The immunogenicity of cancer cells is influenced by several factors, including the expression of the major histocompatibility complex class I (MHC-I), antigen expression, and the repertoire of proteasome-produced epitope peptides. The malignant pleural mesothelioma cell line ACC-MEOS-4 (MESO-4) expresses high levels of MHC-I and Wilms tumor 1 (WT1) tumor antigens. Using a functional T cell reporter assay specific for the HLA-A*24:02 restricted WT1 epitope (WT1235, CMTWNQMNL), we searched for factors that augmented the immunogenicity of MESO-4, focusing on proteasomes, which have a central role in the antigen processing machinery.
View Article and Find Full Text PDFExtracellular vesicles (EVs) in biofluids are highly heterogeneous entities in terms of their origins and physicochemical properties. Considering the application of EVs in diagnostic and therapeutic fields, it is of extreme importance to establish differentiating methods by which focused EV subclasses are operationally defined. Several differentiation protocols have been proposed; however, they have mainly focused on smaller types of EVs, and the heterogeneous nature of large EVs has not yet been fully explored.
View Article and Find Full Text PDFExtracellular vesicles (EVs) in body fluids constitute heterogenous populations, which mirror their diverse parental cells as well as distinct EV-generation pathways. Various methodologies have been proposed to differentiate EVs in order to deepen the current understanding of EV biology. Equilibrium density-gradient centrifugation has often been used to separate EVs based on their buoyant densities; however, the standard conditions used for the method do not necessarily allow all EVs to move to their equilibrium density positions, which complicates the categorization of EVs.
View Article and Find Full Text PDFSilk fibroin (SF) from Bombyx mori has superior properties as both a textile and a biomaterial, and has been used to functionalize the surfaces of various medical inorganic materials including titanium (Ti). In this study, we endowed SF with reversible binding ability to Ti by embedding a titanium binding motif (minTBP-1 and RKLPDA). Artificial SF proteins were first created by conjugating gene cassettes for SF motif (AGSGAG) and minTBP-1 motif with different ratios, which have been shown to bind reversibly to Ti surfaces in quartz crystal microbalance analyses.
View Article and Find Full Text PDFOral fluids (OFs) contain small extracellular vesicles (sEVs or exosomes) that carry disease-associated diagnostic molecules. However, cells generate extracellular vesicles (EVs) other than sEVs, so the EV population is quite heterogeneous. Furthermore, molecules not packaged in EVs can also serve as diagnostic markers.
View Article and Find Full Text PDFBackground/aim: Clusters of circulating tumor cells (CTCs) increase metastatic potential compared to single CTC. However, conventional technologies have been unable to generate an accurate analysis of single and cluster CTCs in the peripheral blood. We propose an effective strategy to detect and isolate both single and cluster CTCs using two size-selective microfilters.
View Article and Find Full Text PDFTo identify factors involved in the earliest phase of the differentiation of human embryonic stem cells (hESCs) into brown adipocytes (BAs), we performed multi-time point microarray analyses. We found that growth/differentiation factor 15 (GDF15) expressions were specifically upregulated within three days of differentiation, when expressions of immature hESC markers were sustained. Although GDF15 expressions continued to increase in the subsequent differentiation phases, -deficient hESCs differentiated into mature BAs (Day 10) without apparent abnormalities.
View Article and Find Full Text PDFPhosphatidylserine (PS) has skewed distributions in the plasma membrane and is preferentially located in the inner leaflet of normal cells. Tumour cells, however, expose PS at the outer leaflet of cell surfaces, thereby potentially modulating the bio-signalling of cells. Interestingly, exosomes - or, more properly, small extracellular vesicles (sEVs) - which are secreted from tumour cells, are enriched with externalized PS, have been proposed as being involved in the progression of cancers, and could be used as a marker for tumour diagnostics.
View Article and Find Full Text PDFA fundamental challenge of biology is to understand the vast heterogeneity of cells, particularly how cellular composition, structure, and morphology are linked to cellular physiology. Unfortunately, conventional technologies are limited in uncovering these relations. We present a machine-intelligence technology based on a radically different architecture that realizes real-time image-based intelligent cell sorting at an unprecedented rate.
View Article and Find Full Text PDFExosomes are extracellular nanovesicles released from any cells and found in any body fluid. Because exosomes exhibit information of their host cells (secreting cells), their analysis is expected to be a powerful tool for early diagnosis of cancers. To predict the host cells, we extracted multidimensional feature data about size, shape, and deformation of exosomes immobilized on solid surfaces by atomic force microscopy (AFM).
View Article and Find Full Text PDFDetection of the cells expressing an epithelial cell adhesion molecule (EpCAM) is a crucial step to identify circulating tumor cells (CTCs) from blood. To detect the EpCAM, we here designed and synthesized a series of fluorogenic peptides. Specifically, we functionalized an EpCAM-binding peptide, Ep114, by replacing its amino acids to an aminophenylalanine that was modified with environmentally sensitive 7-nitro-2,1,3-benzoxadiazole (NBD-amPhe).
