The goal of the proposed research is to understand the basis for alphavirus induced disease. In the previous grant period we deduced a consensus sequence for the prototype alphavirus, Sindbis (SB), eliminating mutations for cell culture-adaptation and attenuation of virulence in animals. The consensus sequence was reconstituted as a cDNA clone, TR339, to provide a stable genotype representing a native isolate. When injected subcutaneously into neonatal mice, TR339 causes an acute, fatal disease. Extensive replication in extraneural tissues is coincident with surprisingly high levels of the proinflammatory cytokines IFNalphabeta, IFNgamma, TNFalpha and IL-6 in a systemic inflammatory response. Attenuation of the virus infection, either with increasing host age or by introduction of attenuating mutations, is associated with more restricted virus replication, reduced cytokine induction, and the onset of classical encephalitis. TR339 and all other non-neuroadapted SB strains are avirulent in adult mice. However, in adult animals lacking a functional receptor for IFNalphabeta (IFNalphabetaR-/- mice), TR339 infection was fatal and was characterized by high proinflammatory cytokine levels. In normal adult mice, infection of macrophages and dendritic cells is suppressed by the IFNalphabeta response, whereas these cells are fully permissive in IFNalphabetaR-/- adult mice and may have been directly or indirectly responsible for the proinflammatory cytokine cascade.
The Specific Aims of this proposal are: 1) to characterize the earliest events in SB infection, 2) to determine the mechanism whereby SB infection induces a systemic inflammatory response, 3) to characterize the effects of IFNalphabeta and IFNgamma on SB infection, and 4) to examine physiological parameters which influence the efficacy of the IFN response and which may contribute to fatal infection of neonatal animals and resistance of adults. These experiments will address fundamental issues in viral pathogenesis using the SB-mouse model, taking advantage of the extensive genetic characterization of this virus, the availability of a genomic clone representative of a native isolate, and expression systems which will allow the identification of the first cells infected in vivo.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI022186-19
Application #
6751256
Study Section
Virology Study Section (VR)
Program Officer
Repik, Patricia M
Project Start
1985-12-01
Project End
2007-05-31
Budget Start
2004-06-01
Budget End
2007-05-31
Support Year
19
Fiscal Year
2004
Total Cost
$331,567
Indirect Cost
Name
Louisiana State University Hsc Shreveport
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
095439774
City
Shreveport
State
LA
Country
United States
Zip Code
71103
Trobaugh, Derek W; Klimstra, William B (2017) Alphaviruses suppress host immunity by preventing myeloid cell replication and antagonizing innate immune responses. Curr Opin Virol 23:30-34
Gardner, Christina L; Trobaugh, Derek W; Ryman, Kate D et al. (2016) Electroporation of Alphavirus RNA Translational Reporters into Fibroblastic and Myeloid Cells as a Tool to Study the Innate Immune System. Methods Mol Biol 1428:127-37
Burke, Crystal W; Gardner, Christina L; Steffan, Joshua J et al. (2009) Characteristics of alpha/beta interferon induction after infection of murine fibroblasts with wild-type and mutant alphaviruses. Virology 395:121-32
Tesfay, Mulu Z; Yin, Jun; Gardner, Christina L et al. (2008) Alpha/beta interferon inhibits cap-dependent translation of viral but not cellular mRNA by a PKR-independent mechanism. J Virol 82:2620-30
Ryman, Kate D; Meier, Kathryn C; Gardner, Christina L et al. (2007) Non-pathogenic Sindbis virus causes hemorrhagic fever in the absence of alpha/beta and gamma interferons. Virology 368:273-85
Zhang, Yugen; Burke, Crystal W; Ryman, Kate D et al. (2007) Identification and characterization of interferon-induced proteins that inhibit alphavirus replication. J Virol 81:11246-55
Ryman, Kate D; Gardner, Christina L; Meier, Kathryn C et al. (2007) Early restriction of alphavirus replication and dissemination contributes to age-dependent attenuation of systemic hyperinflammatory disease. J Gen Virol 88:518-29
Ryman, Kate D; Gardner, Christina L; Burke, Crystal W et al. (2007) Heparan sulfate binding can contribute to the neurovirulence of neuroadapted and nonneuroadapted Sindbis viruses. J Virol 81:3563-73
Ossiboff, Robert J; Sheh, Alexander; Shotton, Justine et al. (2007) Feline caliciviruses (FCVs) isolated from cats with virulent systemic disease possess in vitro phenotypes distinct from those of other FCV isolates. J Gen Virol 88:506-17
Klimstra, William B; Williams, Jacqueline C; Ryman, Kate D et al. (2005) Targeting Sindbis virus-based vectors to Fc receptor-positive cell types. Virology 338:9-21

Showing the most recent 10 out of 54 publications