Exosomes are representative extracellular vesicles (EV) derived from multivesicular endosomes (MVE) and have been described as new particles in the communication of neighborhood and/or distant cells by serving as vehicles for transfer between cells of membrane and cytosolic proteins, lipids, and nucleotides including micro (mi) RNAs. Exosomes from immune cells and tumor cells act in part as a regulator in tumor immunology. CD8+ T cells that show potent cytotoxic activity against tumor cells reside as an inactive naïve form in the T-cell zone of secondary lymphoid organs. Once receiving tumor-specific antigenic stimulation by dendritic cells (DC), CD8+ T cells are activated and differentiated into effector CTL. Subsequently, CTL circulate systemically, infiltrate into tumor lesions through the stromal neovasculature where mesenchymal stromal cells, for example, mesenchymal stem cells (MSC) and cancer-associated fibroblasts (CAF), abundantly exist, destroy mesenchymal tumor stroma in an exosome-mediated way, go into tumor parenchyma, and attack tumor cells by specific interaction. DC-derived and regulatory T (Treg) cell-derived exosomes, respectively, promote and inhibit CTL generation in this setting. In this review, we describe the roles of exosomes from immune cells and tumor cells on the regulation of tumor progression.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSelf-aggregates of hydrophobized polysaccharides in water. Formation and characteristics of nanoparticlesKazunari Akiyoshi, Shigeru Deguchi, Nobuhiro Moriguchi, Shigehiko Yamaguchi, and Junzo SunamotoCite this: Macromolecules 1993, 26, 12, 3062–3068Publication Date (Print):June 1, 1993Publication History Published online1 May 2002Published inissue 1 June 1993https://pubs.acs.org/doi/10.1021/ma00064a011https://doi.org/10.1021/ma00064a011research-articleACS PublicationsRequest reuse permissionsArticle Views4288Altmetric-Citations535LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Synthetic viral nanostructures are useful as materials for analyzing the biological behavior of natural viruses and as vaccine materials. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an enveloped virus embedding a spike (S) protein involved in host cell infection. Although nanomaterials modified with an S protein without an envelope membrane have been developed, they are considered unsuitable for stability and functionality. We previously constructed an enveloped viral replica complexed with a cationic lipid bilayer and an anionic artificial viral capsid self-assembled from
The transamination reaction of pyridoxal-5′-phosphate (PLP) with N-dodecyl-L-alaninamide (AlaC12) was investigated in an aqueous phosphate–borate buffer at pH 7.0, μ 0.10 (KCl), and 30.0±0.1 °C in the presence of single-walled vesicles of N,N-ditetradecyl-Nα-(6-trimethylamnioniohexanoyl)-L-histidinamide bromide(N+C5His2C14). The electrostatic and hydrophobic interactions between the vesicles and the reactants resulted in incorporation of PLP and AlaC12 into polar and hydrophobic domains of the vesicles, respectively, in the Schiff-base formation process. The isomerization of the aldimine Schiff-base to the corresponding ketimine Schiff-base was confirmed to be the rate-determining step in the transamination process. The reaction site in the vesicular system was found to be equivalent in polarity to dioxane–water (7:3 v/v). However, the overall reaction rate in the vesicles was enhanced 230-fold relative to that in dioxane–water (7:3 v/v). A hydrophobic and suitably polar microenvironment constructed at the reaction site is responsible for such a marked rate-enhancement. In addition, each vesicle of N+C5His2C14 provided functional (imidazolyl) groups in its hydrogen-belt domain to catalyze the intramolecular pro to tropic shift to yield the ketimine Schiff-base. The microenvironmental effects of molecular assemblies of N,N-ditetradecyl-Nα-(6-trimethylammoniohexanoyl)-L-alaninamide bromide and CTAB on the overall transamination were also discussed.
Amphiphilic polysaccharide self-assembled (SA) nanogels are attractive nanocarriers for biologics owing to their chaperone-like activity by nano-encapsulating biologics inside their polymer network in the isolated state. Recently, nanogel-tectonic materials that integrate SA nanogels as building blocks have been designed as new hydrogel biomaterials. In article number 1800729, Kazunari Akiyoshi and co-workers describe recent progress and applications of SA nanogel tectonic materials as protein delivery systems for tissue engineering.
