L10 - differentiation of t cells 2

Question 1

where do cytokines act

Answer 1

can have systemic effects, but mostly active over very short distances when cells interact with each other

Question 2

2 classes of Th cells

Answer 2

th1
th2

Question 3

what do th1 respond to

Answer 3

intracellular pathogens

Question 4

what do th2 respond to

Answer 4

extracellular pathogens

Question 5

Th1 cells cytokines

Answer 5

Interleukin 2 (IL-2)
Interferon – gamma (IFN-gamma)
Lymphotoxin (LT)

Question 6

Th2 cells cytokines

Answer 6

IL-4
IL-5
IL-9
IL-13

Question 7

th1 example of activities

Answer 7

Activate macrophages
Stimulate CD8+ T-cells

Question 8

Th2 cells examples of activities

Answer 8

Attract and activate eosinophils and basophils
Help promote tissue repair

Question 9

what is a signal 3

Answer 9

after antigen reconition and co-stim molecule interaction
signal 3 is a cytokine signal that is needed to differentiate the t cell

Question 10

signal 3 for th1

Answer 10

• IL-12 (e.g. from dendritic cell)
• IFNgamma (e.g. from Th1 cell)

Question 11

signal 3 for th2

Answer 11

• a number of cytokines
  from epithelial cells (e.g. TSLP)
• IL-4!!
  
  • from Th2 cells
  • initially from basophil or lymphoid cells?

Question 12

how can the th response become polarised

Answer 12

they regulate each other
Th1 cells down regulate the production of Th2 cells by the secretion of IFN-γ
Th2 cells down regulate the production of Th1 cells by the secretion of IL-4

Question 13

harmful effects of th1 cells

Answer 13

• autoimmunity
• transplantation
  rejection

Question 14

harmful effects of th2 cells

Answer 14

• allergy
• autoimmunity

Question 15

where do th17 cells act

Answer 15

at epithelial surfaces
particularly the lung and intestine

Question 16

which cytokine do th17 release

Answer 16

il-17 mainly
il-21
il-22

Question 17

Cytokines that drive Th17 cells:

Answer 17

TGF beta
IL-6
IL-1

Question 18

what do th17 cells do

Answer 18

Important in fighting some fungal
and bacterial infections

Implicated in some
autoimmune diseases

Question 19

what do T Follicular helper T cells do

Answer 19

specialised to go to the B cell follicles (germinal centres) of lymph nodes to help B cells make antibody

Question 20

what are Tregs

Answer 20

suppress self-harmful immune responses

Question 21

2 ways Tregs are formed

Answer 21

• in thymus as part of normal t-cell development = natural T cells
• in peripheral tissues via IL-2 or TGF beta = induced T cells

Question 22

how do Tregs work

Answer 22

• anti-inflammatory cytokines
• outcompete effector
  T-cells for resources
• kill self-reactive T-cells

Question 23

How do we know Tregs are so important?

Answer 23

Lack of Tregs causes
autoimmune disease

• in mice model, the mouse has multiorgan inflammation if gene is knocked out
• in humans = leads to IPEX disease