W5: T cell

Question 1

T progenitor cells migrate from __ to __ for development

Answer 1

bone marrow to thymus

Question 2

Thymus stroma is epithelial in origin and develops from __.

Answer 2

3rd pharyngeal pouch

Question 3

Thymus: location of

Positive selection
Negative selection

Answer 3

Positive: cTEC (cortical thymic epithelical cell)

Negative mTEC (medullary

Question 4

What happens during:

Positive selection
Negative selection

Answer 4

TCR that binds to self-MHC on cTEC survive

TCR that binds too tightly to self antigen on mTEC die (apoptosis)

Question 5

Negative selection happens in __ of thymus, where the cells express __ gene.

Answer 5

medulla, AIRE

Question 6

Central tolerance is established in the __ of thymus via +/- selection.

Answer 6

medulla, - selection

Question 7

What is RAG gene? What is AIRE gene? Where are they located and what do they facilitate?

Answer 7

RAG - recombination activating gene inside T cell that facilitate genetic diversity of TCR

AIRE - autoimmune regulator protein gene inside mTEC that facilitates Central tolerance

Question 8

+ and - selection screens affinity of __ to self peptides

Answer 8

TCR

Question 9

Lineage commitment happens in the __ of thymus

Answer 9

medulla

recognition of MHC I - CD8 T cell

MHC II - CD4

Question 10

Central tolerance mediated by 2 cells in medulla:

Answer 10

mTEC, Dendritic cells

Question 11

Mutation in __ gene leads to autoimmune disease

Answer 11

AIRE

Question 12

What is APS Type I (Autoimmune Polyendocrinopathy Syndrome)

Answer 12

autoimmune response to own cytokines, caused by mutation in AIRE gene

Question 13

DiGeorge Syndrome patients completely lack __ due to deletion of __.

Answer 13

T cells; 3rd and 4th pharyngeal pouches

Question 14

Both __ and __ arise from 3rd pharyngeal pouch

Answer 14

parathyroid, thymus

Question 15

During thymic selection, the affinity for __ to MHC is assessed

Answer 15

TCR

Question 16

Primary and Secondary lymphoid organs

Answer 16

primary: thymus, bone marrow
secdonary: spleen, lymph node

Question 17

Naive T cells enter the lymph node through __ circulation via opening __.

Answer 17

arterial, HEVs (high endothelial venules)

Question 18

Peyer’s patches are lymphoid nodules in __.

Answer 18

small intestine

Question 19

T cells enter lymph node via __ exit via __.

circulations

Answer 19

arterial circulation

lymphatics

Question 20

Naive T cells are activated in lymph node when it meets __.

Answer 20

APC: DC

Question 21

Activation of T cell: require how many signals (from DC)

CD8:
CD4:

Answer 21

CD8: 2
CD4: 3

TCR-MHC
co-stimulation
(+cytokines for CD4)

Question 22

T cell differentiation upon activation:

CD8:
CD4:

Answer 22

CD8: cytotoxic T cells
CD4: helper T cells

Question 23

CD4 T cells can become (5 types)

Answer 23

Th1
Th2
Th17
Tfh
Treg

Question 24

Maintaining Self Tolerance?

Th1
Th2
Th17
Tfh
Treg

Answer 24

Treg

Question 25

Activate macrophage? ``` Th1 Th2 Th17 Tfh Treg ```

Answer 25

Th1

Question 26

recruit and activate neutrophil? ``` Th1 Th2 Th17 Tfh Treg ```

Answer 26

Th17

Question 27

facilitate long term humoral immunity and B cell class switching? ``` Th1 Th2 Th17 Tfh Treg ```

Answer 27

Tfh

Question 28

Anti-inflammatory? ``` Th1 Th2 Th17 Tfh Treg ```

Answer 28

Treg

Question 29

Triggered by parasites? ``` Th1 Th2 Th17 Tfh Treg ```

Answer 29

Th2

Question 30

Secrete IFN-gamma? ``` Th1 Th2 Th17 Tfh Treg ```

Answer 30

Th1 "IFNγ is an important activator of macrophages and inducer of Class II major histocompatibility complex (MHC) molecule expression."

Question 31

TGFb and IL-10 are anti-inflammatory cytokines, secreted by __ cell

Answer 31

Treg Research paper - "The role of IL-10 and TGF-beta in the differentiation and effector function of T regulatory cells."

Question 32

Mutation in the STAT3 gene leads to recurrent bacterial and fungal infections. Why? Disease name?

Answer 32

failure to make Th17 efficiently; Jobs Disease

Question 33

IPEX disease is caused by mutation in FOXP3 gene that leads to autoimmune enteropathy. Why?

Answer 33

failure to make Treg efficiently

Question 34

Th17 deficiency leads to: Treg deficiency leads to:

Answer 34

Th17: Jobs (STAT3) Treg: IPEX (FOXP3)

Question 35

Differentiation of CD4 T cells is directed by __.

Answer 35

cytokines

Question 36

What is HEVs and where is it located

Answer 36

High endothelial venule in the lymph node; where naive T cell enters via arterial circulation