T cells

Question 1

Where do T cells develop?

Answer 1

Thymus

Question 2

What receptors does T cell have?

Answer 2

TCR, CD4 and CD8

Question 3

Which T cells have CD4?

Answer 3

T reg and Th

Question 4

Which T cells have CD8?

Answer 4

Tc Cells

Question 5

What does the Treg cell do?

Answer 5

suppresses unwanted immune response and limits response to pathogenesis

Question 6

What is the structure of TCR?6

Answer 6

Heterodimer
yd or ab (most)
Has variable region and constant region
Has inter and intra chain disulfide bonds
Variable region recognises particular peptide MHC combination (gives spec to TCR)

Question 7

Binding of MHC TCR, CD4…

Answer 7

TCR binds to MHC +peptide

CD4 or CD8 bind to non polym but of MHC

Question 8

What is a double positive Tcell

Answer 8

While maturing in the thymus - it has both CD4 and CD8

Question 9

How does T cell signal inside the cell?

Answer 9

Cytoplasmic bit of TCR is too short, has CD3 alpha beta epsilon gamma and zeta chains (CD3 co receptor complex)
LCK recognises ITAMS on CD3 co receptor
Protein kinases take up phosphate group and add it to tyrosine
Cell signalling cascade and transcription factors activated

Question 10

What are LCKs and ITAMS?

Answer 10

LCK is a tyrosine kinase associated with the tails of CD4 and CD8
ITAMS - Immune receptor tyrosine based activation motif

Question 11

Are V regions different in one Tcell?

Answer 11

All the same in one T cell

Question 12

How is variability created in TCR?

Answer 12

Genetic recombination

Question 13

What needs to happen after genetic recomb?

Answer 13

Selection in thymus
+ve - recognise own MHC
-ve - Recog peptides from foreign

Question 14

When does anergy happen?

Answer 14

If only CD4/CD8 and TCR activated

Question 15

What do we need so that anergy doesn’t happen?

Answer 15

Costimulation

Question 16

Most important co-stimulatory activities are: 4

Answer 16

CD86 and CD80 interact with CD28 (or CTLA4 to inactivate)
VCAM1 and VLA4
ICAM1 and LFA1
Also need cytokines and soluble mediators

Question 17

3 Functional Activities of T cells

Answer 17

Proliferate, mediate effector functions, form memory cells

Question 18

CD4 Th 1 produces

Answer 18

IFNy, IL2, TNFB

Question 19

CD4 Th1 job

Answer 19

Help CTL and macrophages (and some B)

Inhibit Th2

Question 20

CD4 Th2 produces

Answer 20

IL4, IL5, IL10, IL13

Question 21

CD4 Th2 job:

Answer 21

Help B cells, Inhibit Th1

Question 22

CD4 Th17 produces:

Answer 22

IL17 and IL22

Question 23

CD4 Th17 job:

Answer 23

Promote inflammation

Question 24

CD4 Tfh produces

Answer 24

IL21, ICOS

Question 25

CD4 Tfh job

Answer 25

Help gc B cells

Question 26

CD4 T reg produces

Answer 26

TGFB, IL10, IL35

Question 27

CD4 Treg Job

Answer 27

Suppress immune response

Question 28

CD8 TCL produces

Answer 28

Perforins, granzymes, FasL, cytokines

Question 29

TCL job

Answer 29

Kill infected cells

Question 30

How do Th1 and Th2 inhibit eachother?

Answer 30

Th1 makes IFNy

Th2 makes IL4

Question 31

When do we need Th1 or Th2?

Answer 31

Th1 - mycobacteria

Th2 - Abs needed

Question 32

Th1 interaction with APC:

Answer 32

Has CD40L - interacts with CD40 on APC (macrophage) + MHC and TCR
makes IFNy - superactivate macrophage

Question 33

Th1 interaction with CTL

Answer 33

CTL is also bound to the APC - Th1 makes IL2, IL6… help CTL