Immunology Exam (Ch.5-7)

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5. TCR genes can make nonproductive or productive rearrangements.

True

False

6. The two copies of the Ig-heavy-chain locus helps to increase the likelihood that a pro-B cell will make a productive heavy-chain gene rearrangement.

True

False

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8. Allelic exclusion is the phenomenon whereby a cell expresses only one of its two copies of a gene.

True

False

9. In healthy individuals, approximately twice as many CD4 T cells than CD8 T cells are present in the peripheral circulation.

True

False

10. Mature T cells divide into...

Effector T cells

Repressor T cells

Plasma cells

Post-T cells

Pre-T cells

Submit

12. Mature B cells arise when the B-cell receptor becomes capable of generating positive signals upon binding specific antigen.

True

False

Submit

14. A double-negative thymocyte does not express...

CD4 and CD8

CD34 and CD21

CD7 and CD11

CD14 and CD21

CD4 and CD9

15. How does positive and negative selection help in selecting thymocytes?

Positive selection selects cells that bind to self-antigens and negative selection removes cells that do not bind to antigens

Positive selection requires the cell to expend energy while negative selection gains energy

None of the above

16. A light chain is needed to combine with a heavy chain in order to go to the surface of the cell in B or T cells.

True

False

17. Terminal differentiation defines the process of plasma cells ceasing to divide and no longer expressing Igs and MHC class II molecules.

True

False

18. Which cells become Cytotoxic T cells?

T cells that express CD8

T cells that express CD4

T cells that express CD32

T cells that express CD58

Both a and b

19. Rearrangement of the light-chain genes occurs in the small pre-B cells.

True

False

20. When a rearrangement is successful in the B-chain gene, what two genes are suppressed?

RAG 1 and RAG 2

RAG 3 and RAG 9

PTa

Both a and b

None of the above

21. IL-7 is a growth factor that acts on late pro-B and pre-B cells.

True

False

22. T cells with an initial nonproductive a-gene rearrangement are highly likely to be rescued by a subsequent rearrangement.

True

False

23. How many checkpoints must a pre-T cell undergo before it is given a signal to survive and proceed to positive selection?

2

5

9

0

3

24. Y:D T cells are indifferent to the peptides presented by MHC molecules and recognize different types of antigen.

True

False

25. Self-tolerant mature B cells do not respond to self antigens.

True

False

6-11

Explanation

6-11

26. T-cell tumors mostly correspond to either early or late stages in T-cell development.

True

False

27. Immature B cells arise when the rearrangement of the light chain stops.

True

False

28. Peripheral tolerance is induced to antigens outside the bone marrow that removes circulating B cells reactive against self antigens of tissues other than bone marrow.

True

False

6-13

Explanation

6-13

29. What complement is a characteristic of a stem cell?

CD34

CD7

CD4

CD8

CD24

30. What are immature T cells called?

Thymocytes

Stromal cells

Lymphocytes

Plasma cells

Cytokines

31. Which two loci compete with the B locus on a double-negative thymocyte during rearrangement?

Y and D

B and a

Y and a

D and a

S and z

32. Which TCR does not undergo positive and negative selection?

Y:D TCR

A:B TCR

D:a TCR

Y:B TCR

L:T TCR

33. Which recombination-activating genes must be present in order for pro-B cells to rearrange?

RAG 3 and RAG 8

RAG 4 and RAG 6

RAG 2 and RAG 4

RAG 1 and RAG 2

Just RAG 2

Submit

35. A double negative thymocyte precursor creates:

A:B and y:D T cells

A:B and y:G T cells

L:a and Z:y T cells

All of the above

None of the above

36. Double-positive thymocytes express.....

Both CD4 and CD8 and a functional receptor

CD4 and a functional receptor

CD8 and CD4 with a nonfunctional receptor

CD34

CD58 and a functional receptor

37. The thymic cortical epithelium expresses...

MHC 1 molecules

MHC 2 molecules

Both a and b

CD12

None of the above

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39. How many days does a MHC complex have to be bind to a pre-T-cell in oder to mature further?

