@article{Haas2018,

title = {Viral Targeting of TFIIB Impairs de novo Polymerase II Recruitment and Affects Antiviral Immunity},

author = {D.A. Haas and A. Meiler and K. Geiger and C. Vogt and E. Preuss and G. Kochs and A. Pichlmair},

url = {http://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1006980},

doi = {10.1371/journal.ppat.1006980},

issn = {1553-7374},

year  = {2018},

date = {2018-04-30},

journal = {PLOS Pathogens},

volume = {14},

number = {4},

pages = {e1006980},

abstract = {Viruses have evolved a plethora of mechanisms to target host antiviral responses. Here, we propose a yet uncharacterized mechanism of immune regulation by the orthomyxovirus Thogoto virus (THOV) ML protein through engaging general transcription factor TFIIB. ML generates a TFIIB depleted nuclear environment by re-localizing it into the cytoplasm. Although a broad effect on gene expression would be anticipated, ML expression, delivery of an ML-derived functional domain or experimental depletion of TFIIB only leads to altered expression of a limited number of genes. Our data indicate that TFIIB is critically important for the de novo recruitment of Pol II to promoter start sites and that TFIIB may not be required for regulated gene expression from paused promoters. Since many immune genes require de novo recruitment of Pol II, targeting of TFIIB by THOV represents a neat mechanism to affect immune responses while keeping other cellular transcriptional activities intact. Thus, interference with TFIIB activity may be a favourable site for therapeutic intervention to control undesirable inflammation.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Holze2017,

title = {Oxeiptosis, a ROS-induced Caspase-independent Apoptosis-like Cell-death Pathway},

author = {C. Holze and C. Michaudel and C. Mackowiak and D.A. Haas and C. Benda and P. Hubel and F.L. Pennemann and D. Schnepf and J. Wettmarshausen and M. Braun and D.W. Leung and G.K. Amarasinghe and F. Perocchi and P. Staeheli and B. Ryffel and A. Pichlmair},

url = {https://www.nature.com/articles/s41590-017-0013-y},

doi = {10.1038/s41590-017-0013-y},

year  = {2017},

date = {2017-12-18},

journal = {Nat. Immunol.},

volume = {19},

number = {2},

pages = {130-140},

abstract = {Reactive oxygen species (ROS) are generated by virus-infected cells; however, the physiological importance of ROS generated under these conditions is unclear. Here we found that the inflammation and cell death induced by exposure of mice or cells to sources of ROS were not altered in the absence of canonical ROS-sensing pathways or known cell-death pathways. ROS-induced cell-death signaling involved interactions among the cellular ROS sensor and antioxidant factor KEAP1, the phosphatase PGAM5 and the proapoptotic factor AIFM1. Pgam5 –/– mice showed exacerbated lung inflammation and proinflammatory cytokines in an ozone-exposure model. Similarly, challenge with influenza A virus led to increased infiltration of the virus, lymphocytic bronchiolitis and reduced survival of Pgam5 –/– mice. This pathway, which we have called ‘oxeiptosis’, was a ROS-sensitive, caspase independent, non-inflammatory cell-death pathway and was important for protection against inflammation induced by ROS or ROS-generating agents such as viral pathogens.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Vonderstein2017,

title = {Viperin Targets Flavivirus Virulence by Inducing Assembly of Non-infectious Capsid Particles},

author = {K. Vonderstein and E. Nilsson and P. Hubel and L. Nygård Skalman and A. Upadhyay and J. Pasto and A. Pichlmair and R. Lundmark and A.K. Överby},

url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5730767/},

doi = {10.1128/JVI.01751-17},

issn = {1098-5514},

year  = {2017},

date = {2017-10-18},

journal = {J Virol},

volume = {92},

number = {1},

pages = {e01751-17},

abstract = {Efficient antiviral immunity requires interference with virus replication at multiple layers targeting diverse steps in the viral life cycle. Here we describe a novel flavivirus inhibition mechanism that results in interferon-mediated obstruction of tick-borne encephalitis virus particle assembly, and involves release of malfunctional membrane associated capsid (C) particles. This mechanism is controlled by the activity of the interferon-induced protein viperin, a broad spectrum antiviral interferon stimulated gene. Through analysis of the viperin-interactome, we identified the Golgi Brefeldin A resistant guanine nucleotide exchange factor 1 (GBF1), as the cellular protein targeted by viperin. Viperin-induced antiviral activity as well as C-particle release was stimulated by GBF1 inhibition and knock down, and reduced by elevated levels of GBF1. Our results suggest that viperin targets flavivirus virulence by inducing the secretion of unproductive non-infectious virus particles, by a GBF1-dependent mechanism. This yet undescribed antiviral mechanism allows potential therapeutic intervention. The interferon response can target viral infection on almost every level, however, very little is known about interference of flavivirus assembly. Here we show that interferon, through the action of viperin, can disturb assembly of tick-borne encephalitis virus. The viperin protein is highly induced after viral infection and exhibit broad-spectrum antiviral activity. However, the mechanism of action is still elusive and appear to vary between the different viruses, indicating that cellular targets utilized by several viruses might be involved. In this study we show that viperin induce capsid particle release by interacting and inhibiting the function of the cellular protein Golgi Brefeldin A resistant guanine nucleotide exchange factor 1 (GBF1). GBF1 is a key protein in the cellular secretory pathway and essential in the life cycle of many viruses, also targeted by viperin, implicating GBF1 as a novel putative drug target.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{GebhardtLaudenbach2017,

title = {Discrimination of Self and Non-Self Ribonucleic Acids},

author = {A. Gebhardt and B. Laudenbach and A. Pichlmair},

url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5439445/},

doi = {10.1089/jir.2016.0092},

year  = {2017},

date = {2017-05-01},

journal = {J Interferon Cytokine Res.},

volume = {37},

number = {5},

pages = {184-197},

abstract = {Most virus infections are controlled through the innate and adaptive immune system. A surprisingly limited number of so-called pattern recognition receptors (PRRs) have the ability to sense a large variety of virus infections. The reason for the broad activity of PRRs lies in the ability to recognize viral nucleic acids. These nucleic acids lack signatures that are present in cytoplasmic cellular nucleic acids and thereby marking them as pathogen-derived. Accumulating evidence suggests that these signatures, which are predominantly sensed by a class of PRRs called retinoic acid-inducible gene I (RIG-I)-like receptors and other proteins, are not unique to viruses but rather resemble immature forms of cellular ribonucleic acids generated by cellular polymerases. RIG-I-like receptors, and other cellular antiviral proteins, may therefore have mainly evolved to sense nonprocessed nucleic acids typically generated by primitive organisms and pathogens. This capability has not only implications on induction of antiviral immunity but also on the function of cellular proteins to handle self-derived RNA with stimulatory potential.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{WillemsenBinder2017_MC,

title = {Phosphorylation-Dependent Feedback Inhibition of RIG-I by DAPK1 Identified by Kinome-wide siRNA Screening.},

author = {J. Willemsen and O. Wicht and J.C. Wolanski and N. Baur and S. Bastian and D.A. Haas and P. Matula and B. Knapp and L. Meyniel-Schicklin and C. Wang and R. Bartenschlager and V. Lohmann and K. Rohr and H. Erfle and L. Kaderali and J. Marcotrigiano and A. Pichlmair and M. Binder},