View Article and Find Full Text PDFIntroduction: Inorganic materials are widely used in medical devices, such as artificial hearts, vessels, and joints, in stents, and as nanocarriers for drug-delivery systems. Carbon nanomaterials are of particular interest due to their biological inertness and their capability to accommodate molecules. Several attempts have been proposed, in which carbon nanomaterials are used as nanocarriers for the systemic delivery of drugs.
View Article and Find Full Text PDFAdjuvants are indispensable for achieving a sufficient immune response from vaccinations. From a functional viewpoint, adjuvants are classified into two categories: "physical adjuvants" increase the efficacy of antigen presentation by antigen-presenting cells (APC) and "signal adjuvants" induce the maturation of APC. Our previous study has demonstrated that a physical adjuvant can be encrypted into proteinous antigens by creating artificial proteins from combinatorial assemblages of epitope peptides and those peptide sequences having propensities to form certain protein structures (motif programming).
View Article and Find Full Text PDFExtracellular vesicles (EVs) collectively represent small vesicles that are secreted from cells and carry biomolecules (e.g., miRNA, lncRNA, mRNA, proteins, lipids, metabolites, etc.
View Article and Find Full Text PDFA peptide can be used as a functional building block to construct artificial systems when it has sufficient transplantability and functional independence in terms of its assigned function. Recent advances in in vitro evolution systems have been increasing the list of peptides that specifically bind to certain targets, such as proteins and cells. By properly displaying these peptides on solid surfaces, we can endow the inorganic materials with various biological functions, which will contribute to the development of diagnosis and therapeutic medical devices.
View Article and Find Full Text PDFThis chapter describes a method for isolating human salivary extracellular vesicles (EVs) using density gradient ultracentrifugation. Standard protocols established for isolation of EVs from blood or a conditioned medium of cultured cells do not work for whole saliva, due to its viscosity. Therefore, procedures including a pretreatment step and utilizing iodixanol as a gradient material enable EVs to be concentrated to a 1.
View Article and Find Full Text PDFDiagnostic methods that focus on the extracellular vesicles (EVs) present in saliva have been attracting great attention because of their non-invasiveness. EVs contain biomolecules such as proteins, messenger RNA (mRNA) and microRNA (miRNA), which originate from cells that release EVs, making them an ideal source for liquid biopsy. Although there have been many reports on density-based fractionation of EVs from blood and urine, the number of reports on EVs from saliva has been limited, most probably because of the difficulties in separating EVs from viscous saliva using density gradient centrifugation.
View Article and Find Full Text PDFFor the bridging adhesion of different classes of materials in their intact functional states, the adhesion of biomolecules onto inorganic surfaces is a necessity. A new molecular design strategy for bridging adhesion was demonstrated by the introduction of two independent recognition groups on the periphery of spherical complexes self-assembled from metal ions (M) and bidentate ligands (L). These dual-functionalized M12L24 spheres were quantitatively synthesized in one step from two ligands, bearing either a biotin for streptavidin recognition or a titania-binding aptamer, and Pd(II) ions.
View Article and Find Full Text PDFThe properties of nanocarbons change from hydrophobic to hydrophilic as a result of coating them with dispersants, typically phospholipid polyethylene glycols, for biological studies. It has been shown that the dispersants remain attached to the nanocarbons when they are injected in mice and influence the nanocarbons' biodistribution in vivo. We show in this report that the effects of dispersants also appear at the subcellular level in vivo.
View Article and Find Full Text PDFInvocation of cellular immunity by epitopic peptides remains largely dependent on empirically developed protocols, such as interfusion of aluminum salts or emulsification using terpenoids and surfactants. To explore novel vaccine formulation, epitopic peptide motifs were co-programmed with structural motifs to produce artificial antigens using our "motif-programming" approach. As a proof of concept, we used an ovalbumin (OVA) system and prepared an artificial protein library by combinatorially polymerizing MHC class I and II sequences from OVA along with a sequence that tends to form secondary structures.
View Article and Find Full Text PDFAlmost all highly metastatic tumor cells possess high platelet aggregating abilities, thereby form large tumor cell-platelet aggregates in the microvasculature. Embolization of tumor cells in the microvasculature is considered to be the first step in metastasis to distant organs. We previously identified the platelet aggregation-inducing factor expressed on the surfaces of highly metastatic tumor cells and named as Aggrus.
View Article and Find Full Text PDFNanocarbons have many potential medical applications. Drug delivery, diagnostic imaging, and photohyperthermia therapy, especially in the treatment of tumors, have attracted interest. For the further advancement of these application studies, the microscopic localization of nanocarbons in tumor tissues and cells is a prerequisite.
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