The Phosphoinositide Kinase PIKfyve Promotes Cathepsin-S-Mediated Major Histocompatibility Complex Class II Antigen Presentation

Contains fulltext : 201259.pdf (publisher's version ) (Open Access

Aggregation Properties of Albumin in Interacting with Magnetic Fluids

In this study, interactions of Fe3O4 magnetic nanoparticles with serum albumin biomolecules in aqueous solutions were considered. The studies were conducted with the laser correlation spectroscopy and optical analysis of dehydrated films. It was shown that the addition of magnetite to an albumin solution at low concentrations of up to 10−6 g/L led to the formation of aggregates with sizes of up to 300 nm in the liquid phase and an increase in the number of spiral structures in the dehydrated films, which indicated an increase in their stability. With a further increase in the magnetite concentration in the solution (from 10−4 g/L), the magnetic particles stuck together and to albumin, thus forming aggregates with sizes larger than 1000 nm. At the same time, the formation of morphological structures in molecular films was disturbed, and a characteristic decrease in their stability occurred. Most stable films were formed at low concentrations of magnetic nanoparticles (less than 10−4 g/L) when small albumin–magnetic nanoparticle aggregates were formed. These results are important for characterizing the interaction processes of biomolecules with magnetic nanoparticles and can be useful for predicting the stability of biomolecular films with the inclusion of magnetite particles

Oxidized phagosomal NOX2 complex is replenished from lysosomes

In dendritic cells, the NADPH oxidase 2 complex (NOX2) is recruited to the phagosomal membrane during antigen uptake. NOX2 produces reactive oxygen species (ROS) in the lumen of the phagosome that kill ingested pathogens, delay antigen breakdown and alter the peptide repertoire for presentation to T cells. How the integral membrane component of NOX2, cytochrome b(558) (which comprises CYBB and CYBA), traffics to phagosomes is incompletely understood. In this study, we show in dendritic cells derived from human blood-isolated monocytes that cytochrome b(558) is initially recruited to the phagosome from the plasma membrane during phagosome formation. Cytochrome b(558) also traffics from a lysosomal pool to phagosomes and this is required to replenish oxidatively damaged NOX2. We identified syntaxin-7, SNAP23 and VAMP8 as the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins mediating this process. Our data describe a key mechanism of how dendritic cells sustain ROS production after antigen uptake that is required to initiate T cell responses

Coveted, detested and unattainable?

This article explores how the image of the USA has developed in two major Russian daily newspapers, Izvestiya and Komsomolskaya Pravda, in a time period comprised of a total 20 weeks’ of study in the years of 1984, 1994, 2004 and 2009. For Russia this time span was dramatic: it moved from seemingly stable superpower in the 1980s, over the chaos after the dissolution of the Soviet Union in the 1990s, to the partial comeback to great power status at the beginning of the 21st century. While telling the story of how the image of the USA has evolved, the article also describes how Russian self-images have developed. The image projected of the USA was Manichean in the 1980s, whereas the most benevolent images were found in the 1990s. The examples from 2004 and 2009 reflect an assertive Russia that is back on the world stage. The USA is here again often criticized, but also — as before — comprises the scale against which Russia itself is measured