Chapter 3 Review/questions - Receptors And Signaling: Tcr

Front 1

Antigens bind R via ______ Interactions

Back 1

Noncovalent

(hydrogen bonds, van der waals, etc)

Front 2

________ greatly increases the ____ of R-Ag binding interactions

Back 2

Multivalancy

Avidity

Front 3

What are the T and B cell receptor-associated signal transduction elements?

Back 3

CD3 and Igalpha/beta

Front 4

CD3 and Igalpha/beta use what downstream signaling method? What are they?

Back 4

ITAMs; They are docking points for adaptor molecules

Front 5

T/F The Ag R on T cells is an Immunoglobulin

Back 5

F; however it does belong to Ig superfamily

Front 6

What characteristic between TCR and Ig is common?

Back 6

Ig Fold; binding target of Ag

Front 7

Can Ag-R binding result in covalent interactions in the cell?

Back 7

Yes; it leads to phosphorylation and Receptor cross-linking

Front 8

What is ITAM stand for and what does it do? (3)

Back 8

• ITAM is an Immunoreceptor Tyrosine-based Activation Motif.
  
• Contains Regions of Phosphorylatable Tyrosines
• In B cells IgA and B are part of signaling complex and are P'd by Src-family kinase: LYN

Front 9

What is an adaptor protein (3)

Back 9

• Contains more than one binding site for other proteins
• Brings other proteins into contact with each other
• Has no enzymatic Activity

Front 10

What happens after TCR activation? (2)

Back 10

• SRC-family kinase LYK Phosphorylates Tyrosine Residues on ITAMs of CD3
  
• ZAP-70 binds to pY residues via SH2 regions and beomes P'd
  

Front 11

Because IgM has 10 Ag. binding sites, and IgG has 2, can IgM bind 5x as much as IgG?

Back 11

Not 5 times due to steric hinderance/conformational constraints

Front 12

T/F activation of cell can does not change the phenotype of Rs

Back 12

F; It can. IL2R can have 2 forms

• Mod-affinity: Beta/Gamma Dimer
• High-affinity: Alpha/Beta/Gamma Trimer

Front 13

What is the role of Csk protein

Back 13

Phosphorylates Inhibitory Tyrosine

Front 14

T/F TCR has soluble form

Back 14

F; membrane bound only

Front 15

T/F TCR has weaker interaction with Ag than Ig

Back 15

T

Front 16

TCR must recognize ________ and Ag

Back 16

MHC

Front 17

T/F TCR is easy to purify

Back 17

F

Front 18

% of alpha/beta TCR

% of gamma/delta

Back 18

91-99

1-9

Front 19

Alpha/Beta TCR

How many are CD4+ and how many CD8

Back 19

60% CD4

30% CD8

Front 20

Gamma/Delta TCR

How many are CD4+ and how many CD8

Back 20

30% CD8

60% DN

Front 21

T/F G/D TCR can recognize Peptide and Phospholipid

Back 21

T

Front 22

What 2 things did Zinkernagel and Doherty reveal about MHC and TCR

Back 22

• Needs correct Ag specific for TCR
• Needs self-MHC to present that Ag

Front 23

What process ensures delta genes aren't expressed when Alpha is?

Back 23

Allelic exclusion; alpha chain rearrangement deletes delta genes which are in alpha segment

Front 24

Alpha Chain is Analogous to ____ in Ig

Back 24

Ig Light Chain

V-J join in Variable region

Front 25

Beta Chain is Analogous to ____ in Ig

Back 25

If Heavy Chain

D-J

V-D-J

Front 26

T/F TCR also follows 1 turn 2 turn rule

Back 26

T; also uses same enyzmes (Rag1/2)

Front 27

T/F TCR Delta chains can have alternative D-joinings

Back 27

T;

V-J

V-D-J

V-D-D-J

Front 28

What chains go through:

V-J

V-D-J

V-D-D-J

Back 28

1) alpha, gamma, delta,

2) Beta and delta

3) Delta

Front 29

TCR Complex is made of? ___ and ___

Back 29

TCR and CD3 complexes

Front 30

What 2 things bind CD80/86 on APC?

Back 30

CD28 and CTLA-4

Front 31

What is the role of CD4 between APC and TCR

Back 31

Stabilizes interactions