3-4

7-10

12-18

1-3

19-21

40. What do Regulatory CD4 T cells suppress?

CD4 self-reactive T cells

CD8 self-reactive T cells

AIRE gene mutation

RAG 1 gene

RAG 2 gene

41. Dendritic cells secrete

CCL21

CCL19

Both a and b

CCL7

CCL9

42. The thymic stroma houses what kinds of cells?

Thymocytes

B cells

Plasma cells

Double-negative thymocytes

Double-positive thymocytes

43. Repeated attempts at a-chain gene rearrangement are not possible.

True

False

44. Receptor editing of B cells occurs in

Blood

Thymus

Bone marrow

Red marrow

Yellow pulp

6-12

Explanation

6-12

45. Rearrangement of double-negative thymocytes begins with...

Rearrangement at the y, D, and B loci at the same time

Rearrangement at the y, D, and B loci at a different time

Rearrangement at the a, B, and y loci at the same time

Rearrangement at the D, S, and y loci at the same time

Rearrangement at the a, B, and D loci at the same time

46. Thymocytes that pass a test in which the B-chain is tested for the potential to bind to a-chains are called...

Pre-T-cells

Plasma cells

Follicular cells

Lymphatic cells

Post-T-cells

47. Why are RAG 1 and RAG 2 suppressed when a successful B-chain of a thymocyte is created?

So that only one productive B-chain is expressed

To allow y:D chains to be created

In order to stop rearrangement in the a-chain

To signal apoptosis

RAG 1 and RAG 2 do not get suppressed

48. Which interleukin stimulates further progression of a B cell in the bone marrow?

IL-9

IL-17

IL-5

IL-7

IL-13

49. How many attempts can thymocytes undergo to rearrange a B-chain gene?

4

1

8

10

0

50. Tdt is an enzyme. What is it responsible for?

Insertion of the N-nucleotides

Deletion of P-nucleotides

Suppression of RAG 1

Suppression of RAG 2

Deletion of N-nucleotides

51. Which cells migrate to the thymus?

B cells

Plasma cells

Helper T cells

T lymphoblasts

Cytotoxic T cells

52. Nonproductive rearrangements preserve a correct reading frame and give rise to a complete and functional Ig chain.

True

False

53. In what syndrome does the thymus fail to develop?

DiGeroge's syndrome

Bare lymphocyte syndrome

Follicular center cell lymphoma

Hodgkin's Disease

Lupus

54. B-1 cells are no longer produced by the bone marrow in adults.

True

False

6-10

Explanation

6-10

55. Why is the a:B chain lineage favored over the y:D chain lineage in a thymocyte?

The a:B chain lineage only requires one productive gene rearrangement.

The y:D chain lineage only requires one productive gene rearrangement.

The a:B chain lineage requires two productive gene rearrangements

The a:B chain lineage is stronger and capable of producing better immunity.

None of the above

56. What happens to the D locus situated within the a locus once an a-chain gene is rearranged?

It becomes deleted

It becomes duplicated

It translocates to another chain

It is removed by RAG 1

It incorporates itself within the a-chain

57. Where does negative selection of a T cell take place?

The medulla of the thymus

The cortex of the thymus

Both a and b

The cortex of lymph nodes

The medulla of lymph nodes

58. What syndrome can occur if the AIRE gene is defective?

APECED

Lupus

Bare lymphocyte syndrome

Rheumatoid arthritis

IPEX

Submit

61. Plasma cells cease to divide and no longer express Igs and MHC class II molecules.

True

False

6-15

Explanation

6-15

62. When the B-chain of a thymocyte combines with pTa, what kind of receptor is created?

Pre-T-cell receptor

Post-T-cell receptor

Meta-T-cell receptor

Plasma T-cell receptor

Globular T-cell receptor

63. What reduces the probability that a T cell committed to the aB lineage will end up expressing a yD receptor?

The deletion of the delta locus

The duplication of the a locus

The substitution of the y locus

The translocation of the B locus

The deletion of the B locus

64. The rearrangement of the heavy-chain genes occurs in which stage of a B cell?

Pre-B cell

Pro-B cell

Meta-B cell

Endo-B cell

Ecto-B cell

65. The large pre-B cell is more mature than the small pre-B cell

True

False

66. The second step of recombination/rearrangement is

The joining of D to J

The joining of J to V

The joining of V to D

The joining of V to DJ

The joining of J to DV

67. Rearrangement occurs first in the second chromosome followed by the first if it is unsuccessful.

True

False

Rearrangement occurs first in the first chromosome

Explanation

Rearrangement occurs first in the first chromosome

68. Notch 1 interacts with transmembrane ligands on thymic epithelial cells which initiates a proteolytic cleavage. The process that follows the proteolytic cleavage which involves an intracellular domain of Notch 1 affects the thymocyte in what particular way?

