CD8+ T cels Maturation/ Differentiation/ Development

Question 1

B cells come from

Answer 1

lymphoid progenitors in bone marrow for central tolerance

Question 2

Autoreactive mIg on B cell surface =

Answer 2

anergy or destruction= central tolerance

Question 3

Expression of other cell surface molecules play a role in

Answer 3

B cell activation

Question 4

All naive mature B cells express

Answer 4

IgM or IgD on cell surface

Question 5

BCR+ CD79a/ CD79b links

Answer 5

to intracellular signaling cascade

Question 6

BCR=

Answer 6

two identical light chains and heavy chains with a constant and variable region that is a cell surface membrane immunoglobulin that recognizes and interacts with intact antigen but is not linked to any signal transduction pathways.

Question 7

Light chain and heavy chain variable regions

Answer 7

Light- V,J Heavy- V,D,J

Question 8

Multiple germline genes =

Answer 8

many gene segments for V, D J

Question 9

Combinatorial diversity

Answer 9

combine VDJ in any combination

Question 10

Junctional Diversity

Answer 10

insert nucleotides at junctions if no open reading frame

Question 11

Random Selection/association happens with

Answer 11

light and heavy chains

Question 12

Step 1 Somatic recombination

Answer 12

DNA encoding variable regions is cut and recombined so that intact genes can encode light and heavy chain varible regions

Question 13

Step 2 somatic recombination

Answer 13

Recombinases RAG-1 and RAG2 trigger somatic recombination process

Question 14

Step 3 somatic recombination

Answer 14

Gene rearrangement of VJ in light chain and VDJ in heavy chain

Question 15

Step 4 Somatic recombination

Answer 15

during recombination, unselected VDJ’s are deleted

Question 16

Step 5 Somatic recombination

Answer 16

DNA nucleotides are deleted, inserted in order to maintain an open reading frame

Question 17

Step 6 Somatic recombination

Answer 17

Insertion is mediated by Terminal Deoxynucleotidyl transfeast Tdt

Question 18

Step 7 Somatic Recombination

Answer 18

constructed variable and constant regions are transcribed to hnRNA that is spliced to mRNA

Question 19

Step 8 Somatic Recombination

Answer 19

translated light and heavy chain expressing both a variable and a constant region

Question 20

successful rearrangement of heavy chain variable regions from one chromosome inhibits

Answer 20

the somatic recombination of the heavy chain on the other member of the chromosome pair.

Question 21

all mIgs present on the surface of any one B cell will have

Answer 21

the same heavy chain variable region

Question 22

Pro-B cell stage

Answer 22

1, Transcription of RAG-1, RAG-2, CD19, Tdt and CD79a/b –2.CD19 is expressed throughout all stages of B cell development –3. Btk is expressed in the transition from Pro-B to Pre-B cells stages

Question 23

Pre BCR complex

Answer 23

Pre-BCR, CD79a/b heterodimer

Question 24

Pre BCR=

Answer 24

two heavy mu chains paired with two invariant pseudo light cahins

Question 25

interaction of pBCR with

Answer 25

ligands in bone marrow drives B cell differentiation

Question 26

CD20 is expressed in

Answer 26

the Pre-B cell stage and thereafter

Question 27

Somatic recombination of light chain variable region happens

Answer 27

during Pre-Bcell stage with

Question 28

Somatic recombination of B cell heavy stage and cell surface expression happens during

Answer 28

the immature B cell stage

Question 29

BCR=

Answer 29

assembly of light and heavy chains

Question 30

Pre- BCR is changed to BCR on the cell surface during

Answer 30

the Immature B cell stage

Question 31

destruction of autoreactive B cells takes place during

Answer 31

the immature B Cell stage

Question 32

Tolerance induction marks

Answer 32

the immature B cell stage

Question 33

Immature B cells that survive tolerance induction go

Answer 33

to the spleen

Question 34

Maturation of B cell happens

Answer 34

in the spleen during the Naive Mature B cell stage

Question 35

alternative splicing of hnRNa leads to

Answer 35

surface expression of IgM and IgD during the naive, mature B cell stage

Question 36

CD40 and others are expressed

Answer 36

in transition from immature to mature B cell stage

Question 37

Naive, Mature B cells circulate and

Answer 37

migrate to the other secondary lymphoid tissues.

Question 38

Btk=

Answer 38

Bruton’s tyrosine kinase

Question 39

Btk mutation is associated with

Answer 39

X linked agammagloulinemia

Question 40

Btk plays a critical role in

Answer 40

B cell activation, differentiation, and proliferation

Question 41

initial block of formation of Btk happens

Answer 41

at the pro-B to Pre- B cell transition

Question 42

Pre B cells that form during Btk mutation are defective and so

Answer 42

maturation is halted at this point

Question 43

in the blood of an XLA patient you will find

Answer 43

a small number of B cell numbers (Leaky B cells)

Question 44

XLA patients have

Answer 44

reduced B cells in peripheral blood and reduced serum Ig levels of all classes

Question 45

there may be a compensatory pathway that

Answer 45

can at least parly take over the role of Btk in human B cells.

Question 46

light chain constant regions are called

Answer 46

kappa and lambda

Question 47

pseudolight chains are invariant and

Answer 47

do not have VJ segments.