Search results for "Internalization"

Polityka i instrumenty wsparcia klastrów w perspektywie finansowej 2014-2020

2016

2018

Tetraspanins (Tspans) are a family of four-span transmembrane proteins, known as plasma membrane “master organizers.” They form Tspan-enriched microdomains (TEMs or TERMs) through lateral association with one another and other membrane proteins. If multiple microdomains associate with each other, larger platforms can form. For infection, viruses interact with multiple cell surface components, including receptors, activating proteases, and signaling molecules. It appears that Tspans, such as CD151, CD82, CD81, CD63, CD9, Tspan9, and Tspan7, coordinate these associations by concentrating the interacting partners into Tspan platforms. In addition to mediating viral attachment and entry, these …

Plasma membrane glycoproteins covalently bound to silica beads as a model for molecular studies of cell-cell interactions in culture.

1987

Abstract In previous studies, we have shown that plasma membrane glycoproteins are of major importance in the density-dependent regulation of growth of normal diploid fibroblasts. Due to the hydrophobic portions of these molecules, functional studies in cell culture are often diffucult to perform and to interpret. Specially, the addition of these molecules in soluble form to cell culture, after depletion of detergents needed for their solubilization, leads to aggregation and internalization. Therefore, we developed a method for the covalent immobilization of the solubilized plasma membrane proteins to derivatized silica beads for further investigations on the molecular nature of the active …

Selective uptake of naked vaccine RNA by dendritic cells is driven by macropinocytosis and abrogated upon DC maturation.

2011

Even though it is known for more than one decade that antigen-encoding RNA can deliver antigenic information to induce antigen-specific immunity against cancer, the nature and mechanism of RNA uptake have remained enigmatic. In this study, we investigated the pharmacokinetics of naked RNA administered into the lymph node. We observed that RNA is rapidly and selectively uptaken by lymph node dendritic cells (DCs). Furthermore, in vitro and in vivo studies revealed that the efficient internalization of RNA by human and murine DCs is primarily driven by macropinocytosis. Selective inhibition of macropinocytosis by compounds or as a consequence of DC maturation abrogated RNA internalization and…

Relative expression of cholesterol transport-related proteins and inflammation markers through the induction of 7-ketosterol-mediated stress in Caco-…

2013

Human diets contain sterol oxidation products that can induce cytotoxic effects, mainly caused by cholesterol oxides. However, phytosterol oxides effects have been less extensively investigated. This study evaluates the production of inflammatory biomarkers (IL-1β, IL-8, IL-10, TNFα) and the influence of gene expression transporters and enzymes related to cholesterol absorption and metabolism (NPC1L1, ABCG5/8, HMGCoA, ACAT) produced by 7-ketosterols (stigmasterol/cholesterol) in Caco-2 cells. These effects were linked to intracellular signaling pathways by using several inhibitors. Results showed 7-ketostigmasterol to have a greater proinflammatory potential than 7-ketocholesterol. In non-p…

Low cholesterol stimulates the nonamyloidogenic pathway by its effect on the α-secretase ADAM 10

2001

Biochemical, epidemiological, and genetic findings demonstrate a link between cholesterol levels, processing of the amyloid precursor protein (APP), and Alzheimer's disease. In the present report, we identify the α-secretase ADAM 10 ( a d isintegrin a nd m etalloprotease) as a major target of the cholesterol effects on APP metabolism. Treatment of various peripheral and neural cell lines with either the cholesterol-extracting agent methyl-β-cyclodextrin or the hydroxymethyl glutaryl-CoA reductase inhibitor lovastatin resulted in a drastic increase of secreted α-secretase cleaved soluble APP. This strong stimulatory effect was in the range obtained with phorbol esters and was further increa…

2019

Ultrasmall polyaminocarboxylate-coated gold nanoparticles (NPs), Au@DTDTPA and Au@TADOTAGA, that have been recently developed exhibit a promising potential for image-guided radiotherapy. In order to render the radiosensitizing effect of these gold nanoparticles even more efficient, the study of their localization in cells is required to better understand the relation between the radiosensitizing properties of the agents and their localization in cells and in tumors. To achieve this goal, post-functionalization of Au@DTDTPA nanoparticles by near-infrared (NIF) organic dyes (aminated derivative of cyanine 5, Cy5-NH2) was performed. The immobilization of organic Cy5-NH2 dyes onto the gold nano…

N-Methyl-β-carboline alkaloids: structure-dependent photosensitizing properties and localization in subcellular domains

2020

N-Methyl-β-carboline (βC) alkaloids, including normelinonine F (1b) and melinonine F (2b), have been found in a vast range of living species playing different biological, biomedical and/or pharmacological roles. Despite this, molecular bases of the mechanisms through which these alkaloids would exert their effect still remain unknown. Fundamental aspects including the photosensitizing properties and intracellular internalization of a selected group of N-methyl-βC alkaloids were investigated herein. Data reveal that methylation of the βC main ring enhances its photosensitizing properties either by increasing its binding affinity with DNA as a biomolecular target and/or by increasing its oxid…

Weight Bias Internalization

2018

Weight stigma typically focuses on suggestions that people with overweight and obesity are incompetent and immoral. Integrating so far unconnected lines of research, the current research presents two studies that examine the motivational relevance of these aspects of weight stigma. Specifically, we tested the proposition that people with overweight and obesity respond differently to the public viewing them as incompetent compared to immoral, as these aspects of weight stigma differ in reparability. We expect that threats to competence are more acceptable and thus related to a constructive response that is more effective in losing weight in the long-run. By contrast, we propose that threats …

Modulation of melanoma-associated antigens by monoclonal antibodies as visualized by radioimmunoelectron microscopy and radioantibody binding assay

1987

There is a wealth of information about monoclonal antibody (MAb) specificity and function on fixed tissues, yet little is known about formation and release of antigen-antibody complexes and their functional behavior in vivo. We analyzed the pathway of radiolabeled MAbs directed against melanoma-associated antigens by radioimmunoelectron microscopy (RIEM) on metabolically active cells of the melanoma cell lines SK-MEL-28, MeWo and Colo 38 at different time intervals. In parallel, binding and release of MAbs were investigated by the radioantibody binding assay (RBA). Both procedures gave essentially concordant results. Preferentially stable binding of immune complexes (ICs) to the cell surfac…