Development of RNA aptamers targeting Ebola virus VP35.
Viral protein 35 (VP35), encoded by filoviruses, is a multifunctional dsRNA binding protein that plays important roles in viral replication, innate immune evasion, and pathogenesis. The multifunctional nature of these proteins also presents opportunities to develop countermeasures that target distinct functional regions. However, functional validation and the establishment of therapeutic approaches toward such multifunctional proteins, particularly for nonenzymatic targets, are often challenging. Our previous work on filoviral VP35 proteins defined conserved basic residues located within its C-terminal dsRNA binding interferon (IFN) inhibitory domain (IID) as important for VP35 mediated IFN antagonism and viral polymerase cofactor functions. In the current study, we used a combination of structural and functional data to determine regions of Ebola virus (EBOV) VP35 (eVP35) to target for aptamer selection using SELEX. Select aptamers, representing, two distinct classes, were further characterized based on their interaction properties to eVP35 IID. These results revealed that these aptamers bind to distinct regions of eVP35 IID with high affinity (10-50 nM) and specificity. These aptamers can compete with dsRNA for binding to eVP35 and disrupt the eVP35-nucleoprotein (NP) interaction. Consistent with the ability to antagonize the eVP35-NP interaction, select aptamers can inhibit the function of the EBOV polymerase complex reconstituted by the expression of select viral proteins. Taken together, our results support the identification of two aptamers that bind filoviral VP35 proteins with high affinity and specificity and have the capacity to potentially function as filoviral VP35 protein inhibitors.
Department of Pathology and Immunology, Washington University School of Medicine , St. Louis, Missouri 63110, United States.
Jennifer M
JM
Binning
Tianjiao
T
Wang
Priya
P
Luthra
Reed S
RS
Shabman
Dominika M
DM
Borek
Gai
G
Liu
Wei
W
Xu
Daisy W
DW
Leung
Christopher F
CF
Basler
Gaya K
GK
Amarasinghe
D000595:Amino Acid Sequence; D000998:Antiviral Agents / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D001667:Binding, Competitive; D017124:Conserved Sequence; D029043:Ebolavirus / Q000187:drug effects / Q000378:metabolism; D019142:Hemorrhagic Fever, Ebola / Q000188:drug therapy / Q000378:metabolism; D007700:Kinetics; D058990:Molecular Targeted Therapy; D050505:Mutant Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D009690:Nucleic Acid Conformation; D009698:Nucleoproteins / Q000378:metabolism; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs; D012313:RNA / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D012330:RNA, Double-Stranded / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D052156:SELEX Aptamer Technique; D013045:Species Specificity; D054334:Viral Regulatory and Accessory Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D000998:Antiviral Agents; D052157:Aptamers, Nucleotide; D050505:Mutant Proteins; D009698:Nucleoproteins; D012330:RNA, Double-Stranded; D011994:Recombinant Proteins; C080980:VP35 protein, filovirus; D054334:Viral Regulatory and Accessory Proteins; D012313:RNA