Lecture 15: Cytokine Signals Flashcards
Cytokine signaling function
-macrogphages to induce cell migration
-B cell development for Igs
-blood differentiation
-T cell activation
-cell proliferation
-wound healing
Expression of cytokines and receptors
-highly regulated
-control pro and anti inflammatory response
Macrophage release of chemokines induces
neutrophil migration
Neutrophil migration
-innate immunity
-infection activates macrophage to release chemokines that recruit cells
-IL-1B, TNF-a, IL-6, CXCL8, IL-12
-all lead to inflammation
Cytokines released from macrophages
-IL-1B
-TNF-a
-IL-6
-CXCL8
-IL-12
IL-1B and TNF-a
-increase blood vessel permeability
-allow cells and fluid to enter infected tissue
IL-6
-induces fat and muscle metabolism
-raise temp in tissue
CXCL8
-recruits neutrophils from blood and guides them to tissue
IL-12
-recruits/activates NK cells that secrete cytokines that strengthen macrophage response
Neutrophil in absence of infection
-circulate in blood
-rolling adhesion on selectin
selectin
-glycoproteins that weakly bind to sialyl-Lewis X carbs on neutrophills in blood stream
=rolling adhesion
Neutrophil recruitment
- Rolling adhesion
- Tight binding
- Diapedesis
- Migration
ICAM-1
-cell-adhesion molecule
-induced by TNFa
-binds LFA-1 on neutrophils
Tight binding
-ICAM-1 initiates binding to LFA-1 integrin on neutrophils
Diapedesis
-after binding LFA-1, neutrophils can cross endothelium
Migration
-CXCL8 secreted by macrophages directs neutrophils across endothelium and to the tissue
-moves along gradient of CXCL8
monocytes (premacrophage)
-similar process to neutrophils
-recruited by CCL2
CXCL8 is a chemokine because
it promotes movement of various immune cells in a certain direction
Cytokine Receptor families (excluding chemokine/GPCR)
-TNF
-Type I and II cytokine receptors
-IL-1
-IL-17
TNF receptor family
-trimeric cysteine
-TNF-a
-fibronectin domain
Type I and II families
-both have JAK/STAT pathways
-IL-6
-cysteine