Notch 1 sends signals that controls the pathway of T-cell differentiation and keeps it away from the B-cell

Notch 1 does not allow the binding of MHC I molecules to the thymocyte

CD8 is allowed to bind to the thymocyte receptor

CD4 is not allowed to bind to the thymocyte

Notch 1 sends signals that allow the thymocyte to differentiate into a B-cell

Submit

70. Where does positive selection of a thymocyte take place?

Cortex of the thymus

Medulla of the thymus

Cortex of the bone marrow

Medulla of the bone marrow

Both a and c

71. The a-chain of a T-cell is not subject to allelic expression.

True

False

72. Which cells become regulator T cells?

T cells that express CD4

T cells that express CD8

T cells that express CD32

T cells that express CD58

Both a and b

Submit

74. Define T-cell receptor editing.

The process by which a TCR tries out different a-chains in order to become reactive with self-MHC molecules

The process by which a BCR tires out different a-chains in order to become reactive with MHC I molecules

The process by which a TCR is chosen to proliferate

The process by which a TCR is chosen to die

The process by which a TCR tries out different b-chains in order to become reactive with self-MHC molecules

75. What is a possible outcome of having a defective AIRE gene?

T cells will be able to bind to self-antigens

T cells wont be able to fight off infection

T cells wont be able to differentiate into Helper T or Cytotoxic T cells

T cells wont be able to secrete cytokines

T cells wont be able to bind to pathogens with CD4

76. Alteration, Elimination or inactivation of a B-cell receptor that binds to components of the human body is known as

Attacking infection

Searching for infection

Negative selection

Repertoire assembly

Positive selection

77. Which of the following statements is correct?

In adults the mature T-cell repertoire is self-renewing and does not require a thymus for provision of new T cells

T cells and B cells are both short-lived cells and require continual replenishment from primary lymphoid organs

The human thymus is not fully functional until age 30, at which time it begins to shrink and atrophy

In DiGeorge syndrome the bone marrow takes over the function of the thymus and produces mature peripheral T cells

None of the above statements is correct

78. How many checkpoints must a B cell pass in order to continue development?

1

4

11

2

5

79. Y:D TCR undergo positive and negative selection.

True

False

THey undergo a single rearrangement which allows them to enter circulation because they do not affect the body if they bind to self-antigens or not.

Explanation

THey undergo a single rearrangement which allows them to enter circulation because they do not affect the body if they bind to self-antigens or not.

80. How many screenings do aB double-positive thymocytes undergo?

2

4

9

6

11

81. The function of negative selection of thymocytes in the thymus is to eliminate

Single-positive thymocytes

Double-positive thymocytes

Alloreactive thymocytes

Autoreactive thymocytes

Apoptotic thymocytes

82. The surrogate chain in a B-chain in a B-cell is/are

PTa

Y-chain

A-chain

Pre-VB and Lamda 5

MHC class I

83. Stromal cells have two distinct functions that aid the B cell in development. What are they?

Produce growth factors and inhibit CD8 binding

Suppress the light-chain and speed up the rearrangement of the heavy-chain

Make specific contacts with the developing B cells and produce growth factors

Make specific contacts with the developing B cells and induce a:B chain binding

None of the above

84. Individuals with a defective autoimmune regulator gene (AIRE) exhibit

DiGeroge syndrome

APECED

SCID

MHC class I deficiency

MHC class II deficiency

85. The lamda chain genes are the first to rearrange in light-chain rearrangement of a B cell.

True

False

The k-light chain genes are first to rearrange and if they are not viable, then the lamda chain genes rearrange.

Explanation

The k-light chain genes are first to rearrange and if they are not viable, then the lamda chain genes rearrange.

86. Central and peripheral tolerance do not remove B cells that are reactive to self antigens present in places inaccessible to B cells.

