BS: Innate Immunity Flashcards
Two types of defense mechanisms
Physical and bloodborne
Types of blood borne defense mechanisms
Complement cascade and phagocytes
Types of physical defense mechanisms
Skin, mucous membranes, saliva, flushing action of urine and tears, stomach acid
Critical step of Complement System
Cleavage of C3
End effect of C3A
Recruitment and activation of leukocytes; promotes inflammation
End effect of C3B
MAC, opsinization (bacteria marking for destruction)
Activation mechanisms of complement
Recognition of certain bacterial carbohydrates (Alternative)
Antibody (IgM or IgG) mediated (Traditional)
Mannose binding lectin (Lectin)
Cells of innate immune system
basophils, eosinophils, monocyte/macrophages, neutrophils, NK cells
Innate cells from Lymphoid precursors
NK cells
Innate cells from Myeloid precursors
basophil, eosinophil, monocyte/macrophages, neutrophils
PAMPs
Pathogen associated molecular patterns
DAMPs
Damage associated molecular patterns
Where innate cells are located
Reside in blood, skin, linings of ducts and the mucosal linings of the respiratory, GI and GU tracts
Speed of innate immunity versus cell mediated
Innate immunity works quickly and offers first line of defense
PRRs
Pattern recognition receptors
Pattern recognition receptors (purpose)
Recognize PAMPs and DAMPs
Pattern recognition receptors (location)
On cell and intracellularly in monocytes, macrophages, dendritic cells, fibroblasts, neutrophils and mast cells
Fibroblasts (description)
Cells that reside in the tissue below the skin
Fibroblasts (Function)
Provide some structural rigidity to skin
Provide much of the collagen and other extracellular components that give strength to skin
Toll-like receptors (description)
Surface PRRs that recognize bacterial PAMPs
C-type receptors (description)
Surface PRRs that recognize lectins (protein binding sugars) that are found on bacterial or viral surfaces
Nod-like receptors (description)
Intracellular PRRs that recognize small DNA fragments associated with bacteria
Rig-like receptors (description)
Intracellular PRRs that recognize small DNA fragments associated with viral replication
Benefits of fever during inflammation
Increased temperature helps to release the oxygen from hemoglobin so more oxygen can get to the inflammation for the myeloperoxidase system
Myeloperoxidase system (location)
Inside the phagosome of macrophages and neutrophils
Myeloperoxidase system (purpose)
Convert NADPH from the pentose phosphate pathway to generate superoxide using oxygen
Superoxide (purpose)
Produced by phagosomes to destroy microbes