url = {https://doi.org/10.1016/j.molcel.2016.12.021},

doi = {10.1016/j.molcel.2016.12.021},

issn = {1097-4164},

year  = {2017},

date = {2017-02-02},

journal = {Mol Cell},

volume = {65},

pages = {403--415.e8},

abstract = {Cell-autonomous induction of type I interferon must be stringently regulated. Rapid induction is key to control virus infection, whereas proper limitation of signaling is essential to prevent immunopathology and autoimmune disease. Using unbiased kinome-wide RNAi screening followed by thorough validation, we identified 22 factors that regulate RIG-I/IRF3 signaling activity. We describe a negative-feedback mechanism targeting RIG-I activity, which is mediated by death associated protein kinase 1 (DAPK1). RIG-I signaling triggers DAPK1 kinase activation, and active DAPK1 potently inhibits RIG-I stimulated IRF3 activity and interferon-beta production. DAPK1 phosphorylates RIG-I in vitro at previously reported as well as other sites that limit 5'ppp-dsRNA sensing and virtually abrogate RIG-I activation.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Goonawardane2017a,

title = {Phosphorylation of Serine 225 in Hepatitis C Virus NS5A Regulates Protein-Protein Interactions.},

author = {N. Goonawardane and A. Gebhardt and C. Bartlett and A. Pichlmair and M. Harris},

doi = {10.1128/JVI.00805-17},

issn = {1098-5514},

year  = {2017},

date = {2017-01-01},

journal = {J Virol},

volume = {91},

abstract = {Hepatitis C virus (HCV) nonstructural protein 5A (NS5A) is a phosphoprotein that plays key, yet poorly defined, roles in both virus genome replication and virion assembly/release. It has been proposed that differential phosphorylation could act as a switch to regulate the various functions of NS5A; however, the mechanistic details of the role of this posttranslational modification in the virus life cycle remain obscure. We previously reported (D. Ross-Thriepland, J. Mankouri, and M. Harris, J Virol 89:3123-3135, 2015, doi:10.1128/JVI.02995-14) a role for phosphorylation at serine 225 (S225) of NS5A in the regulation of JFH-1 (genotype 2a) genome replication. A phosphoablatant (S225A) mutation resulted in a 10-fold reduction in replication and a perinuclear restricted distribution of NS5A, whereas the corresponding phosphomimetic mutation (S225D) had no phenotype. To determine the molecular mechanisms underpinning this phenotype we conducted a label-free proteomics approach to identify cellular NS5A interaction partners. This analysis revealed that the S225A mutation disrupted the interactions of NS5A with a number of cellular proteins, in particular the nucleosome assembly protein 1-like protein 1 (NAP1L1), bridging integrator 1 (Bin1, also known as amphiphysin II), and vesicle-associated membrane protein-associated protein A (VAP-A). These interactions were validated by immunoprecipitation/Western blotting, immunofluorescence, and proximity ligation assay. Importantly, small interfering RNA (siRNA)-mediated knockdown of NAP1L1, Bin1 or VAP-A impaired viral genome replication and recapitulated the perinuclear redistribution of NS5A seen in the S225A mutant. These results demonstrate that S225 phosphorylation regulates the interactions of NS5A with a defined subset of cellular proteins. Furthermore, these interactions regulate both HCV genome replication and the subcellular localization of replication complexes. Hepatitis C virus is an important human pathogen. The viral nonstructural 5A protein (NS5A) is the target for new antiviral drugs. NS5A has multiple functions during the virus life cycle, but the biochemical details of these roles remain obscure. NS5A is known to be phosphorylated by cellular protein kinases, and in this study, we set out to determine whether this modification is required for the binding of NS5A to other cellular proteins. We identified 3 such proteins and show that they interacted only with NS5A that was phosphorylated on a specific residue. Furthermore, these proteins were required for efficient virus replication and the ability of NS5A to spread throughout the cytoplasm of the cell. Our results help to define the function of NS5A and may contribute to an understanding of the mode of action of the highly potent antiviral drugs that are targeted to NS5A.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Brady2017,

title = {Molluscum Contagiosum Virus Protein MC005 Inhibits NF-κB Activation by Targeting NEMO-Regulated IκB Kinase Activation.},

author = {G. Brady and D.A. Haas and P.J. Farrell and A. Pichlmair and A.G. Bowie},

doi = {10.1128/JVI.00545-17},

issn = {1098-5514},

year  = {2017},

date = {2017-01-01},

journal = {J Virol},

volume = {91},

abstract = {Molluscum contagiosum virus (MCV), the only known extant human-adapted poxvirus, causes a long-duration infection characterized by skin lesions that typically display an absence of inflammation despite containing high titers of live virus. Despite this curious presentation, MCV is very poorly characterized in terms of host-pathogen interactions. The absence of inflammation around MCV lesions suggests the presence of potent inhibitors of human antiviral immunity and inflammation. However, only a small number of MCV immunomodulatory genes have been characterized in detail. It is likely that many more remain to be discovered, given the density of such sequences in other poxvirus genomes. NF-κB activation occurs in response to both virus-induced pattern recognition receptor (PRR) signaling and cellular activation by virus-induced proinflammatory cytokines like tumor necrosis factor and interleukin-1. Activated NF-κB drives cytokine and interferon gene expression, leading to inflammation and virus clearance. We report that MC005, which has no orthologs in other poxvirus genomes, is a novel inhibitor of PRR- and cytokine-stimulated NF-κB activation. MC005 inhibited NF-κB proximal to the IκB kinase (IKK) complex, and unbiased affinity purification revealed that MC005 interacts with the IKK subunit NEMO (NF-κB essential modulator). MC005 binding to NEMO prevents the conformational priming of the IKK complex that occurs when NEMO binds to ubiquitin chains during pathway activation. These data reveal a novel mechanism of poxvirus inhibition of human innate immunity, validate current dynamic models of NEMO-dependent IKK complex activation, and further clarify how the human-adapted poxvirus MCV can so effectively evade antiviral immunity and suppress inflammation to persist in human skin lesions. Poxviruses adapt to specific hosts over time, evolving and tailoring elegantly precise inhibitors of the rate-limiting steps within the signaling pathways that control innate immunity and inflammation. These inhibitors reveal new features of the antiviral response, clarify existing models of signaling regulation while offering potent new tools for approaching therapeutic intervention in autoimmunity and inflammatory disease. Molluscum contagiosum virus (MCV) is the only known extant poxvirus specifically adapted to human infection and appears adept at evading normal human antiviral responses, yet it remains poorly characterized. We report the identification of MCV protein MC005 as an inhibitor of the pathways leading to the activation of NF-κB, an essential regulator of innate immunity. Further, identification of the mechanism of inhibition of NF-κB by MC005 confirms current models of the complex way in which NF-κB is regulated and greatly expands our understanding of how MCV so effectively evades human immunity.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Abbas2017,

title = {Structure of Human IFIT1 with Capped RNA Reveals Adaptable mRNA Binding and Mechanisms for Sensing N1 and N2 Ribose 2'-O methylations},

author = {Y.M. Abbas and B. Laudenbach and S. Martínez-Montero and R. Cencic and M. Habjan and A. Pichlmair and M.J. Damha and J. Pelletier and B. Nagar},

