MICROB 2300 1nd Edition Lecture 4 Outline of Current Lecture I. Immuno-logicII. Organization of Host Defense SystemIII. Immune Responsea. Innate Immunityb. Adaptive Immunityc. 3 lines of defenseCurrent Lecture1. Immunology Questionsa.What is the nature and function of innate (natural) immunity? b.What is the nature and function of acquired (adaptive) immunity? c.What is an inflammatory response?d.What are macrophages, neutrophils, eosinophils, mast cells and dendritic cells and what do they do?e.What is self and how is it recognized by immune cells? f.How does the pathogen determine the type of immune response?g.What are B cells, CD4+ T cells and CD8+ T cells and how do they recognize andrespond to antigen?h.What is humoral immunity and what is cellular immunity?i.How does the immune system respond against allergens?j.What are cytokines and chemokines and how do they influence the type of immune response that is generated?k.What occurs when the immune system fails to develop or when the immune system overreacts in an immune response?These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.l.How does vaccination induce adaptive immunity?m.How does the immune system respond to pathogens without inducing autoimmunity?n.What are some basic causes of immune pathology?2. Does these immune system kill you of cure you?a. Wouldn't be alive without it3. Immuno-logica. A pathogen can cause disease only if it cani. Gain access to bodyii. Attach itself to host cells1. Helps get in or functionsiii. Evade our health systems long enough to cause harmful changesb. Therefore the immune system has developed specific functions to prevent pathogens from achieving these pathological events4. Organization of host defense systema. Two Arms of Immune Systemb. Innatei. ii.iii.iv. Born withv. All animals within species have same & setc. Adaptive i. Acquiredii. Based on what you experience in your life5. First line of defensea. Barrieri. Physical, chemical, or mechanical, or Microbiomeb. Skin, gut, lungs, eyes, & nose are most directly exposedc. Skin has tight junctionsd.e. Fatty acids are very toxic to bacteriaf. Low pH i. Kids don't have body odor, pH changes at puberty 6. Second line of defensea.b. Starts on inside of bodyc. Lymphatic system & circulatory system covers whole bodyi. Lymph nodes1. Central location that covers an area, overall covering whole body2.7. Immune systema. Cells develop from common progenitorb. NK-natural killer cells8. Basic properties of immune receptora. 2 arms of immunei. Innate1. First and second line of defense2. Keep everything from getting to the body3. Localized in interface between body & outside worldii. Acquired1. Third line of defense2. Localized within secondary lymph node compartmenta. Spleen9. 3 phases Of host defense a. We only want to activate when we need it10. Graph of immunea.b. Cyto something's get turned onc. Virus lowers levels of MHC to hide from immune system 11. Recognition of pathogens leads to the activation of an immune responsea. Cells of immune system can:i. Kill invading pathogensii. Can kill good cellsiii. Block adhesion & entry into cellsiv. Kills cells infected with bacteria, parasite or viruses. 1. Our cells thoughv. Kill cancer cellsb. How does immune know we have infection?c. How can immune tell difference between us & immune?i. Receptors on cells provide the ability to discriminate self from non-self12. Receptorsa. Insert picture (don't memorize)b. Innate immune is coded in immune 13. Innate immune receptorsa. Different immune response to bacteria than virus14. T and Ba. Box is genetic componenti. Top lef1. Can combine 10^20 different ways15. Adaptive immune receptorSa. T cellsi. "Princesses" ii. Green rods foreigniii. Detect a lotb. CTLi. Signal body to killii. Kill intracellular pathogensc. B celli. Detect proteins16. Self non-self discrimination at the heart of a health immune responsea. Recognition of 'non-self' activates an immune responsei. Innate immune system cells recognize broad classes of microbial specific components1. Pathogen associated molecular patterns (PAMPS)ii. Adaptive immune cells recognize & differentiate specific mols on specific pathogens1. Antigenic epitopes expressed by pathogen1. Identity of cellular components/functions of adaptive immunity1.2. Composition & life cycle of a pathogen determines the type of immune responsea. 2 armsi. Humoral immunity1. Most effective against extra cellular microorganisms2. Humoral effector cellsa. B lymphocytesi. Produce antibodiesii. Cellular immunity1. Most effective against intracellular microorganisms2. Cellular immunity effector cellsa. T lymphocytesi. Produce cytokines or function as effector cellsiii. Help each other3. Classes of lymphocytes & their effector functionsa. Regulatory T lymphi. Suppress immune response to keep us from fighting ourselvesii. "Calms everyone down"iii. Prevents over activating 4. Goals of adaptive immune responsea. Provide a pathogen specific responsei. Directed against one pathogenii. Adapted to life cycle & route of entry of pathogeniii. Diversity of responding cells limits pathogen escapeb. Generation of long term memoryi. Enhanced response on repeated exposure to provide long term protection against infection with the same pathogen (secret to how vaccines work)5. Kinetic course of immune responsea. Memory B cells at antigens A+B line6. Outline of protective immunitya. Ultimate goal is provide long-term (life-long) protection against re-exposure to a specific pathogeni. First person in family doesn't get sick again when around family they infected7. Vaccines induce a memory response to fight diseasea. Artificially induce immune responseb. Ex small poxi. Very large virusii. Easy to targetiii. Only reservoir in nature was humans8. What if immune system is broken?a. Primary & secondary immunodeficiency leads to severe defects in immunei. Lack of functioning immune system leads to deathb. Defects in the regulation of development & or activation of the immunec. Cells of immune can basically kill any cell in body9. Abnormal immune functiona. Lack of Tolerance (central or peripheral), over exaggerated responses, absence of response are three basic causes of abnormal immune function.i. Hypersensitivities1. Exaggerate immune responsesii. Autoimmunity1. Immune responses to self/cells or tissueb. Immunodeficienciesi. Primary1. Genetic disorder-failure