Mucosal Immunity Flashcards
What is the function of mucosal cells
gas exchange
food absorption
sensory activities
reproduction
What happens when when a pathogen is found at one mucosal site
All other mucosal sites will also try to block the pathogen
What line the mucosa tissue to prevent infection
Secondary lymphoid tissue as mucosal tissue is the site of entry for most pathogens
What happens at the lymph node
Dendritic cells enter looking for T cells to recognise the antigen they are carrying
If the right match between dendritic and T cell is found there is an immune response
Anatomical features of the GUT mucosal immune system
intimate relationship between mucosal epithelia and lymphoid tissue
organised lymphoid structures unique to mucosal sites
specialised antigen uptake mechanisms
What are the effector mechanisms of GUT mucosal immune system
Activated/memory T cells predominate
‘natural’ effector regulatory T cells
Immunoregulatory environment of GUT mucosal immune system
active down regulation of immune response
inhibitory macrophages and tolerating dendritic cells
What is a Peyer’s patch
A specialised lymph node which samples antigens in the gut
What happens in the lamina propria
effector mechanisms happen, contains all the lymphoid cells you’d expect to see in blood
Describe the appearance of the Peyer’s Patch
Dome of epithelium over the top
epithelium interspersed by M cells containing microbilli increasing their surface area (used for antigen sampling)
dendritic cells sit directly under M cell sampling the antigens which come in
T cells are under dendritic cells and when activated travel to the mesentery
How to dendritic cells capture antigens
By extending processes across the epithelial layer to capture the antigen from the lumen of the gut
Where are effector functions carried out
lamina propria
What are the immune cells of the lamina propria
CD4 T cells Dendritic cells macrophage mast cell plasma cell
What are the immune cells of the epithelial layer
CD8 T cell
How to gut homing T cells enter the epithelium
Bind to MadCAM-1 on endothelium
