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Updated: Mar 10, 2026
Modeling The Lifecycle Of Ebola Virus Under Biosafety Level 2 Conditions With Virus-like Particles Containing Tetracistronic Minigenomes
Published on: September 27, 2014
Novel activities by ebolavirus and marburgvirus interferon antagonists revealed using a standardized in vitro
Jonathan C Guito1, César G Albariño1, Ayan K Chakrabarti1
1Viral Special Pathogens Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States.
Abstract:
Filoviruses are highly lethal in humans and nonhuman primates, likely due to potent antagonism of host interferon (IFN) responses early in infection. Filoviral protein VP35 is implicated as the major IFN induction antagonist, while Ebola virus (EBOV) VP24 or Marburg virus (MARV) VP40 are known to block downstream IFN signaling. Despite progress elucidating EBOV and MARV antagonist function, those for most other filoviruses, including Reston (RESTV), Sudan (SUDV), Taï Forest (TAFV), Bundibugyo (BDBV) and Ravn (RAVV) viruses, remain largely neglected. Thus, using standardized vectors and reporter assays, we characterized activities by each IFN antagonist from all known ebolavirus and marburgvirus species side-by-side. We uncover noncanonical suppression of IFN induction by ebolavirus VP24, differing potencies by MARV and RAVV proteins, and intriguingly, weaker antagonism by VP24 of RESTV. These underlying molecular explanations for differential virulence in humans could guide future investigations of more-neglected filoviruses as well as treatment and vaccine studies.
Insights
Filoviruses antagonize host interferon (IFN) responses, causing severe disease. This study reveals varied IFN antagonist activities across filovirus species, offering insights into differential virulence and guiding future therapeutic strategies.
Area of Science:
- Virology
- Immunology
- Molecular Biology
Background:
- Filoviruses cause severe hemorrhagic fevers by suppressing host immune responses, particularly interferon (IFN) pathways.
- Viral protein 35 (VP35) is a known IFN induction antagonist, while VP24 (Ebolavirus) and VP40 (Marburgvirus) inhibit downstream IFN signaling.
Purpose of the Study:
- To systematically characterize and compare the IFN antagonist activities of proteins from all known filovirus species.
- To elucidate the molecular mechanisms behind differential filovirus virulence and host immune evasion.
Main Methods:
- Utilized standardized expression vectors and reporter assays to assess IFN antagonist functions.
- Side-by-side comparison of VP35 and VP24/VP40 proteins from various ebolaviruses and marburgviruses.
Main Results:
- Identified noncanonical suppression of IFN induction by ebolavirus VP24 proteins.
- Demonstrated varying potencies in IFN antagonism by proteins from Marburg virus (MARV) and Ravn virus (RAVV).
- Observed weaker antagonism by Reston virus (RESTV) VP24 compared to other ebolaviruses.
Conclusions:
- Filovirus IFN antagonist activities differ significantly across species, contributing to their distinct virulence profiles.
- These findings provide molecular insights into filovirus pathogenesis and can inform the development of novel antiviral treatments and vaccines.
