BIOM 250n 1st Edition Lecture 14Outline of Last Lecture I. Membrane-Disrupting ToxinsII. SuperantigensIII. EndotoxinsIV. Plasmids and Lysogeny Outline of Current Lecture I. Concept of ImmunityII. Recognition III. CommunicationIV. Innate Immune CellsCurrent LectureI. Concept of Immunity:a. Immunity: ability of an organism to destroy or inhibit pathogenic agentsb. Susceptibility: inability to fight off pathogenic invaders, toxins, or environmental agentsc. Resistance: ability to fight off pathogensd. Innate immunity: non-specific; immediate responsee. Adaptive immunity: specific; slower response; immunity to a specific pathogen develops after initial exposuref. Basic components an immune system should have:i. Barriers to keep invaders outii. An ability to recognize invaders as foreigniii. Methods to attack invaders that get past the barrieriv. Systems to remember past attacks and prevent them from happening againv. Mechanisms to shut off the immune response when the job is completeg. Physical/Chemical factors: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.i. Eyes: tears produced to wash out particles and lysozyme in the eye has antibacterial propertiesii. Saliva: washes away particles and digests some foodsiii. Mucus: traps particles and can contain antimicrobial agentsiv. Bladder: urine flow removes microbesv. Vaginal secretions: flow removes microbes; low pH inhibits pathogensvi. Normal flora: not technically part of the immune system (still research being conducted) but play a role in defenseII. Recognitiona. Ability to tell self-cells from foreign, or non-self, cellsb. Must be able to bind to and identify foreign cells/substancesc. Immune cells with receptors:i. Certain immune cells have toll-like receptors (TLR’s) on their surface1. Ex: macrophages and dendritic cellsii. Receptors bind to microbial structuresIII. Communicationa. A single immune cell is unable to do much against multiple bacteriab. After contact and recognition immune cells produce soluble signal moleculesi. Ex: cytokines; regulator proteinsc. Cytokines recruit other cells to the site and activate other defensesIV. Innate Immune Cellsa. Blood components: i. Cells and fluid (plasma)ii. Red blood cells—carry oxygeniii. White blood cells—aka leukocytesiv. Platelet: blood clotting factorsb. Leukocytes have 2 main groups: granulocytes and agranulocytesc. Granulocytes: have many easily stained granules that are visible with a light microscopei. Types of granulocytes:1. Neutrophils: highly phagocytic and motilea. Active in initial stage of infectionb. Have the ability to leave the bloodstream and enter tissues2. Basophils: granules contain histaminesa. Induce inflammation and allergic reactions3. Eosinophils: weakly phagocytic, produce toxic proteinsa. Important in attack of parasitesb. High numbers in the blood can indicate a parasitic infectiond. Agranulocytes: granules are not visiblei. Types of agranulocytes:1. Monocytes: immature macrophagesa. Phagocytic when mature and found in tissues2. Dendritic cells: monocyte-derived, phagocytic in tissuesa. Can initiate adaptive immune response3. Lymphocytes: natural killer (NK) cells can kill damaged self and tumor cellsa. Binds to target cell, perforates the membrane or causes programmed cell death4. T cells can be in the lymphatic system and communicate/activate adaptive immunity5. B cells are antibody producing