Immunology Final Exam Study Guide 2023

Immunology Final Exam Study Guide 2023 Immunology Question-based guide 1) How does the epithelial barrier in the skin, gut, and lung differ from a mechanical, chemical and microbiological perspective? PG 5 2) What are the defensive chemical components present in the skin, the external epithelial surface? - Antibacterial peptides and fatty acids 3) What is a macrophage? - A type of phagocytic cell that is part of the innate immune system that is also a WBC - engulf and kill invading microorganisms - help induce inflammation 4) How are the differences between macrophages and neutrophils? ❖ Neutrophils take more of an active role in innate immunity they also have the most phagocytic activity. Not present in healthy tissues and are abundant in the blood. ➢ Most numerous and important in innate immune response ➢ Not tissue resident cells and are only recruited to a site of infection and can only kill and ingest microbes ➢ Short Lived, die after completing one round of phagocytosis ➢ Most effective phagocytes ➢ Neutrophils respond to bacteria by phagocytosis, which results in respiratory burst: a production of nasty reactive species that kill bacteria ➢ In particular neutrophils exposed to CXCL8 and cytokyne TNF-α are activated to produce the respiratory burst that generates oxygen radicals, nitric oxide, and to release their stored lysosomal contents. ❖ Macrophages also take a role in innate immunity, major phagocytic population and they reside in normal tissue even at homeostasis ➢ engulf and kill invading microorganisms. This phagocytic function provides a first defense in innate immunity. ➢ Monocyte (the immature form of a macrophage) circulate in the blood and continually migrate into tissues ➢ Macrophage are relatively long-lived cells and they engulf and kill invading microorganisms ➢ help induce inflammation ➢ act as general scavenger cells in the body. Cleaning dead cells and cell debris 5) What are the events that take place once there is an infection and macrophages start fighting with the microbial invaders? (page 80, fig. 3.2)  Macrophages uses PRR to recognize a pathogen, engulfs the pathogen, forms bubble around the pathogen (phagosome), becomes acidified, and oxidative burst occurs  Infection makes a macrophage release cytokines and chemokines which induce inflammation  Chemokines allow for permeability 6) What is a dendritic cell? And what is its function in immune defense? - A dendritic cell is one that uptakes antigens in peripheral tissues, they are the most potent stimulators of t-cell responses in lymphoid organs - Plasmacytoid dendritic cells main function in an infection is to produce large amounts of antiviral interferons as a result of pathogen recognition through receptors such as TLRs. - Dendritic cells can take up pathogens by a process called micropinocytosis - They recognize pathogens 7) What are the differences among immediate innate response, early induced innate response and adaptive immune response? - Immediate Innate response (relies on the recognition of pathogens) - Physical barrier → epithelial cell wall - Mucosal surfaces have mucus which prevents microbes from sticking or staying on the surface. Also has cilia that moves the mucus to keep the bacteria from staying too long - The release of antimicrobial enzymes and bacterial peptides - Early induced innate immune response - Relies on recognition of pathogens