The document summarizes a study investigating the use of interferon gamma (IFNγ) as a potential prophylactic or therapeutic treatment for Ebola virus infection. The researchers found that IFNγ treatment made macrophages resistant to Ebola virus infection by blocking viral RNA synthesis. IFNγ stimulation in human macrophages altered the expression of over 160 genes, including 3 factors - GBP5, RARRES3, and VAMP5 - that were found to inhibit Ebola virus infection. Mouse studies showed that IFNγ reduced morbidity and mortality from Ebola virus infection and protected mice from the virus. The researchers concluded that IFNγ is a novel and effective therapeutic option for Ebola virus.

1. Infection
Siddhesh Uday Sapre
Roll No. : 17
M.Sc. Virology (Part-I)
National Institute of Virology, Pune
Rhein BA, Powers LS, Rogers K, Anantpadma M, Singh BK, Sakurai Y, et al. (2015)
PLoS Pathog 11(11): e1005263. doi:10.1371/journal. ppat.1005263
Image credits: Visual Science

2. Virus taxonomy
• EBOV: ssRNA (-ve sense), large,
pleomorphic, filamentous
≈ 1400 nm
• Family- Filoviridae (filus= thread like)
• Genus- Ebolavirus
• Species- Bundibugyo EBOV
Sudan EBOV
Zaire EBOV
Reston EBOV
Taї forest EBOV (formerly called Côte d’Ivoire)

3. Ebov Structure
• Shape: enveloped, filamentous (long tube with many
branches and turns); number 6 curvature
• Size : 80 nm (diameter)
• 800-1000 nm (length)
• RNA ≈ 1% of the total mass of the virus!!!

4. Cell Tropism of EBOV
• EBOLA Virus (EBOV) is Pantropic
• Infects all the cells of the body except
Lymphocytes
• MΦs & DCs= Early targets
Nature Reviews Immunology 7, 556-567 (July 2007) | doi:10.1038/nri2098
Image Credits: False colour electron micrograph (NIH)
M1 Phenotype Proinflammatory cytokines IL-6, TNF-α,
CXCL-10

5. Image credits: Molecular mechanisms of Ebola virus pathogenesis doi:10.1038/cdd.2015.67

6. Aims & Objectives:
Basic purpose: To investigate if IFN γ can be used as a prophylactic
and/ or therapeutic treatment option in case of EBOV
infection
(i) time period for a maximum dose response ?
(ii) downstream effects
(iii) molecular level of IFN γ inhibition/ control
(iv) optimal dose of IFN γ

7. Materials and methods used
• Preparation of Virus Stock & Concentration
• Primary cell isolation & cytokine stimulations
• EBOV & EBOV GP/rVSV infection of MΦs
• Mouse cell RNA isolation & qRT- PCR
• Human MΦ RNA extraction & microarray analysis
• ISG Inhibition studies
• IRF1 siRNA knockdown of EBOV GP/rVSV infection by exosome delivery
NOTE :Animal studies- BALB/c mice, C57BL/6 , IFN-γR deficient mice were used

8. Fig 1. IFNγ-treated macrophages are resistant to EBOV infection.
Rhein BA, Powers LS, Rogers K, Anantpadma M, Singh BK, et al. (2015) Interferon-γ Inhibits Ebola Virus Infection. PLoS Pathog 11(11): e1005263.
doi:10.1371/journal.ppat.1005263

9. Fig 2. IFNγ blocks EBOV GP/rVSV and EBOV RNA synthesis.
Rhein BA, Powers LS, Rogers K, Anantpadma M, Singh BK, et al. (2015) Interferon-γ Inhibits Ebola Virus Infection. PLoS Pathog 11(11): e1005263.
doi:10.1371/journal.ppat.1005263

10. Fig 3. Human MDM gene expression is altered by 24 hours of IFNγ treatment.
Rhein BA, Powers LS, Rogers K, Anantpadma M, Singh BK, et al. (2015) Interferon-γ Inhibits Ebola Virus Infection. PLoS Pathog 11(11): e1005263.
doi:10.1371/journal.ppat.1005263

11. Fig 4. Identification of IFNγ-stimulated genes that inhibit EBOV infection.
Rhein BA, Powers LS, Rogers K, Anantpadma M, Singh BK, et al. (2015) Interferon-γ Inhibits Ebola Virus Infection. PLoS Pathog 11(11): e1005263.
doi:10.1371/journal.ppat.1005263

12. Fig 5. IFNγ reduces EBOV-GP/rVSV morbidity and mortality.
Rhein BA, Powers LS, Rogers K, Anantpadma M, Singh BK, et al. (2015) Interferon-γ Inhibits Ebola Virus Infection. PLoS Pathog 11(11): e1005263.
doi:10.1371/journal.ppat.1005263

13. Fig 6. IFNγ protects mice from EBOV morbidity and mortality.
Rhein BA, Powers LS, Rogers K, Anantpadma M, Singh BK, et al. (2015) Interferon-γ Inhibits Ebola Virus Infection. PLoS Pathog 11(11): e1005263.
doi:10.1371/journal.ppat.1005263

14. Conclusions
The researchers carried out the studies in murine models using the actual
EBOV, MA-EBOV, and EBOV GP/rVSV in both, BSL-4 & BSL-2 B2 conditions,
which lead them to the following conclusions:
1.IFN-γ -novel & effective therapeutic option
2. >160 ISGs ≈ 3 novel IFN-γ stimulated factors GBP5, RARRES3 &
VAMP5
3. BSL-2 model = safer and cost effective alternative

15. Reference
s
• Molecular mechanisms of Ebola virus pathogenesis doi:10.138/cdd.2015.67
• Pathogenesis of the Viral Haemorrhagic Fevers doi: 10.1146/annurev-pathol-020712-164041
• How Ebola and Marburg viruses battle the immune system doi: 10.1038/nri2098
• Filovirus pathogenesis and immune evasion: insights from Ebola virus and Marburg virus doi:
10.1038/nrmicro3524
• How Ebola Virus Infects Cells (N ENG J MED 352;25)
• Biological Agents: Viral Haemorrhagic Fevers (Pacific EMPRINTS), University of Hawaii (
http://cdc.train.org/)
• How Ebola Virus Counters the Interferon System doi: 10.1111/j.1863-2378.2012.01454.x
• Immunology of protection from Ebola virus infection (Vaccine perspectives; Science Translational
Medicine)
• Immunopathology of highly virulent pathogens: insights from Ebola virus doi: 10.1038/ni1519

16. Thank
You!!!