Inflammation and Leukocyte migration Flashcards
What are 4 symptoms of the inflammatory response
redness (rubor), heat (calor), swelling (tumor), and pain (dolor)
-also loss of function
What class of molecules are crucial for leukocyte-tissue interactions during inflammation?
Cell adhesion molecules (CAM)
What are 4 members of the CAM class
selectins, integrins, mucins, and immunoglobin-superfamily CAMs
4 steps of the basic inflammatory response following a cut or other tissue trauma
- Tissue damage and bacteria cause resident sentinel cells to release chemoattractants and vasoactive factors
- increase blood flow and permeability in the area - Influx of fluid (exudate) and cells into area
- Neutrophils and other phagocytes migrate by chemotaxis to the site of inflammation
- Phagocytes and antibacterial substances destroy bacteria
What causes bloodstream leukocytes to recognize the site of infection?
Interactions between selectins and mucins as well as integrins binding to CAMs on the endothelial cells
What is the composition of selectins and what is their role?
Glycoproteins that bind specific carbohydrate groups via lectin-like domains
What is the composition of mucins and what is their role?
Mucins are glycosylated proteins that present carbohydrate groups (like sialyl-Lewisx) to selectins
What is the composition of integrins and what is their role?
Cell surface heterodimeric proteins
Bind extracellular matrix molecules and intracellular cell adhesion molecules (ICAMs)
What are ICAMs? `
Immunoglobulin superfamily of glycoproteins that bind integrins
What is one important member of the Mucin-like CAM family?
MAdCAM-1
What is one important member of the Ig-superfamily CAMs?
VCAM-1
What are 3 important members of the Integrin family?
VLA-4, Mac-1, LFA-1
What are 3 general jobs of chemokines?
Control leukocyte adhesion, chemotaxis and activation
What is the mode(s) of chemokine expression
they are constitutively expressed but also produced in response to inflammation
What are the 2 subgroups of chemokines and what is this distinction based on?
CC and CXC subgroups based on the amino acid composition
What is the general structure of a chemokine receptor?
7 transmembrane proteins that signal via heterotrimeric G proteins
Each receptor can bind more than one chemokine
Which subgroup does MIP-1a belong to and what is its role?
MIP-1a:prevents the monocyte from leaving once it enters the tissue
Belongs to the CC subgroup (CCR5)8
What activates neutrophils?
Chemokines like IL-8