doi = {10.1073/pnas.1612444114},

issn = {1091-6490},

year  = {2017},

date = {2017-01-01},

journal = {Proc Natl Acad Sci U S A},

volume = {114},

pages = {E2106--E2115},

abstract = {IFIT1 (IFN-induced protein with tetratricopeptide repeats-1) is an effector of the host innate immune antiviral response that prevents propagation of virus infection by selectively inhibiting translation of viral mRNA. It relies on its ability to compete with the translation initiation factor eIF4F to specifically recognize foreign capped mRNAs, while remaining inactive against host mRNAs marked by ribose 2'-O methylation at the first cap-proximal nucleotide (N1). We report here several crystal structures of RNA-bound human IFIT1, including a 1.6-Å complex with capped RNA. IFIT1 forms a water-filled, positively charged RNA-binding tunnel with a separate hydrophobic extension that unexpectedly engages the cap in multiple conformations ( and ) giving rise to a relatively plastic and nonspecific mode of binding, in stark contrast to eIF4E. Cap-proximal nucleotides encircled by the tunnel provide affinity to compete with eIF4F while allowing IFIT1 to select against N1 methylated mRNA. Gel-shift binding assays confirm that N1 methylation interferes with IFIT1 binding, but in an RNA-dependent manner, whereas translation assays reveal that N1 methylation alone is not sufficient to prevent mRNA recognition at high IFIT1 concentrations. Structural and functional analysis show that 2'-O methylation at N2, another abundant mRNA modification, is also detrimental for RNA binding, thus revealing a potentially synergistic role for it in self- versus nonself-mRNA discernment. Finally, structure-guided mutational analysis confirms the importance of RNA binding for IFIT1 restriction of a human coronavirus mutant lacking viral N1 methylation. Our structural and biochemical analysis sheds new light on the molecular basis for IFIT1 translational inhibition of capped viral RNA.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Mazouzi2016,

title = {A Comprehensive Analysis of the Dynamic Response to Aphidicolin-Mediated Replication Stress Uncovers Targets for ATM and ATMIN.},

author = {A. Mazouzi and A. Stukalov and A.C. Müller and D. Chen and M. Wiedner and J. Prochazkova and S. Chiang and M. Schuster and F.P. Breitwieser and A. Pichlmair and S.F. El-Khamisy and C. Bock and R. Kralovics and J. Colinge and K.L. Bennett and J.I. Loizou},

doi = {10.1016/j.celrep.2016.03.077},

issn = {2211-1247},

year  = {2016},

date = {2016-01-01},

journal = {Cell reports},

volume = {15},

pages = {893--908},

abstract = {The cellular response to replication stress requires the DNA-damage-responsive kinase ATM and its cofactor ATMIN; however, the roles of this signaling pathway following replication stress are unclear. To identify the functions of ATM and ATMIN in response to replication stress, we utilized both transcriptomics and quantitative mass-spectrometry-based phosphoproteomics. We found that replication stress induced by aphidicolin triggered widespread changes in both gene expression and protein phosphorylation patterns. These changes gave rise to distinct early and late replication stress responses. Furthermore, our analysis revealed previously unknown targets of ATM and ATMIN downstream of replication stress. We demonstrate ATMIN-dependent phosphorylation of H2AX and of CRMP2, a protein previously implicated in Alzheimer's disease but not in the DNA damage response. Overall, our dataset provides a comprehensive resource for discovering the cellular responses to replication stress and, potentially, associated pathologies.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Stukalov2015,

title = {Gambling with Flu: "All in" to Maximize Reward},

author = {A. Stukalov and A. Pichlmair},

url = {https://www.sciencedirect.com/science/article/pii/S1931312815004643},

doi = {10.1016/j.chom.2015.11.010},

issn = {1934-6069},

year  = {2015},

date = {2015-12-09},

journal = {Cell host microbe},

volume = {18},

number = {6},

pages = {643--645},

abstract = {In this issue of Cell Host & Microbe, Tripathi et al. (2015) report an in-depth meta-analysis of eight influenza virus siRNA screens combined with viral-host protein interactome data. The integration of the different omics datasets highlights candidate genes and pathways for further investigation and potential therapeutic targeting in the future.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Gebhardt2015,

title = {mRNA Export Through an Additional Cap-binding Complex Consisting of NCBP1 and NCBP3},

author = {A. Gebhardt and M. Habjan and C. Benda and A. Meiler and D.A. Haas and M.Y. Hein and A. Mann and M. Mann and B. Habermann and A. Pichlmair},

url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4595607/},

doi = {10.1038/ncomms9192},

issn = {2041-1723},

year  = {2015},

date = {2015-09-18},

journal = {Nat commun},

volume = {6},

pages = {8192},

abstract = {The flow of genetic information from DNA to protein requires polymerase-II-transcribed RNA characterized by the presence of a 5'-cap. The cap-binding complex (CBC), consisting of the nuclear cap-binding protein (NCBP) 2 and its adaptor NCBP1, is believed to bind all capped RNA and to be necessary for its processing and intracellular localization. Here we show that NCBP1, but not NCBP2, is required for cell viability and poly(A) RNA export. We identify C17orf85 (here named NCBP3) as a cap-binding protein that together with NCBP1 forms an alternative CBC in higher eukaryotes. NCBP3 binds mRNA, associates with components of the mRNA processing machinery and contributes to poly(A) RNA export. Loss of NCBP3 can be compensated by NCBP2 under steady-state conditions. However, NCBP3 becomes pivotal under stress conditions, such as virus infection. We propose the existence of an alternative CBC involving NCBP1 and NCBP3 that plays a key role in mRNA biogenesis.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Heinz2015,

title = {The Lipid-Modifying Enzyme SMPDL3B Negatively Regulates Innate Immunity.},

author = {L.X. Heinz and C.L. Baumann and M.S. Köberlin and B. Snijder and R. Gawish and G. Shui and O. Sharif and I.M. Aspalter and A.C. Müller and R.K. Kandasamy and F.P. Breitwieser and A. Pichlmair and M. Bruckner and M. Rebsamen and S. Blüml and T. Karonitsch and A. Fauster and J. Colinge and K.L. Bennett and S. Knapp and M.R Wenk and G. Superti-Furga},

doi = {10.1016/j.celrep.2015.05.006},

issn = {2211-1247},

year  = {2015},

date = {2015-01-01},

journal = {Cell reports},

volume = {11},

pages = {1919--1928},

abstract = {Lipid metabolism and receptor-mediated signaling are highly intertwined processes that cooperate to fulfill cellular functions and safeguard cellular homeostasis. Activation of Toll-like receptors (TLRs) leads to a complex cellular response, orchestrating a diverse range of inflammatory events that need to be tightly controlled. Here, we identified the GPI-anchored Sphingomyelin Phosphodiesterase, Acid-Like 3B (SMPDL3B) in a mass spectrometry screening campaign for membrane proteins co-purifying with TLRs. Deficiency of Smpdl3b in macrophages enhanced responsiveness to TLR stimulation and profoundly changed the cellular lipid composition and membrane fluidity. Increased cellular responses could be reverted by re-introducing affected ceramides, functionally linking membrane lipid composition and innate immune signaling. Finally, Smpdl3b-deficient mice displayed an intensified inflammatory response in TLR-dependent peritonitis models, establishing its negative regulatory role in vivo. Taken together, our results identify the membrane-modulating enzyme SMPDL3B as a negative regulator of TLR signaling that functions at the interface of membrane biology and innate immunity.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Brady2015,

title = {Poxvirus Protein MC132 from Molluscum Contagiosum Virus Inhibits NF-B Activation by Targeting p65 for Degradation.},

author = {G. Brady and D.A. Haas and P.J. Farrell and A. Pichlmair and A.G. Bowie},

