Innate Immunity Flashcards
Innate Immunity
Innate. First line after physical barriers are breached (fastest acting), responds to infection and damage. Non-specific and no memory produced. Communicates with active immunity
Innate Immune Cells
neutrophil, basophil, mesophile, mast cell and monocytes (macrophage or dendritic cells)
4 key processes on innate immunity
inflammation, phagocytosis, complement and antiviral defense
Inflammation Outline
Activation and accumulation of leukocytes and plasma protein to site of infections or tissue damage. Vasodilation allows immune cells and proteins to site
Cardinal Symptoms of Infection
Heat, swelling, redness, pain and loss of function
Exudative def
blood proteins - antibodies, complement and cytokine
How do blood vessels increase permeability
Macrophages/basophils produce chemokines and cytokines, decreases the tightness of junctions of epithelia cells. Enables vasodilation
How does redness, swelling and heat occur
vasodilation
How does pain occurs
Inflammation cells moving into blood vessels releassing inflammatory mediators
Macrophages Outline
Innate immune cells in tissues of body. Very active, a lot of movement under microscope
Pathogen Recognition Receptors Outline
Surface receptors on macrophages. Looks for pathogen associated molecular patterns. Eg TLR-2s (lipopeptides, peptidoglycan), TLR-4s (lethochic acid/ theoic acid) and TLR 5 (flagellen)
Pathogen Associated Molecular Patterns Outline
carbohydrate/protein/nucleic acid sequence of molecules specific to pathogen that macrophage recognises as foreign to body. conserved on pathogen. Interaction with cells trigger inflammation response
Toll Like Receptor Signaling Outline
When stimulated results in signal transduction cascade changing gene expression. Eg increasing cytokine, adhesion molecules and costimulators (inflammation and adaptive) or INF1 production (antiviral)
Most Phagocytic Cell
Neutrophil. Recruited in high numbers to site of infection. Reach infection site 1st
Monocytes/Macrophages Phagocytosis Outline
Can phagocytose but main function is cytokine production. But it’s so big that when done it can take many at once. APC
Dendritic cells phagocytosis
APCs
Phagocytosis Process
Cell recognises microbe as foreign matter, microbe ingested into phagosome, phagosome fuses with lysosome. Microbe killed by oxygen species, nitric oxide and enzymes
Complement System Outline
Plasma proteins, circulating in blood, work together to promote inflammation, opsonization (antibodies marking cells), phagocytosis and kills microbes. Forms membrane attack complex
Complement Process
Protolytic enzymes (proteases) cleaves proteins in blood/liver, resulting in products having an effector function (inflammation/oponisation/phagocytosis)
Membrane Attack Function
Protein based pipe like structure that penetrates cell membrane and forces cell contents through. Killing cell
Antiviral Defence Outline
Innate immune defence against intracellular pathogens by natural killer cells. Natural killer cells release perforin (damage cell membrane) and granzyme (induces apoptosis). Kill infected cell stopping growth/killing pathogen
IL-12 Outline
Macrophage after phagocytosis release IL-12. IL-12 stimulates NK cells INF-gamma activates macrophages to be more active (increased INF alpha and beta)
