extracellular vesicles with protection against anchorage-loss property.

Eukaryotic cells, including cancer cells, secrete highly heterogeneous populations of extracellular vesicles (EVs). EVs could have different subcellular origin, composition and functional properties, but tools to distinguish between EV subtypes are scarce. Here, we tagged CD63- or CD9-positive EVs secreted by triple negative breast cancer cells with Nanoluciferase enzyme, to set-up a miniaturized method to quantify secretion of these two EV subtypes directly in the supernatant of cells.

Urinary extracellular vesicles contain mature transcriptome enriched in circular and long noncoding RNAs with functional significance in prostate cancer.

Long noncoding (lnc)RNAs modulate gene expression alongside presenting unexpected source of neoantigens. Despite their immense interest, their ability to be transferred and control adjacent cells is unknown. Extracellular Vesicles (EVs) offer a protective environment for nucleic acids, with pro and antitumourigenic functions by controlling the immune response.

Extracellular vesicles from triple negative breast cancer promote pro-inflammatory macrophages associated with better clinical outcome.

Tumor associated macrophages (TAMs), which differentiate from circulating monocytes, are pervasive across human cancers and comprise heterogeneous populations. The contribution of tumor-derived signals to TAM heterogeneity is not well understood. In particular, tumors release both soluble factors and extracellular vesicles (EVs), whose respective impact on TAM precursors may be different.

Unbiased proteomic profiling of host cell extracellular vesicle composition and dynamics upon HIV-1 infection.

Cells release diverse types of extracellular vesicles (EVs), which transfer complex signals to surrounding cells. Specific markers to distinguish different EVs (e.g.

Extracellular vesicles containing ACE2 efficiently prevent infection by SARS-CoV-2 Spike protein-containing virus.

SARS-CoV-2 entry is mediated by binding of the spike protein (S) to the surface receptor ACE2 and subsequent priming by host TMPRSS2 allowing membrane fusion. Here, we produced extracellular vesicles (EVs) exposing ACE2 and demonstrate that ACE2-EVs are efficient decoys for SARS-CoV-2 S protein-containing lentivirus. Reduction of infectivity positively correlates with the level of ACE2, is much more efficient than with soluble ACE2 and further enhanced by the inclusion of TMPRSS2.

SnapShot: Extracellular Vesicles.

Cells release a variety of extracellular vesicles (EVs; including exosomes, microvesicles, and many others) into their environment. EVs can bud in endosomes or directly at the plasma membrane, carrying a selection of components from the cell and displaying various functional properties. Different techniques can be used to separate EV subtypes and EVs from co-isolated components, resulting in preparations of different abundance and purity.

spleen-dependent genes encode antigens associated with cytoadhesion and clinical protection.

, the most widely distributed human malaria parasite, causes severe clinical syndromes despite low peripheral blood parasitemia. This conundrum is further complicated as cytoadherence in the microvasculature is still a matter of investigations. Previous reports in , another parasite species shown to infect humans, demonstrated that variant genes involved in cytoadherence were dependent on the spleen for their expression.

Extracellular vesicles and chronic inflammation during HIV infection.

Inflammation is a hallmark of HIV infection. Among the multiple stimuli that can induce inflammation in untreated infection, ongoing viral replication is a primary driver. After initiation of effective combined antiretroviral therapy (cART), HIV replication is drastically reduced or halted.

Acetylcholinesterase is not a generic marker of extracellular vesicles.

Acetylcholinesterase (AChE) activity is found in abundance in reticulocytes and neurons and was developed as a marker of reticulocyte EVs in the 1970s. Easily, quickly, and cheaply assayed, AChE activity has more recently been proposed as a generic marker for small extracellular vesicles (sEV) or exosomes, and as a negative marker of HIV-1 virions. To evaluate these proposed uses of AChE activity, we examined data from different EV and virus isolation methods using T-lymphocytic (H9, PM1 and Jurkat) and promonocytic (U937) cell lines grown in culture conditions that differed by serum content.

Highlights of the São Paulo ISEV workshop on extracellular vesicles in cross-kingdom communication.

In the past years, extracellular vesicles (EVs) have become an important field of research since EVs have been found to play a central role in biological processes. In pathogens, EVs are involved in several events during the host-pathogen interaction, including invasion, immunomodulation, and pathology as well as parasite-parasite communication. In this report, we summarised the role of EVs in infections caused by viruses, bacteria, fungi, protozoa, and helminths based on the talks and discussions carried out during the International Society for Extracellular Vesicles (ISEV) workshop held in São Paulo (November, 2016), Brazil, entitled Cross-organism Communication by Extracellular Vesicles: Hosts, Microbes and Parasites.

