Immune Background

Question 1

5 general functions of the immune system

Answer 1

Defence against infections
Defence against tumors
Clearance of dead cells and tissue repair
Can injury cells and induce pathologic inflammation
Recognizes and responds to tissue grafts and newly introduced proteins

Question 2

Lymphocytes

Answer 2

Mediators of the adaptive immune response

Only cells with specific receptors for antigens

Question 3

Antigen-presenting cells

Answer 3

Specialized to capture, concentrate, and display antigens for recognition by lymphocytes
Ex: dendritic cells, macrophages, B cells, follicular DCs

Question 4

Development of

1. B cells
2. T cells

Answer 4

1. From stem cells in the bone marrow, mature there and released into blood
2. Created from stem cells in the bone marrow, mature in the thymus and enter the blood and lymph

Question 5

2 steps in B cell activation

Answer 5

Antigen must bind to sites (antibodies on surface)

Stimulation by helper T cells

Question 6

Helper T cells

Answer 6

Respond to nearly all antigens
Produce CD4, which helps bind to class 2 MHC complexes on APCs
Cannot kill, just activate other immune cells

Question 7

Cytolytic T cells

Answer 7

Main response towards infected and cancerous cells
Produce CD8
Binds transplanted tissue, infected cells, cancer cells
Secrete proteins that cause cell death

Question 8

5 components of innate immunity

Answer 8

Epithelial barriers
Phagocytes
Dendritic cells
Complement system
Natural killer cells

Question 9

Innate immunity definition

Answer 9

Always present (ready to defend)
Many pathogenic microbes have evolved to resist innate immunity

Question 10

Adaptive immunity definition

Answer 10

Stimulated by exposure to microbe

More potent than innate

Question 11

Adaptive immunity involves…

Answer 11

B lymphocytes (antibodies
T lymphocytes (effector T cells)

Question 12

Humoral immunity

Answer 12

B lymphocytes

Block infections and eliminate extracellular microbes using antibodies

Question 13

Cell mediated immunity

Answer 13

Helper T cells and cytotoxic T cells
Activate macrophages to kill phagocytosed microbes
Kill infected cells and eliminate reservoirs of infection

Question 14

4 general steps of the immune response

Answer 14

1. Antigen recognition and presentation
2. IL 1 production
3. IL 2 production
4. Lymphocyte proliferation and differentiation