Cell Mediated Immunity Overview
37 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 cytokine is primarily responsible for promoting class switching to IgG1 and IgE?

  • IFN-g
  • IL-4 (correct)
  • IL-10
  • IL-2

What is the main function of IFN-g in the immune response?

  • Enhances T cell growth
  • Increases MHC expression (correct)
  • Promotes neutrophil activation
  • Stimulates B cell differentiation

Which cytokine is known to inhibit Th1 responses and is produced by macrophages and Th2 cells?

  • TNF-a
  • IL-6
  • IL-10 (correct)
  • IL-17

What key role does IL-17 play in the immune system?

<p>Recruits and activates neutrophils (B)</p> Signup and view all the answers

What strategic function do TNF alpha inhibitors serve in therapy?

<p>Suppress the immune system (B)</p> Signup and view all the answers

What is the primary method through which cytotoxic T lymphocytes (CTLs) induce apoptosis in infected cells?

<p>Using perforin and granzymes (A)</p> Signup and view all the answers

Which statement accurately describes the action of CTLs?

<p>They specifically target infected cells while leaving uninfected cells unharmed. (B)</p> Signup and view all the answers

What role do Killer Inhibitory Receptors (KIRs) play in the activity of Natural Killer (NK) cells?

<p>They check for the presence of MHC class I molecules. (B)</p> Signup and view all the answers

What is a consequence of necrosis compared to apoptosis?

<p>Necrosis leads to inflammation. (B)</p> Signup and view all the answers

How do CTLs achieve specificity in targeting infected cells?

<p>Through interactions between MHC Class I and specific peptides. (B)</p> Signup and view all the answers

What determines whether NK cells will proceed to kill a target cell?

<p>The absence of signals from KIRs. (B)</p> Signup and view all the answers

Which mechanism is NOT used by CTLs to kill infected cells?

<p>Antibody-mediated opsonization (B)</p> Signup and view all the answers

What is the primary consequence of CTL killing through apoptosis?

<p>Ensuring the dead cell is removed without inflammation. (B)</p> Signup and view all the answers

What is the primary role of cytokines in the immune response?

<p>To simulate the proliferation and differentiation of immune cells (D)</p> Signup and view all the answers

Which of the following describes a characteristic feature of cytokines concerning their effect?

<p>A single cytokine can act on different types of cells. (D)</p> Signup and view all the answers

What happens when MHC class I is prevented from reaching the cell surface?

<p>KARs are no longer suppressed and the target cell is killed. (C)</p> Signup and view all the answers

Which cytokine is known to activate infected macrophages in a delayed type hypersensitivity response?

<p>IFN-gamma (B)</p> Signup and view all the answers

What type of immune cells do CD8+ cytotoxic T cells primarily target?

<p>Infected or malignant cells (C)</p> Signup and view all the answers

How do Th1 cells contribute to the immune response against intracellular pathogens?

<p>By recognizing infected cells and secreting cytokines like IFN-gamma (A)</p> Signup and view all the answers

In what way do cytokines exhibit redundancy in their function?

<p>Different cytokines can induce the same effect, such as B cell proliferation. (D)</p> Signup and view all the answers

What is the fate of macrophages infected with Mycobacterium tuberculosis when unaffected by activated Th1 cells?

<p>They can survive and grow inside the macrophages. (A)</p> Signup and view all the answers

What is primarily responsible for killing infected cells during a cell mediated immune response?

<p>CD8+ Cytotoxic T cells (D)</p> Signup and view all the answers

What role do natural killer cells play in the immune system?

<p>Kill cancerous or infected cells (C)</p> Signup and view all the answers

Which of the following cytokines is involved in promoting an antiviral response?

<p>IFN-gamma (D)</p> Signup and view all the answers

How does the immune system primarily respond to intracellular pathogens?

<p>By killing the infected cells directly (A)</p> Signup and view all the answers

What is the role of CD4+ T cells in activating CD8+ T cells?

<p>They license dendritic cells to activate CD8+ T cells. (B)</p> Signup and view all the answers

What property describes the ability of multiple cytokines to produce similar effects?

<p>Redundancy (D)</p> Signup and view all the answers

Which statement about MHC class I molecules is correct?

<p>They are found on all nucleated cells. (D)</p> Signup and view all the answers

Which cytokine is primarily involved in promoting the differentiation of T helper cells?

<p>IL-12 (D)</p> Signup and view all the answers

What is the primary role of TNF-alpha in the immune response?