doi = {10.1128/JVI.00799-15},

issn = {1098-5514},

year  = {2015},

date = {2015-01-01},

journal = {J Virol},

volume = {89},

pages = {8406--8415},

abstract = {Molluscum contagiosum virus (MCV) is unique in being the only known extant, human-adapted poxvirus, yet to date, it is very poorly characterized in terms of host-pathogen interactions. MCV causes persistent skin lesions filled with live virus, but these are generally immunologically silent, suggesting the presence of potent inhibitors of human antiviral immunity and inflammation. Fewer than five MCV immunomodulatory genes have been characterized in detail, but it is likely that many more remain to be discovered given the density of such sequences in all well-characterized poxviruses. Following virus infection, NF-B activation occurs in response to both pattern recognition receptor (PRR) signaling and cellular activation by virus-elicited proinflammatory cytokines, such as tumor necrosis factor (TNF). As such, NF-B activation is required for virus detection, antiviral signaling, inflammation, and clearance of viral infection. Hence, we screened a library of MCV genes for effects on TNF-stimulated NF-B activation. This revealed MC132, a unique protein with no orthologs in other poxviral genomes, as a novel inhibitor of NF-B. Interestingly, MC132 also inhibited PRR- and virus-activated NF-B, since MC132 interacted with the NF-B subunit p65 and caused p65 degradation. Unbiased affinity purification to identify host targets of MC132 revealed that MC132 acted by targeting NF-B p65 for ubiquitin-dependent proteasomal degradation by recruiting p65 to a host Cullin-5/Elongin B/Elongin C complex. These data reveal a novel mechanism for poxviral inhibition of human innate immunity and further clarify how the human-adapted poxvirus MCV can so effectively evade antiviral immunity to persist in skin lesions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Habjan2015,

title = {Cytoplasmic Sensing of Viral Nucleic Acids},

author = {M. Habjan and A. Pichlmair},

doi = {10.1016/j.coviro.2015.01.012},

issn = {1879-6265},

year  = {2015},

date = {2015-01-01},

journal = {Current opinion in virology},

volume = {11},

pages = {31--37},

abstract = {Viruses are the most abundant pathogens on earth. A fine-tuned framework of intervening pathways is in place in mammalian cells to orchestrate the cellular defence against these pathogens. Key for this system is sensor proteins that recognise specific features associated with nucleic acids of incoming viruses. Here we review the current knowledge on cytoplasmic sensors for viral nucleic acids. These sensors induce expression of cytokines, affect cellular functions required for virus replication and directly target viral nucleic acids through degradation or sequestration. Their ability to respond to a given nucleic acid is based on both the differential specificity of the individual proteins and the downstream signalling or adaptor proteins. The cooperation of these multiple proteins and pathways plays a key role in inducing successful immunity against virus infections.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Upadhyay2014,

title = {Viperin is an Iron-sulfur Protein that Inhibits Genome Synthesis of Tick-borne Encephalitis Virus via Radical SAM Domain Activity},

author = {A.S. Upadhyay and K. Vonderstein and A. Pichlmair and O. Stehling and K.L. Bennett and G. Dobler and J. Guo and G. Superti-Furga and R. Lill and A.K. Överby and F. Weber},

doi = {10.1111/cmi.12241},

issn = {1462-5822},

year  = {2014},

date = {2014-01-01},

journal = {Cell Microbiol},

volume = {16},

pages = {834--848},

abstract = {Viperin is an interferon-induced protein with a broad antiviral activity. This evolutionary conserved protein contains a radical S-adenosyl-l-methionine (SAM) domain which has been shown in vitro to hold a [4Fe-4S] cluster. We identified tick-borne encephalitis virus (TBEV) as a novel target for which human viperin inhibits productionof the viral genome RNA. Wt viperin was found to require ER localization for full antiviral activity and to interact with the cytosolic Fe/S protein assembly factor CIAO1. Radiolabelling in vivo revealed incorporation of (55) Fe, indicative for the presence of an Fe-S cluster. Mutation of the cysteine residues ligating the Fe-S cluster in the central radical SAM domain entirely abolished both antiviral activity and incorporation of (55) Fe. Mutants lacking the extreme C-terminal W361 did not interact with CIAO1, were not matured, and were antivirally inactive. Moreover, intracellular removal of SAM by ectopic expression of the bacteriophage T3 SAMase abolished antiviral activity. Collectively, our data suggest that viperin requires CIAO1 for [4Fe-4S] cluster assembly, and acts through an enzymatic, Fe-S cluster- and SAM-dependent mechanism to inhibit viral RNA synthesis.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Liehl2014,

title = {Host-cell Sensors for Plasmodium Activate Innate Immunity Against Liver-stage Infection},

author = {P. Liehl and V. Zuzarte-Luís and J. Chan and T. Zillinger and F. Baptista and D. Carapau and M. Konert and K.K. Hanson and C. Carret and C. Lassnig and M. Müller and U. Kalinke and M. Saeed and A.F. Chora and D.T. Golenbock and B. Strobl and M. Prudêncio and L.P. Coelho and S.H. Kappe and G. Superti-Furga and A. Pichlmair and A.M. Vigário and C.M. Rice and K.A. Fitzgerald and W. Barchet and M.M. Mota},

doi = {10.1038/nm.3424},

issn = {1546-170X},

year  = {2014},

date = {2014-01-01},

journal = {Nat Med},

volume = {20},

pages = {47--53},

abstract = {Before they infect red blood cells and cause malaria, Plasmodium parasites undergo an obligate and clinically silent expansion phase in the liver that is supposedly undetected by the host. Here, we demonstrate the engagement of a type I interferon (IFN) response during Plasmodium replication in the liver. We identified Plasmodium RNA as a previously unrecognized pathogen-associated molecular pattern (PAMP) capable of activating a type I IFN response via the cytosolic pattern recognition receptor Mda5. This response, initiated by liver-resident cells through the adaptor molecule for cytosolic RNA sensors, Mavs, and the transcription factors Irf3 and Irf7, is propagated by hepatocytes in an interferon-α/β receptor-dependent manner. This signaling pathway is critical for immune cell-mediated host resistance to liver-stage Plasmodium infection, which we find can be primed with other PAMPs, including hepatitis C virus RNA. Together, our results show that the liver has sensor mechanisms for Plasmodium that mediate a functional antiparasite response driven by type I IFN.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Kainulainen2014,

title = {Virulence Factor NSs of Rift Valley Fever Virus Recruits the F-box Protein FBXO3 to Degrade Subunit p62 of General Transcription Factor TFIIH},

author = {M. Kainulainen and M. Habjan and P. Hubel and L. Busch and S. Lau and J. Colinge and G. Superti-Furga and A. Pichlmair and F. Weber},

doi = {10.1128/JVI.02914-13},

issn = {1098-5514},

year  = {2014},

date = {2014-01-01},

journal = {J Virol},

volume = {88},

pages = {3464--3473},

abstract = {The nonstructural protein NSs is the main virulence factor of Rift Valley fever virus (RVFV; family Bunyaviridae, genus Phlebovirus), a serious pathogen of livestock and humans in Africa. RVFV NSs blocks transcriptional upregulation of antiviral type I interferons (IFN) and destroys the general transcription factor TFIIH subunit p62 via the ubiquitin/proteasome pathway. Here, we identified a subunit of E3 ubiquitin ligases, F-box protein FBXO3, as a host cell interactor of NSs. Small interfering RNA (siRNA)-mediated depletion of FBXO3 rescued p62 protein levels in RVFV-infected cells and elevated IFN transcription by 1 order of magnitude. NSs interacts with the full-length FBXO3 protein as well as with a truncated isoform that lacks the C-terminal acidic and poly(R)-rich domains. These isoforms are present in both the nucleus and the cytoplasm. NSs exclusively removes the nuclear pool of full-length FBXO3, likely due to consumption during the degradation process. F-box proteins form the variable substrate recognition subunit of the so-called SCF ubiquitin ligases, which also contain the constant components Skp1, cullin 1 (or cullin 7), and Rbx1. siRNA knockdown of Skp1 also protected p62 from degradation, suggesting involvement in NSs action. However, knockdown of cullin 1, cullin 7, or Rbx1 could not rescue p62 degradation by NSs. Our data show that the enzymatic removal of p62 via the host cell factor FBXO3 is a major mechanism of IFN suppression by RVFV. Rift Valley fever virus is a serious emerging pathogen of animals and humans. Its main virulence factor, NSs, enables unhindered virus replication by suppressing the antiviral innate immune system. We identified the E3 ubiquitin ligase FBXO3 as a novel host cell interactor of NSs. NSs recruits FBXO3 to destroy the general host cell transcription factor TFIIH-p62, resulting in suppression of the transcriptional upregulation of innate immunity.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Eberle2014,

