INNATE HOST DEFENSES CHAPTER 16
Host Defenses Innate immune systems provide immediate defense against infection, and are found in all classes of plant and animal life. Adaptive immune systems composed of highly specialized, systemic cells and processes that eliminate or prevent pathogenic challenges. Thought to have arisen in the first jawed vertebrates, the adaptive or "specific" immune system is activated by the innate immune system.
Defense Barriers Physical skin/mucous membrane Chemical antimirobial substances in body fluids. Ex. Lysozyme Cellular defenses phagocytes Inflammation swelling, reddening, histamine response Fever pyrogenic Molecular defenses interferon, complement
Physical Barriers Skin- keratinized Mucous membranes
Chemical Barriers Salt pH Lysozyme Transferin Lactoferrin Defensins
Cellular Defenses - Granulocytes Basophils/Mast cells Eosinophils Neutrophils Dendritic cells most abundant migrate toward the site of inflammation predominant cells in pus store histamine, inflammatory response 1-6% of white blood cells ROS and ILs process antigen material and present it on the surface to other cells of the immune system
Cellular Defenses — Agranulocytes Monocytes Lymphocytes natural killer cells (NK cells) small lymphocytes are the T cells and B cells (1) replenish resident macrophages and dendritic cells under normal states, and (2) in response to inflammation signals, monocytes can move quickly (approx. 8-12 hours) to sites of infection in the tissues and divide/differentiate into macrophages and dendritic cells to elicit an immune response
Blood Cells
Phagocytosis Cells Involved = macrophages Process Chemotaxis Adherence Ingestion Digestion
Nucleus Cytoplasmic membrane of phagocyte Phagolysosome Myeloperoxidase NADPH oxidase Nitric oxide synthase Phagolysosome Phagocytosed bacteria
Characteristics of Inflammation Acute Inflammation Repair/ Regeneration Chronic Inflammation
Fever Exogenous/Endogenous Pyrogens Benefits/Risks Leukocyte Endogenous Mediator
Interferon Interferon protein
Complement System
Complement System
Complement — Cytolysis
Complement — Cytolysis
Non-specific Defenses