011615 microbiota Flashcards Preview

Gastrointes 3 > 011615 microbiota > Flashcards

Flashcards in 011615 microbiota Deck (11):
1

mucins' role in host defense

binds some commensals
bacterial exclusion
containment of secreted antibodies and antimicrobials

2

paneth cell AMPs-give ex

defensins
lysozyme
phospholipase A2
RegIIIgamma

3

predominant immunoglobulin secreted as a defense in the mucosal areas

IgA

4

how is mucosal IgA inducted?

1st way: bacteria is engulfed by dendritic cell. DC goes to mesenteric lymph node to induce B cell activation. get plasma cell secretion of IgAs

2nd way: M cell encounters bacteria. then activatres B cells in Peyer's patches

5

activities of IgA

surrounds microbe and repels attachment to mucosal surface

mucus trapping-may associate with mucins and trap microbes in mucus blanket

virus neutralization

etc

6

if you lack a good immune system, what happens?

commensal microbiota can invade

7

healthy microbiota contains what

balancec omposition of three major classes of bacteria:
symbionts, commensals, pathobionts (live as commensals but have potential to induce pathology)

8

microbial composition is determined by

site in GI
O2 tension
innate immune factors
host nutrition/diet

9

role of intestinal microbiome

protective against pathogens
induce immune system development
metabolic fxns

10

fxn of short chain fatty acids

commensal bacteria ferment nondigestable dietary polysaccharides to produce short chain fatty acids

SCFAs regulate PMNs, DCs, macrophages, epithelial cells. SCFAs regulate expression of virulence factors on bacterial pathogens so that they are not so toxic

11

abnormalities in composition of microbiome can result in increased risk of autoimmune, allergic, infectious and metabolic diseases: true or false

true