title = {The Lysine Methyltransferase SMYD3 Interacts with Hepatitis C Virus NS5A and is a Negative Regulator of Viral Particle Production},

author = {C. Eberle and M. Zayas and A. Stukalov and A. Pichlmair and G. Alvisi and A.C. Müller and K.L. Bennett and R. Bartenschlager and G. Superti-Furga},

doi = {10.1016/j.virol.2014.05.016},

issn = {1096-0341},

year  = {2014},

date = {2014-01-01},

journal = {Virology},

volume = {462-463},

pages = {34--41},

abstract = {Hepatitis C virus (HCV) is a considerable global health and economic burden. The HCV nonstructural protein (NS) 5A is essential for the viral life cycle. The ability of NS5A to interact with different host and viral proteins allow it to manipulate cellular pathways and regulate viral processes, including RNA replication and virus particle assembly. As part of a proteomic screen, we identified several NS5A-binding proteins, including the lysine methyltransferase SET and MYND domain containing protein 3 (SMYD3). We confirmed the interaction in the context of viral replication by co-immunoprecipitation and co-localization studies. Mutational analyses revealed that the MYND-domain of SMYD3 and domain III of NS5A are required for the interaction. Overexpression of SMYD3 resulted in decreased intracellular and extracellular virus titers, whilst viral RNA replication remained unchanged, suggesting that SMYD3 negatively affects HCV particle production in a NS5A-dependent manner.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Abbas2013,

title = {Structural Basis for Viral 5'-PPP-RNA Recognition by Human IFIT Proteins},

author = {Y.M. Abbas and A. Pichlmair and M.W. Górna and G. Superti-Furga and B. Nagar},

doi = {10.1038/nature11783},

issn = {1476-4687},

year  = {2013},

date = {2013-01-01},

journal = {Nature},

volume = {494},

pages = {60--64},

abstract = {Interferon-induced proteins with tetratricopeptide repeats (IFITs) are innate immune effector molecules that are thought to confer antiviral defence through disruption of protein-protein interactions in the host translation-initiation machinery. However, it was recently discovered that IFITs can directly recognize viral RNA bearing a 5'-triphosphate group (PPP-RNA), which is a molecular signature that distinguishes it from host RNA. Here we report crystal structures of human IFIT5, its complex with PPP-RNAs, and an amino-terminal fragment of IFIT1. The structures reveal a new helical domain that houses a positively charged cavity designed to specifically engage only single-stranded PPP-RNA, thus distinguishing it from the canonical cytosolic sensor of double-stranded viral PPP-RNA, retinoic acid-inducible gene I (RIG-I, also known as DDX58). Mutational analysis, proteolysis and gel-shift assays reveal that PPP-RNA is bound in a non-sequence-specific manner and requires a 5'-overhang of approximately three nucleotides. Abrogation of PPP-RNA binding in IFIT1 and IFIT5 was found to cause a defect in the antiviral response by human embryonic kidney cells. These results demonstrate the mechanism by which IFIT proteins selectively recognize viral RNA, and lend insight into their downstream effector function.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Habjan2013,

title = {Sequestration by IFIT1 Impairs Translation of 2Ó-unmethylated Capped RNA},

author = {M. Habjan and P. Hubel and L. Lacerda and C. Benda and C. Holze and C.H. Eberl and A. Mann and E. Kindler and C. Gil-Cruz and J. Ziebuhr and V. Thiel and A. Pichlmair},

doi = {10.1371/journal.ppat.1003663},

issn = {1553-7374},

year  = {2013},

date = {2013-01-01},

journal = {PLoS Pathog},

volume = {9},

pages = {e1003663},

abstract = {Viruses that generate capped RNA lacking 2Ó methylation on the first ribose are severely affected by the antiviral activity of Type I interferons. We used proteome-wide affinity purification coupled to mass spectrometry to identify human and mouse proteins specifically binding to capped RNA with different methylation states. This analysis, complemented with functional validation experiments, revealed that IFIT1 is the sole interferon-induced protein displaying higher affinity for unmethylated than for methylated capped RNA. IFIT1 tethers a species-specific protein complex consisting of other IFITs to RNA. Pulsed stable isotope labelling with amino acids in cell culture coupled to mass spectrometry as well as in vitro competition assays indicate that IFIT1 sequesters 2Ó-unmethylated capped RNA and thereby impairs binding of eukaryotic translation initiation factors to 2Ó-unmethylated RNA template, which results in inhibition of translation. The specificity of IFIT1 for 2Ó-unmethylated RNA serves as potent antiviral mechanism against viruses lacking 2Ó-methyltransferase activity and at the same time allows unperturbed progression of the antiviral program in infected cells.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Pichlmair2012,

title = {Viral Immune Modulators Perturb the Human Molecular Network by Common and Unique Strategies},

author = {A. Pichlmair and K. Kandasamy and G. Alvisi and O. Mulhern and R. Sacco and M. Habjan and M. Binder and A. Stefanovic and C. Eberle and A. Goncalves and T. Bürckstümmer and A.C. Müller and A. Fauster and C. Holze and K. Lindsten and S. Goodbourn and G. Kochs and F. Weber and R. Bartenschlager and A.G. Bowie and K.L. Bennett and J. Colinge and G. Superti-Furga},

doi = {10.1038/nature11289},

issn = {1476-4687},

year  = {2012},

date = {2012-01-01},

journal = {Nature},

volume = {487},

pages = {486--490},

abstract = {Viruses must enter host cells to replicate, assemble and propagate. Because of the restricted size of their genomes, viruses have had to evolve efficient ways of exploiting host cell processes to promote their own life cycles and also to escape host immune defence mechanisms. Many viral open reading frames (viORFs) with immune-modulating functions essential for productive viral growth have been identified across a range of viral classes. However, there has been no comprehensive study to identify the host factors with which these viORFs interact for a global perspective of viral perturbation strategies. Here we show that different viral perturbation patterns of the host molecular defence network can be deduced from a mass-spectrometry-based host-factor survey in a defined human cellular system by using 70 innate immune-modulating viORFs from 30 viral species. The 579 host proteins targeted by the viORFs mapped to an unexpectedly large number of signalling pathways and cellular processes, suggesting yet unknown mechanisms of antiviral immunity. We further experimentally verified the targets heterogeneous nuclear ribonucleoprotein U, phosphatidylinositol-3-OH kinase, the WNK (with-no-lysine) kinase family and USP19 (ubiquitin-specific peptidase 19) as vulnerable nodes in the host cellular defence system. Evaluation of the impact of viral immune modulators on the host molecular network revealed perturbation strategies used by individual viruses and by viral classes. Our data are also valuable for the design of broad and specific antiviral therapies.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Pichlmair2011,

title = {IFIT1 is an Antiviral Protein that Recognizes 5'-triphosphate RNA},

author = {A. Pichlmair and C. Lassnig and C. Eberle and M.W. Górna and C.L. Baumann and T.R. Burkard and T. Bürckstümmer and A. Stefanovic and S. Krieger and K.L. Bennett and T. Rülicke and F. Weber and J. Colinge and M. Müller and G. Superti-Furga},

