Mucosal Immunology

Question 1

Structure of GI epithelial barrier:

Answer 1

Single layer of cells with different phenotypes

Question 2

Function of epithelial cells:

Answer 2

Physical barrier between host and environment

Selective permeability of water, ions and nutrients

Secretory functions (Inate immunity):
- cytokines
- antimicrobial proteins

Question 3

Why do we develop self tolerance?

Answer 3

So we are not responsive to self antigens

Question 4

Epithelial barrier growth:

Answer 4

Lgr5+ stem cells in base of crypt

Proliferation and differentiation as move up the crypt

Cell shedding at tip

Control by signalling molecules

Question 5

Why do we develop exogenous tolerance?

Answer 5

So we are non-responsiveness to an enormous array of newly encountered environmental antigens (Food and Microbes)

Question 6

Role of IEC:

Answer 6

Sense and respond to microbes

Express PRRs

Impacts microbial diversity

Question 7

Importance for immune responses to commensal bacteria: tolerance and pathogens (active immunity)

Answer 7

Allow efficient sampling of particulate antigens to deliver to APC