Career Development Projects

CD005 Douglas

NIAID classifies Ebola virus (EBOV) as a Category A pathogen due to its facile transmission in humans and an ensuing hemorrhagic fever that results in a 90% mortality rate. No vaccines or antiviral treatments are available; therefore we must expand our knowledge of the virus and its interaction with the host in order to generate better options for both effective anti-EBOV therapies and successful vaccine development. The human protein BST-2 is an innate immune molecule with the unique ability to restrict the egress of HIV-1 and other enveloped viruses including EBOV. Coincident with this discovery was the finding that the HIV-1 protein Vpu counteracts BST-2, thereby allowing viral progeny to readily escape from infected cells. Recent evidence suggests that the EBOV envelope glycoprotein (GP) antagonizes BST-2. The goals of this application are to characterize the GP/BST-2 interaction, to determine how EBOV GP evades the release restriction by BST-2, and to identify other host proteins involved in this process. The Specific Aims and Research Plan for this application are: S.A.1: To characterize the mechanism of GP-mediated antagonism of BST-2. This aim will be accomplished by first confirming a direct interaction between GP and BST-2 followed by determining the subcellular localization of this interaction. Next, the ability of GP to downregulate BST-2 from the cell surface, resulting in either sequestration or degradation of BST-2 will be determined. Finally, the effect of GP on the incorporation of BST-2 into lipid rafts and or Ebola virus like particles (VLP) will be ascertained. S.A.2: To identify host proteins involved in the GP-mediated antagonism of BST-2. Two separate systems biology approaches will be employed to accomplish this aim, including a phage display screen, and a proteomics-based co-immunoprecipitation strategy. All BST-2 binding proteins that are differentially identified in the presence or absence of GP will then be evaluated for their impact upon GPdependent Ebola VLP release. This novel viral immune evasion strategy is likely an important component of EBOV pathogenicity, so the comprehensive analysis of this virus/host interaction proposed in this application