Lecture 2

Question 1

Where do T cells mature?

Answer 1

Thymus

Question 2

What type of immunity do T cells give rise to upon stimulation by antigens?

Answer 2

Cellular immunity

Question 3

Where do B cells mature?

Answer 3

Bone marrow

Question 4

What type of immunity do B cells give rise to?

Answer 4

Humoral immunity

Question 5

What type of microbes do B lymphocytes work against?

Answer 5

Extracellular microbes

Question 6

What type of microbes do T lymphocytes primarily work against?

Answer 6

Intracellular microbes

Question 7

T helper lymphocytes

Answer 7

Recognize Ags on surfaces of APCs and secrete cytokines; stimulate different mechanisms of immunity and inflammation

Question 8

Cytotoxic T lymphocytes

Answer 8

Recognize Ags on infected cells and directly kill these cells

Question 9

Regulatory T cells

Answer 9

Suppress and prevent immune responses (such as to self antigens)

Question 10

Specificity

Answer 10

Ensures that immune response to a microbe is selective to that microbe

Question 11

Diversity

Answer 11

Enables immune system to respond to a large variety of Ags

Question 12

Memory

Answer 12

Increases ability to combat repeat infections by same microbe

Question 13

Clonal expansion

Answer 13

Increases the number of Ag-specific lymphocytes to keep pace with microbes

Question 14

Specialization

Answer 14

Generates responses that are optimal for defense against different types of microbes

Question 15

Contraction and homeostasis

Answer 15

Allows immune system to recover from one response so that it can effectively respond to newly encountered Ags

Question 16

Nonreactivity to self

Answer 16

Prevents injury to host during responses to foreign Ags

Question 17

What are the primary lymphoid organs?

Answer 17

Thymus and bone marrow

Question 18

What are the secondary lymphoid organs?

Answer 18

Spleen, lymph nodes, MALT

Question 19

What is the lifespan of naive lymphocytes that do not recognize antigens?

Answer 19

1-3 months

Question 20

Define “naive cells”

Answer 20

B-cells or T-cells that have not yet been exposed to antigens

Question 21

What cytokines are important to T cell development?

Answer 21

IL-1, IL-2, IL-6, IL-7

Question 22

Where in the thymus are naive T cells maintained?

Answer 22

Periphery of thymus

Question 23

What happens to B and T cells which are highly reactive with self-antigens?

Answer 23

They are deleted by apoptosis

Question 24

Which T cells express CD4 and provide help for B cell growth and differentiation?

Answer 24

T helper cells

Question 25

Which T cells express CD8 and recognize and kill virus-infected cells?

Answer 25

Cytotoxic T lymphocytes

Question 26

What molecules are involved in development of B cells?

Answer 26

Stromal cells, IL-1, IL-6, IL-7

Question 27

What locations in the body are the only locations where lymphocytes do not continuously circulate?

Answer 27

Eye, brain, testicles

Question 28

High Endothelial Venules (HEVs)

Answer 28

Postcapillary venules where lymphocytes enter secondary lymphoid organs when searching for foreign Ags; contain homing receptors for lymphocytes

Question 29

Through what structure do lymphocytes reenter circulation?

Answer 29

Efferent lymph vessels

Question 30

What is required for antibody responses to protein antigens?

Answer 30

B cells must present the antigens to T helper cells

Question 31

Where do antigen-activated B cells proliferate and mature into memory or plasma cells?

Answer 31

Germinal centers of lymph nodes

Question 32

What are plasma cells?

Answer 32

Terminally differentiated B cells which produce and secrete large amounts of antibodies

Question 33

What types of antibodies are produced in the spleen?

Answer 33

Antibodies that defend against microbial polysaccharides

Question 34

White pulp of the spleen

Answer 34

Contains T and B cell zones

Question 35

What type of cells are found in the periarteriolar lymphoid sheath of the spleen?

Answer 35

T cells

Question 36

What type of cells are found in the lymphoid follicle containing a germinal center?

Answer 36

B cells

Question 37

What must occur before T cells can differentiate into effector or memory T cells?

Answer 37

Activation by antigens

Question 38

How are B and T cells directed to different zones of the lymph node?

Answer 38

Via chemokines

Question 39

How are antigens transported to the lymph node?

Answer 39

Via dendritic cells that pick up antigens from the site of antigen entry

Question 40

To what area of the lymph node do the dendritic cells migrate?

Answer 40

T-cell rich areas

Question 41

What is the structure of the lymph node follicle in the absence of antigen stimulation?

Answer 41

Primary follicle - contains small naive B cells or memory B cells

Question 42

What is the structure of the lymph node follicle in the presence of antigen stimulation?

Answer 42

Conversion to Secondary follicle/germinal center due to proliferation/differentiation of B cells

Question 43

What are the professional APCs required to activate T cells?

Answer 43

Dendritic cells, Tissue macrophages, B cells

Question 44

What is the function of APCs?

Answer 44

Capture, process and display antigens to lymphocytes - stimulate proliferation/differentiation of T cells

Question 45

Which of the APCs can activate naive T cells in the lymph node?

Answer 45

Dendritic cells ONLY

Question 46

Which of the APCs can present antigens for effector T cells only?

Answer 46

Macrophages and B cells

Question 47

What processes are used by dendritic cells to acquire antigens?

Answer 47

phagocytosis, receptor-mediated endocytosis, pinocytosis

Question 48

Classical dendritic cells

Answer 48

Reside in skin, mucosa, organ parenchyma and migrate to lymph nodes when activated by microbes to display protein antigens to T cells

Question 49

Plasmacytoid dendritic cells

Answer 49

Early responders to viral infection; produce soluble proteins such as type I interferons

Question 50

Inflammatory dendritic cells

Answer 50

Derived from circulating monocytes during times of inflammation

Question 51

Follicular Dendritic Cells (FDCs)

Answer 51

Bind and display unprocessed antigens for recognition by B cells only