Lecture 27 Flashcards
(14 cards)
What is horizontal transmission?
microbiomes derived from interactions with the environment
What is vertical transmission?
microbiomes derived from the mother
What is a holobiont?
collection of different species of microorganisms that together form a discrete ecological unit
Why is 16S rRNA sequencing important?
cost of sequencing became really cheap
What are germ free mice?
lack all microorganisms, housed in sterile and controlled environments
How are germ free mice immunologically different from conventional mice?
small underdeveloped secondary lymphoid follicles (peyers’ patches), reduced number of IgA-producing plasma cells, reduced # T cells
What are SPF mice?
specific pathogen free, lack a list of specific disease-causing pathogens but not controlled microbiome
Why would you use GF vs SPF mice?
GF: baseline for comparison of role of microbiota in health/disease
SPF: minimize interference of pathogens, but unknown/variably gut microbiome
What is SFB? What does it do?
segmented filamentous bacteria, induces intestinal Th17 cells
What is Intimin? What is it encoded by?
protein that bacteria uses to bind the epithelium, encoded by Eae
What does endocytosis of commensal antigens by intestinal epithelial cells regulate?
mucosal T cell homeostasis
What does butyrate derived from commensal microbes induce? How?
differentiation of colonic Treg cells through promoting chromatin modification via acetylation of histones
How do secondary bile acids promote induction of Treg differentiation?
promote activation of vitamin D receptor specifically in FoxP3+ cells, promoting gene regulation required for induction
What does bacterial attachment induce? How?
epithelial cell pulls in the antigen, presents to DC, which turns naive CD4+ to Th17
