Chapter 6 AI generated Flashcards
Describe the role of Th1 cells in the immune response.
Th1 cells are activated in response to bacterial infections or viral attacks in tissues. They produce TNF, IFN-y, and IL-2, which help activate macrophages, NK cells, and promote CTL proliferation.
Explain the function of Th2 cells in the immune system.
Th2 cells are involved in defending against parasites or pathogenic bacteria in the digestive tract. They produce IL-4, IL-5, and IL-13, which stimulate B cells to produce antibodies like IgA and IgE.
Define the function of Th17 cells in the immune response.
Th17 cells are activated in response to fungal infections or extracellular bacteria. They produce IL-17 and IL-21, which recruit neutrophils to infection sites and stimulate B cells to produce specific antibodies.
How do Th0 cells differ from Th1, Th2, and Th17 cells in the immune system?
Th0 cells remain unbiased upon activation and have the potential to produce a wide range of cytokines. They are directed by DCs but retain flexibility in their differentiation once they reach the battle scene.
Describe the positive and negative feedback loops involved in Th cell activation.
Th cells stimulate their own growth through positive feedback loops once they have differentiated. Negative feedback loops also exist to regulate this process, ensuring a balanced immune response.
Explain the importance of cytokine range in the immune system.
Cytokines have a limited range of action, traveling only short distances before being captured by receptors or degraded. This localized action allows for specific responses to different invaders, enabling the immune system to defend against multiple threats simultaneously.
Describe Delayed-type hypersensitivity (DTH) in immune system.
DTH involves memory Th1 cells responding to a second infection by releasing IFN-y and TNF to recruit macrophages and neutrophils, causing local inflammation.
What are the weapons used by CTLs to kill infected cells?
CTLs use perforin to drill holes in cell membranes, granzyme B to trigger apoptosis, and Fas ligand to induce cell suicide.
How does apoptosis differ from necrosis in terms of cell death?
Apoptosis is a controlled process where a cell dies inside a vesicle, preventing the release of cell contents into tissues, while necrosis is a messy form of cell death.
Define adhesion molecules and their role in immune cell trafficking.
Adhesion molecules on immune cells’ surfaces control their movement, facilitating the delivery of weapons efficiently by helping cells find each other.
Describe the primary function of lymphoid follicles in secondary lymphoid organs.
Lymphoid follicles in SLOs start as networks of FDCs that present antigens to B cells, aiding in the immune response.
What are the three phases of the immune system related to lymphocyte trafficking?
The phases are recognition of danger in secondary lymphoid organs, production of weapons, and transport of these weapons.
How do FDCs in secondary lymphoid organs present antigens to B cells?
FDCs in SLOs can bind to complement fragments carrying antigens, becoming decorated with these antigens to present to B cells.
Describe the cooperation between adaptive and innate immunity in delayed-type hypersensitivity (DTH).
DTH involves specific recognition by Th cells and non-specific recruitment of neutrophils and macrophages, showcasing the collaboration of adaptive and innate immune responses.
