Hypersensitivity

Question 1

What are the chemokines that mast cells release (and their roles)

Answer 1

MIP-1alpha (CCL3)
- chemotactic for mono, macro, neutro, T cells, eosino

RANTES (CCL5), Eotaxin (CCL11)
- chemotactic for t cells and eosino

Question 2

What are the cytokines that mast cells release (and their roles)

Answer 2

IL-3,4,5,13 GM-CSF, TNF

3, 5 and GM-CSF
- survival and activation of eosino

4, 13
- involved with Th2 and class switching to make IgE

TNF

• some already premeade
• activates endothelial cells –> express adhesion molecules

Question 3

What are the lipid mediators that mast cells release and their roles?

Answer 3

LTC4, LTD4, LTE4

• Lead to eosino migration
• Smooth muscle contraction
• Vascular permeability
• Mucus hypersecretion

PAF

• Attracts eosinophils + Other leukocytes
• Activates PEN (platelets, eosino, neutrophiles)
• Increases production of lipid mediators

Question 4

What are the enzymes released by mast cells and their functions?

Answer 4

Tryptase
- alpha (constitutive), beta (induced with mast cell activation)
- Identifiable in serum for up to 4 hours in serum
- ONLY by mast cells (single best marker for mast cell activation)
- Leads to remodeling of connective tissue matrix
Chymase, Cathepsin G, Carboxypeptidase
- remodeling of connective tissue matrices