Development and evolution of the immune response

Question 1

1. Which of the following is the earliest site of hematopoiesis in the embryo?

A Bone marrow

B Liver

C Spleen

D Yolk sac

E Thymus

Answer 1

D Yolk sac

Question 2

2. Stem cell factor is produced mainly by:

A Stem cells

B Thymic epithelium

C Bone marrow stromal cells

D Megakaryocytes

E The reticuloendothelial system

Answer 2

C Bone marrow stromal cells

Question 3

3. What are the main population of human hematopoietic stem cells positive for?

A B220

B Mac-1

C Gr-1

D CD8

E CD34

Answer 3

E CD34

Question 4

4. An example of a peptide hormone produced by the thymus is:

A Thymulin

B Thyroglobulin

C Thyroxine

D Thy-1

E Thymine

Answer 4

A Thymulin

Question 5

5. Where are Hassall’s corpuscles found?

A Peripheral blood

B Bone marrow

C Spleen

D Thymus

E Peyer’s patches

Answer 5

D Thymus

Question 6

6. Which of the following statements is NOT TRUE?

A Pluripotent hematopoietic stem cells are produced in the bone marrow

B In adults, the thymus is virtually atrophied and is therefore no longer functional

C Thymocytes are educated in the thymus

D Not all lymphocytes are leukocytes

E Plasma cells are always derived from B-lymphocytes

Answer 6

B In adults, the thymus is virtually atrophied and is therefore no longer functional

Question 7

7. In a thymectomized animal, which of the following is irradiated and reconstituted with bone marrow cells?

A The T-lymphocyte population is not restored

B The B-lymphocyte population is not restored

C All lymphocyte populations are restored

D None of the lymphocyte populations are restored

E Rapid death inevitably follows

Answer 7

A The T-lymphocyte population is not restored

Question 8

8. In the thymic medulla, the majority of γδ T-cells are:

A CD4+CD8+

B CD4+CD8−

C CD4−CD8+

D CD4−CD8−

E Surface Ig+

Answer 8

D CD4−CD8−

Question 9

9. Which of the following statements is TRUE of NKT cells?

A NKT cells have rearranged TCR αβ genes

B NKT cells express a γδ TCR

C NKT cells have rearranged immunoglobulin genes

D NKT cells lack NK1.1

E NKT cells can only recognize lipid antigens presented by MHC

Answer 9

A NKT cells have rearranged TCR αβ genes

Question 10

10. CD8+ T-cells bearing an αβ TCR:

A Always co-express CD4

B Will have expressed terminal deoxynucleotidyl transferase (TdT) during their early development

C Do not require the presence of a thymus for their development

D Recognize native antigen

E Recognize MHC class II molecules

Answer 10

B Will have expressed terminal deoxynucleotidyl transferase (TdT) during their early development

Question 11

11. Which of the following statements is TRUE of αβ T-cells?

A αβ T-cells initially express a pre-TCR bearing an invariant pre-β chain

B αβ T-cells arise earlier in ontogeny than γδ T-cells

C αβ T-cells can be CD4+CD8− but not CD4−CD8+

D Unlike γδ T-cells, αβ T-cells do not rely on Notch-1 signaling pathways during their development

E αβ T-cells express RAG-1 and RAG-2 at the pre-T stage

Answer 11

E αβ T-cells express RAG-1 and RAG-2 at the pre-T stage

Question 12

12. Allelic exclusion is not seen for:

A T-cell receptor α genes

B T-cell receptor β genes

C T-cell receptor γ genes

D T-cell receptor δ genes

E T-cell receptor gene D region segments

Answer 12

A T-cell receptor α genes

Question 13

13. The first wave of fetal γδ T-cell receptor cells in mouse colonize the:

A Female reproductive tract

B Skin

C Peripheral blood

D Thymus

E Gut

Answer 13

B Skin

Question 14

14. What is the percentage of γδ T-cells bearing Vγ9, Vδ2 T-cell receptors in human adult peripheral blood?

A <1%

B 25%

C 50%

D <30%

E 70%

Answer 14

E 70%

Question 15

15. The T-cells in male H-2b SCID mice bearing a transgenic αβ T-cell receptor gene specific for H–Y in association with H-2Db will:

A All be CD4+CD8−

B All be CD4−CD8+

C All recognize H-Y alone

D Undergo continuous proliferation

E Be deleted

Answer 15

E Be deleted

Question 16

16. In Sir Peter Medawar’s classic experiments demonstrating the development of immunological tolerance:

A Thymectomized mice had to be used

B Severe combined immunodeficient (SCID) mice were used

C The mice were chimeric

D Skin grafts were always rejected

E Tolerance could not be induced in neonatal mice

Answer 16

C The mice were chimeric

Question 17

17. Genuine adaptive T- and B-cell responses are seen in:

A The Californian hagfish

B The horseshoe crab

C Xenopus

D Drosophila

E Marine sponges

Answer 17

C Xenopus

Question 18

18. Of the following, which is the protein superfamily with the single most members?

A Integrin

B Chemokine

C Immunoglobulin

D Complement

E Caspase

Answer 18

C Immunoglobulin

Question 19

19. Which is the single cytokine that is most characteristically required for the final differentiation of eosinophils?

A Flt3L

B G-CSF

C IL-4

D IL-6

E IL-5

Answer 19

E IL-5

Question 20

20. Which of the following is the single best defining molecule on, or in, a B-cell?

A CD5

B CD19

C CD25

D CD45

E RAG-1

Answer 20

B CD19