4.1 (Quiz 1) Flashcards
First line of defense, rapid activation/response (immediately present)
Innate Immune System
Broadly distinguish self from non-self using PRRs
Innate Immune System
No memory
Innate Immune System
Subsequent response will be largely unchanged
Innate Immune System
Recruited response (delay) when innate response cannot control/eliminate
Adaptive Immune System
Highly specific using antigen specific T and B cell receptors
Adaptive Immune System
Immunological memory
Adaptive Immune System
Subsequent response is fast and will be improved
Adaptive Immune System
Tissue resident sensors of invasion
macrophages, dendritic cells, and mast cells
Serve as sentinel sensors of cell stress
tissue resident sensors
Tissue resident sensors of invasion form an important
first line defense barrier
Tissue resident sensors of invasion elicit
neutrophil recruitment to site of injury from blood stream
Up-regulation of adhesion molecules on endothelial cells is induced by
inflammatory mediators (i.e. TNF, IL-1
Pre-formed receptors (___) bind to structures that occur on pathogens (___) — NOT present on human cells
PRRs, PAMPs
Toll-like receptors (TLRs) located in endosomal membranes of cells recognize:
nucleic acids
PRRs are encoded by
germ-line DNA
Canonical inflammatory pathway
NF-kB:
Transcription factor that increases expression of proteins involved in acute inflammation
NF-kB:
Important bridge to trigger adaptive immune response
NF-kB:
Alternative pathway triggered by viral infections
Interferon regulatory factor (IRF)
Triggers production of type 1 interferons (IFN alpha, beta)
Interferon regulatory factor (IRF)
Induces an anti-viral state in neighboring cells
Interferon regulatory factor (IRF)
inhibits protein synthesis/viral gene expression, degrades viral RNA, enhances killing by NK cells
Anti-viral state
Inflammasome activation results in formation of
active caspase 1
Proteolytic cleavage of pro-IL1β and pro-IL18 into
active IL1β and IL18
inflammatory programmed cell death
Pyroptosis
Pyroptosis of macrophages and dendritic cells cause release of
IL1β and IL18
O2 —> H2O2 by SOD (NADPH oxidase system):
oxidative burst
contain bactericidal and cell degrading enzymes (MPO)
Lysosomal granules
catalyzes formation of bleach
MPO
most efficient bactericidal system in vitro
H2O2-MPO-halide:
molecules that label foreign materials and invaders for better recognition and destruction by phagocytes
Opsonin
most important factor of complement system
C3
split product C3b
Powerful opsonin
Activation of complement results in 3 effector functions
initiation of Inflammation, pathogen opsonization, pathogen lysis
leukocytes migrate towards site of injury along chemical gradient of chemo-attractants
Chemotaxis
stimuli that can act as chemoattractants
Exogenous and endogenous:
Most chemotactic agents signal via
G-protein-coupled 7 transmembrane receptors
Intracellular signaling event leads to
directional filopodia formation
Scan for normal cells and kill abnormal cells (“altered self”)
Natural killer cells:
Important for defense against viral infections, malignancy
Natural killer cells:
Killer cells of innate immune response
Natural killer cells:
Contain cytotoxic granules
Natural killer cells:
Major source of IFN-g
Natural killer cells:
Perforin and granzyme release
Natural killer cells:
Survey targets via invariant inhibitory and activating receptors
Natural killer cells:
NK cell activating cytokines (4)
Type-I-IFNs, IL-12, IL-15, TNF-α
tissue resident and respond to stimuli via secretion of histamine
Mast cells
very low numbers in blood
Basophils
kill parasites and promote allergic inflammation
Eosinophils
