Human Viral Diseases Review

• What are the 5 main stages of the virus lifecycle shown in the diagram?

  1. Attachment
  2. Entry
  3. Replication & gene expression
  4. Assembly
  5. Release
• What is the name of the structure that the virus attaches to on the host cell?

  Receptor
• What are the three main stages of viral replication?

  1. Attachment to host cell surface
  2. Penetration and release of viral genetic material
  3. Replication of viral components and assembly into new virions
• Why does the viral capsid come apart after the virus enters the host cell?

  To allow the viral RNA to enter the host cell
• How do the new virus particles exit the host cell during the release stage?

  They bud off from the host cell membrane
• How does the virus exit the host cell?

  • New virus particles assemble
  • The virus particles are released from the host cell to infect new cells
• How do viruses survive?

  By hijacking host cells for replication
• What is the purpose of the viral proteins produced during the replication and gene expression stage?

  To assemble new virus particles
• What are the main components of a virus?

  Nucleic acid genome and protein coat
• How does the virus enter the host cell?

  • The virus attaches to the host cell
  • The viral capsid comes apart, allowing the viral RNA to enter the host cell
• What type of parasites are viruses classified as?

  Obligate intracellular parasites
• How does SARS-CoV-2 infection lead to blood-brain barrier inflammation and permeability?

  • SARS-CoV-2 infects monocytes and lymphocytes
  • These immune cells release cytokines and chemokines
  • This leads to inflammation of the blood-brain barrier
  • Increased permeability allows more immune cells and virus to enter the brain
• How does the mechanism of SARS-CoV-2 brain infection differ from other respiratory viruses?

  SARS-CoV-2 can directly infect immune cells, leading to blood-brain barrier inflammation and permeability, allowing virus entry
• What does tropism explain in relation to viruses?

  Why viruses target specific cells
• What causes indirect damage from viruses?

  Immune response, inflammation, or secondary effects
• What are the two main mechanisms through which viruses cause harm?

  Direct damage and indirect damage
• What is the scale bar in the images?

  94 μm
• How does the structure of a virus facilitate its replication process?

  The capsid protects the genome during infection
• How is mumps transmitted?

  Respiratory droplets
• What are the key steps in the SARS-CoV-2 infection process?

  1. SARS-CoV-2 spike glycoprotein binds to ACE-2 receptors on neural/glial cells
  2. Virus enters the cell and releases its genetic material
  3. Viral RNA hijacks the cell's machinery to replicate
  4. New virus particles are assembled and released to infect more cells
• What occurs in the third stage of viral replication?

  Replication of viral components and assembly
• What receptors on the surface of neural/glial cells does the SARS-CoV-2 virus bind to?

  ACE-2 Receptors
• How is measles transmitted?

  Respiratory droplets
• What is the chronicity status of HEV?

  No, it does not cause chronic infections
• What does VHF stand for?

  Viral Hemorrhagic Fever
• What is the first stage of viral replication?

  Attachment to host cell surface
• What is the name of the spike glycoprotein on the SARS-CoV-2 virus?

  Spike Glycoprotein
• What are the key features of measles?

  Red rash and fever
• What is the magnification of the images?

  94 μm
• What are the main stages of the Epstein-Barr virus (EBV) infection cycle?

  • Primary infection
  • EBV replication
  • Latency 0, I, II, III
  • Persistent infection
• What is direct damage in the context of viral injury?

  Damage occurring during viral replication inside cells
• What do the different labels (U87MG-C, U87MG-T, U138G-C, U138G-T, GBM10-C, GBM10-T, GBM23-C, GBM23-T, BV2-C, BV2-T) represent?

  • The labels represent different cell types or treatments that were imaged.
  • The "C" and "T" likely stand for "control" and "treated" conditions.
  • The cell types include U87MG, U138G, GBM10, GBM23, and BV2.
• What are the mechanisms of viral injury and their implications?

  • Direct damage: occurs during viral replication
  • Indirect damage: caused by immune response and inflammation
  • Tropism: explains virus targeting specific cells via receptors
• What is a characteristic of chronic productive infections?

  They can lead to a carrier state
• What pathogen causes mumps?

  Paramyxovirus
• If a patient has a chronic hepatitis infection, which syndrome might they progress to?

  Chronic hepatitis
• What are the unique latency patterns of the three herpesvirus families?

  • Alpha (HSV-1): Latent in neurons, reactivates in epithelial cells
  • Beta (HCMV): Latent in myeloid progenitors/neural stem cells
  • Gamma (EBV): Latent in B lymphocytes
• What is the name of the cell type that is involved in the immune suppression response to the HSV-1 virus?

  Neuron
• What is the prevention strategy for mumps?

  Vaccination (MMR vaccine)
• What is the prevention strategy for measles?

  Vaccination (MMR vaccine)