Spring Conference 2011 - Society for General Microbiology

More documents

Recommendations

Info

Please note: Abstracts are published as received from the authors and are not subject to editing. 5 Spring Meeting 11–14 April 2011 Harrogate – www.sgmharrogate2011.org.uk SESSION AbSTrACTS ↑Contents HA01 Cont. but also transport of the reverse transcription complex to the nucleus and exit of the cell. Key regulators of microtubule dynamics such as histone deacetylase 6 have been described to be modulated upon HiV-1 infection. recently, we have identified a motif located in the cytoplasmic tail of HiV-1 transmembrane protein (gp41) that modulates microtubule stability (tubulin acetylation) in tail- expressing cells, this effect being a unique feature of the lentiviral transmembrane protein (Malinowsky, K. et al., Virology 376: 69–78, 2008). Moreover, this modulation of microtubule stability reduced virus-cell fusion in Hela-CD4 cells and PM1 T-cells. it is therefore important to gain a more detailed knowledge of the upstream and downstream effectors that regulate microtubule dynamics in early HiV-1 infection. Currently, we are investigating the effects on microtubule stability (tubulin acetylation) upon expression of various gp41 cytoplasmic tail constructs in macrophages and T-lymphocytes using quantitative confocal microscopy. results will be discussed. Offered paper Dissecting the different mechanisms of calicivirus cell entry NiCOlE DOYlE1 , Terry Jackson2 , Andreas Gerondopoulos3 , Elisabetta Groppelli4 , Paul Monaghan5 , lisa roberts1 1 2 3 University of Surrey, Guildford, Surrey; Institute of Animal Health, Pirbright, Surrey; University of Liverpool, Cancer Research Centre, Liverpool; 4University College London, London; 5Australian Animal Health Laboratory, Geelong, Australia Caliciviruses are responsible for many diseases of man and animals, for example noroviruses cause outbreaks of human gastroenteritis. Although studies on norovirus replication have previously been hampered by the lack of an efficient culture system, the recently identified murine norovirus (MNV-1) has provided an excellent model for studying norovirus replication. it was known from previous work in our lab that MNV-1 infection of rAW264.7 macrophages does not use the clathrin, caveolin, or flotillin-dependent pathways. However, MNV-1 infection does require cholesterol and the presence of active dynamin. in contrast, previous work on the entry of feline calicivirus showed that it enters cells via a clathrin-dependent pathway, but is independent of caveolin and cholesterol; clearly these related viruses are using very different cell entry mechanisms. We are now using pharmacological inhibitors of signaling pathways (genistein, okadaic acid and wortmannin) and dominant negative inhibitors of proteins involved in endocytic and signaling pathways (rab proteins, Arf 6), as well as colocalization studies with specific endocytic markers to further elucidate the specific entry pathways used by these viruses. Offered paper A two-step mechanism for trafficking of influenza A virus vrNAs to the apical plasma membrane that involves the microtubule network MAriA-JOAO AMOriM, Eliot read, Emily Bruce, Amanda Stuart, Paul Digard University of Cambridge, Cambridge The segmented vrNA genome of influenza A virus (iAV) is replicated in the nucleus, exported to the cytoplasm as ribonucleoproteins (rNPs) and trafficked to the plasma membrane (PM). Cytoplasmic trafficking of rNPs is not well defined, either for route or when the 8 segments meet to assemble a full genome. using fluorescent in situ hybridization to detect vrNA and live-cell imaging of rNPs, we show the initial stages of rNP trafficking involves accumulation of all segments at the pericentriolar recycling endosome (rE), in multiple cell types and viral strains. Here, rNPs surrounded gamma-tubulin and colocalized with rab11. As infection progressed, rNPs dispersed throughout the cytoplasm in structures of ~250–600 nm that again, contained multiple segments. GFP-tagged rNPs in living cells demonstrated rapid (average 1.3 micron/sec), bi-directional and saltatory movement, and characteristic of microtubule-based transport, inhibited by MT-drugs, and also co-trafficked with fluorescent rab11. We conclude that iAV rNPs concentrate at