lecture 5

Question 1

T cells circulate via blood and lymphatics through?

Answer 1

secondary lymphoid tissue

Question 2

the t cells binds to an antigen on an APC the t cell does what

Answer 2

proliferated and differentiates

Question 3

after this binding the naive t cells become what cells

Answer 3

effector t cells or memory t cells

Question 4

what is the effector function of CD8 cells

Answer 4

kill infected cells (cytotoxic)

Question 5

what is the effector function of CD4 cells

Answer 5

secrete cytokines (helper t cells)

Question 6

what do t cells go through to get to lymph node from blood

Answer 6

High endothelial venule (HEV)

Question 7

t cells not activated exit the lymph node via what

Answer 7

the cortical sinuses

Question 8

what ligand binds to its receptor on the surface of T cells to tell them where to go

Answer 8

chemokines

Question 9

what allows the t cell to contact the APC initially to see if theres a peptide being presented that binds to the TCR

Answer 9

CAMs (cell adhesion molecules)

Question 10

if there is recognition what happens

Answer 10

affinity of CAM interactions
T cell divides
differentiate to effector cells

Question 11

what is signal 1

Answer 11

naive T cells receive a signal from TCR contacting MHC on APC

Question 12

co stimulation (signal 2)
APC express co stimulatory molecules B7.1/2 which binds to what on the T cell

Answer 12

CD28

Question 13

signal 3:
APCs release what

Answer 13

cytokines

Question 14

the cytokines bind to the cytokine receptors and tell the T cell what?

Answer 14

what type of T cell it needs to become

Question 15

what is the type of CAM on a CD4 t cell

Answer 15

LFA-1

Question 16

what CAM does LFA-1 bind to on the APC

Answer 16

ICAM-1

Question 17

if the naive t cell gets all 3 signals it becomes an

Answer 17

effector t cell

Question 18

once T cells activated what what molecules do they release to turn off activation of T cells

Answer 18

ICOS and CTLA-4

Question 19

what does ICOS do

Answer 19

binds to ICOSL on APC to induce cytokine secretion

Question 20

what does CTLA-4 do

Answer 20

CTLA-4 binds to B7.1/2 better than CD28 so displaces CD28
antagonist of CD28 to limit the t cell response so effector cells dont keep getting made

Question 21

mutations in CTLA-4 causes autoimmune diseases e.g

Answer 21

type 1 diabetes

Question 22

signal 3 (differentiation)
what type of effector cells can CD4 t cells become

Answer 22

T helper 1
T helper 2
T helper 17
T follicular helpers
T regulatory cells

Question 23

release of IL-4 from APC causes differentiation to which T cell type

Answer 23

T helper 2 cells

Question 24

release of IL-12 and IFN-γ from APC causes

Answer 24

T helper 2 cells

Question 25

TGF-β and IL-6 from APC causes

Answer 25

T heper 17 cells

Question 26

IL-6 from APC causes

Answer 26

T fh cells

Question 27

TGF-β from APC causes

Answer 27

T reg cells

Question 28

mains dendritic cells are

Answer 28

DC2 and 3

Question 29

specialised DC (DC1) take up and process exogenous antigens and present it on

Answer 29

MHC I molecules

Question 30

this allows DC to activate which cells

Answer 30

naive CD8 T cells

Question 31

once naive cells have become effector cells the no longer need

Answer 31

co stimulation so they can kill infected cells

Question 32

macrophages prime funcion is what

Answer 32

to engulf pathogens

Question 33

macrophages also express peptides on MHC class II and activate T cells, the T cells activates by a macrophage will make the macrophage

Answer 33

more active

Question 34

B cells make antibodies more efficiently if they

Answer 34

get help from T cells

Question 35

when T cells become activated they the IL-2 receptors have a higher affinity to IL-2
IL-2 binding to IL2R causes

Answer 35

lots of T cell proliferation

Question 36

CD8 cells when activated become

Answer 36

cytotoxic cells
they kill cells expressing peptide/MHC class I complexes

Question 37

CD4 cells when activated secrete

Answer 37

cytokines that help other cells
they are activated by recognising MHC class II complexes