The objective of this project is to analyze host-defense mechanisms against viral infection in the model organism Drosophila melanogaster, and to do so in the light of concurrent studies of viral infection in mice, carried out by our colleagues in La Jolla and in Osaka. By studying the response of Drosophila to viral infection we will uncover evolutionarily conserved mechanisms of innate immunity that, together with the programs developed in the other participating laboratories, will help to unravel the essential aspects of the antiviral response in mammals. The project has two specific aims, which are based on the original results obtained by the laboratory in the past five years. The picture emerging from these studies is that of a complex, multi-faceted program of defense, essentially based on RNA interference and an inducible response, on which our knowledge is still fragmentary. In this new application, we aim to produce an integrative view of the sensing, signaling and effector mechanisms leading to resistance to virus infection in drosophila.
The first aim i s to conduct unbiased forward genetic screens to identify mutations that impair the antiviral response. The readout for the screens will be the viral load (using GFP-expressing recombinant viruses), and the survival to viral infection. We propose to take advantage of the technological breakthrough of SOLiD high throughput sequencing to rapidly identify the mutated genes in a cost effective manner by whole genome resequencing.
The second aim i s to characterize the role of three evolutionarily conserved pathways, namely RNAi, Toll and Imd, in antiviral defense in drosophila. The experimental strategy will be to identify by a powerful method combining the unparalleled affinity of avidin for biotin and the exquisite sensitivity of nanoLC-tandem mass spectrometry the molecules interacting with selected components of the RNA interference, Imd and Toll pathways. The composition of these complexes will be compared in cells either uninfected or infected by viruses replicating in different cytoplasmic locations. The function of the identified molecules will be characterized in cells and flies. In addition, we will study by live imaging in infected cells the interaction of the canonical molecules of the RNAi pathway (Dicer-2, R2D2 and AGO2) with viral RNAs.
We anticipate that this project will allow us to reveal novel evolutionarily conserved pathways of host-defense, as we earlier did for Toll-like receptors. Understanding the molecular mechanisms of antiviral immunity in drosophila may also lead us to propose novel strategies to fight viral infections. Finally, this project is expected to shed light on the interaction between vector insects and the pathogenic arthropod- borne viruses they transmit to humans.
|Kuniyoshi, Kanako; Takeuchi, Osamu; Pandey, Surya et al. (2014) Pivotal role of RNA-binding E3 ubiquitin ligase MEX3C in RIG-I-mediated antiviral innate immunity. Proc Natl Acad Sci U S A 111:5646-51|
|Zeng, Ming; Hu, Zeping; Shi, Xiaolei et al. (2014) MAVS, cGAS, and endogenous retroviruses in T-independent B cell responses. Science 346:1486-92|
|Lamiable, Olivier; Imler, Jean-Luc (2014) Induced antiviral innate immunity in Drosophila. Curr Opin Microbiol 20:62-8|
|Majzoub, Karim; Hafirassou, Mohamed Lamine; Meignin, Carine et al. (2014) RACK1 controls IRES-mediated translation of viruses. Cell 159:1086-95|
|Colak, Elif; Leslie, Alasdair; Zausmer, Kieran et al. (2014) RNA and imidazoquinolines are sensed by distinct TLR7/8 ectodomain sites resulting in functionally disparate signaling events. J Immunol 192:5963-73|
|Lee, Hanna; Komano, Jun; Saitoh, Yasunori et al. (2013) Zinc-finger antiviral protein mediates retinoic acid inducible gene I-like receptor-independent antiviral response to murine leukemia virus. Proc Natl Acad Sci U S A 110:12379-84|
|Fukuyama, Hidehiro; Verdier, Yann; Guan, Yongsheng et al. (2013) Landscape of protein-protein interactions in Drosophila immune deficiency signaling during bacterial challenge. Proc Natl Acad Sci U S A 110:10717-22|
|Kemp, Cordula; Mueller, Stefanie; Goto, Akira et al. (2013) Broad RNA interference-mediated antiviral immunity and virus-specific inducible responses in Drosophila. J Immunol 190:650-8|
|Baccala, Roberto; Gonzalez-Quintial, Rosana; Blasius, Amanda L et al. (2013) Essential requirement for IRF8 and SLC15A4 implicates plasmacytoid dendritic cells in the pathogenesis of lupus. Proc Natl Acad Sci U S A 110:2940-5|
|Coste, Franck; Kemp, Cordula; Bobezeau, Vanessa et al. (2012) Crystal structure of Diedel, a marker of the immune response of Drosophila melanogaster. PLoS One 7:e33416|
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