doi = {10.1038/ni.2048},

issn = {1529-2916},

year  = {2011},

date = {2011-01-01},

journal = {Nat Immunol},

volume = {12},

pages = {624--630},

abstract = {Antiviral innate immunity relies on the recognition of microbial structures. One such structure is viral RNA that carries a triphosphate group on its 5' terminus (PPP-RNA). By an affinity proteomics approach with PPP-RNA as the 'bait', we found that the antiviral protein IFIT1 (interferon-induced protein with tetratricopeptide repeats 1) mediated binding of a larger protein complex containing other IFIT family members. IFIT1 bound PPP-RNA with nanomolar affinity and required the arginine at position 187 in a highly charged carboxy-terminal groove of the protein. In the absence of IFIT1, the growth and pathogenicity of viruses containing PPP-RNA was much greater. In contrast, IFIT proteins were dispensable for the clearance of pathogens that did not generate PPP-RNA. On the basis of this specificity and the great abundance of IFIT proteins after infection, we propose that the IFIT complex antagonizes viruses by sequestering specific viral nucleic acids.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Schulz2010,

title = {Protein Kinase R Contributes to Immunity Against Specific Viruses by Regulating Interferon mRNA Integrity},

author = {O. Schulz and A. Pichlmair and J. Rehwinkel and N.C. Rogers and D. Scheuner and H. Kato and O. Takeuchi and S. Akira and R.J. Kaufman and C. Reis e Sousa},

doi = {10.1016/j.chom.2010.04.007},

issn = {1934-6069},

year  = {2010},

date = {2010-01-01},

journal = {Cell Host Microbe},

volume = {7},

pages = {354--361},

abstract = {Cytosolic viral RNA recognition by the helicases RIG-I and MDA5 is considered the major pathway for IFN-alpha/beta induction in response to RNA viruses. However, other cytoplasmic RNA sensors, including the double-stranded RNA-binding protein kinase R (PKR), have been implicated in IFN-alpha/beta production, although their relative contribution and mechanism have been unclear. Using cells expressing nonfunctional PKR or reduced levels of kinase, we show that PKR is required for production of IFN-alpha/beta proteins in response to a subset of RNA viruses including encephalomyocarditis, Theiler's murine encephalomyelitis, and Semliki Forest virus, but not influenza or Sendai virus. Surprisingly, although IFN-alpha/beta mRNA induction is largely normal in PKR-deficient cells, much of that mRNA lacks the poly(A) tail, indicating that its integrity is compromised. Our results suggest that PKR plays a nonredundant role in IFN-alpha/beta production in response to some but not all viruses, in part by regulating IFN-alpha/beta mRNA stability.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Baumann2010,

title = {CD14 is a Coreceptor of Toll-like Receptors 7 and 9},

author = {C.L. Baumann and I.M. Aspalter and O. Sharif and A. Pichlmair and S. Blüml and F. Grebien and M. Bruckner and P. Pasierbek and K. Aumayr and M. Planyavsky and K.L. Bennett and J. Colinge and S. Knapp and G. Superti-Furga},

doi = {10.1084/jem.20101111},

issn = {1540-9538},

year  = {2010},

date = {2010-01-01},

journal = {The Journal of experimental medicine},

volume = {207},

pages = {2689--2701},

abstract = {Recognition of pathogens by the innate immune system requires proteins that detect conserved molecular patterns. Nucleic acids are recognized by cytoplasmic sensors as well as by endosomal Toll-like receptors (TLRs). It has become evident that TLRs require additional proteins to be activated by their respective ligands. In this study, we show that CD14 (cluster of differentiation 14) constitutively interacts with the MyD88-dependent TLR7 and TLR9. CD14 was necessary for TLR7- and TLR9-dependent induction of proinflammatory cytokines in vitro and for TLR9-dependent innate immune responses in mice. CD14 associated with TLR9 stimulatory DNA in precipitation experiments and confocal imaging. The absence of CD14 led to reduced nucleic acid uptake in macrophages. Additionally, CD14 played a role in the stimulation of TLRs by viruses. Using various types of vesicular stomatitis virus, we showed that CD14 is dispensable for viral uptake but is required for the triggering of TLR-dependent cytokine responses. These data show that CD14 has a dual role in nucleic acid-mediated TLR activation: it promotes the selective uptake of nucleic acids, and it acts as a coreceptor for endosomal TLR activation.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Pichlmair2010,

title = {Virus-like Particles Expressing the Nucleocapsid Gene as an Efficient Vaccine Against Rift Valley Fever Virus},

author = {A. Pichlmair and M. Habjan and H. Unger and F. Weber},

doi = {10.1089/vbz.2009.0248},

issn = {1557-7759},

year  = {2010},

date = {2010-01-01},

journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)},

volume = {10},

pages = {701--703},

abstract = {Rift Valley fever virus (RVFV), a member of the family Bunyaviridae, regularly accounts for large and severe outbreaks among humans and livestock in Africa and Arabia. Therefore, safe and efficient vaccines are highly needed. Here, we report the production of recombinant virus-like particles (VLPs) that, in addition to their similarity to RVFV particles, are able to express the viral nucleocapsid (N) gene. A single inoculation of 1 × 10(6) of these N-VLPs was sufficient to protect 100% of mice from infection with a lethal dose of 1 × 10(5) PFU of RVFV. Our study demonstrates that N-VLPs can be considered as a safe and efficient vaccine against the emerging pathogen RVFV, and that VLPs that actively produce a viral antigen may be considered a strategy to improve the immunogenicity of VLPs in general.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Rehwinkel2010,

title = {RIG-I Detects Viral Genomic RNA During Negative-strand RNA Virus Infection},

author = {J. Rehwinkel and C. Tan and D. Goubau and O. Schulz and A. Pichlmair and K. Bier and N. Robb and F. Vreede and W. Barclay and E. Fodor and C. Reis e Sousa},

doi = {10.1016/j.cell.2010.01.020},

issn = {1097-4172},

year  = {2010},

date = {2010-01-01},

journal = {Cell},

volume = {140},

pages = {397--408},

abstract = {RIG-I is a key mediator of antiviral immunity, able to couple detection of infection by RNA viruses to the induction of interferons. Natural RIG-I stimulatory RNAs have variously been proposed to correspond to virus genomes, virus replication intermediates, viral transcripts, or self-RNA cleaved by RNase L. However, the relative contribution of each of these RNA species to RIG-I activation and interferon induction in virus-infected cells is not known. Here, we use three approaches to identify physiological RIG-I agonists in cells infected with influenza A virus or Sendai virus. We show that RIG-I agonists are exclusively generated by the process of virus replication and correspond to full-length virus genomes. Therefore, nongenomic viral transcripts, short replication intermediates, and cleaved self-RNA do not contribute substantially to interferon induction in cells infected with these negative strand RNA viruses. Rather, single-stranded RNA viral genomes bearing 5'-triphosphates constitute the natural RIG-I agonists that trigger cell-intrinsic innate immune responses during infection.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Pichlmair2009,

title = {Activation of MDA5 Requires Higher-order RNA Structures Generated During Virus Infection},

author = {A. Pichlmair and O. Schulz and C. Tan and J. Rehwinkel and H. Kato and O. Takeuchi and S. Akira and M. Way and G. Schiavo and C. Reis e Sousa},

