2 Immunogenetics (2 Hours)

Question 1

The B cell receptors function in expression of immunoglobulin and what other task?

Answer 1

Signal transduction

Question 2

What are the two subunits of the TCR invariant chains?

Answer 2

Alpha and beta

Question 3

The portion of the TCR that is involved is signal transduction

Answer 3

CD3-zeta

Question 4

What is the main signal to stimulate lymphoid development?

Answer 4

IL-7

Question 5

Clonal selection occurs in _________________________

Answer 5

Absence of antigen

Question 6

Allelic exclusion is ________________

Answer 6

Monospecific

Question 7

The heavy chain is known as what in T cells?

Answer 7

Beta

Question 8

The light chain in T cells is called the ______ chain

Answer 8

Alpha

Question 9

Where does somatic hypermutation occur?

Answer 9

BCR production

Question 10

What do the following letters stand for associated with heavy and light chains of B/T cells: V, D, J, C?

Answer 10

V-variable, D-diversity, J-Joining, C-constant

Question 11

What is the process of the combination of the heavy chain in B cells?

Answer 11

1 of the DJ region combinations combine and then the V region is added

Question 12

What is the process of assembling the B cell light chain

Answer 12

V region binds to J region (no D region)

Question 13

Recombination of signal sequences in B cells serves what 2 roles?

Answer 13

Provide recognition sites for endonucleases to cleave and then rejoin

Ensure gene segments are joined in the correct order (especially important in VDJ of heavy chain_

Question 14

What two genes code for V(D)J recombinase?

Answer 14

RAG 1 and 2

Question 15

Where on the heavy chain of B cells is junctional diversity important?

Answer 15

Between the D and J segments

Question 16

What creates sticky ends of B and T cell receptors?

Answer 16

RAG proteins

Question 17

What fills in the sticky ends of T/BCR? What are these nucleotides called?

Answer 17

RAG1/2, P nucleotides

Question 18

What are the random nucleotides that are added to the blunt ends of the junction called? What does this?

Answer 18

N nucleotides, TdT

Question 19

The recombination of VJ and VDJ are not always perfect as a result it can lead to _______________ mutations

Answer 19

Frameshift

Question 20

The light chain in B cells is called what? Heavy chain?

Answer 20

Light = kappa; heavy = mu

Question 21

At what stage of B cell development is the heavy chain checked? Where does this take place? What is bound to the heavy chain?

Answer 21

Pre-B (3 of 5); bone marrow; surrogate light chain

Question 22

At what stage does CD19 show up?

Answer 22

Pro B (2 of 5) CD10 shows up as as well; this is in the bone marrow

Question 23

At what stage of B cell development do the genes get recombined?

Answer 23

Pre-B (3 of 5)

Question 24

What is the marker of immature B cells

Answer 24

CD43 (loses this at stage 4 of 5)

Question 25

At what stage of B cell development does the cell start expressing IgM?

Answer 25

Immature B (4 of 5)

Question 26

When does the B cell do negative selection? what is negative selection?

Answer 26

Immature B cell (4 of 5); negative selection is checking self reactivity

Question 27

What is allelic exclusion?

Answer 27

Allelic exclusion is the process in which one set of genes for either the heavy or light chain is active at a time and the other set it turned off

Question 28

When does TdT get expressed?

Answer 28

End of pro-B (2 of 5) and beginning of pre-B (3 of 5)

Question 29

When does RAG get expressed in B cell development

Answer 29

End of Pro-B (2 of 5) and beginning of Pre-B (3 of 5); beginning of immature B (4 of 5)

Question 30

Where does IL-7 for B and T cell support come from?

Answer 30

Stromal cells

Question 31

How do stomal cells interact with B cells?

Answer 31

VCAM1 and VLA4 (same as macrophages)

Question 32

When does a T cell become double positive? What is it before?

Answer 32

Step 4 of 6; double negative

Question 33

When do T cells become recombined?

Answer 33

Pre-T (step 3 of 6)

Question 34

What CD marker do Pro T (step 2 of 6) have?

Answer 34

CD25

Question 35

When does a T cell lose it’s CD44?

Answer 35

After Pro-T (step 2 of 6)

Question 36

When does a T cell leave the bone marrow?

Answer 36

After the stem cell phase (1 of 6)

Question 37

Where are double positive T cells found?

Answer 37

Medulla

Question 38

At what stage does the receptor get checked in T cell development?

Answer 38

Pre-T (3 of 6)

Question 39

What step is negative selection done in T cells?

Answer 39

Double positive (4 of 6)

Question 40

What portion of the T cell does signaling?

Answer 40

Zeta section

Question 41

How is the CD4/CD8 fate of a T cell determined?

Answer 41

Whatever MHC interacts with the cell first

Question 42

Which cells pass self selection?

Answer 42

Those with weak antigen recognition

Question 43

What process allows B cells to be rescued if they are self reactive?

Answer 43

Receptor editing

Question 44

What direction do T cells move as they mature in the thymus?

Answer 44

Cortex —> medulla

Question 45

Where does positive selection of T cells occur?

Answer 45

Cortex of thymus

Question 46

Where does negative selection of T cells occur?

Answer 46

Cortex/medulla junction

Question 47

What properties cause a cell to be selected to become a Treg?

Answer 47

Decent reaction to self

Question 48

Which cell receptors undergo somatic hypermutation?

Answer 48

BCR