immuno tolerance and autoimmunity

Question 0

is tolerance Antigen specific?

Answer 0

yes

Question 1

Central tolerance is induced in?

Answer 1

Immature self-reactive lymphocytes in generative lymphoid organs

Question 2

Peripheral tolerance is induced in?

Answer 2

mature self-reactive lymphocytes in peripheral sites

Question 3

What does Central tolerance ensure?

Answer 3

that mature lymphocytes are NOT reactive to self-antigens. however, it is not perfect and occasionally some self reactive lymphocytes appear.

Question 4

Why is Peripheral tolerance needed?

Answer 4

to prevent activation of potentially dangerous self-reactive lymphocytes.

Question 5

Central tolerance is located in the?

Answer 5

Thymus

Question 6

Recognition of self-antigens by immature T cells in the thymus leads to 2 pathways. They are?

Answer 6

1. Apoptotic death by negative selection

2. development of Regulatory T Cells that enter the peripheral tissues.

Question 7

Cell injury results in T cell deletion by apoptosis via?

Answer 7

Mitochondrial Intrinsic pathways using Cytochrome C, Caspase 9, BH3 proteins, and endonuclease activation. This pathway can be in either Central or Peripheral tolerance.

Question 8

Receptor-ligand interactions of Fas and TNF-receptor are involved with T cell deletion by Apoptosis in which pathway?

Answer 8

Death Receptor Extrinsic pathways using Caspase 8 initiation and various executioner caspases that activate endonucleases and cytoskeletal breakdown. This is primarily in Peripheral Tolerance.

Question 9

Cells with T cell receptors with NO affinity for self-peptide and MHC do NOT receive?

Answer 9

a survival signal therefore undergo apoptosis in the Thymus

Question 10

Cells whose T cell receptors have a high affinity for self peptides and MHC receive?

Answer 10

the death signal and eliminated by apoptsis

Question 11

Cells with intermediate….

Answer 11

survive and lwave the thymus…..

Question 12

impaired production of Regulatory T cells express this deficiency

Answer 12

FoxP3 that causes IPEX syndrome.

Question 13

Decreased clearance and impaired tolerance induction by apoptotic cells are deficient in?

Answer 13

Complement proteins C1q and C4

Question 14

incomplete induction of tolerance in the thymus leads to?

Answer 14

AIRE deficiency to cause Autoimmune polyendocrine syndrome

Question 15

Systemic Lupus Erythmatosis is a mutation in gene C4 which is the breakdown of?

Answer 15

Peripheral tolerance.

Question 16

AIRE is the only mutation thats involved the failure of?

Answer 16

Central Tolerance

Question 17

AIRE regulated the expression of?

Answer 17

tissue restricted antigens (TRAs)

Question 18

If a T cell does not have a normal response with costimulators and MHC then it becomes SAD…

Answer 18

Suppression, Anergy, and Deletion by apoptosis

Question 19

If the T cell recognizes the self-antigen without the costimulators it becomes Anergic. blocking of the signal from the TCR complex may be result of?

Answer 19

1.recruitment of phosphatases to TCR complex
2.
3. ….

Question 20

CTLA4 belongs to this family?

Answer 20

CD28 family receptor

Question 21

CTLA4 is not expressed on naive T cells. only on active T cells and compared to CD28, CTLA4 has?

Answer 21

high affinity

Question 22

CTLA4 is associated with polymorphisms in several AI diseases such as?

Answer 22

Graves disease and Type 1 diabetes.

Question 23

blocking of CTLA4 with antibodies results in?

Answer 23

enhancement of Autoimmune diseases

Question 24

low expression of CTLA4 allows DC’s to activate….

Answer 24

…..

Question 25

APC’s regulate the fate of?

Answer 25

T cells. if they want to express Costimulators or not.

Question 26

T cell precursors with gamma chain cytokines bind to FoxP3 to stimulate IL-2….

Answer 26

…..

Question 27

T regulatory cells express FoxP3 transcriptional factor and are

Answer 27

CD4+ and CD25+ positive

Question 28

Do T reg cells express high levels of CTLA4?

Answer 28

yes

Question 29

generation of T regulatory cells requires?

Answer 29

TGF-beta

Question 30

production of anti-apoptotic molecules by T reg cells protect them from?

Answer 30

negative selection in the Thymus

Question 31

development and survival of Regulatory T cells require?

Answer 31

IL-2 and FoxP3

Question 32

in peripheral tissues, T reg cells?

Answer 32

suppress activation of self reactive lymphocytes

Question 33

IL-10 blocks expression of ?

Answer 33

CD40, CD80/86, and IL-12.

Question 34

TGF-beta regulates the differentiation of?

Answer 34

peripheral FoxP3+ T regulatory cells

Question 35

TGF-beta stimulates production of?

Answer 35

IgA by inducing B cell isotype switching in mucosal tissue.

Question 36

defects in Lyn tyrosine kinase, SHP-1 tyrosine phosphatase, and CD22 inhibitory receptor lead to?

Answer 36

autoimmune disease

Question 37

Rheumatic fever is triggered by Strep infection and mediated by

Answer 37

cross-reactivity between strep antigens and cardiac myosin

Question 38

estrogens exacerbate SLE by altering?

Answer 38

B-cell repertoire in the absence of inflammation. more common in women than in men.