Chapter 33 extras

  1. The entry of enveloped viruses into cells also triggers an antiviral response. Explain this response.
    It is non-specific. Instead of producing cytokines, interferon-stimulated genes are produced that encode intracellular proteins that block virus transcription and translation 
  2. autophagy
    • an intrinsic cellular process that increases cell survival during periods of stress
    • stressed cells degrade their contents by forming phagosomes.
  3. RIG-I and MDA5
    recognize RNAs from different viruses, with the recognition depending on both RNA structure and length

    RIG-I recognizes short dsRNA and ssRNA 

    MDA5 recognizes long dsRNA
  4. What is the signal transduction pathway that occurs when viral components are recognized?
    viral proteins or NA bind to TLRs--> MyD88 and TRIF

    • All TLRs except TLR-3 interact with MyD88
    • TLR-3 interacts with TRIF

    Through a series of associations, protein kinases are recruited, which leads to the NF-kappaB signal transduction cascade, which translocates into the nucleus and activates cytokines
  5. Explain the activity of perforin.
    makes holes in the cell surface membrane as well as intracellular membranes, facilitating the entry of a second cytotoxic protein, granzyme B, which cativates apoptosis

    Granzyme B activates both caspase-3 and the pathway leading to release of mitochondrial proteins and the formation of the apoptosome
  6. clonal selection theory
    antigen-specific cells of the imune system with a great variety of binding specificities are created in an antigen-independent manner in the bone marrow

    these naive B and T cells are then selected and acivated upon contact with antigens in the lymph nodes or spleen to generate the immune response
  7. What are antigen presenting cells?
    • macrophages
    • dendritic cells
    • B cells
  8. How are Tc cells prouced?
    by an encounter between an antigen presentingg cell adn a naive CD8 positive T cell
Card Set
Chapter 33 extras