An exosome is one of the extracellular vesicles containing specific proteins, nucleic acids, and sugars. A number of recent reports have shown that exosomes contribute to transporting functions among cells. To facilitate the exosome studies, we focus on the specific separation of exosomes by the recognition of sugar chains on the surface of exosomes. As a typical separation based on sugar chains, lectin affinity chromatography (LAC) which is currently used to purify glycoproteins, is usually employed. However, the pore size of the LAC packing material is fairly small, so that the use of such materials is not suitable for the separation of exosomes having over 100 nm in diameter. To achieve an effective exosome separation, a spongy monolith (SPM), which consists of poly(ethylene-co-glycidyl methacrylate) (PEGM), is expected as a separation medium for LAC. In this study, we prepared two kinds of LAC columns made of the SPMs, immobilized with sambucus sieboldiana agglutinin (SSA) or concanavalin A (ConA). As results, glycoproteins (transferrin and glucose oxidase) were effectively interacted with their respective lectins. Along with glycoproteins, mannose-integrated liposomes were also interacted and rapidly desorbed using the ConA-immobilized SPM (ConA-SPM). Finally, the ConA-SPM was employed for the separations of exosomes, and then the exosomes after passing through the ConA-SPM represented different glycan profiles against the original sample. These results suggest that the lectin-immobilized SPMs will be useful for the separation of exosomes based on the recognition of the surface sugar chains.
Cationic cholesteryl-group-bearing pullulan nanogel (cCHP-nanogel) is an effective drug-delivery system for nasal vaccines. However, cCHP-nanogel-based nasal vaccines might access the central nervous system due to its close proximity via the olfactory bulb in the nasal cavity. Using real-time quantitative tracking of the nanogel-based nasal botulinum neurotoxin and pneumococcal vaccines, we previously confirmed the lack of deposition of vaccine antigen in the cerebrum or olfactory bulbs of mice and non-human primates (NHPs), rhesus macaques. Here, we used positron emission tomography to investigate the biodistribution of the drug-delivery system itself, cCHP-nanogel after mice and NHPs were nasally administered with 18F-labeled cCHP nanogel. The results generated by the PET analysis of rhesus macaques were consistent with the direct counting of radioactivity due to 18F or 111In in dissected mouse tissues. Thus, no depositions of cCHP-nanogel were noted in the cerebrum, olfactory bulbs, or eyes of both species after nasal administration of the radiolabeled cCHP-nanogel compound. Our findings confirm the safe biodistribution of the cCHP-nanogel-based nasal vaccine delivery system in mice and NHPs.
Ionic liquids (ILs) are room-temperature molten salts that have applications in both physical sciences and more recently in the purification of proteins and lipids, gene transfection and sample preparation for electron microscopy (EM) studies. Transfection of genes into cells requires membrane fusion between the cell membrane and the transfection reagent, thus, ILs may be induce a membrane fusion event. To clarify the behavior of ILs with cell membranes the effect of ILs on model membranes, i.e., liposomes, were investigated. We used two standard ILs, 1-ethyl-3-methylimidazolium lactate ([EMI][Lac]) and choline lactate ([Ch][Lac]), and focused on whether these ILs can induce lipid vesicle fusion. Fluorescence resonance energy transfer and dynamic light scattering were employed to determine whether the ILs induced vesicle fusion. Vesicle solutions at low IL concentrations showed negligible fusion when compared with the controls in the absence of ILs. At concentrations of 30% (v/v), both types of ILs induced vesicle fusion up to 1.3 and 1.6 times the fluorescence intensity of the control in the presence of [Ch][Lac] and [EMI][Lac], respectively. This is the first demonstration that [EMI][Lac] and [Ch][Lac] induce vesicle fusion at high IL concentrations and this observation should have a significant influence on basic biophysical studies. Conversely, the ability to avoid vesicle fusion at low IL concentrations is clearly advantageous for EM studies of lipid samples and cells. This new information describing IL-lipid membrane interactions should impact EM observations examining cell morphology.
