Lecture 28

Question 1

What is polymeric Ig receptor (Pigr)?

Answer 1

binds J chain of dimeric IgA antibody and translocates to the luminal space

Question 2

What is HA107? What is it used for?

Answer 2

auxotrophic E. coli that cannot grow without supplementation, which is not present in the animal –> depleted from the gut after a few days (transient colonization)

Question 3

What is ASF? What was it used for?

Answer 3

community of different microorganisms, no E. coli ( = control)

Question 4

What was discovered about IgA responses from the reversible microbial colonization studies?

Answer 4

microorganisms induce IgA responses, and if a specific species is removed, the corresponding IgA producing plasma cell is also removed = IgA responses are microbial-dependent and modular

Question 5

How were GF mice used to elucidate IgA function?

Answer 5

Derive both Balbc and C57bkl/6 germ-free, transplant microbiome from each into each –> some genetic backgrounds make CD4+ T cells

Question 6

What did Cd11c, CCR7, and CX3CR1 mark in the mesenteric lymph node study?

Answer 6

CD11c- Dendritic Cell Marker
CCR7- Lymph node migration marker
CX3CR1- APC marker

Question 7

How does the microbiome impact APCs?

Answer 7

When the microbiome is depleted APCs migrate to mesenteric lymph nodes to promote increased T-cell activation

Question 8

What impact do wild microbiomes have on mice? How?

Answer 8

make mice more resistant to infection, improve disease resistance through increased B-cell, neutrophil, eosinophil, and other granulocytes (SSC-hi)

Question 9

What are CD62L and CXCR4 markers for?

Answer 9

neutrophil markers
CXCR4 hi CD62L lo mark aged neutrophils; neutrophils are short live and die in about
24hr - new neutrophils are constantly made