Barrier Immunity
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Questions and Answers

What are the immediate release cytokines from mast cells?

  • IL-18 and IL-4
  • TGF-β and IL-6
  • IL-4 and TNF-α (correct)
  • IL-2 and IL-10
  • Which type of inflammation is associated with the release of IL-4, TGF-β, IL-6, and IL-18 from mast cells?

  • Type III inflammation
  • Type I inflammation
  • Type II inflammation (correct)
  • Type IV inflammation
  • What are the mast cell factors that stimulate tissue remodeling?

  • IL-6 and IL-18
  • IL-4 and TGF-β (correct)
  • IL-4 and TNF-α
  • Histamine and Heparin
  • What is responsible for many signs and symptoms of atopic dermatitis and allergic rhinitis?

    <p>Mast cell degranulation resulting in an acute response</p> Signup and view all the answers

    What happens if mast cell activation occurs repeatedly?

    <p>'Pro-fibrotic' growth factors stimulate tissue remodeling</p> Signup and view all the answers

    Which molecule serves as a 'specific' receptor for antigen on mast cell membranes?

    <p>IgE</p> Signup and view all the answers

    When antigen binds to IgE attached to the mast cell membrane, what process occurs?

    <p>Degranulation</p> Signup and view all the answers

    Apart from IgE, what other receptors can trigger degranulation in mast cells?

    <p>TLRs, NLRs, and C-type lectins</p> Signup and view all the answers

    Which of the following is NOT a function of histamine released by mast cells?

    <p>Platelet activation</p> Signup and view all the answers

    What is the function of heparin released by mast cells?

    <p>Coagulation</p> Signup and view all the answers

    Which of the following is an example of a chemotactic factor produced by mast cells?

    <p>Eotaxin</p> Signup and view all the answers

    What is the function of leukotrienes released by mast cells?

    <p>Smooth muscle constriction</p> Signup and view all the answers

    Which type of T-helper response is commonly associated with atopic dermatitis?

    <p>Th2</p> Signup and view all the answers

    Where are key mediators like histamine and leukotrienes typically located in mast cells and eosinophils?

    <p>Granules</p> Signup and view all the answers

    What is the primary function of IgE and its Fc receptor in relation to mast cells and eosinophils?

    <p>Trigger degranulation of mast cells and eosinophils</p> Signup and view all the answers

    Which type of inflammation is characterized by the activation of eosinophils and the production of cytokines such as IL-4 and IL-5?

    <p>Type 2 inflammation</p> Signup and view all the answers

    What is the impact of defects in the barrier function of the skin on the development of atopic dermatitis?

    <p>It leads to a Th2 response</p> Signup and view all the answers

    During a viral upper respiratory infection, which type of inflammatory response is predominantly activated?

    <p>&quot;Type 1&quot; inflammatory response</p> Signup and view all the answers

    How do innate lymphoid cells impact the overall immune response at barrier tissues?

    <p>By releasing pro-inflammatory mediators</p> Signup and view all the answers

    What is the main polarizing cytokine that transforms a naive Th cell into a Th2 cell?

    <p>IL-4</p> Signup and view all the answers

    Which type of T-helper cells secrete IFN-y to stimulate class switching to IgG subtypes?

    <p>Th1 cells</p> Signup and view all the answers

    Which protein is important in tight junction formation and interacts with the cytoskeleton?

    <p>ZO-proteins</p> Signup and view all the answers

    Which cells seem to leave the bone marrow as relatively undifferentiated cells and then mature in the peripheral tissues that they migrate into?

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

    Which cytokines stimulate class switching to IgA?

    <p>TGF-beta and Retinoic Acid</p> Signup and view all the answers

    Which cytokines are secreted by Th2 cells to stimulate class switching to IgE?

    <p>IL-4 and IL-5</p> Signup and view all the answers

    What is the main determining transcription factor for Th2 cells?

    <p>GATA-3</p> Signup and view all the answers

    What is the net result of the skin maturing from deeper layers with respect to junctions?

    <p>Loss of hemidesmosomes and modification of tight junctions</p> Signup and view all the answers

    What signals seem to promote survival and migration of mast cells?

    <p>High circulating IgE and IL-4</p> Signup and view all the answers

    Which signal inhibits the survival of mast cells?

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

    Which of the following is true?

    <p>Proteases may have an anti-inflammatory effect when released in granules</p> Signup and view all the answers

    Which of the following is true regarding mast cells and the cytokines they release?

    <p>All of the above</p> Signup and view all the answers

    Mast cells play an important role in Type 1 hypersensitivity reactions

    <p>True</p> Signup and view all the answers

    Mast cells are always pro-inflammatory

    <p>False</p> Signup and view all the answers

    Which of the following cytokines is the major driver of eosinophils proliferation and activation?

    <p>IL-5</p> Signup and view all the answers

    Eosinophils granule contents do NOT include.....

    <p>IL-5</p> Signup and view all the answers

    Which of the following promotes migration of eosinophils into peripheral tissue?

    <p>Eotaxin</p> Signup and view all the answers

    Mast cells are long lived cells, unlike eosinophils which are short lived cells

    <p>True</p> Signup and view all the answers

    Which of the following activate ILC-1 cells?

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

    Which of the following activate ILC-2 cells?

    <p>Alarmins</p> Signup and view all the answers

    Both ILC-1 and ILC-2 need IL-2 to get activated

    <p>True</p> Signup and view all the answers

    Langerhans cells are dendritic cells and are usually found in the dermis

    <p>False</p> Signup and view all the answers

    Which of the following cells are found in the dermis?

    <p>All of the above</p> Signup and view all the answers

    Which of the following microbes can activate ILC2 cells?

    <p>None of the above</p> Signup and view all the answers

    Macrophages are not able to detect allergens and worms

    <p>True</p> Signup and view all the answers

    Which of the following cytokines are produced by ILC-2 cells in the presence of alarmins?

    <p>All of the above</p> Signup and view all the answers

    Study Notes

    Cytokines and Inflammation

    • Immediate release cytokines from mast cells include tumor necrosis factor-alpha (TNF-α) and various interleukins like IL-4, IL-6, IL-13.
    • IL-4, TGF-β, IL-6, and IL-18 released from mast cells are associated with allergic inflammation.

    Mast Cell Functions

    • Mast cell factors that stimulate tissue remodeling include IL-4 and IL-13.
    • Key mediators such as histamine and leukotrienes are stored in granules within mast cells and eosinophils.

    Atopic Dermatitis & Allergic Rhinitis

    • The release of cytokines and other mediators by mast cells is responsible for many signs and symptoms of atopic dermatitis and allergic rhinitis.
    • Repeated mast cell activation can lead to chronic inflammation and tissue damage.

    Antigen Interaction

    • IgE serves as a specific receptor for antigens on mast cell membranes.
    • Binding of antigens to IgE on mast cells triggers degranulation, releasing inflammatory mediators.

    Receptor Activation

    • Apart from IgE, other receptors like toll-like receptors (TLRs) can trigger mast cell degranulation.

    Histamine Functions

    • Histamine released by mast cells is involved in promoting inflammation, but it does NOT directly kill pathogens.

    Other Mediators

    • Heparin released from mast cells functions as an anticoagulant, inhibiting blood clotting.
    • Leukotrienes released by mast cells play a role in bronchoconstriction and increasing vascular permeability.

    T-Helper Response

    • Atopic dermatitis is commonly associated with a Th2 type immune response.
    • Activation of eosinophils and production of cytokines IL-4 and IL-5 characterize a Th2-associated inflammatory response.

    Barrier Function and Skin Health

    • Defects in the skin barrier can lead to increased susceptibility to atopic dermatitis.
    • During viral upper respiratory infections, a mixed inflammatory response is predominantly activated.

    Innate Lymphoid Cells (ILCs)

    • Innate lymphoid cells enhance the immune response at barrier tissues, influencing local inflammation and tissue repair.

    Cytokine Polarization

    • IL-4 is the main polarizing cytokine that transforms naïve T-helper (Th) cells into Th2 cells.
    • Th1 cells secrete IFN-γ, which stimulates class switching to IgG subtypes.

    Cellular Mechanisms

    • Proteins important in tight junction formation interact with the cytoskeleton to maintain barrier integrity.
    • Certain cells, including mast cells, leave the bone marrow as undifferentiated cells and mature in peripheral tissues.

    Class Switching and Cytokines

    • Cytokines such as IL-5 and IL-6 stimulate class switching to IgA.
    • Th2 cells secrete IL-4 and IL-13 to promote class switching to IgE.
    • GATA-3 is the main determining transcription factor for Th2 cells.

    Skin Maturation and Junction Integrity

    • As skin matures from deeper layers, junction integrity improves, enhancing barrier function.

    Mast Cell Survival Signals

    • Signals like stem cell factor (SCF) promote mast cell survival, while cytokines such as IL-10 can inhibit their survival.

    True Statements about Mast Cells

    • Mast cells play significant roles in Type 1 hypersensitivity reactions, though they are not universally pro-inflammatory.

    Eosinophil Activation

    • IL-5 is a major driver of eosinophil proliferation and activation.
    • Eosinophils migrate into peripheral tissues promoted by factors like eotaxin.

    ILC Activation

    • ILC-1 cells can be activated by IL-12 and IL-18, while ILC-2 cells are activated by IL-25 and IL-33.
    • Both ILC-1 and ILC-2 require IL-2 for activation.

    Dendritic Cells and Dermis

    • Langerhans cells, a type of dendritic cell found in the dermis, play a role in immune surveillance and response.

    Microbial Interaction

    • Certain microbes can activate ILC2 cells, contributing to an immune response against allergens.
    • Macrophages are unable to directly detect allergens and worms.

    Cytokine Production by ILC-2

    • ILC-2 cells produce cytokines like IL-4, IL-5, and IL-13 in the presence of alarmin signals.

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    Related Documents

    BMS150 Barrier Immunity PDF

    Description

    Test your knowledge about the function and activation of mast cells in the immune system. This quiz covers topics such as Fc receptor for IgE, degranulation, and the activation of pattern recognition receptors (PRRs) on mast cells.

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