Leukocyte Trafficking Flashcards
recruitment of immune cells into tissues occurs in _
post-capillary venules
post-capillary venules
thinnest walls and lowest BP
recognition of bacteria by macrophages stimulates _
expression of adhesion molecules on endothelial cells
selectins
slow rolling
ICAM-1
adhesion (binds beta-2 integrin on immune cell)
chemokine receptor on immune cells binds _
chemokine on endothelium for leukocyte activation –> changes conformation of beta-2 integrin to allow it to bind to ICAM-1
chemoattractants on endothelial cell surface
chemokines, platelet activating factor, TNF-alpha, IL-1b, IFN-gamma
Which chemoattractants guide immune cells to site of inflammation?
LTB4, IL-8, C3a and C5a
selectins bind _
mucin-like CAMs
Ig-superfamily CAMs bind _
integrins (mainly LFA-1 and Mac-1)
Ig-superfamily CAMs
ICAM-1,2,3 and LFA-2,3
mucin-like CAMs
CD34, glyCAM-1
post-capillary venules in lymph nodes
HEV (high endothelial venules)
immature DC pathway
internalize antigens –> lose E-selectin binding –> travel through afferent lymph into lymph node –> move to paracortical region –> present antigen and die
naive T cells
express L-selectin which binds PNAds in HEV
L-selectin on T cells binds _
GlyCAM and CD34 and PNAd (on HEVs) for slow rolling
chemokine activation of T cells
CCL21 (SLC) binds CCR7 on T cells
LFA-1 on T cells binds _
ICAM-1
chemokines for diapedesis
CXCL12 on endothelium binds CXCR4 on T cells
CCL21 (SLC)
binds CCR7 on T cells for integrin activation
CCL19
also binds CCR7 but not on HEVs
What happens after T cell encounters its ligand (antigen) in the lymph node?
it will lost the ability to leave and begin to proliferate in T cell zones –> will then express CXCR5 allowing them to migrate to primary follicles to activate B cells
What happens once a cell is an effector T cell?
it loses its expression of L-selectin and can no longer enter HEV
central memory T lymphocytes
re-express L-selectin and localize to secondary lymphoid organs
L-selectin is _
CD62L