Rab27a controls HIV-1 assembly by regulating plasma membrane levels of phosphatidylinositol 4,5-bisphosphate

During the late stages of the HIV-1 replication cycle, the viral polyprotein Pr55(Gag) is recruited to the plasma membrane (PM), where it binds phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and directs HIV-1 assembly. We show that Rab27a controls the trafficking of late endosomes carrying phosphatidylinositol 4-kinase type 2 α (PI4KIIα) toward the PM of CD4(+) T cells. Hence, Rab27a promotes high levels of PM phosphatidylinositol 4-phosphate and the localized production of PI(4,5)P2, therefore controlling Pr55(Gag) membrane association. Rab27a also controls PI(4,5)P2 levels at the virus-containing compartments of macrophages. By screening Rab27a effectors, we identified that Slp2a, Slp3, and Slac2b are required for the association of Pr55(Gag) with the PM and that Slp2a cooperates with Rab27a in the recruitment of PI4KIIα to the PM. We conclude that by directing the trafficking of PI4KIIα-positive endosomes toward the PM, Rab27a controls PI(4,5)P2 production and, consequently, HIV-1 replication.Universidad de Buenos Aires and CONICET doctoral fellowships, Agencia Nacional de Pro- moción Científica y Tecnológica (Argentina) grants: (2010-1681, 2012-00353), Creative and Novel Ideas in HIV Research Program, University of Alabama at Birmingham Center for AIDS Research funding grant P30 AI027767-24

Inmate Recidivism as a Measure of Private Prison Performance

The growth of the private corrections industry has elicited interest in the comparative performance of state and private prisons. One way to measure the service quality of private prisons is to examine inmates' postrelease performance. Current empirical evidence is limited to four studies, all conducted in Florida. This analysis replicates and adds to the Florida measures in a different state and enhances previous methods. It uses data for a large cohort of Oklahoma state prison inmates released between 1997 and 2001. Controlling for known covariates, multivariate survival analysis revealed comparative rates of reincarceration for inmates in multiple exposure and comparison groups. These results are unique among prior studies on this topic; private prison inmates had a greater hazard of recidivism in all eight models tested, six of which were statistically significant. Finding no empirical support for claims of superior service from private corrections, the authors discuss policy implications and prospects for future research.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Taming trilogues: the EU's law-making process in a comparative perspective.

Trilogues have become the modus operandi of EU decision-making. They are an informal but institutionalised mechanism providing for in camera discussions of legislative texts between the three main EU decision-making institutions, with a view to securing legislative compromises. Trilogues present risks to an organ of parliamentary representation through their potential to depoliticise conflict and by reducing the accountability and transparency of the decision-making process. We examine how the European Parliament (EP) has responded to trilogues and what this response tells us about the development of the EP as an institutionalised organ of representative democracy. We compare these with arrangements for bicameral conflict resolution in the United States, where similar issues are presented by informal mechanisms of decision-making. We assess the institutionalisation of trilogues from a democratic perspective, highlighting achievements and future challenges, and the value of these findings for the ongoing reflection on the EP as a normal parliament and the role of informal institutions in EU law-making

Evolving neural network optimization of cholesteryl ester separation by reversed-phase HPLC

Cholesteryl esters have antimicrobial activity and likely contribute to the innate immunity system. Improved separation techniques are needed to characterize these compounds. In this study, optimization of the reversed-phase high-performance liquid chromatography separation of six analyte standards (four cholesteryl esters plus cholesterol and tri-palmitin) was accomplished by modeling with an artificial neural network–genetic algorithm (ANN-GA) approach. A fractional factorial design was employed to examine the significance of four experimental factors: organic component in the mobile phase (ethanol and methanol), column temperature, and flow rate. Three separation parameters were then merged into geometric means using Derringer’s desirability function and used as input sources for model training and testing. The use of genetic operators proved valuable for the determination of an effective neural network structure. Implementation of the optimized method resulted in complete separation of all six analytes, including the resolution of two previously co-eluting peaks. Model validation was performed with experimental responses in good agreement with model-predicted responses. Improved separation was also realized in a complex biological fluid, human milk. Thus, the first known use of ANN-GA modeling for improving the chromatographic separation of cholesteryl esters in biological fluids is presented and will likely prove valuable for future investigators involved in studying complex biological samples

