Exam II Lecture 7

Question 1

Peyer’s patches can serve as a site of _____ activation

Answer 1

T cell

Question 2

what cells do Peyer’s patches utilize to transport antigens into it?

Answer 2

M-cells

Question 3

what are M-cells?
what do they do?
what is the purpose of their role?

Answer 3

special epithelial cells which transport antigens or commensal bacteria from intestinal lumen into the Payer’s patch to initiate an immune response if needed

Question 4

which type of T cell is within the walls of the epithelial cells?

Answer 4

CD8+

Question 5

CD8+ T cells:
where are they formed?
what molecule binds by presenting peptides which gives this cell information to target non-self antigens?
when it becomes activated, what 2 cytokines does it secrete?
what do they produce and release to attack viral proteins and cause apoptosis?

Answer 5

thymus
MHC class I
TNF-a & IFN-y
cytotoxic granules

Question 6

how many more microbial cells are there to human cells? (excluding RBCs)

Answer 6

10x

Question 7

how many more microbial genes are there to human genes?

Answer 7

100x

Question 8

where are TLRs located on epithelial cells?

Answer 8

basal membrane side

Question 9

where are NLRs located in the intestine?

Answer 9

within epithelial cells

Question 10

where are dendritic cells located in the intestine?

what do they express on their surface?

Answer 10

lamina propria (underneath epithelial layer
TLRs

Question 11

DC cells that express CD11b+ and CX3CR1+ recognize antigens in what way? what type of T cell do they activate?
what cytokines do DC cells release to the T cell? what cytokines does this cause the T cell to release?

Answer 11

They can reach into lumen and engulf antigens
T-helper 17 cells
TGF-b & IL-6
IFN & IL-17

Question 12

DC cells that express CD103+ and CX3CR1 recognize antigens in what way?
These DC cells induce T-cell activation, what does the DC cell produce?
this production induces naive T-cell formation into what type of T cells?
What do these resulting T cells (with B-cells) produce?

Answer 12

antigens that pass through the epithelial layer
TGF-b & retinoic acid
T-regulatory cells
IgA

Question 13

Defect in the function of T-reg cells are associated with? (loss of immune function)

Answer 13

defects in autoimmunity such as inflammatory bowel disease

Question 14

what cytokine do T-cells produce for preventing unnecessary inflammation?

Answer 14

IL-10

Question 15

After use of antibiotics, what protein production might be compromised? why?

Answer 15

IgA

IgA is induced by microbiota in the gut and production is dependent on the presence of microbiota

Question 16

if an antigen comes in contact with the lamia propria (e.g. M-cell transcytosis), DC cells would respond and activate what type of cell?
Activated T-helper cells then activate B-cells via self-recognition and ___-____ _________.
once this occurs, B-cells can isotype switch to produce what?
This entire process is called?

Answer 16

CD4 T cells
CD40-CD40L mechanism
IgA
T-cell Dependent IgA class switching in the Gut

Question 17

When a bacterium enters the lamia propria, DC TLR response is initiated, which stimulates the release of cytokines such as? (3)
these three cytokines induce isotype switching on B-cells to produce?
This entire process is called?

Answer 17

APRIL, TGF-B, and BAFF
IgA
T-cell Independent IgA class switching in the Gut

Question 18

IgA must bind to what receptor to be transported into the gut lumen?

Answer 18

Poly-Ig receptor

Question 19

T/F IgA is a main immunoglobulin protecting mucosa

Answer 19

True

Question 20

Adaptive immunity to pathogens in the intestinal lumen is mediated in part by antibodies.
Which of the following statements about these antibodies is false?
A. IgA is a main immunoglobulin protecting mucosa
B. Treg cells provide help for IgA production
C. IL-12 is required for B cells to class switch to the isotype the antibodies to IgA
D. Binding to Poly-Ig receptor is required to transport IgA into the gut lumen
E. BAFF and APRIL stimulate T cell independent switching to IgA

Answer 20

C

Question 21

patients with primary immune deficiency will have B-cells but will not produce ______

Answer 21

antibodies

Question 22

epithelial cells can have two different functions in the body. However, they cannot effectively do both functions simultaneously. what are the two different cell functions?

Answer 22

immune cells and digestive cells

Question 23

how are IgA important for allowing our epithelial cells to focus on nutrient absorption?

Answer 23

IgA allows us to protect against microbes and prevents the need for epithelial cells to act in immunity functions