Innate vs adaptive immunity Mike Kemeny Professor of Immunology, GKT School of Medicine and Dentistry, King’s College, London, UK
Janeway & TraversImmunobiology Abbas Lichtman PoberCellular & Molecular Immunology Peakman & VerganiBasic and Clinical Immunology Various Roitt textbooks Textbooks
Useful web sites and reading 1. Immunologic Diseases excellent resource A comprehensive list of links to websites related to immune diseases. 2. The PathoPlus Page Good introductory lectures on cells of the immune system and inflammation. 3. The Macrophage Home Page A recently updated introduction to the cells of the mononuclear phagocyte family. 4. Antigen Presentation A nice introduction to antigen presentation, part of Kimball's Biology Pages. 5. Clinical and basic Immunology tutorials
What is the immune system for Protect against pathogens Eliminate damaged or malignant cells
Bacteria Tubercule bacillus StaphylococciFungi Candida albicans Virus Influenza Polio mellitus Parasites Tapeworms Malaria Helminths Role of the immune system is to protect from:
Immediate protection Low specificity broad reactivity Important for first exposure Innate immunity
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 The innate immune system
Bacteria Cell wall proteins Bacterial DNA Activated dendritic cell (DC) DANGER!
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 Receptors/ ligands Grade of response Age InnateAdaptive Conserved Invariant Fully mature at birth Diverse Modulated (ie memory) Immature at birth
Ligands that bind pathogens:Pattern recognition receptors (Toll like receptors, mannose receptors) Secreted agents:Interferon (IFN) Complement activation:Alternative pathway - secretion of anaphylatoxins C3a and C5a The innate immune system
Later protection High specificity Important for lasting protection 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 Components of the adaptive immune system
B cells T cells NK cells Monocytes/macrophages Neutrophils Eosinophils Basophils/Mast cells Cells of the immune system
Eosinophil Monocyte Macrophage Neutrophil Basophil Origin of cells involved in the immune response Haemopoietic stem cell B cell Thymus NK cell Dendritic cell Mast cell Plasma cell CD4 T cell Myeloid progenitor Lymphocyte progenitor CD8 T cell
A collection of cells and molecules that protect the body against infection, malignancy and damaged cells What is the immune system
1. 1. A molecule that can be recognised by the immune system Usually foreign to the body although our own molecules can serve as antigens Proteins eg:Grass pollen, egg albumin. bacterial endotoxin, Haptens eg:Nickel salts which bind to proteins Antigen
1. 1. Specialised molecules that recognise and bind to antigens All antibodies are immunoglobulins Antibody
B Lymphocytes 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 B cell
Immunoglobulin Antigen Hinge Combining site Epitope Heavy chain Light chain