T cell activation, differentiation and memory

Question 1

What is a naïve T cell?

Answer 1

mature T cell but has not learned anything so has no memory so considered naïve

Question 2

what three signals are required for T cell activation?

Answer 2

1. TCR signaling
2. costimulatory interaction
3. cytokine signaling

Question 3

what is TCR signaling?

Answer 3

provides and sets the stage for T cell activation
a) TCRab: peptide/MHC
B)CD4 OR CD8: MHC
C) adhesion molecules

Question 4

what are costimulatory molecules?

Answer 4

co-stimulators on T cells CD 28

binding between CD80/86 (APC) and CD28 (T cell) needed for activation

lack of response means no activation of T cells

Question 5

what are co-inhibitory molecules?

Answer 5

function to terminate T cell responses by turning off their activation

Question 6

Engagement of CD-80/86 (APC) and CTL-4 leads to:

Answer 6

no response

Question 7

Engagement of PD-1 and PDL1/2 leads to :

Answer 7

inactivation (anergy) of T cells in the periphery

Question 8

what is anergy?

Answer 8

induction of non-responsiveness to further stimuli (functional inactivation of cells)

Question 9

what does CTLA-4 bind to?

Answer 9

CD80/CD86

Question 10

WHAT DOES PD 1 DO?

Answer 10

programmed cell death

Question 11

what are cytokines?

Answer 11

activated different transcription factors that guide T cells to differentiate into various subsets

Question 12

what is necessary for activation of T cells?

Answer 12

binding between B7 ad CD 28

Question 13

what does T helper 1 cells do?

Answer 13

combats intracellular pathogens activates macrophages, IgG production

Question 14

what diseases do Th1 cells have a role in?

Answer 14

autoimmune diseases, tissue damage associated with chronic infection

Question 15

what does T helper 2 cells do?

Answer 15

combats helminth infection activates eosinophils, IgE production, alternative macrophage activation

Question 16

what diseases does Th2 play a role in?

Answer 16

allergic reactions

Question 17

what does T helper 17 cells do?

Answer 17

combats extracellular pathogens, bacteria and fungi in barrier tissues

Question 18

what does Th17 role in disease?

Answer 18

organ specific autoimmunity

Question 19

what is the polarization response?

Answer 19

each T cell subset produces cytokine that amplifies itself and inhibits others making the response increasingly polarized

Question 20

T Helper 1 cells APC produce

Answer 20

IL-12

Question 21

T Helper 1 cells activate:

Answer 21

T bet

Question 22

T Helper 1 cells induce naïve T cells to ___________

Answer 22

differentiate into Th1 cells

Question 23

what does Th1 produce

Answer 23

interferon gamma (INF y)

which activates macrophages

Question 24

Th1 enhance what?

Answer 24

antigen presentation
cytokine production
nitric oxide production
killing of microbes

Question 25

what reciprocal relationship do helper t cell 1 participate in?

Answer 25

activate macrophages

Question 26

what stimulates macrophages to ingest microbes?

Answer 26

IFNg (gamma)

Question 27

Th1 and IFNg mediate ____

Answer 27

antibody class switching

Question 28

antibody class switching stimulates

Answer 28

production of IgG

Question 29

IgG binds to Fc receptors on phagocytic cells to:

Answer 29

enhance phagocytosis

Question 30

Th2 induces naïve T cells to differentiate into

Answer 30

Th2 cells, which is especially effective against worms

Question 31

what do Th2 cells produce

Answer 31

IL 4, IK 5, IL 13

Question 32

what class switching does Th2 allow?

Answer 32

IgE and IgG4

Question 33

what does IgE do?

Answer 33

gE activates mast cells degranulation

Question 33

what do cytokines IL 3 and 13 induce?

Answer 33

alternative pathway of macrophage activation

Question 34

what does M1 macrophages do?

Answer 34

induced by ILR and IFNg
killing of bacteria/fungi
inflammation

Question 35

what does macrophage M2 do?

Answer 35

anti-inflammatory effects
wound repair and fibrosis

Question 36

Activation of transcription factor RORΥt Induces naïve T cells to

Answer 36

differentiate into
Th17 cells (induces inflammation)

Question 37

Th17 produce which IL?

Answer 37

17 and 22

Question 38

what do Th17 do?

Answer 38

recruit neutrophils, increase barrier function (like in GI tract)

Question 39

what is critical for fighting a fungal infection?

Answer 39

Th17