Biology subjects

Kuttler, F.

Publications and source records attributed to Kuttler, F..

3 recordsLinked to original sources

bioRxiv2020

The FDA-approved drug Nelfinavir inhibits lytic cell-free transmission of human adenoviruses

Adenoviruses (AdVs) are prevalent and give rise to chronic and recurrent disease. The human AdV (HAdV) species B and C, such as HAdV-C2, C5 and B14, cause respiratory disease, and constitute a health threat for immuno-compromised individuals. HAdV-Cs are well known for lysing cells, owing to the E3 CR1-{beta}-encoded adenovirus death protein (ADP). We previously reported a high-throughput image-based screening framework and identified an inhibitor of HAdV-C2 multi-round infection, Nelfinavir Mesylate. Nelfinavir is the active ingredient of Viracept, an FDA-approved inhibitor of the human immuno-deficiency virus (HIV) aspartyl protease, and used to treat acquired immunodeficiency syndrome (AIDS). It is not effective against single round HAdV infections. Here, we show that Nelfinavir inhibits the lytic cell-free transmission of HAdV, indicated by the suppression of comet-shaped infection foci in cell culture. Comet-shaped foci occur upon convection-based transmission of cell-free viral particles from an infected cell to neighbouring uninfected cells. HAdV lacking ADP was insensitive to Nelfinavir, but gave rise to comet-shaped foci indicating that ADP enhances but is not required for cell lysis. This was supported by the notion that HAdV-B14 and B14p1 lacking ADP were highly sensitive to Nelfinavir, although HAdV-A31, B3, B7, B11, B16, B21, D8, D30 or D37 were less sensitive. Conspicuously, Nelfinavir uncovered slow-growing round-shaped HAdV-C2 foci, independent of neutralizing antibodies in the medium, indicative of non-lytic cell-to-cell transmission. Our study demonstrates the repurposing potential of Nelfinavir with post-exposure efficacy against different HAdVs, and describes an alternative non-lytic cell-to-cell transmission mode of HAdV. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=181 SRC="FIGDIR/small/098061v1_ufig1.gif" ALT="Figure 1"> View larger version (85K): org.highwire.dtl.DTLVardef@8aa32corg.highwire.dtl.DTLVardef@1dea943org.highwire.dtl.DTLVardef@13aa2fborg.highwire.dtl.DTLVardef@a23352_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFigure 1.C_FLOATNO C_FIG

microbiology↗

bioRxiv2020

A full cycle anti-viral drug screen identifies a clinical compound against adenovirus infection

Human adenoviruses (HAdVs) are fatal to immuno-suppressed people, but no effective anti-HAdV therapy is available. Here, we present a novel image-based high-throughput screening (HTS) platform, which scores the full viral replication cycle from virus entry to dissemination of progeny. We analysed 1,280 small molecular weight compounds of the Prestwick Chemical Library (PCL) for interference with HAdV-C2 infection in a quadruplicate, blinded format, and included robust image analyses, and hit filtering. We present the entire set of the screening data including all the images, image analyses and data processing pipelines. The data are made available at the Image Data Repository (IDR) 1, accession number idr0081. Our screen identified Nelfinavir mesylate as an inhibitor of HAdV-C2 multi-round plaque formation, but not single round infection. Nelfinavir has been FDA-approved for anti-retroviral therapy in humans. Our results underscore the power of image-based full cycle infection assays in identifying viral inhibitors with clinical potential.

microbiology↗

bioRxiv2019

The process of Lewy body formation, rather than simply alpha-synuclein fibrillization, is the major driver of neurodegeneration in synucleinopathies

Parkinsons disease (PD) is characterized by the accumulation of misfolded alpha-synuclein (-syn) into intraneuronal inclusions named Lewy bodies (LB). Although it is widely believed that -syn plays a central role in the pathogenesis of PD and synucleinopathies, the processes that govern -syn fibrillization and LB formation in the brain remain poorly understood. In this work, we sought to reverse engineer LBs and dissect the spatiotemporal events involved in their biogenesis at the genetic, molecular, biochemical, structural, and cellular levels. Toward this goal, we took advantage of a seeding-based model of -syn fibril formation in primary neurons and further developed this model to generate the first neuronal model that reproduces the key events leading to LB formation; including seeding, fibrillization, and the formation of LB-like inclusions that recapitulate many of the biochemical, structural, and organizational features of LBs found in post-mortem human PD brain tissues. Next, we applied an integrative approach combining confocal and correlative light-electron microscopy (CLEM) imaging methods with biochemical profiling of -syn species and temporal proteomic and transcriptomic analyses to dissect the molecular events associated with LB formation and maturation and to elucidate their contributions to neuronal dysfunctions and neurodegeneration in PD and synucleinopathies. The results from these studies demonstrate that LB formation involves a complex interplay between -syn fibrillization, post-translational modifications, and interactions between -syn aggregates and membranous organelles, including mitochondria and the autophagosome and endolysosome. Furthermore, we demonstrate that the process of LB formation and maturation, rather than simply fibril formation, is the major driver of neurodegeneration through disruption of cellular functions and inducing mitochondria damage and deficits, as well as synaptic dysfunctions. Having a neuronal model that allows for unlinking of the key processes involved in LB formation is crucial for elucidating the molecular and cellular determinants of each process and their contributions to neuronal dysfunction and degeneration in PD and synucleinopathies. Such a model is essential to efforts to identify and investigate the mode of action and toxicity of drug candidates targeting -syn aggregation and LB formation.

neuroscience↗