Immune Cell Movement and Chemotaxis Flashcards
What does interstitial leukocyte movement result from?
Amoeboid polarization and migration
Name the 4 types of cell movement.
- Random migration (undirected, spontaneous)
- Chemokinesis (stimulated, undirected)
- Chemotaxis (stimulated, direct) - directed movement of cells towards or away from a diffusible chemical
- Haptotaxis (directed) - directed movement of cells along a gradient of substances bound to the substratum or ECM, analogous to chemotaxis, but the attractant is not diffusible but bound to the substratum or ECM.
Give an example of an exogenous chemoattractant.
Bacterial oligopeptides such as F-met-leu-phe (FMLP), that attracts and activates circulating blood leukocytes by binding to specific GPCR on these cells
Give an example of endogenous chemoattractant.
Humour - (e.g. complement fragments, kallikrein)
Cellular - (e.g. leukotriene B, chemokines, platelet activating factor)
Name the 6 steps of recruitment of leukocytes from blood into tissues.
- Capture
- Rolling
- Activation
- Adhesion
- Diapedesis
- Migration
Which selectins are involved in recruitment of neutrophils, monocytes, NK cells, effector T cells?
P- and E- selectin
Which selectin initiates naive T-lymphocytes capture events in high endothelial venules in secondary lymphoid tissues?
L-selectin
What is the principal ligand on TH17 cells for E-selectin?
Leukosialin (CD43)
Name some types of integrins.
ICAM-1 and VCAM-1
Where are chemokines stored?
Weibel-Palade bodies in endothelial cells
Where are CCR2 receptor found?
On monocytes, T cells
Where are CCR5 receptor found?
Monocytes and T-lymphocytes
Name the 4 subfamilies of chemokine receptors.
- CC chemokine receptors
- CXC chemokine receptors
- C chemokine receptors
- CX3C chemokine receptors
What is the process in which leukocytes move within the tissue called?
Extravasation
Where are dendritic cells located?
Epithelia and subepithelial tissues - also present in T-cell rich areas of peripheral lymphoid organs
