title: A two-phase innate host response to alphavirus infection identified by mRNP-tagging in vivo.
abstract: A concept fundamental to viral pathogenesis is that infection induces specific changes within the host cell, within specific tissues, or within the entire animal. These changes are reflected in a cascade of altered transcription patterns evident during infection. However, elucidation of this cascade in vivo has been limited by a general inability to distinguish changes occurring in the minority of infected cells from those in surrounding uninfected cells. To circumvent this inherent limitation of traditional gene expression profiling methods, an innovative mRNP-tagging technique was implemented to isolate host mRNA specifically from infected cells in vitro as well as in vivo following Venezuelan equine encephalitis virus (VEE) infection. This technique facilitated a direct characterization of the host defense response specifically within the first cells infected with VEE, while simultaneous total RNA analysis assessed the collective response of both the infected and uninfected cells. The result was a unique, multifaceted profile of the early response to VEE infection in primary dendritic cells, as well as in the draining lymph node, the initially targeted tissue in the mouse model. A dynamic environment of complex interactions was revealed, and suggested a two-step innate response in which activation of a subset of host genes in infected cells subsequently leads to activation of the surrounding uninfected cells. Our findings suggest that the application of viral mRNP-tagging systems, as introduced here, will facilitate a much more detailed understanding of the highly coordinated host response to infectious agents.
authors.affiliation: Department of Microbiology and Immunology University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America. jennifer.konopka@vanderbilt.edu
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Konopka
authors.forename: Luiz O
authors.initials: LO
authors.lastname: Penalva
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Thompson
authors.forename: Laura J
authors.initials: LJ
authors.lastname: White
authors.forename: Clayton W
authors.initials: CW
authors.lastname: Beard
authors.forename: Jack D
authors.initials: JD
authors.lastname: Keene
authors.forename: Robert E
authors.initials: RE
authors.lastname: Johnston
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D003713:Dendritic Cells / Q000821:virology; D004666:Encephalitis Virus, Venezuelan Equine / Q000235:genetics*; D004685:Encephalomyelitis, Venezuelan Equine / Q000235:genetics*; D005260:Female; D005347:Fibroblasts / Q000821:virology; D005434:Flow Cytometry; D015870:Gene Expression; D020869:Gene Expression Profiling / Q000379:methods*; D015967:Gene Expression Regulation, Viral; D006790:Host-Parasite Interactions; D047468:Immunoprecipitation; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D012333:RNA, Messenger / Q000302:isolation & purification*; D053633:Receptor, Interferon alpha-beta / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012261:Ribonucleoproteins; D012680:Sensitivity and Specificity
chemical_list: C508034:Ifnar2 protein, mouse; D012333:RNA, Messenger; D012261:Ribonucleoproteins; D053633:Receptor, Interferon alpha-beta