LMP299Y1 Lecture Notes - Lecture 9: Endothelium, Cell Adhesion Molecule, White Blood Cell

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6 May 2014
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LMP402 - Fall 2013 - Lecture 9 - Leukocyte Emigration
Leukocyte emigration in postcapillary venules consists of a series of adhesive interactions
between leukocytes and endothelial cells
Sequential binding and detachment of adhesion molecules expressed on leukocytes and
endothelial cells
1. Tethering/rolling (transient adhesive interactions)
2. Arrest
3. Firm/stable adhesion (leukocyte flattens)
4. Intravascular crawling
5. Transendothelial migration/diapedesis which can be betwen or through endothelial cells
Intravital microscopy exteriorizes a piece of tissue to examine the microvasculature
For example, cremaster muscle, frog tongue
Endothelial cell activation via IL-1, TNF, and LPS
IL-1 acts on cultured endothelial cells to increase adhesion of leukocytes, etc.
IL-1 must be added to endothelial cells at least four hours before leukocytes to see adhesion
Add immediately after, no adhesion
Treat IL-1 to leukocytes, no adhesion
Treat activated endothelial cells to protein synthesis inhibitor (actinomysin D, cyclohexaide) and
see no adhesion - this indicates that protein synthesis is required