True

False

6-13

Explanation

6-13

87. Plasma cells secrete

IgM

IgD

IgA

IgG

IgE

88. What cells secrete cytokine 7?

Stromal cells

Goblet cells

B lymphocytes

T lymphocytes

Follicular cells

89. Productive rearrangements in B cells gives rise to

A functional B-chain

A functional Ig-chain

A functional y-chain

A functional a-chain

None of the above

90. Immature B cells are not released into the blood.

True

False

91. Which transcription factor is expressed in late development of a T-cell?

Th-POK

RAG2

GATA-3

Ikaros

None of the above

92. When a T cell recognizes self-MHC molecules, this is known as negative selection.

True

False

Positive selection recognizes self-MHC moleucules

Explanation

Positive selection recognizes self-MHC moleucules

93. What kind of a gene is AIRE?

A regulator

A transcription factor

A promoter

A suppressor

Both b and d

94. IPEX is a deficiency in what?

FoxP3 and Regulatory T cells

RAG1

AIRE gene

PTa

RAG2

pg 203

Explanation

pg 203

95. IgM is formed when the _ chain is synthesized and assembled in the ER with the chains.

Heavy; a

A; light

Heavy; u

Light; u

U; a

96. Recirculation of mature B cells between lymph, blood, and secondary lymphoid tissues is known as

Finding infection

Negative selection

Positive selection

Searching for infection

Attacking infection

97. If developing B cells make nonproductive rearrangements at both copies of the heavy-chain gene, what happens?

They undergo a second recombination

They are let out into circulation

They not develop further

They die in the bone marrow

Both C and D

98. When recombination/rearrangement is occurring in a gene, what is the first step?

Joining of V to J

Joining of V to DJ

Joining D to J

Joining of D to V

None of the above

99. Which proteins are responsible for creating the surrogate light chain of a B cell?

L5

VpreB

VpreA

L1

Both a and b

100. B-2 cells are the minority subset of B cells.

True

False

6-10

Explanation

6-10

101. Other activated B cells migrate to a nearby primary follicle, which changes its morphology to become a _ containing a _______.

Secondary lymphoid follicle, terminal center

Primary lymphoid follicle, terminal center

Secondary lymphoid follicle, germinal center

Primary lymphoid follicle, germinal center

None of the above

102. Rearrangements can not occur at both copies of the a-chain of a T-cell,

True

False

The a-chain can have rearrangements occur at both copies because they are not subject to allelic expression like B-chain genes.

Explanation

The a-chain can have rearrangements occur at both copies because they are not subject to allelic expression like B-chain genes.

103. The tyrosin kinase is essential for B-cell development beyond the pre-B cell stage.

Atk

Ctk

Btk

Gtk

PtK

6-8

Explanation

6-8

104. T-cells interact with which complement on other cells in order to generate signals?

CD58

CD7

CD9

CD1

CD88

105. FOXP3, a transcriptional repressor protein, is found in which cells?

CD4 Regulatory T-cells

B-cells

CD8 Regulatory T-cells

Plasma cells

Double-negative T cells

106. Memory B cells originate from

Central centers

Terminal centers

Primary lymphoid follicles

Germinal centers

None of the above

6-15

Explanation

6-15

107. What are the T-cell receptor a-chain genes?

V and J

V, D, and J

V and D

D and J

None of the above

108. When is a single positive thymocytes created?

After positive and negative selection

Before positive selection

After negative selection

After positive selection

None of the above

109. What are the most important cells responsible for negative selection?

Dendritic cells

Macrophages

B-cells

Helper T cells

Both a and b

110. Which cells are the earliest identifiable cells of the B-cell lineage?

Pro-T cells

Pre-B cells

Pro-B cells

Late pre-B cells

Small pre-cells

111. Which is true for B-1 cells?

Polyspecificity

Develop in fetal life

Need no help from T cells

Have decreased somatic hypermutation

All of the above

112. What are the two types of T-cells?

A:B T cells and y:S T cells

A:B T cells and D:Z T cells

Y:S T cells and a:L T cells

None of the Above

113. Cells with receptors that bind a multivalent self antigen are signaled to arrest their developmental progression.

Immature B

Mature B

Immature T

Mature T

Plasma cells

6-11

Explanation

6-11

114. B cells express ______ a receptor that binds CCL21.

CCR1

CCR9

CCR7

CCR8

CCR 10

Submit

116. Generation of diverse and clonally expressed B-cell receptors in the bone marrow is known as

Attacking infection

Finding infection

Positive selection

Negative selection

Repertoire assembly

117. Which is the correct order of B cell development?

Repertoire assembly, Negative selection, searching for infection, Attacking infection, Finding Infection, Positive selection

Positive selection, Negative selection, searching for infection, Attacking infection, Finding Infection, Repertoire assembly

Repertoire assembly, Negative selection, Positive selection, Attacking infection, searching for infection, Finding Infection

Repertoire assembly, Negative selection, Positive selection, searching for infection, Finding infection, Attacking Infection

Negative selection, Positive selection, Repertoire assembly, searching for infection, Attacking infection, Finding Infection

