Review Session Extra Info

Question 1

Fas Ligand

Answer 1

Fas ligand is on the surface of CD8+ cells, when it binds to the FAS receptors on infected cells, signals the cell to kill itself (apoptosis)

Question 2

Describe T cell maturation

Answer 2

start in bone marrow

travel to thymus, become CD4 or CD8

travel to lymph, need dendrite to be activated via

1) B7 of dendrite to CD28 of T-cell
2) MHC of dendrite presenting antigen to TCR of Tcell
3) clonal proliferation

Question 3

how does a T-cell interact with a macrophage or B cell?

Answer 3

TCR interacts with the MHC, the CD40ligand interacts with the CD40 receptor on the macrophage/b-cell

Question 4

Describe the B cell and the FDC

Answer 4

B-cell deposits the antigen on the FDC, then becomes activated to proliferate, then the clones with different somatic hypermutation compete for binding to the antigen

Question 5

when T cells get activated

Answer 5

downregulate CD28, upregulate CTLA to bind to the b7

Question 6

lack of CTLA4 will cause

Answer 6

autoimmunity

Question 7

telomerase does what?

Answer 7

extends the parental strand by laying down an RNA template

Question 8

DNA damage response does what?

Answer 8

phosphorylates p53 which then can do the following

1. induce apoptosis
2. activate DNA repair
3. activate p21 which halts the cell cycle by binding CDK’s

Question 9

HOT T-Bone stEAK

Answer 9

IL1 - pyrogen, increase heat, cause inflammation, sticky endothelium
IL2 - stimulate T-cells to proliferate (clonal expansion), done on self
IL3 - stimulates bone marrow
IL4 - induce b cells to make IgE, stimulates TH2 differentiation
IL5 - tells b cells to class switch to IgA - stimulate eosinophils

Question 10

IL12

TNF alpha

IFN-gamma

IL10

Answer 10

differentiate to TH1

septic shock mediator

activate macrophages and TH1 differntiation

inhibits activated T-cells, secreted by T-regs

Question 11

Once in thymus, T-cells are classified as

Answer 11

double positive

Question 12

in T-cells, after the alpha chain is successfully rearranged

Answer 12

the gamma is excised, in order to make the alpha, two segments which flank the gamma must be connected.

Question 13

the b7 signal is needed for

Answer 13

activation of naive T-cells and cloncal expansion

Question 14

TH1 is good for

Answer 14

intracellular defenses

stim by IL12 and IFNgamma

makes IL2 and IFN gamma

Question 15

TH2 good for

Answer 15

parasites, extracellular

stim by IL4, makes IL4, 5, 6 for b cells to make IgE

Question 16

CD2

Answer 16

on immature t-cell progenitors double -

Question 17

cd4

Answer 17

located on helper T cells

Question 18

cd8

Answer 18

located on cytotoxic t cells

Question 19

CD28

Answer 19

found on T-cells, allows activation by dendritic b7

Question 20

CD40L

Answer 20

on CD4 cells, activates APC by binding CD40

Question 21

FasL

Answer 21

found on cd8 cells, binds to Fas on cells and induced apoptosis

Question 22

Macrophage receptors

Answer 22

CD40, MHC2, CD14 (special marker, only on macrophages)

Question 23

NKT recetors

what do they do?

Answer 23

alpha/beta receptor

they dont kill, secrete IL4 and IFN-Gamma to stim macrophages and TH1

Question 24

HLA-E presents what to show its not infected?

Answer 24

a self “leader sequence”

Question 25

B cell receptors

Answer 25

cd19, 20, 21, 40, 81, MHC1, MHCII

Question 26

NK cell receptors

Answer 26

CD56, CD16 (recognizes Fc on IgG, stimulating), and CD94 (recognizes HLA-E, inhibitory)

Question 27

MHC1a is recognized by

MHC1b is recognized by

Answer 27

1a = CD8+ t cells

1b = Natural KIller Cells

Question 28

gamma delta recognize, located on?

Answer 28

lipids on CD1d receptor

NKT cells.