Question 1

Match between columns
                        Premises: The expression of the pre-T-cell receptor is required in order to halt β-,γ-,and δ-chain rearrangements.
Allelic exclusion of the T-cell receptor α and β chains is effective; therefore,all T cells express only one T-cell receptor on the cell surface.
Immature T cells failing to successfully recombine a β-chain locus die by apoptosis.
Apoptotic T cells are ingested by medullary epithelial cells.
T-cell receptor rearrangements have many features in common with immunoglobulin rearrangement,including the use of the RAG-1 and RAG-2 genes.

Accepted Answer

The Answer of False and True is...

Question 2

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

Accepted Answer

A)  single-positive thymocytes
B)  double-positive thymocytes
C)  alloreactive thymocytes
D)  autoreactive thymocytes
E)  apoptotic thymocytes.

Question 3

As we age,our thymus shrinks,or atrophies,by a process called involution,yet T-cell immunity is still functional in old age.
A.Explain how T-cell numbers in the periphery remain constant in the absence of continual replenishment from the thymus.
B.How does this differ from the maintenance of the B-cell repertoire?

Accepted Answer

A.After thymic atrophy or thymectomy,T c...

Question 4

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

Accepted Answer

A)  γ and δ
B)  β
C)  α and β
D)  α,γ,and δ
E)  β,γ,and δ.

Question 5

Healthy individuals have approximately ____ of CD4 T cells compared with CD8 T cells.

Accepted Answer

A)  one quarter the number
B)  half the number
C)  equal numbers
D)  twice the number
E)  four times the number

Question 6

Which of the following is the first T-cell receptor complex containing the β chain to reach the cell surface during the development of T lymphocytes?

Accepted Answer

A)  γ:β:CD3
B)  β:CD3
C)  α:β:CD3
D)  β:CD44
E)  pTα:β:CD3.

Question 7

Which of the following processes is not dependent on an interaction involving MHC class I or class II molecules? (Select all that apply.)

Accepted Answer

A)  positive selection of α:β T cells
B)  intracellular signaling by pre-T-cell receptors
C)  negative selection of αβ T cells
D)  peripheral activation of mature naive T cells
E)  positive selection of γ:δ T cells.

Question 8

Mature B cells undergo somatic hypermutation after activation,which,after affinity maturation,results in the production of antibody with a higher affinity for antigen than in the primary antibody response.Suggest some reasons why T cells have not evolved the same capacity.

Accepted Answer

Because T cells drive almost all immune ...

Question 9

The surrogate light chain operating during pre-B-cell development is made up of VpreB:λ.Its expression with μ on the pre-B-cell surface is an important checkpoint in B-cell maturation.Name the T-cell analog of VpreB:λ5 and discuss how it is functionally similar.

Accepted Answer

The analog of VpreB:λ5 in developing T c...

Question 10

_______ of thymocytes is necessary to produce a T-cell repertoire capable of interacting with self-MHC molecules.

Accepted Answer

A)  positive selection
B)  negative selection
C)  apoptosis
D)  receptor editing
E)  isotype switching.

Question 11

The human thymus begins to degenerate as early as one year after birth.This process is called ______ and is marked by the accumulation of ___ once occupied by thymocytes.

Accepted Answer

A)  thymectomy; dendritic cells
B)  involution; fat
C)  differentiation; γ:δ T cells
D)  negative selection; γ:δ T cells
E)  involution; thymic stroma.

Question 12

_____ is a T-cell-specific adhesion molecule expressed before the expression of a functional T-cell receptor while the thymocytes are still in their double-negative stage of development.

Accepted Answer

A)  CD4
B)  CD8
C)  CD25
D)  CD2
E)  CD3.

Question 13

Which of the following statements about Notch 1 is correct? (Select all that apply.)

Accepted Answer

A)  Notch 1 is expressed on thymic epithelial cells.
B)  In the absence of Notch 1 expression,T cells can complete their differentiation.
C)  Notch 1 is to T-cell development as Pax-5 is to B-cell development.
D)  Notch 1 contains two distinct domains,one of which is proteolytically cleaved and becomes a transcription factor in the nucleus.
E)  The extracellular domain of Notch 1 must interact with a ligand on thymic epithelium to initiate cleavage and separation of the Notch 1 extracellular and intracellular domains.

Question 14

There are many parallels between the development of B cells and T cells.Identify the incorrectly matched counterpart in B cells (left) versus T cells (right) .

Accepted Answer

A)  VpreBλ5: pTα
B)  Igα/Igβ:CD3
C)  Pax-5: FoxP3
D)  multiple κ and λ light-chain gene rearrangements: multiple α-chain gene rearrangements.

