Viral Latency: Definition and Examples in Human Diseases

📚 Viral Latency: A Quick Study Guide

• 🔬 Definition: Viral latency is the ability of a virus to remain dormant within a host cell, without causing immediate disease symptoms.
• 🧬 Mechanisms: Latency can be established through various mechanisms, including integration into the host genome or existing as an episome (a circular DNA molecule outside the chromosome).
• ⏰ Reactivation: Latent viruses can reactivate due to factors such as stress, immunosuppression, or other infections.
• ⚠️ Key Examples:
  • Herpes Simplex Virus (HSV): Causes cold sores and genital herpes. Remains latent in nerve cells.
  • Varicella-Zoster Virus (VZV): Causes chickenpox and shingles. Latent in dorsal root ganglia.
  • Human Immunodeficiency Virus (HIV): Can establish latency in T cells.
  • Epstein-Barr Virus (EBV): Causes mononucleosis and is associated with certain cancers. Latent in B cells.
• 📊 Significance: Understanding viral latency is crucial for developing effective antiviral therapies and preventative strategies.

🧪 Practice Quiz

1. Which of the following best defines viral latency?

   1. A) The rapid replication of a virus leading to immediate symptoms.
   2. B) The ability of a virus to remain dormant within a host cell without causing immediate symptoms.
   3. C) The complete eradication of a virus from the host's body.
   4. D) The process by which a virus mutates rapidly.

2. Which virus is commonly associated with causing both chickenpox and shingles due to its ability to establish latency?

   1. A) Herpes Simplex Virus (HSV)
   2. B) Varicella-Zoster Virus (VZV)
   3. C) Human Immunodeficiency Virus (HIV)
   4. D) Epstein-Barr Virus (EBV)

3. In which type of cells does the Epstein-Barr Virus (EBV) typically establish latency?

   1. A) T cells
   2. B) B cells
   3. C) Nerve cells
   4. D) Epithelial cells

4. What is a common trigger for the reactivation of a latent virus?

   1. A) Increased physical activity
   2. B) Immunosuppression
   3. C) High sugar intake
   4. D) Exposure to sunlight

5. Which of the following is NOT a characteristic of viral latency?

   1. A) Dormancy
   2. B) Integration into host genome
   3. C) Active replication and immediate cell lysis
   4. D) Potential for reactivation

6. Where does the Herpes Simplex Virus (HSV) typically remain latent?

   1. A) Liver cells
   2. B) Nerve cells
   3. C) Muscle cells
   4. D) Blood cells

7. Which of the following viruses can establish latency in T cells?

   1. A) Varicella-Zoster Virus (VZV)
   2. B) Herpes Simplex Virus (HSV)
   3. C) Human Immunodeficiency Virus (HIV)
   4. D) Epstein-Barr Virus (EBV)