CHAPTER 6.2 - STAGES OF B AND T CELL DIFFERENTIATION

Question 1

Derived from a multipotential progenitor cell particularly, the lymphoid-myeloid progenitor

Answer 1

PRO-B CELL

Question 2

IL-7 is necessary

Answer 2

PRO-B CELL

Question 3

CD 24, CD19 and CD45R are the present surface markers

Answer 3

PRO-B CELL

Question 4

Rearrangement of genes on chromosome 14 coding for the heavy chain

Answer 4

PRO-B CELL

Question 5

When synthesis of the heavy chain part of the antibody molecule occurs, it begins

Answer 5

PRE-B CELL

Question 6

Mu chains in cytoplasm (IgM) are prominent

Answer 6

PRE-B CELL

Question 7

first heavy chains synthesized

Answer 7

IgM

Question 8

Rearrangement of genes coding for light chains
o Kappa = chromosome 2
o Lambda = chromosome 22

Answer 8

PRE-B CELL

Question 9

1st expressed Ab on the surface: IgM

Answer 9

IMMATURE B CELL

Question 10

Monomer

Answer 10

IgM

Question 11

This indicates that rearrangement of the genetic sequence coding for light chains on either chromosome 2 or 22 has taken place by this time. Completion of light chain rearrangement commits a cell to produce an antibody molecule with specificity for a particular antigen or group of related antigens.

Answer 11

IMMATURE B CELL

Question 12

CD21 (Epstein-Barr virus) and CD 35

Answer 12

IMMATURE B CELL

Question 13

2nd on the surface: IgD

Answer 13

MATURE B CELL

Question 14

Released in the bone marrow

Answer 14

MATURE B CELL

Question 15

Naïve B cell – encountered not Ag

Answer 15

MATURE B CELL

Question 16

When activated by an Ag. CD25 appears which is a receptor for lI-2 to enhance proliferation of lymphocytes

Answer 16

ACTIVATED T CELL

Question 17

Result of Ag stimulation and transformation of activated B cells

Answer 17

PLASMA CELLS

Question 18

B cell surface markers disappears

Answer 18

PLASMA CELLS

Question 19

Abundant cytoplasmic Ig which are excreted in the blood stream as ANTIBODIES/ IMMUNOGLOBULINS

Answer 19

PLASMA CELLS

Question 20

Early thymocytes lack CD4 and CD8 markers

Question 21

– T helper T cells

Answer 21

o CD4

Question 22

– Cytotoxic T cells

Answer 22

o CD8

Question 23

Large thymocytes actively proliferate in the outer cortex under the influence of interleukin-7.

Answer 23

DOUBLE NEGATIVE STAGE

Question 24

Rearrangement of the genes that code for the antigen receptor known as TCR begins at this stage

Answer 24

DOUBLE NEGATIVE STAGE

Question 25

The combination of beta chain with CD3 forms the pre-TCR receptor.

Answer 25

DOUBLE NEGATIVE STAGE

Question 26

Signaling by the Beta chain also triggers the thymocyte to become CD4 positive and CD8 positive.

Answer 26

DOUBLE NEGATIVE STAGE

Question 27

– the complex that will serve as the main part of the T cell antigen receptor (TCR)

Answer 27

CD3

Question 28

thymocytes express both CD4 and CD8 antigens

Answer 28

DOUBLE POSITIVE STAGE

Question 29

rearrangement of the genes coding for the alpha chain

Answer 29

DOUBLE POSITIVE STAGE

Question 30

CD3-αβ receptor complex (TCR) is expressed

Answer 30

DOUBLE POSITIVE STAGE

Question 31

process takes place that allows only doublepositive cells with functional TCR receptors to survive

Question 32

T cells must recognize foreign anti gen in association with class I or class II MHC molecules

Question 33

class I –

Answer 33

CD8

Question 34

class II –

Answer 34

CD4

Question 35

Any thymocytes that are unable to recognize selfMHC antigens die without leaving the thymus.

Answer 35

Positive selection

Question 36

process, whereby the surviving cells recognize MHC determinants along with foreign antigen.

Answer 36

Negative selection

Question 37

The T cells are responsible for cell-mediated immunity, which involves production of cytokines that serve as regulatory factors for the immune response.

Answer 37

Negative selection

Question 38

Have single –positive expression of the surface markers

Question 39

MATURE T CELL TYPES

Question 40

1. CD4+ / T-helper cells

Question 41

Activation of Tc and delayed hypersensitivity

Answer 41

Th1

Question 42

Produce: interferon gamma (IFN-γ) and tumor necrosis factor-beta (TNFβ)

Answer 42

Th1

Question 43

Activation of B cell

Answer 43

Th2

Question 44

Produce: IL-4, IL-5

Answer 44

Th2

Question 45

: used for IL-2 receptor in ACTIVATED T CELL

Answer 45

CD25

Question 46

: Promotes further proliferation of lymphocytes in ACTIVATED T CELL

Answer 46

IL-2

Question 47

Secretes lymphokines

Answer 47

SENSITIZED T CELL

Question 48

Produced by T lymphocyte

Answer 48

lymphokines

Question 49

maturation stages of B cells

Answer 49

B CELL DIFFERENTIATION

Question 50

– bone marrow derived lymphocytes

Answer 50

B lymphocytes

Question 51

precursor cell in antibody production

Answer 51

B lymphocytes

Question 52

T CELL DIFFERENTIATION (?)of circulating lymphocytes in the peripheral blood are (?), and these become differentiated in the thymus.

Answer 52

60 to 80 percent T cells

Question 53

T CELL DIFFERENTIATION is also needed and critical for growth and differentiation

Answer 53

Interleukin 7

Question 54

Lymphocyte precursors called (?) enter the thymus from the bone marrow.

Answer 54

thymocytes

Question 55

T CELL DIFFERENTIATION A significant selection process occurs as maturation takes place, because it is estimated that approximately (?) of the cortical cells die intrathymically before becoming mature T cells.

Answer 55

97 percent

Question 56

Much more strict compared to B cell differentiation

Answer 56

T CELL DIFFERENTIATION

Question 57

Similar to Pro-B cell with the need of IL-7

Answer 57

DOUBLE NEGATIVE STAGE

Question 58

important when interacting with an antigen

Answer 58

Positive selection

Question 59

takes place among the surviving double-positive T cells with functional TCR

Answer 59

Negative selection

Question 60

Strong reactions with self-peptides send a signal to delete the developing T cell by means of apoptosis, or programmed cell death.

Answer 60

Negative selection

Question 61

Most T cells that would be capable of an autoimmune response are eliminated

Answer 61

Negative selection

Question 62

This selection process is very rigorous

Answer 62

Negative selection

Question 63

Thymus checks if the double positive thymocytes are capable of reacting to self-molecules (came w/ BM function)

Answer 63

Negative selection

Question 64

Only (?) of the doublepositive thymocytes in the cortex survive

Answer 64

1-3 %

Question 65

– released from the thymus → peripheral blood or SLO

Answer 65

CD4 and CD4

Question 66

has encountered Ag; another surface marker (CD25) will be visible

Answer 66

ACTIVATED T CELL