doi = {10.1128/JVI.00770-09},

issn = {1098-5514},

year  = {2009},

date = {2009-01-01},

journal = {J Virol},

volume = {83},

pages = {10761--10769},

abstract = {Recognition of virus presence via RIG-I (retinoic acid inducible gene I) and/or MDA5 (melanoma differentiation-associated protein 5) initiates a signaling cascade that culminates in transcription of innate response genes such as those encoding the alpha/beta interferon (IFN-alpha/beta) cytokines. It is generally assumed that MDA5 is activated by long molecules of double-stranded RNA (dsRNA) produced by annealing of complementary RNAs generated during viral infection. Here, we used an antibody to dsRNA to show that the presence of immunoreactivity in virus-infected cells does indeed correlate with the ability of RNA extracted from these cells to activate MDA5. Furthermore, RNA from cells infected with encephalomyocarditis virus or with vaccinia virus and precipitated with the anti-dsRNA antibody can bind to MDA5 and induce MDA5-dependent IFN-alpha/beta production upon transfection into indicator cells. However, a prominent band of dsRNA apparent in cells infected with either virus does not stimulate IFN-alpha/beta production. Instead, stimulatory activity resides in higher-order structured RNA that contains single-stranded RNA and dsRNA. These results suggest that MDA5 activation requires an RNA web rather than simply long molecules of dsRNA.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Habjan2009,

title = {NSs Protein of Rift Valley Fever Virus Induces the Specific Degradation of the Double-stranded RNA-dependent Protein Kinase},

author = {M. Habjan and A. Pichlmair and R.M. Elliott and A.K. Överby and T. Glatter and M. Gstaiger and G. Superti-Furga and H. Unger and F. Weber},

doi = {10.1128/JVI.02148-08},

issn = {1098-5514},

year  = {2009},

date = {2009-01-01},

journal = {J Virol},

volume = {83},

pages = {4365--4375},

abstract = {Rift Valley fever virus (RVFV) continues to cause large outbreaks of acute febrile and often fatal illness among humans and domesticated animals in Africa, Saudi Arabia, and Yemen. The high pathogenicity of this bunyavirus is mainly due to the viral protein NSs, which was shown to prevent transcriptional induction of the antivirally active type I interferons (alpha/beta interferon [IFN-alpha/beta]). Viruses lacking the NSs gene induce synthesis of IFNs and are therefore attenuated, whereas the noninducing wild-type RVFV strains can only be inhibited by pretreatment with IFN. We demonstrate here in vitro and in vivo that a substantial part of the antiviral activity of IFN against RVFV is due to a double-stranded RNA-dependent protein kinase (PKR). PKR-mediated virus inhibition, however, was much more pronounced for the strain Clone 13 with NSs deleted than for the NSs-expressing strain ZH548. In vivo, Clone 13 was nonpathogenic for wild-type (wt) mice but could regain pathogenicity if mice lacked the PKR gene. ZH548, in contrast, killed both wt and PKR knockout mice indiscriminately. ZH548 was largely resistant to the antiviral properties of PKR because RVFV NSs triggered the specific degradation of PKR via the proteasome. The NSs proteins of the related but less virulent sandfly fever Sicilian virus and La Crosse virus, in contrast, had no such anti-PKR activity despite being efficient suppressors of IFN induction. Our data suggest that RVFV NSs has gained an additional anti-IFN function that may explain the extraordinary pathogenicity of this virus.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Habjan2008,

title = {Processing of Genome 5' Termini as a Strategy of Negative-strand RNA Viruses to Avoid RIG-I-dependent Interferon Induction},

author = {M. Habjan and I. Andersson and J. Klingström and M. Schümann and A. Martin and P. Zimmermann and V. Wagner and A. Pichlmair and U. Schneider and E. Mühlberger and A. Mirazimi and F. Weber},

doi = {10.1371/journal.pone.0002032},

issn = {1932-6203},

year  = {2008},

date = {2008-01-01},

journal = {PLoS One},

volume = {3},

pages = {e2032},

abstract = {Innate immunity is critically dependent on the rapid production of interferon in response to intruding viruses. The intracellular pathogen recognition receptors RIG-I and MDA5 are essential for interferon induction by viral RNAs containing 5' triphosphates or double-stranded structures, respectively. Viruses with a negative-stranded RNA genome are an important group of pathogens causing emerging and re-emerging diseases. We investigated the ability of genomic RNAs from substantial representatives of this virus group to induce interferon via RIG-I or MDA5. RNAs isolated from particles of Ebola virus, Nipah virus, Lassa virus, and Rift Valley fever virus strongly activated the interferon-beta promoter. Knockdown experiments demonstrated that interferon induction depended on RIG-I, but not MDA5, and phosphatase treatment revealed a requirement for the RNA 5' triphosphate group. In contrast, genomic RNAs of Hantaan virus, Crimean-Congo hemorrhagic fever virus and Borna disease virus did not trigger interferon induction. Sensitivity of these RNAs to a 5' monophosphate-specific exonuclease indicates that the RIG-I-activating 5' triphosphate group was removed post-transcriptionally by a viral function. Consequently, RIG-I is unable to bind the RNAs of Hantaan virus, Crimean-Congo hemorrhagic fever virus and Borna disease virus. These results establish RIG-I as a major intracellular recognition receptor for the genome of most negative-strand RNA viruses and define the cleavage of triphosphates at the RNA 5' end as a strategy of viruses to evade the innate immune response.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Pichlmair2007,

title = {Innate Recognition of Viruses},

author = {A. Pichlmair and C. Reis e Sousa},

doi = {10.1016/j.immuni.2007.08.012},

issn = {1074-7613},

year  = {2007},

date = {2007-01-01},

journal = {Immunity},

volume = {27},

pages = {370--383},

abstract = {Virus infection elicits potent responses in all cells intended to contain virus spread before intervention by the adaptive immune system. Central to this process is the virus-elicited production of type I interferons (IFNs) and other cytokines. The sensors involved in coupling recognition of viruses to the induction of the type I IFN genes have only recently been uncovered and include endosomal and cytosolic receptors for RNA and DNA. Here, we review their properties and discuss how their ability to recognize the unusual presence of atypical nucleic acids in particular subcellular compartments is used by the body to detect virus presence.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Pichlmair2007a,

title = {Tubulovesicular structures within vesicular stomatitis virus G protein-pseudotyped lentiviral vector preparations carry DNA and stimulate antiviral responses via Toll-like receptor 9.},

author = {Andreas Pichlmair and Sandra S Diebold and Stephen Gschmeissner and Yasuhiro Takeuchi and Yasuhiro Ikeda and Mary K Collins and Caetano Reis e Sousa},

doi = {10.1128/JVI.01818-06},

issn = {0022-538X},

year  = {2007},

date = {2007-01-01},

journal = {J Virol},

volume = {81},

pages = {539--547},

abstract = {Recombinant lentiviral vectors (LVs) are commonly used as research tools and are being tested in the clinic as delivery agents for gene therapy. Here, we show that Vesicular stomatitis virus G protein (VSV-G)-pseudotyped LV preparations produced by transient transfection are heavily contaminated with tubulovesicular structures (TVS) of cellular origin, which carry nucleic acids, including the DNA plasmids originally used for LV generation. The DNA carried by TVS can act as a stimulus for innate antiviral responses, triggering Toll-like receptor 9 and inducing alpha/beta interferon production by plasmacytoid dendritic cells (pDC). Removal of TVS markedly reduces the ability of VSV-G-pseudotyped LV preparations to activate pDC. Conversely, virus-free TVS are sufficient to stimulate pDC and act as potent adjuvants in vivo, eliciting T- and B-cell responses to coadministered proteins. These results highlight the role of by-products of virus production in determining the immunostimulatory properties of recombinant virus preparations and suggest possible strategies for diminishing responses to LVs in gene therapy and in research use.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Pichlmair2006,

