Mucosal Immunity Flashcards
MUCOSA ASSOCIATED LYMPHATIC TISSUE IS DIVIDED INTO
Bronchus associated lymphatic tissue
Gut associated lymphatic tissue
Surface area of mucosa?
400m2 60% of effector cells
Endogenous flora number is?
10 to power of 14- x10 more than human body cells
Regionalised immune system?
Peyer’s patches
Waldeyer’s ring ( lingual, palatine and nasopharyngeal tonsils)
Microbiota?
Actual microorganisms
Microbiome?
Totality of their genes
Healthy food increase?
Mucus secretion and antimicrobial peptides
Unhealthy food cause>
Enhance mucus degradation
Reduce antimicrobial peptides
What is the function of mucus?
Keep bacteria away from epithelium
Prudent diet gives rise to?
Rich in fibre
Production of SCFA by bacteria
Increase mucus production
Increased expression of tight junction proteins
On basolateral surface of gut which TLR do you have?
5 and it tightens tight junction upon contact with bacteria
What is NLR in cytoplasm activated by?
Flagellins ( invading bacteria)
Paneth cell produce?
Defensins 5 and 6 and trypsin
What does trypsin do?
Activates human Defensin 5 and 6 by proteolytic cleavage
What is in the mucus?
Antibacterial peptides and antibodies of IgG and igA
What do M cells do?
Transport antigens from gut lumen to supepithelial lymphoid structures
Largest amount of lymphoid tissue is found?
Waldeyer’s ring and terminal ileum
Peyers patches are located in?
Distal ileum in areas of follicle associated epithelium
Peyers patches increase from?
60 in foetal life to 240
Peyers patches contain?
Germinal centres for b and t cells
Follicle associated epithelium contains?
M cells, about 100-150 per PP
What are M cell features?
Small microvilli
Large cell membrane fenestrations ( antigen uptake from gut lumen - fluid phase endocytosis)
Transcellular transport mechanism for antigen
Exocytosis at basolateral membrane- delivering antigen to dendritic cells of underlying lymphatic structures
Follicular dendritic cells are not?
APCS no class II MHC, fix antigen of surface to make it easy for B cells
Follicular areas contain?
Follicular dendritic cells
Lymphoid follicles
Macrophages
Interfollicular areas contain?
B cells
T cells
Macrophages
Dendritic cells
B cells/ T cells enter via?
High endothelial venules
Hyper igM syndrome is?
X linked
Lack of CD40L on T cells
Plasma cells in gut produce?
igA- produced in presence of TGF beta/ nitric oxide, which come from dendritic cells
What percent of effector cells in the mucosa?
60
What are the induction sites?
Peyers patches
Mesenteric lymph nodes
What are the effector sites?
Lamina propria immune cells and intraepithelial immune cells
How are igA formed?
Dendritic cells release NO and TGF beta to class switch
