Allergy

Question 1

cellular mechanism of Type 4 Hypersensitivity

Answer 1

antigen activates macrophages, releasing IL-12 to activate CD4+ T cells

sensitised T cells release IFN-g, IL-2 and IL-3 causing CD8 T cells to activate and macrophages to release TNF-a

Question 2

examples of Type 4 hypersensitivity

Answer 2

contact dermatitis
multiple sclerosis (T4S to myeline basic protein and proteolipi protein)
rheumatoid arthritis (reaction to the synovial membrane)
T1 DM (reaction to beta-cell proteins)