title = {RIG-I-mediated antiviral responses to single-stranded RNA bearing 5'-phosphates.},

author = {Andreas Pichlmair and Oliver Schulz and Choon Ping Tan and Tanja I Näslund and Peter Liljeström and Friedemann Weber and Caetano Reis e Sousa},

doi = {10.1126/science.1132998},

issn = {1095-9203},

year  = {2006},

date = {2006-01-01},

journal = {Science (New York, N.Y.)},

volume = {314},

pages = {997--1001},

abstract = {Double-stranded RNA (dsRNA) produced during viral replication is believed to be the critical trigger for activation of antiviral immunity mediated by the RNA helicase enzymes retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (MDA5). We showed that influenza A virus infection does not generate dsRNA and that RIG-I is activated by viral genomic single-stranded RNA (ssRNA) bearing 5'-phosphates. This is blocked by the influenza protein nonstructured protein 1 (NS1), which is found in a complex with RIG-I in infected cells. These results identify RIG-I as a ssRNA sensor and potential target of viral immune evasion and suggest that its ability to sense 5'-phosphorylated RNA evolved in the innate immune system as a means of discriminating between self and nonself.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Spiegel2005,

title = {Inhibition of Beta interferon induction by severe acute respiratory syndrome coronavirus suggests a two-step model for activation of interferon regulatory factor 3.},

author = {Martin Spiegel and Andreas Pichlmair and Luis Martínez-Sobrido and Jerome Cros and Adolfo García-Sastre and Otto Haller and Friedemann Weber},

doi = {10.1128/JVI.79.4.2079-2086.2005},

issn = {0022-538X},

year  = {2005},

date = {2005-01-01},

journal = {J Virol},

volume = {79},

pages = {2079--2086},

abstract = {Severe acute respiratory syndrome (SARS) is caused by a novel coronavirus termed SARS-CoV. We and others have previously shown that the replication of SARS-CoV can be suppressed by exogenously added interferon (IFN), a cytokine which is normally synthesized by cells as a reaction to virus infection. Here, we demonstrate that SARS-CoV escapes IFN-mediated growth inhibition by preventing the induction of IFN-beta. In SARS-CoV-infected cells, no endogenous IFN-beta transcripts and no IFN-beta promoter activity were detected. Nevertheless, the transcription factor interferon regulatory factor 3 (IRF-3), which is essential for IFN-beta promoter activity, was transported from the cytoplasm to the nucleus early after infection with SARS-CoV. However, at a later time point in infection, IRF-3 was again localized in the cytoplasm. By contrast, IRF-3 remained in the nucleus of cells infected with the IFN-inducing control virus Bunyamwera delNSs. Other signs of IRF-3 activation such as hyperphosphorylation, homodimer formation, and recruitment of the coactivator CREB-binding protein (CBP) were found late after infection with the control virus but not with SARS-CoV. Our data suggest that nuclear transport of IRF-3 is an immediate-early reaction to virus infection and may precede its hyperphosphorylation, homodimer formation, and binding to CBP. In order to escape activation of the IFN system, SARS-CoV appears to block a step after the early nuclear transport of IRF-3.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Pichlmair2004,

title = {Thogoto virus lacking interferon-antagonistic protein ML is strongly attenuated in newborn Mx1-positive but not Mx1-negative mice.},

author = {Andreas Pichlmair and Johanna Buse and Stephanie Jennings and Otto Haller and Georg Kochs and Peter Staeheli},

doi = {10.1128/JVI.78.20.11422-11424.2004},

issn = {0022-538X},

year  = {2004},

date = {2004-01-01},

journal = {J Virol},

volume = {78},

pages = {11422--11424},

abstract = {The Thogoto virus ML protein suppresses interferon synthesis in infected cells. Nevertheless, a virus mutant lacking ML remained highly pathogenic in standard laboratory mice. It was strongly attenuated, however, in mice carrying the interferon-responsive Mx1 gene found in wild mice, demonstrating that enhanced interferon synthesis is protective only if appropriate antiviral effector molecules are present. Our study shows that the virulence-enhancing effects of some viral interferon antagonists may escape detection in conventional animal models.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Spiegel2004,

title = {The antiviral effect of interferon-beta against SARS-coronavirus is not mediated by MxA protein.},

author = {Martin Spiegel and Andreas Pichlmair and Elke Mühlberger and Otto Haller and Friedemann Weber},

doi = {10.1016/j.jcv.2003.11.013},

issn = {1386-6532},

year  = {2004},

date = {2004-01-01},

journal = {Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology},

volume = {30},

pages = {211--213},

abstract = {Severe acute respiratory syndrome (SARS) is caused by a novel coronavirus termed SARS-CoV. No antiviral treatment has been established so far. Interferons are cytokines which induce the synthesis of several antivirally active proteins in the cell. In this study, we demonstrated that multiplication of SARS-CoV in cell culture can be strongly inhibited by pretreatment with interferon-beta. Interferon-alpha and interferon-gamma, by contrast, were less effective. The human MxA protein is one of the most prominent proteins induced by interferon-beta. Nevertheless, no interference with SARS-CoV replication was observed in Vero cells stably expressing MxA. Therefore, other interferon-induced proteins must be responsible for the strong inhibitory effect of interferon-beta against SARS-CoV.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Pichlmair2004a,

title = {[The first answer to viral infections: type I interferon].},

author = {Andreas Pichlmair and Matthias Pollak and Andreas Bergthaler},

issn = {0005-9366},

year  = {2004},

date = {2004-01-01},

journal = {Berl Munch Tierarztl Wochenschr},

volume = {117},

pages = {252--265},

abstract = {The interferon system is part of the innate immune system in vertebrates. It represents the first line of host defence against viral infections. Virus entry triggers intracellular signalling pathways which lead to the secretion of soluble factors such as interferons and other cytokines. Interferons signal to neighbouring cells that a viral infection has occurred and induce an äntiviral state" resulting in inhibition of virus replication. The first recombinant interferons were produced in the 1980ies and were considered to be a major breakthrough. At present, interferons are routinely used in the therapy of certain viral and autoimmune diseases as well as for neoplastic disorders in man. In 2001 the first interferon preparation for veterinary use was licensed in the European Union. This review summarises the molecular mechanisms of the interferon system and the viral counteractions. The current type I interferon therapies in humans are described and an overview of recent clinical studies in veterinary medicine, including cat, dog, horse, cow, sheep, pig, and poultry, is given. We review the potential application of interferons and arguments in favor or against its therapeutic use in veterinary medicine.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Weissenboeck2003,

title = {Screening for West Nile virus infections of susceptible animal species in Austria.},

author = {H Weissenböck and Z Hubálek and J Halouzka and A Pichlmair and A Maderner and K Fragner and J Kolodziejek and G Loupal and S Kölbl and N Nowotny},

issn = {0950-2688},

year  = {2003},

date = {2003-01-01},

journal = {Epidemiol Infect},

volume = {131},

pages = {1023--1027},

abstract = {Avian mortality and encephalomyelitis in equines are considered good indicators for West Nile virus (WNV) activity. We retrospectively tested 385 horse sera for WNV antibodies and looked for WNV nucleic acid and/or WNV antigen in paraffin embedded tissues from 12 horses with aetiologically unresolved encephalomyelitis and 102 free-living birds of different species which had been found dead. With the exception of four horses originating from eastern European countries investigated on the occasion of transit through Austria, all horse sera were negative. Nested RT-PCR of the horse tissues yielded no amplification of WNV-RNA. Also, all bird samples, examined by immunohistochemistry, in situ hybridization and nested RT-PCR were negative for WNV. These results indicate that currently WNV cannot be considered a significant pathogen in Austria.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}