118. IgA and IgB are always turned on once they are turned on.

True

False

119. Tumors derived from mature, naive B cells grow in follicles of lymph nodes and form

Myelomas

Follicular center cell lymphoma

DiGeroge's disease

Both a and b

None of the above

6-16

Explanation

6-16

120. What is the percentage of making a productive rearrangement of a B-chain in a thymocyte?

80%

100%

35%

50%

75%

121. Regulatory CD4 T cells are distinguished from other CD4 T cells by the expression of what complement?

CD25

CD34

CD58

CD2

CD4

122. In order to create a thymic anlage, what occurs?

Thrombocytes are added to the thymus

Thymocytes are added to the thymus

Blastocytes are added to the thymus

Both A and C

Lymphocytes are added to the thymus

123. Which of the following statements is true?

The pre-B-cell receptor is created by the assembly of VpreA, L1, Iga, and IgB disulfide bonding to the u chain

Pro-B cells only need to create VpreB to create a surrogate light chain

Only a single event joining V with J is needed to rearrange a light-chain gene

Recombination is not necessary for the development of the B cell

T cells are able to secrete Ig if necessary

6-5

Explanation

6-5

124. CCL21 is a chemokine secreted by

B cells

T cells

Stromal cells

Follicular cells

Stem cells

6-14

Explanation

6-14

125. The involution of the thymus affects T-cell count.

True

False

Submit

127. What is the B-chain of the thymocyte test for when translocated to the ER after double-negative rearrangement?

The capacity to bind to pTa

The capacity to bind to y:D chain

The capacity to bind to self-antigens

The capacity to bind to CD3

The capacity to bind to CD34

128. Promotion of a fraction of immature B cells to become mature B cells in the secondary lymphoid tissues is known as

Negative selection

Searching for infection

Finding infection

Positive selection

Repertoire assembly

129. Which proteins are made by the pro-B cell that mimic the Ig light chain and bind to the u chain?

L6 and VproB

L1 and VpreA

L2 and VpreB

L5 and VpreB

L1 and VproB

6-4

Explanation

6-4

Submit

131. Which immunoglobulin(s) does IgM associate with in order to form a functional B-cell receptor?

Iga

IgB

IgG

Both A and B

All of the above

132. Which process assesses the quality of the Ig chains?

Negative selection

Apoptosis

Somatic recombination

Allelic exclusion

Checkpoints

133. Co-receptors CD4 and CD8, the signaling complex CD3, the tyrosine kinase ZAP-70 and the tyrosine kinase Lck are factors needed by the pre-T cell to_____.

Send signals

Activate rearrangement

Develop a successful B-chain

To pass positive selection

To induce apoptosis

134. A transcription factor that defines the B-cell lineage is

Pax-1

PTa

Myc protein

Pax-5

None of the above

6-8

Explanation

6-8

135. What cells are responsible for the development of the cortex in the thymus?

Ectodermal cells

Endodermal cells

Mesodermal cells

Exodermal cells

Psuedodermal cells

136. What complement does IL-7 bind to?

CD34

CD21

CD4

CD5

CD8

137. When does a T-cell a-chain rearrange?

After their partner receptor chain has been expressed

Before their partner receptor chain has been expressed

During the same time as their partner receptor

Before their partner receptor has been expressed

After two successful B-chains are expressed

138. FoxP3 is encoded by a gene on which chromosome?

X

Y

12

13

21

139. Immature B cells that leave the bone marrow

Are not able to proliferate

Are able to interact with MHC I

Express high levels of surface IgM and low levels of surface IgD

Express high levels of surface IgD and low levels of surface IgM

Can bind with T cells

140. Why is AIRE important in to T-cells?

The peptides derived from it can form complexes with MHC I which participate in negative selection

AIRE can form complexes with MHC I which participate in positive selection

AIRE can form complexes with MHC II which participate in negative selection

AIRE allows the a-chain to create two successful chains

AIRE allows the B-chain genes to create a successful chain that will bind to an a-chain

141. Immature B cells mature in the bone marrow.

True

False

Immature B cells mature in secondary lymphoid regions (6-2)

Explanation

Immature B cells mature in secondary lymphoid regions (6-2)

