Chapter 8

Question 1

Lymphocyte maturation

Answer 1

Process by which bone-marrow lymphocyte progenitors are converted to naive lymphocytes in the periphery

Question 2

Lymphocyte repertoire

Answer 2

Collection of antigen receptors on B and T cells of a given individual

Question 3

Stages of lymphocyte maturation

Answer 3

Stem cell
Pro-lymphocyte

Pre-lymphocyte

Immature lymphocyte

Mature lymphocyte

Differentiated effector lymphocyte

Question 4

Somatic recombination

Answer 4

Each receptor is pieced together from different gene segments

Question 5

Pre-lymphocytes express how many receptor chains?

Answer 5

One

Question 6

Immature lymphocytes express how many receptor chains?

Answer 6

Two

Question 7

@ what stage to lymphocytes leave the primary organ?

Answer 7

Immature lymphocyte

Question 8

What is a mature lymphocyte?

Answer 8

A naive lymphocyte in the secondary organ

Question 9

The common lymphoid progenitor cell gives rise to what types of cells?

Answer 9

T cells, B cells and NK cells

Question 10

A Pro-T cell can become what types of cells

Answer 10

Alpha-beta T cell or gamma-delta T cell

Question 11

How many chances does each cell get to recombinate?

Answer 11

2 chances for each chain of the receptor because there are 2 copies of each gene

Question 12

Which type of cell only expresses one chain of the antigen receptor?

Answer 12

Pre- T and B cells

Question 13

T or F:

Lymph nodes are considered generative organs

Answer 13

False!

Question 14

L

Answer 14

leader sequence in the DNA that precedes each variable region gene

Question 15

V

Answer 15

variable region

Question 16

H

Answer 16

heavy chain variable region

Question 17

kappa

Answer 17

one of the light chains

Question 18

lambda

Answer 18

one of the light chains

Question 19

D

Answer 19

Diversity region

Question 20

Where are diversity regions located?

Answer 20

On the Heavy chain for Immunoglobulins and the beta chain of the T cell receptor

Question 21

Enh

Answer 21

enhancer region

Question 22

C

Answer 22

constant regions

Question 23

Combinatorial diversity

Answer 23

diversity achieved from rearrangement of gene segments

Question 24

junctional diversity

Answer 24

diversity achieved though the addition of templated and nontemplated nucleotides at the junction regions between gene segments

Question 25

What helps to catalyze recombinations?

Answer 25

heptamer and nonamer sequences between gene segments

Question 26

Which receptor has greater potential for diversity? TCR or Ig

Answer 26

TCR

Question 27

P nucleotides

Answer 27

templated junctional nucleotides

Question 28

N nucleotides

Answer 28

non-templated junctional nucleotides

Question 29

What drives commitment to T and B cell lineages?

Answer 29

specific transcriptional mediators T cells: Notch-1 and GATA-3 B cells: EBF, E2A and Pax-5

Question 30

When does proliferation occur in B cell maturation?

Answer 30

Between stem cell and Pro-B cell Between Pre-B cell and Immature B cell

Question 31

When is Rag expressed in B cell maturation?

Answer 31

between Pro-B and Pre-B between Pre-B and immature B

Question 32

When is TdT expressed?

Answer 32

between Pro-B and Pre-B

Question 33

What does TdT do?

Answer 33

Adds non-templated nucleotides

Question 34

When does recombination of the heavy chain occur in B cell maturation?

Answer 34

During Pre-B stage

Question 35

When does recombination of the light chain occur in B cell maturation?

Answer 35

During immature B cell stage

Question 36

@ what stage can a B cell go to the periphery?

Answer 36

Immature B

Question 37

@ what stage does negative selection and receptor editing occur with B cells?

Answer 37

Immature B

Question 38

@ what stage does activation of B cells occur?

Answer 38

Mature B 

Question 39

Which Ig chain recombines first?

Answer 39

Heavy chain

Question 40

Which segments of the heavy chain recombine and in what order?

Answer 40

First D and J Then V is added

Question 41

What is the function of surrogate light chain in B cell maturation?

Answer 41

stabilizes the heavy chain until the cell gets the signal to continue to the next stage

Question 42

What gene segments recombine in the light chain of Ig and in what order?

Answer 42

V and J

Question 43

Which Igs can be produced by mature naive B cells?

Answer 43

IgM and IgD

Question 44

What chains are present in the pre-B cell receptor?

Answer 44

heavy chain and surrogate light chain

Question 45

What chains are present int he pre-T cell receptor?

Answer 45

beta chain and pre-T alpha chain

Question 46

B1 cells

Answer 46

B cells made in the fetal liver before birth

Question 47

Function of B1 cells

Answer 47

produce natural antibodies that bind nonspecifically to antigens to give quick protection

Question 48

B2 cells

Answer 48

B cells made int he bone marrow after birth

Question 49

Can a naive B cell express IgM and IgD on its surface?

Answer 49

yes

Question 50

RAG

Answer 50

recombinase activating gene

Question 51

What are the stages of B cell maturation?

Answer 51

Stem cell Pro-B Pre-B Immature B Mature B

Question 52

What are the stages of T cell maturation?

Answer 52

Stem Cell Pro-T Pre-T Double Positive Single positive (immature T cell) Naive mature T cell

Question 53

When does proliferation occur during T cell maturation?

Answer 53

Between stem and Pro-T Between Pre-T and double positive

Question 54

When is Rag expressed?

Answer 54

Between Pro-T and Pre-T Between Pre-T and double positive

Question 55

When is TdT expressed?

Answer 55

between Pro-T and Pre-T

Question 56

@ which stage of T cell maturation is a recombined beta chain present with pre-T alpha chain?

Answer 56

Pre-T

Question 57

@ which stage are CD4 and CD8 expressed?

Answer 57

double positive

Question 58

@ which stage of T cell maturation is a full TCR first expressed?

Answer 58

Double positive

Question 59

@ which stage is either CD4 or CD8 first expressed alone?

Answer 59

Single positive (immature cell)

Question 60

@ which stage does the T cell undergo positive ad negative selection?

Answer 60

Double positive

Question 61

@ which stage does the T cell under go activation?

Answer 61

Naive mature T cell

Question 62

What chains are present in a Pre-T cell receptor?

Answer 62

beta chain and pre-T alpha chain

Question 63

Double negative cells are found where?

Answer 63

In the cortex of the thymus

Question 64

Single positive cells are first found where?

Answer 64

Medulla of the thymus

Question 65

Which chain of the TCR recombines first?

Answer 65

beta chain

Question 66

What is the order of the rearrangement of the beta chain segments?

Answer 66

D-J | Then V is added

Question 67

What is the order of recombination of the segments of the alpha chain?

Answer 67

V-J

Question 68

Failure of a T cell to recognize a self MHC-peptide complex in the thymus results in:

Answer 68

death by neglect | lack of positive selection

Question 69

What are the 3 possibilities for selection in the thymus?

Answer 69

Positive selection Lack of positive selection (death by neglect) Negative selection

Question 70

Central tolerance

Answer 70

mechanism by which T and B cells are rendered non-reactive to self (occurs in the thymus and bone marrow)

Question 71

Peripheral tolerance

Answer 71

process by which auto-reactive T and B cells that escape central organs are deleted (occurs in the periphery)