Activation of Innate Immunity Flashcards
Anatomic and physical barrier effectors?
skin and mucous membranes, temperature, acidic pH, lactic acid, chemical mediators
Function of anatomic and physical barriers?
limit entry, spread, and replication of pathogens
Effectors of immune cells?
granulocytes and macrophages
function of granulocytes
phagocytosis, release of mediators
function of macrophages?
phagocytosis, release of mediators, Ag presentation
Effectors/Inflammatory mediators
complement, cytokines, lysozyme, acute-phase proteins, leukotienes and prostaglandins
function of complement
lysis of pathogen
function of cytokines
activation of immune cells
function of lysozyme
bacterial wall destruction
function of acute phase proteins
mediation of response
function of leukotrienes and prostaglandins
vasodilation and vascular permeability
Immune responses of innate immune system provide natural immunity via what 3 processes?
- phagocytosis and intracellular killing
- recruitment of other inflammatory cells
- presentation of antigens
what are the leukocytes?
neutrophils, monocytes and tissue macrophages, and eosinophils
natural killer cells are what kind of cells?
lymphocytes
NK cells
are large granular lymphocytes that kill infected host cells by a cytolytic mediator perforin
Neutrophils
first cells to arrive at site of tissue damage
activation of neutrophils lead to
respiratory bursts and release of granules to control bacterial growth
Macrophages
engulf organisms via multiple mechanisms
macrophages release?
many inflammatory mediators
Eosinophils
contain cationic granule proteins; fight helminthes and other multicellular parasites
Inflammation activated endothelial cells increase expression of?
E-selectin and P selectin adhesion molecules
First step in leukocyte extravasation
slow down and roll along endothelium
Second step in leukocyte extravasation
tight binding: integrins (leukocyte and endothelial cells)
Third step in leukocyte extravasation
diapedesis: migration thru endothelium
Forth step in leukocyte extravasation
IL-8 controls migration of neutrophils to inflammatory sites
Neutrophils contain what within their granules?
Cathepsin G, defensins, BPI, Lysozyme and lactoferrin
Lysozyme and lactoferrin
bactericidal or bacteriostatic proteins
BPI
increase permeability of bacterial membrane
Defensins
cationic (rich in Arg) antibiotic peptides:
- insert into microbial membranes-> destabilize ion channels
- Effect against gram positive and negative bacteria, fungi and enveloped viruses
Mononuclear phagocytes arise from?
precursors in bone marrow
Circulating mononuclear phagocytes?
monocytes
In tissues monocytes become
macrophages
macrophages may be activated by
microbes or microbial products
once monocyte become macrophages they can do what two things?
Differentiate or activate