Ch. 11 Intestinal Immunity Flashcards
(21 cards)
What do colonocytes do
Microbes digest fiber into short chain fatty acids (SCFA), providing up to 80% of energy for colonocytes
What is a good treatment for recurrent clostridium difficile
Fecal microbiota transplant (FMT)
What is the brain-gut-microbiota axis?
Communication between brain-gut-enteric microbiota
Where is it inflammatory in our microbiome system
Interface between lumen and tissue
What are two studies that illustrate impact of gut microbiota on immune system funx
- SCFA, butyrate causes production of Treg cells
- intro of human microbes in germ free mice induce treg cells
How do we cultivatea healthy gut
Prebiotics in food that promote good flora. Need to survive passage through upper GI, fiber broken down by good flora
What are some good prebiotics
Lactobacillus, bifidobacterium, bacillus, saccharomyces = mix is better than single species. Foods containing good bacteria (fermented)
What are good things about microbiome
Competes with pathogens, produce vitamins, digest foods, provide energy, talk to immune system, prevent over reaction and allow symbiosis
Where are non inflammatory macrophages located
Lamina propria
What do non inflammatory macrophages do
Don’t release a great deal of cytokines, deal with normal microbiota and small attacks
What is specifically designed for mucosal surfaces
IgA
What does IgA do on mucosal surfaces of gut
Transcytosed into lumen and neutralize invaders by binding in lamina propria bring them back to lumen
What is significant about IgA
Don’t cause inflammation! IgA is isotype that doesn’t bind to and activate immune cells
What else reduces inflammation in GI
Lymphocytes
Where are DC’s and lymphocytes
Stay in messenteric lymph nodes and lamina propria
Intestinal epithelial cells produce what
TGFbeta and promotes development of iTregs
What do iTregs do in GI
Produce IL-10 and TGFbeta which are anti-inflammatory
Normal microbiota produce SCFA to promote what?
Itregs
When TLR’s on DC’s bind to specific bacteria what do they do
Produce cytokines that calm immune response
What can turn on intestinal system
DC’s sample lumen, TLR5 and DC’s detect flagella on pathogens
What do DC’s produce when they recognize flagella of pathogens
Produce IL-6 driving Th17 development
