Epstein-Barr virus

Definition

Epstein-Barr virus (EBV) is a member of the herpesvirus family, known for its ability to establish lifelong infections in humans and its association with various diseases, including infectious mononucleosis and certain cancers. As a prominent member of the herpesviruses, EBV demonstrates unique characteristics that link it to cancer development, immune evasion, and its interactions with different organ systems.

5 Must Know Facts For Your Next Test

1. EBV is one of the most common human viruses, with about 90% of adults worldwide being infected by it at some point in their lives.
2. The virus primarily infects B cells and epithelial cells, leading to a complex immune response and sometimes causing the proliferation of infected cells.
3. EBV is linked to several malignancies, including Hodgkin lymphoma, nasopharyngeal carcinoma, and gastric cancer.
4. The virus employs various strategies to evade the immune system, including downregulating major histocompatibility complex (MHC) molecules on infected cells.
5. Individuals with compromised immune systems, such as those with HIV/AIDS or organ transplant recipients, are at increased risk for EBV-related diseases.

Review Questions

• How does Epstein-Barr virus establish lifelong infections in humans, and what implications does this have for public health?
  • Epstein-Barr virus establishes lifelong infections by entering B lymphocytes and entering a latent phase where the virus remains dormant. This allows the virus to evade immune detection while still being capable of reactivation later. The widespread prevalence of EBV poses public health challenges as it can lead to various diseases, including infectious mononucleosis and certain cancers, emphasizing the need for continued surveillance and research into vaccines or treatments.
• Discuss the role of Epstein-Barr virus in oncogenesis and how it contributes to specific cancers.
  • Epstein-Barr virus contributes to oncogenesis through mechanisms such as the expression of viral oncogenes that promote cell proliferation and inhibit apoptosis. Its association with cancers like Burkitt lymphoma and Hodgkin lymphoma suggests that EBV plays a critical role in disrupting normal cellular processes. The viral proteins can alter signaling pathways in host cells, leading to uncontrolled growth and malignancy, highlighting the importance of understanding EBV's mechanisms in cancer biology.
• Evaluate the significance of Epstein-Barr virus's immune evasion strategies in relation to chronic infections and disease outcomes.
  • The immune evasion strategies employed by Epstein-Barr virus are crucial for its ability to persist in the host and contribute to disease outcomes. By downregulating MHC molecules on infected cells and producing proteins that inhibit immune responses, EBV can avoid detection by cytotoxic T cells. This persistence can lead to chronic infection scenarios, where the immune system is unable to effectively eliminate the virus, ultimately increasing the risk of developing associated diseases such as lymphomas or chronic fatigue syndrome.

Related terms

Infectious Mononucleosis: A viral infection commonly caused by Epstein-Barr virus, characterized by fever, sore throat, swollen lymph nodes, and fatigue.

Burkitt Lymphoma: A type of aggressive non-Hodgkin lymphoma that is associated with Epstein-Barr virus and often affects children.

Latency: A phase in viral infection where the virus remains dormant within host cells, such as B lymphocytes in the case of Epstein-Barr virus.