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Innate vs adaptive immunity Mike Kemeny Professor of Immunology, GKT School of Medicine and Dentistry, King’s College, London, UK Textbooks Janeway & Travers Immunobiology Abbas Lichtman Pober Cellular & Molecular Immunology Peakman & Vergani Basic and Clinical Immunology Various Roitt textbooks Useful web sites and reading 1. Immunologic Diseases http://www.mic.ki.se/Diseases/c20.html excellent resource A comprehensive list of links to websites related to immune diseases. 2. The PathoPlus Page http://pathoplus.com/newpage7.htm Good introductory lectures on cells of the immune system and inflammation. 3. The Macrophage Home Page http://www.path.ox.ac.uk/sg A recently updated introduction to the cells of the mononuclear phagocyte family. 4. Antigen Presentation http://www.ultranet.com/~jkimball/BiologyPages/A/AntigenPresentation.html A nice introduction to antigen presentation, part of Kimball's Biology Pages. 5. Clinical and basic Immunology tutorials http://www.ozemail.com.au/~davidful/Net_Path_Immunology/tutes.html What is the immune system for 1. Protect against pathogens 2. Eliminate damaged or malignant cells Virus Role of the immune system is Parasites to protect from: Tapeworms Influenza Polio mellitus Malaria Helminths Fungi Bacteria Candida albicans Tubercule bacillus Staphylococci Innate immunity Immediate protection Low specificity broad reactivity Important for first exposure The innate immune system Physicochemical barriers: Skin, mucus, cilia Secreted agents: Lysozyme, acidic pH, saliva, urine Protective organisms: Commensal bacteria Phagocytic cells: Macrophages, Neutrophils secrete free radicals (superoxide and cationic proteins) Natural Killer (NK) cells Cell wall proteins Bacterial DNA DANGER! Bacteria Activated dendritic cell (DC) Features of pattern recognition: • Conserved receptors and ligands • Invokes same response in immune system • You are born with it (innate) Comparison of Innate and Adaptive immune system Innate Adaptive Receptors/ ligands Conserved Diverse Grade of response Invariant Modulated (ie memory) Age Fully mature at birth Immature at birth The innate immune system Ligands that bind pathogens: Pattern recognition receptors (Toll like receptors, mannose receptors) Secreted agents: Complement activation: Interferon (IFN) a, b, g Alternative pathway secretion of anaphylatoxins C3a and C5a The adaptive immune system Later protection High specificity Important for lasting protection Components of the adaptive immune system Molecules: Antibody Complement Cytokines Cells: Lymphocytes (T & B cells) Natural Killer cells Monocytes/Macrophages Dendritic cells Neutrophils & Eosinophils Basophils/Mast cells Cells of the immune system • B cells • T cells • NK cells • Monocytes/macrophages • Neutrophils • Eosinophils • Basophils/Mast cells Origin of cells involved in the immune response Myeloid progenitor Haemopoietic stem cell Monocyte Lymphocyte progenitor Macrophage Basophil Dendritic cell Neutrophil B cell NK cell Thymus Mast cell CD8 T cell CD4 T cell Plasma cell Eosinophil What is the immune system A collection of cells and molecules that protect the body against infection, malignancy and damaged cells Antigen 1. A molecule that can be recognised by the immune system 2. Usually foreign to the body although our own molecules can serve as antigens 3. Proteins eg: Grass pollen, egg albumin. bacterial endotoxin, 4. Haptens eg: proteins Nickel salts which bind to Antibody 1. Specialised molecules that recognise and bind to antigens 2. All antibodies are immunoglobulins B Lymphocytes Qui ck Ti me™and a GIF dec om pres sor are needed to s ee th i s pi c tu re. BBcell cell 10% of blood mononuclear cells Make immunoglobulin (antibody) Each B cell only makes antibody of one specificity B cells that make antibody are called plasma cells Plasma cell Immunoglobulin Epitope Combining site Antigen Light chain Hinge Heavy chain