Flashcards in Immunological Mechanisms and Infections of the GIT Deck (21)
State three infections of the GIT.
What does H. pylori cause?
Increased acid secretion
State three causes of Traveller's Diarrhoea.
Name a superbug.
What is the treatment for C. difficile?
Metronidazole and Vancomycin
What components make up mucosal defence?
Anatomical and chemical barriers
GALT and MALT
What makes up the epithelial barrier?
Goblet cells, Paneth cells, antimicrobial peptides, secretory IgA
What is GALT and what does it do?
Collections of T and B cells which generate lymphoid cells and antibodies
Produces secretory and interstitial IgA, IgM, IgG and cell mediated immunity
What do Peyer's Patches consist of?
Naïve T and B cells
How is the epithelium above Peyer's patches different to normal gut epithelia?
It is Follicle Associated Epithelium (FAE) - there are no goblet cells, no microvilli and no secretory IgA
In which layer of the gut wall are Peyer's patches found?
Where do activated T and B cells go to proliferate?
Superior Mesenteric Lymph Nodes
What is the role of secretory IgA?
Prevent attachment and entry of pathogens
What immune cell makes up 1/5 of intestinal epithelium?
What is the difference between conventional and unconventional T cells?
Conventional - migrate from other tissues
Unconventional - resident
What other innate cells are involved?
What three signals determine the T cell response?
Presentation of antigen on MHC
What are the mechanisms of immune tolerance?
What is Crohn's disease?
Inflammatory thickening of the bowel wall - leads to ulceration, diarrhoea and pain
Name 4 structures where GALT is ORGANISED
Isolated lymphoid follicles
Mesenteric lymphoid follicles