Session 15- Cell-mediated immunity

Question 1

Which of the following is the primary site for T-cell activation?
a. Thymus
b. Lymph node
c. Bone marrow
d. Bursa of Fabricius

Answer 1

Lymph node

Question 2

What creates the diversity that we see in T-lymphocytes?
a. Mutations that take place in mature cells
b. Rearrangements in the CD4 receptor
c. T-cells originate from numerous different progenitor cells in the bone marrow
d. Rearrangements in T-cell receptor (TCR) genes during development

Answer 2

Rearrangements in T-cell receptor (TCR) genes during development

Question 3

What is positive selection?
a. Selection process that removes lymphocytes that bind too strongly to self-antigen
b. Selection process that identifies and retains those lymphocytes that bind self-antigens with moderate affinity
c. Selection process in which T-lymphocytes are removed if there is no interaction with self-antigen
d. Selection process in which a potentially harmful immune response is converted to a less harmful response

Answer 3

Selection process that identifies and retains those lymphocytes that bind self-antigens with moderate affinity

Question 4

What is a primary function of the T-helper cells?
a. Produce antibodies in response to infection
b. Produce cytokines that affect the actions of other cells
c. Secrete perforins to induce cell lysis
d. Identify and remove clones of T-cells that react too strongly to foreign antigens

Answer 4

Produce cytokines that affect the actions of other cells

Question 5

Which of the following mechanisms of peripheral tolerance involves inactivation of self-reactive lymphocytes?
a. Non-selection
b. Clonal deletion
c. Immune privilege
d. Anergy

Answer 5

Anergy

Question 6

Which T-cells produce interleukin-2 (IL-2) and interferon-gamma (IFN-γ) in response to intracellular microbes?
a. T-helper 1 lymphocytes
b. T-helper 2 lymphocytes
c. T-helper 17 lymphocytes
d. Cytotoxic T-cells

Answer 6

T-helper 1 lymphocytes

Question 7

What is a feature of CD8+ T-cells?
a. They recognize MHC class II molecules.
b. They contain perforins and granzymes.
c. They kill extracellular bacteria and fungi.
d. They activate to become T-helper cells.

Answer 7

They contain perforins and granzymes.

Question 8

Put the steps of CD4+ T-cell activation and differentiation in order.
a. Binding of B7 to CD28 (costimulation)
Presentation of antigen by dendritic cells
Production of IL-2
Binding of TCR and CD4 to the MHC II molecule
b. Production of IL-2
Binding of B7 to CD28 (costimulation)
Presentation of antigen by dendritic cells
Binding of TCR and CD4 to the MHC II molecule
c. Presentation of antigen by dendritic cells
Binding of TCR and CD4 to the MHC II molecule
Binding of B7 to CD28 (costimulation)
Production of IL-2

Answer 8

Presentation of antigen by dendritic cells
Binding of TCR and CD4 to the MHC II molecule
Binding of B7 to CD28 (costimulation)
Production of IL-2

Question 9

What is true about T-regulatory cells?
a. They guide B-cells to help clear infections.
b. They produce cytokines that destroy immune cells.
c. They recruit neutrophils to the site of infection.
d. They suppress T-cell responses.

Answer 9

They suppress T-cell responses.

Question 10

What T-helper cell subset is involved in parasitic infections?
a. T-helper 1 cells
b. T-helper 2 cells
c. T-helper 17 cells
d. T-regulatory cells

Answer 10

T-helper 2 cells