Lecture 25- NK cells
44 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which receptor on NK cells primarily facilitates antibody-dependent cell-mediated cytotoxicity (ADCC)?

  • CD16 (correct)
  • CD56
  • FcgRIIIA (correct)
  • NCAM

    • What is the typical life span of mature NK cells in the absence of activation?

  • 6-12 months
  • 1-3 days
  • 7-10 days (correct)
  • 2-4 weeks

    • Which of the following mechanisms is NOT a method by which NK cells can induce cytolysis?

  • Cytotoxic cytokines
  • Antibody-Dependent Cell-mediated Cytotoxicity (ADCC)
  • Natural cytotoxicity
  • Inhibition by MHC molecules (correct)

    • How do NK cells influence the immune response in the context of pregnancy?

    <p>By promoting fetal tolerance</p> Signup and view all the answers

    What is the primary cytokine released by NK cells that helps regulate the activity of T and B cells?

    <p>Interferon-gamma</p> Signup and view all the answers

    Which type of receptors on NK cells are primarily responsible for their activation?

    <p>Activating receptors</p> Signup and view all the answers

    Which is a characteristic feature differentiating NK cells from B and T cells?

    <p>Lack of TCRs or BCRs expression</p> Signup and view all the answers

    What is the primary functional role of NK cells during an immune response?

    <p>Directly killing virally-infected or tumor cells</p> Signup and view all the answers

    What primarily determines the intensity of the NK cell response?

    <p>The combination of engaged inhibitory and activatory receptors.</p> Signup and view all the answers

    What is meant by the term 'missing self' in the context of NK cell function?

    <p>The downregulation of MHC class I expression on abnormal cells.</p> Signup and view all the answers

    Which of the following cytokines is NOT mentioned as a priming cytokine for NK cells?

    <p>Tumor Necrosis Factor (TNF)</p> Signup and view all the answers

    What characterizes a host cell displaying 'induced self'?

    <p>Normal levels of self MHC and elevated activating ligands.</p> Signup and view all the answers

    Which receptor class exclusively contains activating receptors?

    <p>Natural cytotoxicity receptor (NCR).</p> Signup and view all the answers

    How do activating receptors signal within NK cells?

    <p>By utilizing associated signaling units with ITAMs.</p> Signup and view all the answers

    What is the primary role of NK cells in pregnancy?

    <p>To modulate the maternal immune response to tolerate the fetus.</p> Signup and view all the answers

    NK cell-mediated ADCC involves which of the following processes?

    <p>Utilization of antibodies bound to target cells to enhance cytotoxicity.</p> Signup and view all the answers

    What is the role of NK cells in pregnancy?

    <p>They secrete cytokines that promote new blood vessel formation.</p> Signup and view all the answers

    Which receptor is involved in triggering ADCC by NK cells?

    <p>FcgRIIIA (CD16)</p> Signup and view all the answers

    Which combination of cytokines is primarily produced by NK cells to influence innate immunity?

    <p>IFN-g, TNF, IL-1</p> Signup and view all the answers

    What effect does IFN-g produced by NK cells have on TH cell development?

    <p>Enhances TH1 cell development via inhibitory effects on TH2.</p> Signup and view all the answers

    How do activating receptors on NK cells contribute to their function upon stimulation?

    <p>They cause NK cells to secrete growth factors and chemokines.</p> Signup and view all the answers

    What triggers the initial priming of NK cells?

    <p>Cytokines produced by phagocytes and innate leukocytes.</p> Signup and view all the answers

    The engagement of which receptor activates NK cells to release their cytotoxic granules?

    <p>FcgRIIIA (CD16)</p> Signup and view all the answers

    What is the primary function of NK cells in the context of ADCC?

    <p>Binding to antibodies and lysing target cells.</p> Signup and view all the answers

    What distinguishes natural killer (NK) cells from NKT and T cells?

    <p>They lack TCRs or BCRs expression.</p> Signup and view all the answers

    Which statement accurately describes the tissue distribution of NK cells?

    <p>NK cells are present in high frequency in the spleen and liver.</p> Signup and view all the answers

    How do NK cells primarily recognize target cells without being MHC restricted?

    <p>By using a broad recognition of antigens independent of pMHC complexes.</p> Signup and view all the answers

    Which of the following is NOT a known function of NK cells?

    <p>Production of antibodies.</p> Signup and view all the answers

    In what way do NK cells contribute to the process of immune tolerance?

    <p>By remaining dormant and not responding to self-antigen.</p> Signup and view all the answers

    What primarily determines whether NK cells will activate against a target cell?

    <p>The ratio of activating to inhibitory receptor engagement</p> Signup and view all the answers

    Which of the following correctly describes a scenario in which a host cell may be killed by NK cells due to 'induced self'?

    <p>The host cell expresses high levels of activating ligands while normal levels of MHC class I are present</p> Signup and view all the answers

    What is a key outcome of priming NK cells with cytokines such as IL-12 or IL-15?

    <p>Upregulation of activating and inhibitory receptors</p> Signup and view all the answers

    Which type of receptors signal through ITAMs in NK cells?

    <p>Activating receptors</p> Signup and view all the answers

    Which factor does NOT typically contribute to the intensity of the NK cell response?

    <p>The age of the organism</p> Signup and view all the answers

    What characterizes the intracellular domains of activating versus inhibitory NK cell receptors?

    <p>Inhibitory receptors contain ITIMs while activating receptors contain ITAMs</p> Signup and view all the answers

    What is primarily responsible for the 'missing self' mechanism that activates NK cells?

    <p>Downregulation of MHC class I expression on abnormal cells</p> Signup and view all the answers

    Which characteristic distinguishes activated NK cells from activated T and B cells?

    <p>Activated NK cells can function within hours of infection.</p> Signup and view all the answers

    What mechanisms allow NK cells to differentiate between healthy and abnormal cells?

    <p>The balance of activating and inhibitory signals from surface receptors.</p> Signup and view all the answers

    Which statement accurately describes the nature of 'experienced NK cells'?

    <p>They can proliferate upon re-exposure to the same pathogen.</p> Signup and view all the answers

    What role do innate immune cytokines play in NK cell activity?

    <p>They stimulate NK activity during the early stages of viral infections.</p> Signup and view all the answers

    How do NK cells contribute to the immune response against viruses?

    <p>They provide immediate defense while CTLs are activated.</p> Signup and view all the answers

    Which statement best describes the granules found in activated NK cells?

    <p>They are preformed and ready to induce apoptosis in target cells.</p> Signup and view all the answers

    What is a significant factor contributing to the mortality of patients with a complete absence of NK cells?

    <p>Enhanced susceptibility to viral infections.</p> Signup and view all the answers

    Which of the following best describes the concept of 'missing self' as it relates to NK cells?

    <p>NK cells identify and target cells lacking MHC class I molecules.</p> Signup and view all the answers

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser