Immune Health - T-helper cells Flashcards
Q: What is the function of Th1 cells?
A: Th1 cells defend against intracellular pathogens (e.g., viruses) and have anti-cancer/tumor activity.
Q: What cytokine promotes Th1 differentiation?
A: IL-12 promotes differentiation into Th1 cells.
Q: What triggers Th1 activation?
A: Production of cytotoxic (CD8) T-cells, macrophages, IFN-γ, and TNF-α/β.
Q: What is the function of Th2 cells?
A: Th2 cells defend against extracellular threats (e.g., parasites).
Q: What cytokines promote Th2 differentiation?
A: IL-2, IL-4, and IL-5 promote Th2 differentiation.
Q: What triggers Th2 activation?
A: Production of IL-4, IL-5, IL-10, and IL-13, increased B-cell antibody production (e.g., IgE), and induction of eosinophils.
Q: What is the function of Th17 cells?
A: Th17 cells defend against extracellular pathogens and play a role in chronic inflammatory diseases.
Q: What cytokines promote Th17 differentiation?
A: IL-1, IL-6, and TGF-β promote Th17 cell differentiation.
Q: What does Th17 activation trigger?
A: Production of pro-inflammatory cytokines IL-17, IL-6, IL-22, and TNF-α, often involved in allergies and autoimmune diseases.
Q: What is the function of T-regulatory (T-reg) cells?
Q: What is the function of T-regulatory (T-reg) cells?
Q: What cytokines do T-reg cells produce?
A: T-reg cells produce TGF-β and IL-10, which inhibit helper T-cell activity.
Q: Where are most peripherally produced T-reg cells found?
A: The majority originate in the gut-associated lymphoid tissue (GALT).
Q: What is Th1/Th2 dominance?
A: Over-activation of either Th1 or Th2 pathways can downregulate the other, leading to immune imbalance.
Q: What conditions are associated with Th1 dominance?
A: Th1 dominance drives chronic inflammation and autoimmunity.
Q: What conditions are associated with Th2 dominance?
A: Th2 dominance drives allergies, including asthma and the atopic triad.
Q: What is the ideal Th1/Th2 balance?
A: A well-balanced Th1 and Th2 response, regulated by T-reg cells and various nutrients.
Q: How do Th1 and Th2 cells regulate each other?
A: IL-12 and IFN-γ from Th1 downregulate Th2, while IL-4 from Th2 downregulates Th1.
Q: Why is classifying immune diseases by T-helper cell type an oversimplification?
A: Different Th cell profiles can be present at different stages of disease, and there is significant crosstalk between Th1, Th2, and Th17 responses.
Q: How do Th profiles shift in eczema?
A: Acute eczema is Th2-dominant, but chronic inflammation can increase Th1 and Th17 activity.