142. Bcl-2 protein prevents

Over-formation of B cells

Premature apoptosis of B cells

Apoptosis of T cells

Over-formation of phagocytes

Deletion of oncogenes

6-9

Explanation

6-9

143. Which statement is true?

B-1 cells are a minority subset of human B cells

B-1 cells carry CD5

B-1 cells are largely produce in fetal life

Both a and b

All of the above

6-10

Explanation

6-10

144. What is the a-chain in a TCR tested for?

The capacity to bind to the B-chain

The capacity to bind to self-antigens

The capacity to bind to a MHC class II molecule

The capacity to bind to a MHC class I molecule

A and C

145. Which complement is an adhesion molecule on T-cells?

CD2

CD34

CD21

CD4

CD8

146. Which transcription factors are expressed in early T-cell progenitors?

Ikaros

GATA-3

RAG1

RAG2

Both a and b

147. What mechanism will occur if a T cell that is in circulation encounters a self-anitgen in the absence of infection?

Activation-induced cell death

Somatic recombination

Apoptosis

Anergy

None of the above

148. In which stage of a pro-B cell does the joining of V and D gene segments occur?

Late pro-B cell

Large pre-B cell

Early pro-B cell

Meta-late pro-B cell

None of the above

149. The stage of the small pre-B cell where cells are selected for survival is

The first checkpoint

The second checkpoint

The third checkpoint

The fourth checkpoint

Positive selection

6-7

Explanation

6-7

150. Primary lymphoid follicles consist of an area principally of T cells enmeshed in a network of specialized stromal cells.

True

False

6-14 It only involves B cells

Explanation

6-14 It only involves B cells

151. Why is the lack of allelic exclusion at the T-cell receptor a chain locus not so disruptive?

Because each TCR only contains one a-chain

Because each TCR only contains one B-chain

Because each TCR contains two B-chains

Because each TCR contains two a-chains

Both a and b

152. How does the processing and presentation of self antigens by thymic epithelium differ from that in other cells?

By the use of protease cathepsin L

By the use of protease cathepsin

By the use of pTa

By the use of the transcription factor Th-POK

By the use of the transcription factor GATA-3

153. Double-negative thymocytes initiate rearrangement at the ____ locus (loci) before all other T-cell receptor genes.

Y and D

B

A and B

A, y, and D

B, y, and D

154. Survival signals allow B cell to

Die by apoptosis

To undergo positive selection

To differentiate

To evade macrophages

To evade dendritic cells

155. How is a diverse population of immature B cells achieved?

By creating different u chains

By creating different a chains

By creating different B chains

By creating different k and L chains

All of the above

156. CXCL13 is secreted by

Macrophages

B cells

T cells

Follicular dendritic cells

Stromal cells

157. If a T-cell receptor on a double-positive thymocyte binds to a self-peptide: self-MHC class I complex with low affinity the result is

Negative selection and apoptosis

Cell proliferation

Rearrangement of the second B-chain locus

Positive selection of a CD4 T cell

Positive selection of a CD8 T cell

158. What transcription factor signals for a CD4 T cell choice?

P-Ta

AIRE gene

Th POK

GATA-3

Ikaros

159. The selective death of developing lymphocytes and the consequent removal of their self-reacive receptor specificities from the B-cell repertoire.

Receptor editing

Apoptosis

Somatic recombination

Clonal deletion

Negative selection

6-12

Explanation

6-12

160. B-1 cells depend on which cytokine in order to maintain it's population?

IL-9

IL-76

IL-1

IL-8

IL-10

6-10

Explanation

6-10

161. FDCs attract

T cells

Dendritic cells

Stromal cells

B cells

Lymphoblasts

6-14

Explanation

6-14

162. B cells in germinal centers in secondary lymphoid follicles are called

Lymphocytes

Lymphoblasts

Erthyrocytes

Centerblasts

T cells

6-15

Explanation

6-15

163. Lymphomas can be caused by

PTa

Deletion of oncogenes

Deletion of proto-oncogenes

Bcl-2

Btk

164. Differentiation to antibody-secreting plasma cells and memory B cells in secondary lymphoid tissue is known as

Positive selection

Finding infection

Negative selection

Attacking infection

None of the above

165. Promotes cell growth.

RSS

Btk

Myc protein

Bcl-2

Pax-5

6-9

Explanation

6-9

166. When a stem cell expresses and _ it becomes a T cell.

CD2 and CD5

CD4 and CD8

CD34 and CD2

CD34 and CD5

CD12 and CD21

167. The subendosteum is the location in the bone marrow where

Macrophages develop

Dendritic cells carry information to

T cells interact with B cells

B cells die

Immature B cells reside

168. Which of the following statements is correct.

In early pro-B cells joining of the D,J and V segment occurs

In late pro-B cells joining of the D and J segment occurs

In large pre-B cells, the heavy-chain is rearranged

Pre-B cells express a u-chain

None of the above

169. What is the fraction of pro-B cells that will make a functional heavy-chain?

1

2/3

1/4

2/8

1/2

Submit

172. Regulatory CD4 T cells proliferate and suppress naive T cells that respond to self-antigens.

True

False

CD4 regulatory T cells do suppress naive T cells that react to self-antigens, but they do not proliferate.

