Samspillet mellem cyklister, fodgængere og automatiske køretøjer.

Med danske forsøg i udsigt og et udtalt ønske om at adressere samspillet mellem automatiske køretøjer og cyklister og fodgængere, har Vejdirektoratet sammen med Trafitec gennemgået, de erfaringer der ved udgangen af 2017 forelå fra forsøg i europæiske lande. Erfaringsopsamlingen peger på en række opmærksomhedspunkter, der kan være at interesse for bl.a. danske forsøgsaktiviteter. Opmærksomhedspunkterne er bl.a. den uformelle karakter af samspillet mellem motorkøretøjer som det er vanskeligt at overføre til automatiske køretøjer, et behov for kommunikation mellem trafikanter – herunder kommunikation fra automatiske køretøjer til andre, en stor og ofte overdreven tillid til automatiske køretøjer, behov for gradvis tilvænning til samspillet med nye trafiktyper, samt at forsøg generelt har været planlagt med lave hastigheder og stor sikkerhed i fokus

Identification of a residue in hepatitis C virus E2 glycoprotein that determines scavenger receptor BI and CD81 receptor dependency and sensitivity to neutralizing antibodies.

Hepatitis C virus (HCV) infection is dependent on at least three coreceptors: CD81, scavenger receptor BI (SR-BI), and claudin-1. The mechanism of how these molecules coordinate HCV entry is unknown. In this study we demonstrate that a cell culture-adapted JFH-1 mutant, with an amino acid change in E2 at position 451 (G451R), has a reduced dependency on SR-BI. This altered receptor dependency is accompanied by an increased sensitivity to neutralization by soluble CD81 and enhanced binding of recombinant E2 to cell surface-expressed and soluble CD81. Fractionation of HCV by density gradient centrifugation allows the analysis of particle-lipoprotein associations. The cell culture-adapted mutation alters the relationship between particle density and infectivity, with the peak infectivity occurring at higher density than the parental virus. No association was observed between particle density and SR-BI or CD81 coreceptor dependence. JFH-1 G451R is highly sensitive to neutralization by gp-specific antibodies, suggesting increased epitope exposure at the virion surface. Finally, an association was observed between JFH-1 particle density and sensitivity to neutralizing antibodies (NAbs), suggesting that lipoprotein association reduces the sensitivity of particles to NAbs. In summary, mutation of E2 at position 451 alters the relationship between particle density and infectivity, disrupts coreceptor dependence, and increases virion sensitivity to receptor mimics and NAbs. Our data suggest that a balanced interplay between HCV particles, lipoprotein components, and viral receptors allows the evasion of host immune responses