Regulation of immune response

Question 1

tolerance

Answer 1

lack response to an antigen

Question 2

three mechanisms of tolerance for T cells

Answer 2

• eliminate reactive cell populations
• neutralize reactive cell populations
• generate unique cell populations which can produce antigen-specific tolerance

Question 3

role of thymus in T cell negative selection

Answer 3

expresses tissue-specific proteins

Question 4

major process of eliminating auto-reactive T cells as they develop in the thymus; programmed cell death

Answer 4

clonal deletion

Question 5

if T cells make it out of the thymus but then are found to be auto-reactive, what happens

Answer 5

clonal anergy

Question 6

what structures perform negative selection of aB T cells in thymus

Answer 6

macrophages, dendritic cells

Question 7

process that gets rid of 99% of T cells

Answer 7

central tolerance

Question 8

AIRE

Answer 8

autoimmune regulator

Question 9

if a naive T cell recognizes self antigen on an epithelial cell, is a coreceptor necessary to induce anergy?

Answer 9

no

Question 10

functional deletion of T cells

Answer 10

produce Tregs

Question 11

Tregs

Answer 11

react with same cell as auto-reactive T cell

-suppress autoimmune response

Question 12

FoxP3

Answer 12

txn factor for Tregs

Question 13

what cytokine induces differentiation of Tregs

Answer 13

TGF-beta

Question 14

FoxP3+, CD25+, CD4+ T cells

Answer 14

Tregs

Question 15

how are Tregs selected

Answer 15

in thymus on MHC Class II

Question 16

mutation in FoxP3

Answer 16

IPEX = autoimmune (enteropathy, diabetes, thyroiditis, eczema)

Question 17

turns off T cells

Answer 17

CTLA-4

Question 18

CTLA-4 antibody causes

Answer 18

persistent activation of T cells

Question 19

Is there AIRE in bone marrow? what does this mean

Answer 19

• no –> B cells are more likely than T cells to be self reacting
• need T cells, or TLR to respond

Question 20

do rearrangements occur after a B cell has Ig status?

Answer 20

yes

-light chain can still be rearranged once IhM is present

Question 21

mechanisms of tolerance for B cells

Answer 21

clonal deletion, clonal anergy, functional deletion

Question 22

how is the developmental environment different for B and T cells

Answer 22

thymus educates, bone marrow not as much

Question 23

weak immunogen

Answer 23

requires less stringent regime for induction of tolerance

Question 24

what kind of drugs generate self tolerance

Answer 24

immunosuppressants

Question 25

once a cell expresses TCR, CD4 and CD8, but no binding results….

Answer 25

double positive thymocyte -> programmed cell death

Question 26

antigen blocking

Answer 26

antibodies sequester antigen by binding -> B cell’s affinity for antigen goes up -> binds all the antigen and regulates the immune response

Question 27

cross-linking Ig with Fc via antigen

Answer 27

proliferative signal