lecture 16 multiple chocie quiz- immunology
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What is the main function of effector CTLs?

  • Inducing DNA fragmentation in target cells
  • Promoting the entry of viruses into host cells
  • Producing cytokines to suppress inflammation
  • Recognizing and eliminating infected or abnormal cells (correct)

    • How do perforin and granzymes contribute to apoptosis?

  • Perforin induces DNA fragmentation in target cells
  • Granzymes form pores in the target cell membrane
  • Perforin inhibits the entry of granzymes into the cytosol
  • Perforin forms pores allowing granzymes to enter the cytosol (correct)

    • Which cytokine produced by effector CTLs promotes inflammation and enhances immune responses?

  • Interleukin-2 (IL-2)
  • Tumor necrosis factor (TNF)
  • Interleukin-10 (IL-10)
  • Interferon-gamma (IFN-γ) (correct)

    • What is the main role of DCs in presenting viral or tumor antigens to naive CD8+ T cells?

    <p>Providing costimulation via B7 and other signals</p> Signup and view all the answers

    What is the specificity of CD8+ TCRs in recognizing antigens?

    <p>Only recognizing cytosolic antigens presented by class I MHC molecules</p> Signup and view all the answers

    What is the main function of effector CTLs during acute infection?

    <p>Secretion of cytokines</p> Signup and view all the answers

    In chronic infections like HIV or HCV, what is a common characteristic of exhausted CTLs?

    <p>Reduced cytokine production</p> Signup and view all the answers

    Which receptor is upregulated on exhausted CTLs in chronic infections?

    <p>PD-1</p> Signup and view all the answers

    How do cytotoxic granules released by CTLs contribute to cell killing?

    <p>Produce toxins to damage cell membranes</p> Signup and view all the answers

    What is the primary function of cytotoxic T lymphocytes (CTLs)?

    <p>Targeting and eliminating cells infected with intracellular pathogens</p> Signup and view all the answers

    What is the primary process through which CTLs eliminate target cells?

    <p>Perforin/granzyme-mediated cell killing</p> Signup and view all the answers

    How do CTLs recognize the target cells they need to eliminate?

    <p>By recognizing specific antigens presented on the surface of infected cells</p> Signup and view all the answers

    What role do CTLs play in the immune response against intracellular pathogens?

    <p>Recognizing specific antigens on infected cells and inducing their apoptosis</p> Signup and view all the answers

    How do cytokines like interleukin-2 (IL-2) affect CD8+ T cell responses?

    <p>Enhancing the proliferation and differentiation of CD8+ T cells</p> Signup and view all the answers

    What is a key aspect of the interaction between CTLs and infected cells?

    <p>Recognition of specific antigens presented by infected cells</p> Signup and view all the answers

    What is the function of perforin in cytotoxic T lymphocytes (CTLs)?

    <p>Forms pores in the target cell membrane</p> Signup and view all the answers

    How do effector CTLs induce apoptosis in target cells?

    <p>Release cytotoxic molecules like perforin and granzymes</p> Signup and view all the answers

    What is the primary function of granzymes released by CTLs during cytotoxic activity?

    <p>Cleave key intracellular substrates</p> Signup and view all the answers

    In addition to combating intracellular pathogens, what other role do CTLs play?

    <p>Immune surveillance against cancer</p> Signup and view all the answers

    What happens to target cells when CTLs release cytotoxic molecules like perforin and granzymes?

    <p>Undergo apoptosis</p> Signup and view all the answers

    What is the main role of CD8+ T cells in response to antigens?

    <p>Recognizing and responding to antigens derived from infected or abnormal cells</p> Signup and view all the answers

    Which signal is essential for optimizing CD8+ T cell activation and proliferation?

    <p>CD40-CD40L interactions</p> Signup and view all the answers

    What happens during the differentiation of CD8+ T cells into effector cytotoxic T lymphocytes (CTLs)?

    <p>Acquisition of effector functions and changes in gene expression</p> Signup and view all the answers

    How do effector CTLs combat pathogens?

    <p>By inducing apoptosis in infected or abnormal cells</p> Signup and view all the answers

    What guides the migration of immune cells, including effector CTLs, to the site of infection?

    <p>Chemokines and adhesion molecules</p> Signup and view all the answers

    What is the role of perforin in CTL-mediated killing of target cells?

    <p>It forms transmembrane channels in the target cell membrane, allowing for the influx of water and ions.</p> Signup and view all the answers

    Which cell component is responsible for the precise delivery of cytotoxic molecules from CTLs to target cells?

    <p>Immune synapse</p> Signup and view all the answers

    What is the primary function of granzymes in the process of CTL-mediated killing?

    <p>Inducing apoptosis by disrupting the integrity of the target cell membrane</p> Signup and view all the answers

    What is the initial step taken by CTLs before initiating the killing of target cells?

    <p>Formation of the immune synapse</p> Signup and view all the answers

    Which feature distinguishes granzymes from perforin in CTL-mediated killing?

    <p>Storage within cytotoxic granules</p> Signup and view all the answers

    What is the purpose of CD8+ T cell activation?

    <p>To maintain immune homeostasis</p> Signup and view all the answers

    Which cells are involved in antigen cross-presentation during CD8+ T cell activation?

    <p>Dendritic cells</p> Signup and view all the answers

    What happens when naive CD8+ T cells encounter their specific antigen?

    <p>They bind to the antigen-presenting cells in lymph nodes</p> Signup and view all the answers

    What is the role of CD4+ Helper T cells during CD8+ T cell activation?

    <p>Provide assistance in the activation process</p> Signup and view all the answers

    Which molecule is responsible for presenting antigenic peptides on dendritic cells during CD8+ T cell activation?

    <p>Major histocompatibility complex class I (MHC-I)</p> Signup and view all the answers

    What is the significance of antigen cross-presentation in CD8+ T cell activation?

    <p>It enables CD8+ T cells to respond to endogenous antigens</p> Signup and view all the answers

    Which type of cells are targeted by CTLs during immune responses?

    <p>Cells containing specific microbes or antigens in their cytosol</p> Signup and view all the answers

    What factor is essential for the proliferation and differentiation of CD8+ T cells into effector CTLs?

    <p>Interleukin-2 (IL-2)</p> Signup and view all the answers

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