Question 15

A.Explain two ways in which the expression and processing of self antigens in thymic epithelium differs from the expression and processing of self antigens outside the thymus.
B.In what way is the thymic situation advantageous for the purposes of negative selection?

Accepted Answer

A. (i)As well as expressing their own th...

Question 16

A.What is immunological tolerance?
B.What is the general name for the antigens against which the immune system is normally tolerant?

Accepted Answer

A.Immunological tolerance is the mechani...

Question 17

Which of the following statements are true of a T cell that expresses two α chains (and thus two different T-cell receptors) as a result of ineffective allelic exclusion of the α chain during rearrangement? (Select all that apply.)

Accepted Answer

A)  Engaging either of the T-cell receptors on MHC molecules of the thymic epithelium will result in positive selection.
B)  One of the T-cell receptors will be functional while the other will most probably be non-functional.
C)  If either T-cell receptor binds strongly to self-peptides presented by self-MHC molecules,the thymocyte will be negatively selected.
D)  One of the T-cell receptors may be autoreactive but escape negative selection because its peptide antigen is present in tissues other than the thymus.
E)  Subsequent gene rearrangements may give rise to a γ:δ T-cell receptor.

Question 18

All of the following types of protein are processed and presented by macrophages in the thymus except _____ proteins.

Accepted Answer

A)  tissue-specific
B)  soluble proteins from extracellular fluids
C)  ubiquitous proteins
D)  proteins made by macrophages
E)  proteins derived from other cells that macrophages phagocytose.

Question 19

After interaction with thymic stromal cells,_____,a glycoprotein not expressed by the uncommitted progenitor cell is activated in developing thymocytes.(Select all that apply.)

Accepted Answer

A)  CD2
B)  CD34
C)  CD5
D)  CD127 (IL-7 receptor) 
E)  CD44.

Question 20

Once a thymocyte has productively rearranged a β-chain gene,which of these event(s) can occur subsequently? (Select all that apply.)

Accepted Answer

A)  β binds to pTα and is expressed on the cell surface with the CD3 complex and ζ chain.
B)  Rearrangement of β-,γ-,and δ-chain genes ceases as a result of the suppression of expression of RAG-1 and RAG-2.
C)  The pre-T cell proliferates and produces a clone of cells all expressing an identical β chain.
D)  Expression of CD34 and CD2 gives rise to double-positive thymocytes.
E)  α-,γ-,and δ-chain loci rearrange simultaneously.

Exam 7: The Development of T Lymphocytes

Indicate which of the following statements is true (T)or false (F).

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

Correct Answer
verified

A.What is immunological tolerance? B.What is the general name for the antigens against which the immune system is normally tolerant?

Correct Answer
verified
A.Immunological tolerance is the mechani...
View Answer

Which of the following processes is not dependent on an interaction involving MHC class I or class II molecules? (Select all that apply.)

Correct Answer
verified

_______ of thymocytes is necessary to produce a T-cell repertoire capable of interacting with self-MHC molecules.

Correct Answer
verified

Which of the following statements are true of a T cell that expresses two α chains (and thus two different T-cell receptors) as a result of ineffective allelic exclusion of the α chain during rearrangement? (Select all that apply.)

Correct Answer
verified

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

Correct Answer
verified

A.Explain two ways in which the expression and processing of self antigens in thymic epithelium differs from the expression and processing of self antigens outside the thymus. B.In what way is the thymic situation advantageous for the purposes of negative selection?

Correct Answer
verified
A. (i)As well as expressing their own th...
View Answer

Which of the following is the first T-cell receptor complex containing the β chain to reach the cell surface during the development of T lymphocytes?

Correct Answer
verified

All of the following types of protein are processed and presented by macrophages in the thymus except _____ proteins.

Correct Answer
verified

The surrogate light chain operating during pre-B-cell development is made up of VpreB:λ.Its expression with μ on the pre-B-cell surface is an important checkpoint in B-cell maturation.Name the T-cell analog of VpreB:λ5 and discuss how it is functionally similar.

Correct Answer
verified
The analog of VpreB:λ5 in developing T c...
View Answer

Which of the following statements about Notch 1 is correct? (Select all that apply.)

Correct Answer
verified

Mature B cells undergo somatic hypermutation after activation,which,after affinity maturation,results in the production of antibody with a higher affinity for antigen than in the primary antibody response.Suggest some reasons why T cells have not evolved the same capacity.

Correct Answer
verified
Because T cells drive almost all immune ...
View Answer

Correct Answer
verified
A.After thymic atrophy or thymectomy,T c...
View Answer

After interaction with thymic stromal cells,_____,a glycoprotein not expressed by the uncommitted progenitor cell is activated in developing thymocytes.(Select all that apply.)