Explanation

CD4 regulatory T cells do suppress naive T cells that react to self-antigens, but they do not proliferate.

173. What is mostly likely to occur if a patient lacks Bruton's tyrosin kinase?

T cell development wont be able to complete

Antibodies will be able to bind to self-antigens

There wont be any circulating antibodies

There wont be a diverse population of B cells

Antibodies wont function properly

174. Which enzyme that is involved in somatic recombination is expressed throughout the T-cell development?

Tdt

PTa

RAG 1

RAG 2

Both C and D

Submit

176. Activation and clonal expansion of B cells by pathogen-derived antigens in secondary lymphoid tissues is known as

Searching for infection

Repertoire assembly

Attacking infection

Finding infection

Negative selection

177. What percentage of the pre-B cells become immature B cells making IgM?

50%

32%

99%

2%

85%

6-6

Explanation

6-6

178. Antibody secretion is effected by a change in the processing of the

Light-chain B cell

Heavy-chain of T cell

Heavy-chain of plasma cell

Heavy-chain mRNA

Light-chain mRNA

6-15

Explanation

6-15

179. B cells react to self antigens in the bone marrow causing

Apoptosis

Receptor editing

Anergy

Both a and B

All of the above

6-13

Explanation

6-13

180. What fraction of pro-B cell rearrangements will be unsuccessful?

1/4

2/7

1/2

2/3

3/4

181. Pax-5 binds to enhancer sequences in a pro-B cell located

5' of the heavy-chain C region genes

3' of the light-chain C region genes

3' of the heavy-chain C region genes

5' of the light-chain C region genes

3' of the heavy-chain V region genes

6-8

Explanation

6-8

182. Which statement is correct?

B-1 cells are the majority subset of B cells

Mature B cells are not capable of fighting infection

Self antigens do not affect negative selection

B-2 cells are polyspecific

Tdt is not expressed in early prenatal period

6-10

Explanation

6-10

183. Thymocytes are considered to be double-negative cells. This is possible because...

Thymocytes are in the process of rearranging their genes

Thymocytes are unable to express the required complements to divide

Thymocytes lack CD4 and CD8

None of the above

A and C

184. The synthesis of the IgA and IgB polypeptides is turned on at the

Pre-B cell stage

Second checkpoint

First checkpoint

Pro-B cell stage

Both a and d

6-8

Explanation

6-8

Immunology Exam (Ch.5-7)

1. The state of developmental arrest of a self-reactive B cell that binds to monovalent self antigens.

2.

What first name or nickname would you like us to use?

2. Default pathway of death

3. _________ is present on all human hematopoietic stem cells. (Hint: a complement)

4. The period of time over which a population of cells reduces to half its original size.

5. TCR genes can make nonproductive or productive rearrangements.

6. The two copies of the Ig-heavy-chain locus helps to increase the likelihood that a pro-B cell will make a productive heavy-chain gene rearrangement.

7. How do lymphocytes enter and leave the thymus?

8. Allelic exclusion is the phenomenon whereby a cell expresses only one of its two copies of a gene.

9. In healthy individuals, approximately twice as many CD4 T cells than CD8 T cells are present in the peripheral circulation.

10. Mature T cells divide into...

11. ____________ are viral genes that cause transformation.

12. Mature B cells arise when the B-cell receptor becomes capable of generating positive signals upon binding specific antigen.

13. _________ ________ cells posses a high-affinity, isotype-switched antigen receptor.

14. A double-negative thymocyte does not express...

15. How does positive and negative selection help in selecting thymocytes?

16. A light chain is needed to combine with a heavy chain in order to go to the surface of the cell in B or T cells.

17. Terminal differentiation defines the process of plasma cells ceasing to divide and no longer expressing Igs and MHC class II molecules.

18. Which cells become Cytotoxic T cells?

19. Rearrangement of the light-chain genes occurs in the small pre-B cells.

20. When a rearrangement is successful in the B-chain gene, what two genes are suppressed?

21. IL-7 is a growth factor that acts on late pro-B and pre-B cells.

22. T cells with an initial nonproductive a-gene rearrangement are highly likely to be rescued by a subsequent rearrangement.