Qualitative differences in T-cell activation by dendritic cell-derived extracellular vesicle subtypes.

Exosomes, nano-sized secreted extracellular vesicles (EVs), are actively studied for their diagnostic and therapeutic potential. In particular, exosomes secreted by dendritic cells (DCs) have been shown to carry MHC-peptide complexes allowing efficient activation of T lymphocytes, thus displaying potential as promoters of adaptive immune responses. DCs also secrete other types of EVs of different size, subcellular origin and protein composition, whose immune capacities have not been yet compared to those of exosomes.

Corrigendum: Spleen-Dependent Immune Protection Elicited by CpG Adjuvanted Reticulocyte-Derived Exosomes from Malaria Infection Is Associated with Changes in T Cell Subsets' Distribution.

[This corrects the article on p. 131 in vol. 4, PMID: 27900319.

Spleen-Dependent Immune Protection Elicited by CpG Adjuvanted Reticulocyte-Derived Exosomes from Malaria Infection Is Associated with Changes in T cell Subsets' Distribution.

Reticulocyte-derived exosomes () are 30-100 nm membrane vesicles of endocytic origin released during the maturation of reticulocytes to erythrocytes upon fusion of multivesicular bodies with the plasma membrane. Combination of CpG-ODN with rex obtained from BALB/c mice infected with the reticulocyte-prone non-lethal 17X malaria strain (), had been shown to induce survival and long lasting protection. Here, we show that splenectomized mice are not protected upon +CpG inmunizations and that protection is restored upon passive transfer of splenocytes obtained from animals immunized with +CpG.

Size-exclusion chromatography as a stand-alone methodology identifies novel markers in mass spectrometry analyses of plasma-derived vesicles from healthy individuals.

Plasma-derived vesicles hold a promising potential for use in biomedical applications. Two major challenges, however, hinder their implementation into translational tools: (a) the incomplete characterization of the protein composition of plasma-derived vesicles, in the size range of exosomes, as mass spectrometric analysis of plasma sub-components is recognizably troublesome and (b) the limited reach of vesicle-based studies in settings where the infrastructural demand of ultracentrifugation, the most widely used isolation/purification methodology, is not available. In this study, we have addressed both challenges by carrying-out mass spectrometry (MS) analyses of plasma-derived vesicles, in the size range of exosomes, from healthy donors obtained by 2 alternative methodologies: size-exclusion chromatography (SEC) on sepharose columns and Exo-Spin™.

Extracellular vesicles in parasitic diseases.

Parasitic diseases affect billions of people and are considered a major public health issue. Close to 400 species are estimated to parasitize humans, of which around 90 are responsible for great clinical burden and mortality rates. Unfortunately, they are largely neglected as they are mainly endemic to poor regions.

The Role of Extracellular Vesicles in Modulating the Host Immune Response during Parasitic Infections.

Parasites are the cause of major diseases affecting billions of people. As the inflictions caused by these parasites affect mainly developing countries, they are considered as neglected diseases. These parasitic infections are often chronic and lead to significant immunomodulation of the host immune response by the parasite, which could benefit both the parasite and the host and are the result of millions of years of co-evolution.

Reticulocyte-prone malaria parasites predominantly invade CD71hi immature cells: implications for the development of an in vitro culture for Plasmodium vivax.

Background: The lack of a continuous in vitro culture system for blood stages of malarial parasites with a unique tropism for reticulocytes, such as Plasmodium vivax and the Plasmodium yoelii 17X reticulocyte-prone strain, hinders research in these organisms. The maturation of reticulocytes into erythrocytes is a complex process involving the selective removal of membrane proteins such as the transferrin receptor, CD71. In order to advance in the characterization of infected cells during experimental infections of BALB/c mice with P.

Imaging of the spleen in malaria.

Splenomegaly, albeit variably, is a hallmark of malaria; yet, the role of the spleen in Plasmodium infections remains vastly unknown. The implementation of imaging to study the spleen is rapidly advancing our knowledge of this so-called "blackbox" of the abdominal cavity. Not only has ex vivo imaging revealed the complex functional compartmentalization of the organ and immune effector cells, but it has also allowed the observation of major structural remodeling during infections.