Mucosal Immunity

Question 1

Crohn’s disease

Answer 1

caused by underproduction of alpha defensins made by paneth cells –> commensal bacteria get in –> cause inflammation

Question 2

MIC-A, MIC-B

Answer 2

Expressed by epithelial cells under stress –> bind to NKG2D on intraepithelial lymphocytes –> activates IEL that carry CD8 alpha:alpha –> contribute to recognition of infected cell by binding directly to nonclassical MHC class 1 molecules

Question 3

NKG2D

Answer 3

Expressed on NKG2D on intraepithelial lymphocytes
Activated by binding of MIC-A and MIC-B
Contribute to recognition of infected cell by binding directly to nonclassical MHC class 1 molecules

Question 4

M cells

Answer 4

Antigens enter through M cell to get to Peyer’s patch

Question 5

CD103+ DC

Answer 5

In Peyer’s patches and mesenteric lymph nodes

Induce CD4+ regulatory T cells to release TGF-beta and retinoic acid

Question 6

IL-10

Answer 6

anti-inflammatory

Question 7

TGF-beta + IL-10

Answer 7

Induce T cells to become FOXP3 regulatory cells –> suppress inflammation –> become toleragenic

Question 8

CD11b+ DC

Answer 8

In Peyer’s patches –> induce differentiation of T cells that produce TGF-beta and IL-10

Question 9

TGF-beta, BAFF, APRIL

Answer 9

Made in epithelial cells –> drive B cells to turn into IgA producing cells (class switching)

Question 10

retinoic acid

Answer 10

Made by DCs in Peyers patch –> Induce IgA class switching

Question 11

TNF-alpha, NO

Answer 11

Made by DCs in lamina propria –> enhance BAFF and APRIL production

Question 12

Polymeric Ig Receptor

Answer 12

Expressed on epithelial cells –> bind IgA and IgM –> get expressed on apical face of cell by secretory component

Question 13

Which cells express Fcepsilon receptor? What does it do?

Answer 13

Mast cells, Basophils

Binds IgE –> cause cell to degranulate

Question 14

Which cells express Fcalpha receptor? What does it do?

Answer 14

Eosinophils

Binds IgA