Correct Answer
verified

_____ is a T-cell-specific adhesion molecule expressed before the expression of a functional T-cell receptor while the thymocytes are still in their double-negative stage of development.

Correct Answer
verified

Healthy individuals have approximately ____ of CD4 T cells compared with CD8 T cells.

Correct Answer
verified

Once a thymocyte has productively rearranged a β-chain gene,which of these event(s) can occur subsequently? (Select all that apply.)

Correct Answer
verified

The human thymus begins to degenerate as early as one year after birth.This process is called ____ and is marked by the accumulation of _ once occupied by thymocytes.

Correct Answer
verified

There are many parallels between the development of B cells and T cells.Identify the incorrectly matched counterpart in B cells (left) versus T cells (right) .

Correct Answer
verified

Exam 7: The Development of T Lymphocytes

Indicate which of the following statements is true (T)or false (F).

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

Correct AnswerverifiedShow Answer

A.What is immunological tolerance? B.What is the general name for the antigens against which the immune system is normally tolerant?

Correct AnswerverifiedA.Immunological tolerance is the mechani...View AnswerShow Answer

Which of the following processes is not dependent on an interaction involving MHC class I or class II molecules? (Select all that apply.)

Correct AnswerverifiedShow Answer

_______ of thymocytes is necessary to produce a T-cell repertoire capable of interacting with self-MHC molecules.

Correct AnswerverifiedShow Answer

Which of the following statements are true of a T cell that expresses two α chains (and thus two different T-cell receptors) as a result of ineffective allelic exclusion of the α chain during rearrangement? (Select all that apply.)

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

A.Explain two ways in which the expression and processing of self antigens in thymic epithelium differs from the expression and processing of self antigens outside the thymus. B.In what way is the thymic situation advantageous for the purposes of negative selection?

Correct AnswerverifiedA. (i)As well as expressing their own th...View AnswerShow Answer

Which of the following is the first T-cell receptor complex containing the β chain to reach the cell surface during the development of T lymphocytes?

Correct AnswerverifiedShow Answer

All of the following types of protein are processed and presented by macrophages in the thymus except _____ proteins.

Correct AnswerverifiedShow Answer

The surrogate light chain operating during pre-B-cell development is made up of VpreB:λ.Its expression with μ on the pre-B-cell surface is an important checkpoint in B-cell maturation.Name the T-cell analog of VpreB:λ5 and discuss how it is functionally similar.

Correct AnswerverifiedThe analog of VpreB:λ5 in developing T c...View AnswerShow Answer

Which of the following statements about Notch 1 is correct? (Select all that apply.)

Correct AnswerverifiedShow Answer

Mature B cells undergo somatic hypermutation after activation,which,after affinity maturation,results in the production of antibody with a higher affinity for antigen than in the primary antibody response.Suggest some reasons why T cells have not evolved the same capacity.

Correct AnswerverifiedBecause T cells drive almost all immune ...View AnswerShow Answer

Correct AnswerverifiedA.After thymic atrophy or thymectomy,T c...View AnswerShow Answer

After interaction with thymic stromal cells,_____,a glycoprotein not expressed by the uncommitted progenitor cell is activated in developing thymocytes.(Select all that apply.)

Correct AnswerverifiedShow Answer

_____ is a T-cell-specific adhesion molecule expressed before the expression of a functional T-cell receptor while the thymocytes are still in their double-negative stage of development.

Correct AnswerverifiedShow Answer

Healthy individuals have approximately ____ of CD4 T cells compared with CD8 T cells.

Correct AnswerverifiedShow Answer

Once a thymocyte has productively rearranged a β-chain gene,which of these event(s) can occur subsequently? (Select all that apply.)

Correct AnswerverifiedShow Answer

The human thymus begins to degenerate as early as one year after birth.This process is called ______ and is marked by the accumulation of ___ once occupied by thymocytes.

Correct AnswerverifiedShow Answer

There are many parallels between the development of B cells and T cells.Identify the incorrectly matched counterpart in B cells (left) versus T cells (right) .

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified
A.Immunological tolerance is the mechani...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
A. (i)As well as expressing their own th...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
The analog of VpreB:λ5 in developing T c...
View Answer

Correct Answer
verified

Correct Answer
verified
Because T cells drive almost all immune ...
View Answer

Correct Answer
verified
A.After thymic atrophy or thymectomy,T c...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

The human thymus begins to degenerate as early as one year after birth.This process is called ____ and is marked by the accumulation of _ once occupied by thymocytes.

Correct Answer
verified

Correct Answer
verified