E3: L21 Discussion

Question 1

What percentage of thymocytes pass both positive and negative selection and leave the thymus to circulate as functional T cells?

A. 5%
B. 15%
C. 25%
D. 35%
E. 45%

Answer 1

A

Question 2

Where does central tolerance occur

Answer 2

primary lymphoid organs

Question 3

Where does peripheral tolerance occur

Answer 3

outside the bone marrow and thymus

Question 4

Match each statement to it’s outcome

1. strong binding with MHC I
2. strong binding with MHC II
3. TOO strong of binding
4. weak binding

A. CD8+ cell
B. death by neglect
C. CD4+ cell
D. death by apoptosis

Answer 4

1-A 2-C 3-D 4-B

Question 5

What do Postive selection recognize and what is it mediated with?

Answer 5

recognizes MHC and are cTEC mediated.

Question 6

What does negative selection recognize and what is it mediated with

Answer 6

self (apoptosis) and are mTEC mediated.

Question 7

What cells are invloved in peripheral tolerance?

1. B cells 2. T cells 3. Dendritic cells 4. Macrophages

A. 1 and 2

B. 2 and 4

C. 1, 2, and 3

D. 2, 3, and 4

E. 1, 2, 3, and 4

Answer 7

E

Question 8

Which of the following is NOT a consequence of the immune system lacking an immune tolerance?

A) The immune system cells will only recognize and attack foreign antigens.
B) The immune system cells will recognize and attack foreign and self-antigens.
C) The immune system will attack self-cells causing autoimmune diseases.
D)The immune system will not remove T and B lymphocytes that bind to self-antigens.

Answer 8

A

Question 9

True or False.

Positive selection is about recognition of self, is cTEC mediated, and its T cells have the ability to recognize self.

Answer 9

Fale

Question 10

How do tolerogens influence T cells?
AAR

Answer 10

die by apoptosis, become anergic, be regulated

Question 11

How do tolerogens influence pTreg cells?
CCDDI

Answer 11

deplte proinflammatory cytokines, secrete inhibitory cytokines, directly kill, shut down allergies, inhibit APCs

Question 12

True/False: Does central tolerance include the deletion of lymphocytes BEFORE they mature

Answer 12

true

Question 13

Peripheral Tolerance takes place…

a) In the bone marrow

b) In the thymus

c) In both the bone marrow and thymus

d) Outside the bone marrow and thymus

Answer 13

D

Question 14

Where does T cell central tolerance take place…

a) bone marrow

b) cortex of thymus

c) medulla of thymus

d) In the perophery

Answer 14

C