Ebola

Fruit Bat Reservoirs

Monocistronic - an mRNA that codes for only one protein

Polycistronic - mRN codes for more than one protein

Introduction

• Termed as ‘hot’ viris, mortality rate ranges from 50-90%

• Ebola is one of the most lethal viruses that infects primates

Family

• Belong to a family Filoviridae

  • “threadlike”

  • Filamentous morphology

  • Surrounded by a lipid viral envelope

Marburg Virus

• Nearly identical to Ebola virus in structure

• Antigenicaly distinct from Ebola virus

• The first filovirus to be identified

Marburg vs. Ebola

• You can’t treat Ebola or Marburg with any antiviral drug; the only thing a doctor can do is keep the patient hydrated and provide drugs that help blood clot

Subtypes

• Five identified

• Three cause disease in humans

  • Ebola-sudan

  • Ebola-Zaire

  • Ebola-Bundibugyo

• Fifth Ebola virus subtype, Ebola-Reston has caused disease in nonhuman primates, but not in humans

Proteins

• L protein - polymerase

• VP24 + VP35 antagonize the type I interferon pathway

• NP, VP30, VP45

• VP40, VP24 underneath GP for structural integrity

IFN pathway

• Interferons “interfere” with viral replication in host cells

• Activate signal transducer and activator of transcription complexes (STAT), regulators of immune system

Overview of Infection

• Initiated by the fusion between viral and host cell membrane

• Niemann-Pick C1 (NPC1) is essential, binds GP (NPC1 is important for cholestoral trafficking)

• DC-SIGN plays a role in endocytosis

  • DC-SIGN on dendtric cells and macrophages

  • L-SIGN on endothelial cells of liver