Leukocyte Migration (Exam 1) Flashcards
Term for movement of cells to infection sites to perform their function
recruitment
Term for movement of lymphocytes from maturation sites to secondary lymphoid organs where they are activated
homing
Leukocytes adhere to endothelial cells on post-capillary venules by expression of what 3 things?
- adhesion molecules
- chemokines
- chemokine receptors
Site-specific expression of ________ on endothelial cells allow effector cells to migrate into the tissues where they are needed.
adhesion molecules
2 types of major adhesion molecules
- selectins
- integrins
What is the function of major adhesion molecules?
help circulating cells identify and stick where they need to go
What 2 things do sentinel cells release when activated? And what do these things do?
- cytokines
- chemokines
activate vasculature to put up “stop signs”
How is high-affinity LFA-1 induced?
endothelial cells interact with chemokines produced by sentinel cells and they change from low to high affinity
_________ are a family of structurally homologous cytokines that stimulate movement of leukocytes (homing and recruitment).
chemokines
What letter indicates the chemokine in its nomenclature and what indicates its receptor?
L (ex. CXCL)
R (ex. CXCR)
Leukocytes get out of the vasculature and into lymph nodes through ___________.
high endothelial venules
Lymphocytes leave lymph nodes via __________, then enter _________, and then go back into the circulation.
efferent lymphatic vessels
thoracic duct
How do microbes enter lymph nodes?
via afferent lymphatic vessels
_______ weakly adheres naive T cells to high endothelial venules in lymph nodes.
L-selectin
Where is L-selectin located?
on lymphocytes
Where is E-selectin located?
on endothelium
Where is P-selectin located?
on platelets
________ and _______ weakly adhere activated T cells to endothelium at site of infection.
E & P selection (on platelets & endothelium)
_______ expression activates integrins and chemokinesis for naive T cells while _______ and _______ do it for activated T cells.
(types of chemokine receptors).
CCR7
CXCR3 & CCR5
Which integrin allows for stable stopping/arrest of naive T cells on high endothelial venule?
LFA-1 (B2-integrin)
Which two integrins allow for a stable stopping/arrest of activated T cells on endothelium at the sight of infection?
LFA-1 (B2-integrin) or VLA-4 (B1-integrin)
What does S1P stand for?
sphingosine-1 phosphate
S1P is a lipid that is high in ______ and ______ but low in _______.
blood + lymph
lymph node
What is the significance of S1P being high in blood/lymph and low in lymph nodes?
regulates T cell receptor expression to control their location
When B cells are activated, they go into ________ with the S1P receptor and enter the bloodstream.
follicles