the pericentriolar rE, are loaded onto vesicles and traffic to the PM. This work shows an important understanding on how the 8 vrNA segments are funneled together to the PM, facilitating viral assembly by placing them at the same location where viral budding occurs. Offered paper Disruption of microtubule dynamics activates latent KSHV and HIV-1 EDWArD TSAO1 , Paul Dobson2 , Katarzyna Wisniewska1 , Claire Pardieu1 , Sam Wilson1 , richard Jenner1 , Paul Kellam1,3 1 2 3 University College London, London; University of Manchester, Manchester; Wellcome Trust Sanger Institute, Cambridge latency establishment is a key strategy used by herpesviruses and retroviruses for viral persistence and immune evasion and the resulting viral reservoirs prevent the eradication of infection. latency is characterized by the ability of latent viral genomes to reactivate into the replicative cycle for producing virus progeny. This phase in the virus life cycle is particularly amenable to immune control and therapeutic intervention. understanding the molecular mechanisms through which latency is maintained allows it to be targeted therapeutically to clear the host of latent infection. Here, we report the use of a chemical genetic screen to both investigate pathways required for viral latency and to identify small molecules as potential therapeutics. We screened the NCi DTP Diversity set and identified 25 small molecules that reactivate Kaposi’s sarcoma-associated herpesvirus (KSHV) from latency. We show one compound, uClB-15026, disrupts microtubule dynamics and triggers, through the extracellular signal-regulated kinase (ErK) pathway, KSHV lytic replication. We demonstrate enhanced killing of KSHV-associated tumor cells by ganciclovir when pre-treated with uClB-15026. Furthermore, we show uClB-15026, through s o c i e t y f o r g e n e r a l Microbiology
Please note: Abstracts are published as received from the authors and are not subject to editing. 6 Spring Meeting 11–14 April 2011 Harrogate – www.sgmharrogate2011.org.uk SESSION AbSTrACTS ↑Contents HA01 Cont. the ErK pathway, can induce transcriptional activity from the human immunodeficiency virus type-1 (HiV-1) long-terminal repeat (lTr) in a latency model, revealing commonalities between KSHV and HiV-1 reactivation from latency. Offered paper The hunt for a host protein that is crucial for arterivirus replication ADriAAN H. DE WilDE, Ali Tas, Eric J. Snijder, Martijn J. van Hemert Leiden University Medical Center, Leiden, Netherlands The replication complexes of positive-stranded rNA viruses are associated with cytoplasmic membrane structures and many steps of their replicative cycle heavily depend on cellular processes and host factors. Our research focuses on the replication/transcription complexes (rTCs) and host factors involved in nidovirus replication. We previously discovered that the in vitro rNA-synthesizing activity of semi-purified Equine arteritis virus (EAV) rTCs depends on a host factor that does not co-purify with rTCs. This host factor has now been characterized in more detail. Differential centrifugation of EAV-infected cell lysates yielded a pellet that contained heavy membrane structures and all of the viral rNA polymerase. The pelleted rTCs were inactive in an in vitro rNA synthesis assay unless supplemented with a host factor preparation. Basic biochemical analyses revealed that this crucial host factor is a cytosolic protein that is conserved among higher eukaryotes. We set out to identify this factor by purifying it from Hela cell lysates using size exclusion, ion-exchange- and hydrophobic interaction chromatography. Protein fractions were tested for their ability to reconstitute rTC activity. Both ‘serial’ and ‘parallel’ purification strategies were applied and the host factor is currently being analysed by conventional mass spectrometry and comparative quantitative mass spectrometry-based proteomics. Offered paper Using quantitative proteomics to understand how respiratory viruses interact with the host cell Brian Dove3 , rebecca Surtees1,3 , Thomas Bean3 , Diane Munday1 , Helen Wise2 , Paul Digard2 , John Barr1 , JuliAN HiSCOx1 1 2 3 University of Leeds, Leeds; University of Cambridge, Cambridge; Health Protection Agency, Porton Down The advent of stable isotope labeling with amino acids