C1.2 Structures

Question 1

Peyer’s patches are comprised of

Answer 1

Specialised follicle-associated epithelium (FAE)
Overlying a sub epithelial dome (SED)
Overlying multiple Bc follicles that contain germinal centres (GC containing Tc, Bc & APC)
- (w/in GC have) Interfollicular regions (IFR) contain Tc, high endothelial venules (HEV) and efferent lymphatics
- All lymphoid migration occurs from the blood across HEV as there are no afferent lymphatics

Question 2

describe M (microfold) cells structure

Answer 2

Specialised epithelial cells
Poorly developed brush border (don’t absorb nutrients)
No microvilli
Thin glycocalyx
Absence of hydrolytic enzymes
Express MHC class II on basolateral surface & can present antigens to B & Tc
Rich in pinocytotic vesicles
can engulfed antigen in gut
V. Easy from antigen to cross –> Primary site of antigen handling in the gut

Question 3

Describe gastic molecules involved in lumenal preprocessing

Answer 3

Gastric acid
Gastric enzymes
Pancreatic proteases (breakdown protein into smaller peptides)
Antigen is absorbed (across leminal surface) but does not evoke a response

Question 4

What is it called when dendrite pushes arm through epithelial cell

Answer 4

Antigen sampling

Question 5

How will an antigen travel taken up by peyers patch (what will it travel through)

Answer 5

Peyer’s patch > Efferent lymphatics > Mesenteric lymph node > Thoracic duct > Blood