Chapter 6: Role of Lymphocytes in Adaptive Immunity

Question 1

What cells process antigens to present them to lymphocytes

Answer 1

Monocytes and macrophages (APCs)

Question 2

Which cells respond to foreign antigens that have been processed by monocytes and macrophages?

Answer 2

Lymphocytes

Question 3

General term for chemical messengers

involved in immune system communication

Answer 3

Cytokines

Question 4

Cytokines secreted by lymphocytes

Answer 4

Lymphokines

Question 5

Cytokines secreted by monocytes

Answer 5

Monokines

Question 6

Cytokines that interfere with the multiplication of viruses within the cell (and adjacent cells)

Answer 6

Interferons

Question 7

Cytokines that convey regulatory signals between cells

(including leukocytes) of the immune system

Answer 7

Interleukons

Question 8

Cytokines that destroy foreign or abnormal cells,
including tumor cells; act early in inflammatory cytokine
signaling cascades

Answer 8

Tumor necrosis factors

Question 9

Where do precursor cells of the lymphatic system form/

Answer 9

Bone marrow

Question 10

What are the two fates of precurser cells of lymphocytes in the bone marrow?

Answer 10

1) Migrate to the thymus to become T lymphocytes (CD4+ or CD8+)
2) Remain in bone marrow and develop B lymphocytes.

Question 11

What are the primary lymphoid organs?

Answer 11

Bone marrow and thymus

Question 12

What types of T cells’ TCRs recognize Ag/MHC II?

Answer 12

CD4+

Question 13

What types of T cells’ TCRs recognize Ag/MHC I?

Answer 13

CD8+

Question 14

Which types of T cells are helper cells?

Answer 14

CD4+

Question 15

Which types of T cells are cytotoxic?

Answer 15

CD8+

Question 16

What is needed to stimulate CD4+ T helper cells?

Answer 16

Presentation of antigens from the processed (phagocytosed, lysomally digested, with surface displayiing MHC II carrier) pathogen by macrophages/APCs.

Question 17

What happens when CD4+ T helper cells are stimulated?

Answer 17

1) They help the proper Ab-producing B cells proliferate, differentiate into plasma cells, and make Ab.
2) Activate CD8+ cytotoxic T cells that can eliminate infected cells by recognizing Ag with MHC I on their surface and destroying them.

Question 18

Why are certain B cells chosen by stimulated CD4+ cells?

Answer 18

Their surface Ab could bind the foreign Ag, internalize it, and display pieces on their surface with MHC II to indicate they would be useful Ab-producing cells to expand

Question 19

How do CD8+ cells eliminate infected cells?

Answer 19

Either by perforin or apoptosis

Question 20

Make up 2/3 of circulating lymphocytes

Answer 20

T cells

Question 21

Make up 10-15% of circulating lymphocytes.

Answer 21

Natural killer cells

Question 22

True or false: Natural Killer cells need time to become activated and function effectively

Answer 22

False

Question 23

True or false: B and T cells must already be immune competent in order to participate in immune responses.

Answer 23

True

Question 24

True or false: The programming process by which lymphocytes acquire immune competence involves rearrangement of gene segments within the developing B and T lymphocytes; this occurs after Ag exposure

Answer 24

False: Occurs before Ag exposure

Question 25

What are the antigen receptors on T cells?

Answer 25

TCRs

Question 26

What are the antigen receptors on B cells?

Answer 26

Ab

Question 27

What does the programming process by which B and T cells gain immune competence involve?

Answer 27

Rearrangement of gene segments resulting in antigen receptors on the cell surface that allow the lymphocyte to recognize and respond to a specific antigen.