Innate Immunity Activation Lecture Flashcards
(62 cards)
Innate defensive components:
Anatomic & physical barriers
effectors: skin, mucous membranes, temperature, acidic pH, lactic acid, chemical mediators
Innate defensive components:
Immune cells
effectors Granulocytes: phagocytosis, release of mediators. macrophages: phagocytosis, release of mediators, Ag presentation
Innate defensive components:
Inflammatory mediators
effectors: complement, cytokines, lysozyme, acute-phase proteins, leukotrienes and prostaglandins
function: lysis of pathogens, activation of immune cells
bacterial cells wall destruction
mediation of reponse
vasodilation, vascular perm.
Skin: mechanical/Chemical/Microbiological roles
M: flow of fluid, perspiration, sloughing off skin
C: Sebum (contains fatty acids, lactic acid, lysozyme)
M: normal flora of the skin
Gastrointestinal tract: mechanical/Chemical/Microbiological roles
M: Flow of fluid, mucus, food and saliva
C: acidity, protease enzymes
M: normal flora of the GI
Resp. Tract: mech/chem/micrbio roles
M: flow of fluid, mucus, cilia by air flow
C: lysozyme in nasal secretions
M: normal flora of rest t.
Urogenital tract
M: flow of fluid, urine, mucus, sperm
C: acidity in vaginal secretions/sperm
M: normal flora
Eyes
M: flow of fluid
C: lysozyme in tears
M: normal flora of the eyes
“natural immunity” is associated with which aspect of the immune system?
innate
What does “PRP” represent for innate immunity?
Phagocytosis
Recruitment
Presentation
Neutrophils: high lighted points
1) first cells to arrive at site of tissue damage
2) activation leads to respiratory burst and release of granules to control bacterial growth
Macrophages: high lighted points
Engulf organisms
Release inflammatory mediators
THEY DO NOT LEAVE THE TISSUES
Eosinophils: high lighted points
contain cationic granules (basic protein, peroxidases, antimicrobial proteins)
fight HELMINTHES and multicellular parasites
NK cells: high lighted points
large, granular lymphocytes that kill infected host cells by cytolytic mediator perforin
Neutrophils and Monocytes
Where they arive, how they get to sites of inflammation/infection
they arise in bone marrow
they are ready to be activated, and do not require activation
How do neuts and monocytes physically access tissues where they are recruited?
they are recruited through post-capillary venules EXCEPT for parenchymal tissues like lungs, liver, kidneys
where all WBCs enter through capillaries
name the 3 functions of myeloid leukocytes
elimination of infectious pathogens
clear dead tissues
repair the damage
“how neutrophils come into the tissues”
inflammation activated endothelial cells express which selectins? and in response to what?
E and P selectin
P selectin arises in response to histamine
E selectin arises in response to IL-1 and TNF from Macrophages
both P and E are used by monocytes and neutrophils
“how neutrophils come into the tissues”
Chemotaxis the 4 general steps
1) Neutrophils “slow down and roll” along endothelium
i. selectin-selectin co receptor interactions
2) tight binding
i. integrins (on leukocytes) and integrin ligands (on
endothelia)
3) Diapedesis
i. transmigration through endothelium
4) Chemoattractant controls migration (IL-8 controls neutrophil migration to inflammatory sites)
LFA-1
What is it?
What is its receptor?
neutrophil integrin (low affinity integrin-1)
its affinity for its ligand increases as chemokine IL-8 binds to chemoattractant receptor on cell
ICAM-I is LFA-1’s receptor
ICAM-1
neutrophil integrin LFA-1’s endothelia receptor
Transmigration of Leukocytes “big” picture steps
1) capture: mediated by selectin
2) rolling: mediated by selectin
3) activation: IL-8 (neutrophils), MCP-1 (monocytes)
4) arrest: VCAM-1 (Baso/Eosino/Mono), ICAM-1 (neutro)
5) firm adhesion VCAM-1, ICAM-!
6) transmigration
IL-8
mast cell released chemoattractant for neutrophils
ICAM-1
endothelial neutrophil integrin receptor (LFA-1)
