T Cell Essay

Question 1

What are T cells involved in?

Answer 1

Cellular responses to intracellular pathogens such as virus’ and regulation of B cells

Question 2

What are the 4 groups of R cells ?

Answer 2

Th1,
Th2
Cytotoxic T cells
Regulatory T cells

Question 3

How come T cells can’t recognise antigens in native form?

Answer 3

They must be presented with an antigen which has been processed and bound to HMC

Question 4

How are MHC 1 molecules expressed ?

Answer 4

Found and expressed on the surface of uncleated cells in the body

Question 5

How are MHC 11 molecules expressed ?

Answer 5

Found and expressed on antigen presenting cells

Question 6

What are T cells developed from?

Answer 6

Haemopoetic stem cells

Question 7

Where are they produced ? And as what?

Answer 7

Bone marrow
Double negative thymocytes

Question 8

Where do they migrate too?

Answer 8

Thymus for further development

Question 9

What happens in gene rearrangement in T cells ?

Answer 9

VDJ rearranged which encode variable region

Question 10

What happens to genes encoding TCR a&B?

Answer 10

Expressed at low density on cell surface and randomly switch segments of their genes to create diversity to recognise a variety of antigens

Question 11

What is the process mediated by ?

Answer 11

Rag1/2

Question 12

What is the first gene to rearrange ?

Answer 12

TCR b chain and if the cell doesn’t make this chain it dies

Question 13

What does successful rearrangement indicate ?

Answer 13

Prevent cell from creating further rearrangement and to express both CD4&CD8

Question 14

What is the thymocytes considered now ?

Answer 14

Double positive

Question 15

What does this signal the cell to do?

Answer 15

Start rearrangement on the TCR a chain

Question 16

What does successful rearrangement allow ?

Answer 16

Binding to the B chain

Question 17

Where does positive selection occur ?

Answer 17

Cortex of thymus

Question 18

What do they encounter ?

Answer 18

Cortical epithelial cells

Question 19

What do CEC do?

Answer 19

Express both classes of MHC on their surface and only thymocytes that can bind to either class receive a survival signal

Question 20

What do thymocytes which bind to MHC class I become ?

Answer 20

CD8 due to loosing CD4 expression

Question 21

What do thymocytes which bind to MHC class II become ?

Answer 21

CD4 due to loosing CD8 expression

Question 22

Where does negative selection occur ?

Answer 22

Corticomedullary junction

Question 23

What happens ?

Answer 23

Thymocytes which bind too strong to MHC derived from self antigens receive the death signal

Question 24

When do cell leave the thymus and as what?

Answer 24

Following selection process as mature T cells

Question 25

Where do they migrate too and what do they do?

Answer 25

White pulp in secondary lymphoid tissues and respond against forgein antigens

Question 26

What do they pass through to enter LN?

Answer 26

High endothelial venules

Question 27

What is it crucial CD4 cell becomes?

Answer 27

Th1 or th2

Question 28

What type of infection requires Th1 response ?

Answer 28

Intracellular

Question 29

What type of response requires Th2 ?

Answer 29

Extra cellular