23. How many checkpoints must a pre-T cell undergo before it is given a signal to survive and proceed to positive selection?

24. Y:D T cells are indifferent to the peptides presented by MHC molecules and recognize different types of antigen.

25. Self-tolerant mature B cells do not respond to self antigens.

26. T-cell tumors mostly correspond to either early or late stages in T-cell development.

27. Immature B cells arise when the rearrangement of the light chain stops.

28. Peripheral tolerance is induced to antigens outside the bone marrow that removes circulating B cells reactive against self antigens of tissues other than bone marrow.

29. What complement is a characteristic of a stem cell?

30. What are immature T cells called?

31. Which two loci compete with the B locus on a double-negative thymocyte during rearrangement?

32. Which TCR does not undergo positive and negative selection?

33. Which recombination-activating genes must be present in order for pro-B cells to rearrange?

34. Cytokine ______ is critical in the development of T-cells.

35. A double negative thymocyte precursor creates:

36. Double-positive thymocytes express.....

37. The thymic cortical epithelium expresses...

38. ________ _______ _________ is characterized by a lack of expression of either MHC class I or II molecules by lymphocytes and thymic epithelial cells. (Hint: a syndrome)

39. How many days does a MHC complex have to be bind to a pre-T-cell in oder to mature further?

40. What do Regulatory CD4 T cells suppress?

41. Dendritic cells secrete

42. The thymic stroma houses what kinds of cells?

43. Repeated attempts at a-chain gene rearrangement are not possible.

44. Receptor editing of B cells occurs in

45. Rearrangement of double-negative thymocytes begins with...

46. Thymocytes that pass a test in which the B-chain is tested for the potential to bind to a-chains are called...

47. Why are RAG 1 and RAG 2 suppressed when a successful B-chain of a thymocyte is created?

48. Which interleukin stimulates further progression of a B cell in the bone marrow?

49. How many attempts can thymocytes undergo to rearrange a B-chain gene?

50. Tdt is an enzyme. What is it responsible for?

51. Which cells migrate to the thymus?

52. Nonproductive rearrangements preserve a correct reading frame and give rise to a complete and functional Ig chain.

53. In what syndrome does the thymus fail to develop?

54. B-1 cells are no longer produced by the bone marrow in adults.

55. Why is the a:B chain lineage favored over the y:D chain lineage in a thymocyte?

56. What happens to the D locus situated within the a locus once an a-chain gene is rearranged?

57. Where does negative selection of a T cell take place?

58. What syndrome can occur if the AIRE gene is defective?

59. ____ of human Ig has k chains.(Hint: a fraction)

60. __________ antigens are most effective at linking B-cell receptors together and activating B cells.

61. Plasma cells cease to divide and no longer express Igs and MHC class II molecules.

62. When the B-chain of a thymocyte combines with pTa, what kind of receptor is created?

63. What reduces the probability that a T cell committed to the aB lineage will end up expressing a yD receptor?

64. The rearrangement of the heavy-chain genes occurs in which stage of a B cell?

65. The large pre-B cell is more mature than the small pre-B cell

66. The second step of recombination/rearrangement is

67. Rearrangement occurs first in the second chromosome followed by the first if it is unsuccessful.

68. Notch 1 interacts with transmembrane ligands on thymic epithelial cells which initiates a proteolytic cleavage. The process that follows the proteolytic cleavage which involves an intracellular domain of Notch 1 affects the thymocyte in what particular way?

69. PTa is an invariant polypeptide that acts as a _________ __________.

70. Where does positive selection of a thymocyte take place?

71. The a-chain of a T-cell is not subject to allelic expression.

72. Which cells become regulator T cells?

73. Reactivity with monovalent antigens. (Hint: a process)

74. Define T-cell receptor editing.

75. What is a possible outcome of having a defective AIRE gene?

76. Alteration, Elimination or inactivation of a B-cell receptor that binds to components of the human body is known as

77. Which of the following statements is correct?

13. _ cells posses a high-affinity, isotype-switched antigen receptor.

38. ____ _ _______ is characterized by a lack of expression of either MHC class I or II molecules by lymphocytes and thymic epithelial cells. (Hint: a syndrome)

69. PTa is an invariant polypeptide that acts as a _ __.

95. IgM is formed when the _ chain is synthesized and assembled in the ER with the chains.

101. Other activated B cells migrate to a nearby primary follicle, which changes its morphology to become a _ containing a _______.