in cell culture (SilAC) coupled with lC-MS/MS allows different virus-host cell proteome interactions to be identified and quantified on a large scale, to the depth of several thousand proteins. Coupled to bioinformatic analysis using ingenuity Pathway Analysis provides the resolution of detailed signaling and canonical pathways that are activated/suppressed in virus-infected cells. using these approaches we have investigated how the avian coronavirus and human respiratory syncytial virus interact with the host cell proteome, mapping the balance between pro-viral and anti-viral activity, specifically focusing on sub-cellular organelles. More recently we have used the SilAC approach to simultaneously compare clinical isolates of influenza A virus focusing on 2009-swine origin H1N1 with A/Solomon islands/03/06, a seasonal H1N1 strain, in A549 cells, a model respiratory epithelial cell line. These data were integrated with transcriptomic and rNAi analysis to provide a detailed global overview of host cell changes in the context of virus-infection. A number of common and virus-specific affects were found including the sequestration of rNA hyper mutating enzymes to areas of virus replication and the recruitment of immune complex proteins to mitochondria. The functional implications of these results will be discussed. Offered paper repulsion of superinfecting virions: a mechanism for rapid virus spread VirGiNiE DOCEul1 , Michael Hollinshead1 , lonneke van der linden2 , Geoffrey Smith1 1 2 Imperial College London, Section of Virology, London; Radboud University Nijmegen, Nijmegen, Netherlands Viruses were thought to spread across susceptible cells by an iterative process of infection, replication and release, so the rate of spread is limited by replication kinetics. recently, we described a novel mechanism that enables vaccinia virus (VACV) to spread across one cell every 1.2 hours, fourfold faster than predicted from its replication kinetics. using live video microscopy we showed that actin tails are formed early during infection on cells not producing any virions, indicating that infected cells are able to form actin tails upon contact with incoming virions. Early expression of VACV proteins A33 and A36 is critical for optimal virus spread and both proteins are necessary and sufficient for the formation of actin tails upon contact with extracellular enveloped virus (EEV) particles. These data reveal a novel mechanism for rapid virus spread by which infected cells repel superinfecting virus particles on actin tails toward non-infected cells. Current work is focussing on determining which protein(s) on the incoming EEV is required for induction of actin tail formation and the effect of A33 and A36 expression at the cell surface on the spread, membrane breakage and entry of VACV. Offered paper The solution structure of the hepatitis C virus (HCV) p7 protein identifies an external, membrane-exposed rimantadine binding site TOSHANA FOSTEr1,2 , Arnout Kalverda2 , Gary Thompson2 , richard Foster3 , Arwen Pearson2 , Steve Homans2 , Mark Harris2 , Stephen Griffin1,2 s o c i e t y f o r g e n e r a l Microbiology
Page 1 and 2: ↑Contents Society for General Mic
Page 4 and 5: Please note: Abstracts are publishe
Page 56 and 57:
Please note: Abstracts are publishe
Page 58 and 59:
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Page 72 and 73:
Page 74 and 75:
Page 76 and 77:
Page 78 and 79:
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
Page 100 and 101:
Page 102 and 103:
Page 104 and 105:
Page 106 and 107:
Page 108 and 109:
Page 110 and 111:
Page 112 and 113:
Page 114 and 115:
Page 116 and 117:
Page 118 and 119:
Page 120 and 121:
Page 122 and 123:
Page 124 and 125:
Page 126 and 127:
Page 128 and 129:
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
Page 140 and 141:
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
Page 150 and 151:
Page 152 and 153:
Page 154 and 155:
Page 156 and 157:
Page 158 and 159:
Page 160 and 161:
Page 162 and 163:
Page 164 and 165:
Page 166 and 167:
Caws, M., 28 Cebolla, A., 163 Cehov
Page 168 and 169:
Hood, S., 54, 111, 112 Hope, G., 9
Page 170 and 171:
Page 172 and 173:
Page 174:
show all

Spring Conference 2011 - Society for General Microbiology

Create successful ePaper yourself

Delete template?

Save as template?