<p>To promote the formation of granulomas (B)</p> Signup and view all the answers

What is a significant consequence of inhibiting TNF-alpha?

<p>Development of latent TB infection (C)</p> Signup and view all the answers

Which cytokine is primarily responsible for promoting antibody production and activating macrophages?

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

In response to an APC, what process allows TH cells to proliferate?

<p>Clonal Selection (D)</p> Signup and view all the answers

What primarily maintains the granuloma formed during a TB infection?

<p>Activated macrophages and Th1 cells (B)</p> Signup and view all the answers

Which of the following is a major characteristic of a super-killing macrophage?

<p>Increased TNF-alpha receptor expression (C)</p> Signup and view all the answers

What role do cytokines play in TH cell differentiation?

<p>They serve as signaling molecules (C)</p> Signup and view all the answers

What is a potential outcome if the functions of TNF-alpha remain intact?

<p>Granuloma maintained for life (B)</p> Signup and view all the answers

Study Notes

Cell Mediated Immunity

  • How the cell-mediated immune response gets activated and responds to intracellular pathogens:
    • CD8+ T cells (cytotoxic T cells) are activated by MHC Class I presenting viral peptides.
    • CD4+ T cells help activate CD8+ T cells, which then differentiate into cytotoxic T cells (CTLs).
    • CTLs recognize infected cells by MHC Class I and directly kill the cells (without causing inflammation) via apoptosis.
    • CTLs kill through perforin/granzyme, Fas/Fas-ligand, TNF-beta (lymphotoxin).

Natural Killer Cells

  • Role of Natural Killer cells:
    • They kill cells that lack MHC Class I expression (e.g., virus-infected cells, tumor cells).
    • They can also be activated by antibodies bound to the surface of target cells.
    • They have killer activating receptors (KARs) and killer inhibitory receptors (KIRs) on their surface.
    • KIRs prevent NK cells from attacking normal cells by recognizing MHC Class I molecules.

Cytokines

  • What are cytokines?

    • Small proteins that stimulate immune cells to proliferate and differentiate.
    • Many are called interleukins (IL-1,IL-2), but there are other important ones like interferon gamma (IFN-g) and tumor necrosis factor alpha (TNF-a).
  • General properties of cytokines:

    • Pleiotropy: A single cytokine can act on different cells, causing different effects.
    • Redundancy: Multiple cytokines can exert the same effect.
    • Synergy: Combined cytokines can produce greater effects than alone
    • Antagonism: Some cytokines can block the effects of other cytokines.

Cytokine Short List

  • IL-2: T cell growth factor; enhances CTLs and NK cells.
  • IL-4: Key Th2 cytokine; promotes antibody production, class switching to IgG1 and IgE, differentiation of B cells.
  • IFN-g: Key Th1 cytokine; promotes MHC expression, blocks IgE production, inhibits Th2 proliferation, activates macrophages in delayed-type hypersensitivity (DTH) response.
  • IL-10: Key Th2 cytokine; inhibits Th1 responses, produced by Th2 cells and macrophages.
  • IL-17: Key Th17 cytokine; recruits and activates neutrophils.
  • TNF-a: Involved in inflammation, DTH response, granuloma formation.

Delayed-Type Hypersensitivity (DTH) Response

  • How it works:
    • Macrophages ingest intracellular pathogens, like Mycobacterium tuberculosis.
    • Some pathogens evade phagocytosis and live inside macrophages.
    • IFN-g helps activate macrophages to kill the pathogen.
    • TNF-a also plays a role in DTH and formation of granulomas, which wall off infected areas.

Cytokine Inhibition in Treatment

  • TNF-alpha Inhibitors: Used for Crohn's disease and rheumatoid arthritis.
  • IL-17 Inhibitors: Used for psoriasis.
  • IL-6 Inhibitors: Used for severe COVID-19, hyperinflammatory states.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Immunology Lecture 4 2023 PDF

Description

Explore the mechanisms of cell-mediated immunity through a quiz focusing on CD8+ T cells and Natural Killer cells. Understand how these immune cells are activated, differentiate, and respond to intracellular pathogens while learning about their roles in combating infections and tumors.

More Like This

Mastering T Cell-Mediated Immunity
90 questions
Cell-Mediated Immunity Quiz
5 questions
Cell-Mediated Immunity Quiz
18 questions

Cell-Mediated Immunity Quiz

AccommodativePlumTree avatar
AccommodativePlumTree
Cell-Mediated Immunity Overview
18 questions
Use Quizgecko on...
Browser
Browser