Introduction The innate immune system provides the first line of defense against pathogens It consists of multiple lines of defense including login to view 3 more bullets The innate immune system is broadly effective but not adaptive because login to view 2 more bullets The innate immune system interacts with the adaptive immune system in important ways such as login to view 2 more bullets Innate Immune Activation The innate immune system recognizes pathogen-associated molecular patterns (PAMPs) PAMPs are structures that are conserved among large pathogen classes including login to view 3 more bullets PAMPs are not present on mammalian cells ensuring that login to view 2 more bullets PAMPs are detected by diverse pattern recognition receptors (PRRs) that login to view 2 more bullets The Acute Inflammatory Reponse The acute inflammatory response is triggered when login to view 2 more bullets The acute inflammatory response consists of login to view 3 more bullets The soluble protein response is known as the acute phase reaction login to view 1 more bullet The protein components of the acute phase reaction consist of login to view 10 more bullets Neutrophils are recruited in a coordinated fashion After arrival, neutrophils perform a variety of actions including login to view 2 more bullets Neutrophil Recruitment Neutrophil recruitment is a key part of the innate immune response because they login to view 3 more bullets Neutrophil recruitment is a tightly coordinated process Steps Involved in Neutrophil Recruitment Stage Purpose Mediators Magination Dilates blood vessels around areas of damage Allows blood to flow slowly in potentially infected areas Nitric oxide Other vasoactive substrances Rolling Loose attachment of neutrophils to vessel walls Concentrates neutrophils near the endothelial cells of areas that have been previously damaged Selectins Glycoproteins Adhesion Tight attachment of neutrophils to the epithelium Stops the movement of neutrophils and primes them for further activity LFA integrins ICAM proteins Extravasation Diapedesis of neutrophils across vessel wall Localization of neutrophils to region of damage Integrins Pseudopodia Chemotaxis Extravascular attraction of neutrophils to pathogens Migration of neutrophils to sites of highest pathogen concentration IL-8 C5a Leukotriene B4 5-HETE Formyl-methionyl peptides Effector Mechanisms Three key effector mechanisms used by the innate immune system include login to view 3 more bullets Opsonization is the process by which effector mechanisms are enhanced by login to view 2 more bullets Phagocytosis is the process by which pathogens can be degraded and includes login to view 4 more bullets Reactive oxygen species are toxic metabolites that are login to view 2 more bullets Enzymes Involved in Reactive Oxygen Species Metabolism Activators Function Inhibitors Function NADPH oxidase Transform oxygen into superoxide radicals Glutathione peroxidase Inactivation of hydrogen peroxide into water by oxidizing glutathione Superoxide dismutase Transform superoxide radicals into hydrogen peroxide Glutathione reductase Reduction of glutathione to original state by oxidizing NADPH to NADP+ Myeloperoxidase Transformation of hydrogen peroxide into hypochlorite (bleach) Final toxic compound used to damage pathogens G6PD Reduction of NADP+ to original state via the hexose monophosphate shunt