Acidosis Potentiates the Host Proinflammatory Interleukin-1β Response to Pseudomonas Aeruginosa Infection

Infection by Pseudomonas aeruginosa, and bacteria in general, frequently promotes acidification of the local microenvironment, and this is reinforced by pulmonary exertion and exacerbation. However, the consequence of an acidic environment on the host inflammatory response to P. aeruginosa infection is poorly understood. Here we report that the pivotal cellular and host proinflammatory interleukin-1β (IL-1β) response, which enables host clearance of the infection but can produce collateral inflammatory damage, is increased in response to P. aeruginosa infection within an acidic environment. Synergistic mechanisms that promote increased IL-1β release in response to P. aeruginosa infection in an acidic environment are increased pro-IL-1β induction and increased caspase-1 activity, the latter being dependent upon a functional type III secretion system of the bacteria and the NLRC4 inflammasome of the host. Using an in vivo peritonitis model, we have validated that the IL-1β inflammatory response is increased in mice in response to P. aeruginosa infection within an acidic microenvironment. These data reveal novel insights into the regulation and exacerbation of inflammatory responses to P. aeruginosa

Murine Leukemia Virus Spreading in Mice Impaired in the Biogenesis of Secretory Lysosomes and Ca2+-Regulated Exocytosis

Retroviruses have been observed to bud intracellularly into multivesicular bodies (MVB), in addition to the plasma membrane. Release from MVB is thought to occur by Ca(2+)-regulated fusion with the plasma membrane.To address the role of the MVB pathway in replication of the murine leukemia virus (MLV) we took advantage of mouse models for the Hermansky-Pudlak syndrome (HPS) and Griscelli syndrome. In humans, these disorders are characterized by hypopigmentation and immunological alterations that are caused by defects in the biogenesis and trafficking of MVBs and other lysosome related organelles. Neonatal mice for these disease models lacking functional AP-3, Rab27A and BLOC factors were infected with Moloney MLV and the spread of virus into bone marrow, spleen and thymus was monitored. We found a moderate reduction in MLV infection levels in most mutant mice, which differed by less than two-fold compared to wild-type mice. In vitro, MLV release form bone-marrow derived macrophages was slightly enhanced. Finally, we found no evidence for a Ca(2+)-regulated release pathway in vitro. Furthermore, MLV replication was only moderately affected in mice lacking Synaptotagmin VII, a Ca(2+)-sensor regulating lysosome fusion with the plasma membrane.Given that MLV spreading in mice depends on multiple rounds of replication even moderate reduction of virus release at the cellular level would accumulate and lead to a significant effect over time. Thus our in vivo and in vitro data collectively argue against an essential role for a MVB- and secretory lysosome-mediated pathway in the egress of MLV

Dispositifs at Play: Artist's Moving Image in the Gallery

Artists’ moving image work today occupies a key place in contemporary art. This is evident from the sheer amount of moving image media in public galleries and museums, retrospectives, biennales and artist-run initiatives. This chapter focuses on the installation of Australian artists’ moving image production, with an emphasis on installation and the way in which the work meets its audience. It examines the recent work of Brian Fuata, Pia van Gelder, Biljana Jancic and Angelica Mesiti with respect to exhibitions mounted in Sydney from 2012 to 2018. The concept of the dispositif—as a set of interrelated elements of an artwork for spatial display in the gallery—is put to work to confront the heterogeneity of forms, practices and experiences within four specified categories: ‘Document, Signal, Space and Channel’. This research connects the experience of the artists and curators in question, drawing on interviews, and links this with historical and theoretical discourse in relation to moving image (and sound) in the gallery. The chapter aims to show the inventive ways in which contemporary artists rely on inherited twentieth-century traditions of this relatively new (historically speaking) medium and engage with digital media convergence. This research finds Australian artists to be at the cutting edge of the field and provides a foundation to extend this research to the wider Asia Pacific region or international context. This chapter should be of interest to artists, filmmakers, screen and art theorists and creative practice-based researchers working in this domain