Chapter 22 - Immunity Lecture 1 PDF

Part 1: Basic Terminology and an Introduction to the First Three Innate Defenses. Part 2: Completion of the Innate Defenses and a Review of the Main White Blood Cells. Ability to resist infection and defend against pathogens. pathogens Examples? ◦ Disease causing organisms. organisms ◦ Viruses, bact...

Part 1: Basic Terminology and an Introduction to the First Three Innate Defenses. Part 2: Completion of the Innate Defenses and a Review of the Main White Blood Cells. Ability to resist infection and defend against pathogens. pathogens Examples? ◦ Disease causing organisms. organisms ◦ Viruses, bacteria, fungi, + parasites. Discriminates between self & nonnon-self. 2 Types of “immunity immunity.” immunity 1) Innate (nonspecific) immunity, immunity ex.? characteristics? ◦ anatomical barriers and defense cells/chemicals. cells/chemicals ◦ Do not distinguish pathogens (nonspecific). (nonspecific) 2) Adaptive (specific) immunity, immunity, cell type? ◦ Lymphocytes that respond to specific pathogens. pathogens ◦ Response to specific antigens = immune response. response. Nonspecific immunity that works the same way against any type of invading agent. ◦ defenses present at birth, birth examples? examples ◦ physical barriers, inflammation, phagocytic cells, others Protects against specific pathogens, relies on lymphocytes (primarily), & requires prior exposure to a pathogen/foreign substance. ◦ Develop over time! These defenses result in resistance –ability ability to maintain immunity – naturally or acquired! MPs: Immune system functions to: to ◦ Distinguish b/n self & nonnon-self ◦ Defend against pathogens & toxic substances ◦ Destroy abnormal cells 1st line of defense = Physical barrier? barrier ◦ cutaneous membrane+ membrane mucus mem.! mem. ◦ Sebaceous glands + lysozyme secretion kills/inhibits growth 2) Phagocytes – engulf + destroy invaders. invaders ◦ Monocytes circulate; circulate macrophages w/in tissue. 3) Immunological surveillance = destruction of abnormal cells via NK cells in peripheral tissues. ◦ Tumor antigens ◦ Virally infected cells Engulf foreign substances, substances ex? ex ◦ Fixed + free macrophages, neutrophils, eosinophils, + monocytes. monocytes Utilize TollToll-like receptors (TLR) – receptors on neutrophils & macrophages that recognize pathogenpathogen-associated molecular patterns present (PAMPS) – markers w/in or on pathogens. pathogens The movement toward or away from chemical signals =? Chemotaxis The ability to squeeze between capillary walls? walls ◦ Diapedesis– Diapedesis endothelial cells @ injured site release chemicals for attracting macrophages (chemotaxis) & increases permeability of endothelial lining. Provide “immunological survelience. survelience. Kill abnormal cells via perforins. perforins ◦ Proteins that “create” pores in abnormal cells. Are“innate innate lymphocytes” lymphocytes ◦ Develop via lymphopoiesis, but do NOT require prior exposure to pathogen. pathogen Travel throughout tissues ◦ B- & TT-cells mainly found w/in lymphatic organs. organs 1. 2. 3. 4. 5. 6. 7. 8. What are pathogens, immunity and how does innate differ from adaptive immunity? What are physical barriers? The first line of cellular defense and how they differ? Immunological surveillance and the main cell? What are the molecules found on pathogens that phagocytes recognize, & what are the molecules phagocytes use to recognize pathogens? Why are these important for immunity? What are interferons, the 3 different types, and how do they differ in functions? How many proteins make up the complement system and what's the functions of this system? What is inflammation, what stimulates the process, & it’s overall function/importance? What is a fever & the proteins that cause it? Which WBC is first to arrive? Attacks parasites? Releases histamine? Attacks bacteria? Main warrior? Dyes dark purple? Dyes bright red? Part 1: Basic Terminology and an Introduction to the First Three Innate Defenses. Part 2: Completion of the Innate Defenses and a Review of the Main White Blood Cells. Specific chemical (cytokine) that inhibits viral replication released by: lymphocytes, macrophages, + virally infected cells release. chemical molecules that tissues release to coordinate local activities. MP: Stimulates nearby cells to produce antianti-viral proteins. proteins A “system” of ~30 proteins w/in blood plasma that “compliment” antibody action & phagocytosis. phagocytosis Pathway of proteins = cascade of events that leads to the conversion of inactive C3 to active C3b, C3b which leads to? (answers on next slide) 1) kill foreign cells via pore formation of plasma membrane = membrane attack complex (MAC). (MAC) 2) Enhancement of phagocytosis = opsonization 3) Histamine release via mast cells + basophils enhancing/regulating inflammation. inflammation 4) Chemotaxis – recruit phagocytes. phagocytes MPs: Function to compliment immune function. Localized tissue response to injury; common signs? Redness, swelling, heat, and pain Caused by impact, abrasion, distortion, chemical irritation, infection, and extreme temps. ◦ All disrupt normal IF composition signaling inflamm. Cell death due to environmental causes = necrosis. necrosis. Multiple effects: effects 1) Temporary barrier/repair provides protection against pathogens 2) Slows spread of pathogens 3) Mobilize defense to destroy pathogens 4) facilitate tissue repair (regeneration regeneration) regeneration 5) increases metabolism (cell activity) 1) Mast cells release histamine + other chemicals. 2) Abnormal cond. + chemicals stimulate neurons ◦ Causes pain 3) Increased blood flow = redness + heat ◦ heat helps denature foreign proteins; enhances metabolsm 4) Clot forms sealing area ◦ Prevents cell movement 5) Phagocytes clean area 6) Tissue regeneration occurs Body temperature set above 99.5°F Requires pyrogens = circulating proteins that target hypothalamus to raise body temp. temp Functions to: ◦ Increases metabolism (increases cell movement + enzymatic reactions) ◦ Inhibits viral + bacterial growth via high heat ◦ Tissue defenses mobilized and repair sped up. up These 7 make up our innate (nonspecific) immunity. immunity Neutrophil – 1st on scene, attack bacteria (phagocytic), die after initial attack. Eosinophil – attacks parasites (phagocytic), responsible for allergic reaction, very low numbers. Monocytes (in circulation) or Macrophage (w/in tissues) – main phagocytic warriors, attack everything, don’t die after initial attack. attack Basophil – NOT phagocytic – release heparin (anticoagulant) and histamine (inflammation).