@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{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{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{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{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{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{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{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{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{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{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{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{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{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{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}

}