B Cell Tolerance (Exam 2)

Question 1

What is the definition of tolerance?

Answer 1

unresponsiveness to antigen induced by previous exposure to same antigen

Question 2

Term for antigens that result in tolerance.

Answer 2

tolerogens

Question 3

Term for antigens that result in immunity.

Answer 3

immunogens

Question 4

Regarding B cell tolerance, it is necessary to be unresponsiveness to thymus (dependent/independent) self-antigens such as _______ and _______.

Answer 4

independent
polysaccharides + lipids

Question 5

Which cells type(s) respond to antigen with repeating subunits? What are two examples of these types of antigen?

Answer 5

marginal zone B cells + B1 cells
polysaccharides + lipids

Question 6

What B cell type responds to antigen in T-dependent responses? What kind of antigen does it respond to?

Answer 6

follicular B cells
protein antigen

Question 7

When B cells encounter _______, they become activated undergo proliferation + differentiation.

When B cells encounter _______, they undergo anergy, deletion, or receptor editing.

Answer 7

microbes
self-antigens

Question 8

Explain central tolerance.

Answer 8

naive B cells in bone marrow encounter self-antigen and are regulated before being sent to the periphery

Question 9

What are the 3 outcomes of central tolerance of B cells?

Answer 9

1. apoptosis
2. reactivate Rag genes
3. anergy

Question 10

During central tolerance, if B cells strongly react to self-antigen, they undergo _______.

Answer 10

apoptosis

Question 11

During central tolerance, if B cells have weak reactivity to self-antigen, they undergo _______ or _______.

Answer 11

anergy
receptor editing

Question 12

How do B cells edit their receptors in central tolerance?

Answer 12

by reactivating Rag genes

Question 13

What does it mean when a B cells becomes anergic?

Answer 13

becomes unresponsive, eventually leading to cell death

Question 14

Explain peripheral tolerance.

Answer 14

process of dealing with mature B cells in periphery that “escaped” central tolerance

Question 15

What are the 3 outcomes of peripheral tolerance of B cells?

Answer 15

1. deletion (apoptosis)
2. anergy
3. regulation by inhibitory receptors

Question 16

Explain how peripheral tolerance of B cells by regulation of inhibitory receptors works.

Answer 16

foreign antigen causes strong signals to be sent from combination of BCR + coreceptors when self-antigen only engages BCR so no B cell response occurs from self-anitgen

Question 17

(T/F) Anergy and apoptosis can occur as a result of central or peripheral tolerance of B cells.

Answer 17

True

Question 18

(T/F) Receptor editing of B cells only occurs in peripheral tolerance.

Answer 18

False - central tolerance

Question 19

(T/F) Failure of T cells tolerance has no correlation to activation of B cells that react to self-antigen.

Answer 19

False (can lead to activation of self-reactive B cells)

Question 20

A FcyRIIb mutation can lead to __________.

Answer 20

autoimmune disease