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Flashcards in CD4+ T Cells Deck (29):
1

What are T effector and B effector cells?

Effector cells = relatively short-lived activated and defend the body in an immune response


Effector B cells = called plasma cells and secrete antibodies

Effector T cells:
- cytotoxic T cells
- helper T cells

= which carry out cell-mediated responses

2

What are T helper cells defined by?

Cytokines they produce

3

Which cytokines do both Th1 and Th2 produce?

GM-CSF
IL-3

4

What do naive T cells (Th0) differentiate into?

Th1 or Th2

5

What cytokines do Th1 cells produce?

1) IL-2
2) IFN-y
3) TNF-b

6

Which cytokines do Th2 cells produce?

1) IL-4
2) IL-5
3) IL-13

7

What are T cell effector functions?

- proliferation
- cytokines
- B cell help
- APC interaction

HELPER T CELL

8

Which signal transducers and transcription factors activate Th1 and Th2 cells?

Th1:
STAT4
T-bet

Th2:
STAT6
Gata3

9

Which signal transducers and transcription factors activate Th17, iTreg and Tfh cells?

Th17:
STAT3
Roryt

iTreg:
STAT5
Foxp3

Tfh:
STAT3
Bcl-6

10

What do Th1 cells do?

Co-ordinate inflammatory immune responses to intracellular pathogens (intracellular bacteria, viruses)

= so Th1 attack intracellular pathway

11

What is the role of IL-2?

- growth factor
- proliferation of activated T cells (on the same cell)
- enhancement of NK and T cell activity

12

What is the role of IFN-y?

- mac activation
- elevation of MHC I and II expression on APCs
- enhances NK and CD8+ activity
- class switching to IgG2a (opsonic)

13

What is the role of TNF-a/b?

- mac activation
- killing of transformed cells

14

What is the role of Th2 cells?

Help B cells make antibodies required for immune responses to extra cellular pathogens

15

What is the role of IL-4?

- B cell proliferation
- class switching to IgE
- suppresses Th0 > Th1 differentiation

16

What is the role of IL-5?

- B cell proliferation
- class switching IgA

17

What is the role of IL-13?

- B cell proliferation
- class switching to IgE

18

What is the role of IL-3?

Heamatopoiesis

19

What is the role of GM-CSF?

- haematopoiesis
- differentiation of monocytes to mac

20

What is the role of Th1 AND Th2 cells?

Both promote the generation of more leukocytes

= activate T cells to proliferate

21

What is differentiation of Th1 and Th2?

Cytokine-driven

22

Which receptor is positively expressed in all T cells?

IL-12Rb1

23

Which types of pathogens are invoked in Th1 and Th2 differentiation?

Th1:
Type 1 pathogens (bac, virus)
Intracellular

Th2:
Type 2 pathogens (helminthes)
Extracellular

24

What is positive selection of CD4+ (and CD8+) T cells?

Select T cells that recognise antigen on self MHC

25

What is negative selection of CD4+ (and CD8+) T cells?

Delete T cells that recognise self peptides on MHC with too high affinity (i.e. delete auto reactive T cells)

26

What cells is IL-17 produced by?

- CD4+ T cells (Th17) = main
- CD8+
- yd
- NK cells
- innate lymphoid cells

27

What type of cell is Th17?

Pro-inflammatory CD4+ T cell

28

Describe the IL-17 receptor and what IL-17 acts on and induces

- IL-17R ubiquitously expressed in tissue, hence IL-17 effects are wide-ranging

- acts on monocytes/macs, stromal cells, epithelial cells, endothelial cells

- induces IL-6, TNF-a, G-CSF, GM-CSF, chemokines, MMPs (and GC development in B cells?)

29

Describe the interleukin-17 family

It has 6 members:
IL-17A-F (IL-17E = IL-25)