T cells immunity

Question 1

What do mature native T cells have on their cell surface?

Answer 1

CD4 OR CD8 
CD28
MHC Class I 
TCR complex (w/ CD3 molec & zeta)
LFA-1 & VLA-4 adhesion molecules
CCR7

Question 2

What is the chemokine receptor on T cells?

Answer 2

CCR7

Question 3

TCR complex

Answer 3

CD3 molec & zeta

Question 4

What cells do CD4 T cells activate?

Answer 4

B cells & macrophages

Question 5

Lymph node migration of naive T cells

Answer 5

L selectin, LFA-1, CCR7
to
L selectin ligand, ICAM-1, CCL19/21

Question 6

Peripheral tissue migration of activated (effector & memory) T cells

Answer 6

E/P selectin ligand, LFA-1 & VLA-4, CXCR3
to
E/P selectin, ICAM or VCAM, CXCL10

Question 7

CD28

Answer 7

signal transduction (co-stimulation)

bids CD80/B7 from APCs

Question 8

CD3

Answer 8

signal transduction by TCR complex

Question 9

CTLA-4

Answer 9

binds CD80/B7 from APCs, inhibition of T cell signaling

Question 10

PD-1

Answer 10

binds PDL-1/2 on APCs, inhibition of T cell signaling

Question 11

LFA-1

Answer 11

binds ICAM-1 on APC & endothelial cells, signal transduction & adhesion

Question 12

CD40L

Answer 12

on T CELLS!

upregulated expression when binds to CD40 on APCs/B cells

Question 13

ITAM

Answer 13

motif activated by TCR, works thru Zap-70 & PLCy1

Question 14

CD25

Answer 14

receptor on T cell for IL-2a cytokine

Question 15

IL-2

Answer 15

from activated T cells

binds IL-2R (low affinity receptor)

T cell proliferation & survival

Question 16

IFN-y

Answer 16

from CD4/CD8 T cells & NK cells

activates MOs

Question 17

IL-4

Answer 17

from CD4 T cells & mast cells

causes B switching to IgE

Question 18

IL-5

Answer 18

from CD4 T, mast cells, lymphoid cells

activates eosinophils

Question 19

IL-17

Answer 19

from CD4 T cells

stimulates acute inflammation

Question 20

IL-22

Answer 20

from CD4, NK cells

maintains epithelial barrier

Question 21

TGF-B

Answer 21

from CD T cells

inhibits T cell activation, promotes T reg cells

Question 22

CD69

Answer 22

expressed on T cells after binding Ag (now activated) to S1PR

impairs migration of T cell so stuck in node

Question 23

Cytokines for Th1 cell develop

Answer 23

IL-18, IL-12

Question 24

Cytokines for Th2 cell develop

Answer 24

IL-4

Question 25

Effector T cells

Answer 25

Th1, Th2, Th17, Tfh

Question 26

Th1 secretion

Answer 26

IFN-y (to MOs)

Question 27

Th2 secretion

Answer 27

IL-4, 5, 13 to eosinophils (v allergies)

Question 28

Th17 secretion

Answer 28

IL-7, 22 to neutrophils (inflammation)

Question 29

Tfh secretion

Answer 29

IL-21 & IFN-y, to B cells for Ab production v extracell pathogens

Question 30

T reg cells

Answer 30

CD4+ T cells need IL-2 & TGF B always express CTLA-4 & CD25 transcrip factor FOXp3 secrete TGF-B & IL-10

Question 31

Gamma delta T cells

Answer 31

mostly in epithelial boundaries (gut mucosa)

Question 32

Th1 cells

Answer 32

activate DCs, MOs & NKs (via IL-2 & IFN-y) novel TF T-bet IFN-y to activate B cell switching & complement binding

Question 33

IFN-y

Answer 33

stimulates class II & B7 expression

Question 34

Th2 cells

Answer 34

proliferate in response to IL-4 novel TF GATA-3 secrete IL4, 5, 13 **stimulate IgE, mast cell & eosinophils, & alternative MOs

Question 35

Th17

Answer 35

grow in response to IL-1 & IL-6 induce inflammation/leukocyte recruitment via IL-17 & IL-22 novel TF RORyt

Question 36

Cytotoxic CD8+ cells

Answer 36

TCR recognizes class I MHC kill cells w/ intracell pathogens or tumor cells depend on Th1 (IL-2) for proliferation/cloning

Question 37

CD8 cell killing mechanisms

Answer 37

granular proteins (granzymes & perforin) FasL/Fas induction of apoptosis

Question 38

NK cell surface markers

Answer 38

CD16 & CD56

Question 39

memory T cells

Answer 39

both CD4 & CD8, need re-activation for effector function can respond in peripheral tissues, faster response than naive T cells **need IL-7 & IL-15 for survival

Question 40

Mechanisms of Evasion (by pathogens)

Answer 40

inhibit fusion w/ phagosome, inhibit Ag presentation, inhibit proteasome activity, produce IL-10 to block MO/DC activation, inhibit production of cytokine receptors