Test 2: Intro to immunology

Question 1

What are the 2 types of immune system?

Answer 1

adaptive and innate immunity

Question 2

What is the protective response for immune system?

Answer 2

defense against microbes and tumors

Question 3

What happens if immune system goes out of control?

Answer 3

can cause autoimmune (type 1 diabetes) or inflammatory diseases, also cause hypersensitivities and allergies

Question 4

T/F: immune system also can react to self

Answer 4

True!
Immune can react to substance, infection or non-infection, foreign or self

Question 5

What is the substance that induces a specific adaptive immune response (T and B cells)?

Answer 5

Antigen
- can be proteins, nucleic acids, lipids, polysaccharides, and metals only in adaptive immune response

Question 6

What is the difference between primary and secondary immune response?

Answer 6

primary: first antigen encounter
secondary: second encounter with same antigen (usually respond quicker and differently because more antibodies are ready)

Question 7

T/F: Immune system is controlled randomly.

Answer 7

False!
It is a very controlled and coordinated action of cells and molecules

Question 8

T/F: Immune system can respond to tissue grafts

Answer 8

True!
Immune response can give barriers to transplant and gene therapy

Question 9

What are characteristics of innate immunity?

Answer 9

immediate, non-antigen specific response, no memory, no activation necessary

(fast and dumb)

Question 10

T/F: Innate immunity isn’t always present

Answer 10

False!
Innate immunity is always present to block microbe entry

Question 11

What are characteristics of adaptive immunity?

Answer 11

require specific antigen recognition, expansion, activation, and involve long lasting memory

Question 12

Which is immediate and which is delayed: innate vs adaptive?

Answer 12

innate= immediate
adaptive= delayed

Question 13

What does the adaptive immune system require involving lymphocytes?

Answer 13

adaptive immunity requires expansion/differentiation of lymphocytes

Question 14

In adaptive immunity, what is humoral immunity mediated by?

Answer 14

antibodies; extracellular microbe
(B lymphocyte is the responder)
goal: block infections and eliminate extracellular microbes

Question 15

In adaptive immunity, what is cell-mediated immunity?

Answer 15

T-lymphocytes– intracellular microbes
goal: eliminate phagocytosed microbes (helper T cells) and kill infected cells and eliminate reservoirs of infection (cytotoxic T cells)

Question 16

In adaptive immunity, where do they recognize microbial antigens?

Answer 16

on microbes or host cell surface

Question 17

In memory response, how long does the primary and secondary response take to arise?

Answer 17

primary: 1-3 weeks
(the antibodies die but some remain to become memory B cells to allow for a faster response the next exposure)
secondary: 2-7 days

Question 18

Where do B and T cells mature?

Answer 18

B=bone marrow
T=thymus

Question 19

What are the stages for B/T cell maturation?

Answer 19

antigen recognition-proliferation-differentiation-memory lymphocyte

Question 20

What is the life span of naive T/B cells?

Answer 20

weeks-months but will die if no antigen

Question 21

What is the life span of effector T/B cells?

Answer 21

short lived and die when antigen is eliminated

Question 22

What is the life span of memory T/B cells?

Answer 22

for long period of time (years)

Question 23

What does the organization of secondary lymphoid organs enable?

Answer 23

antigen present cells to concentrate antigens, lymphocytes to locate and respond to antigens, and cells to interact with each other

Question 24

What does lymph draining into lymph nodes allow?

Answer 24

concentrate antigens, allow sampling of antigens by antigen presenting cells at the site

Question 25

T/F: There are distinct B and T cell zones

Answer 25

True!

B cells on the outside (cortex)
T cells on the inside (paracortex)

Question 26

What do dendritic cells do for lymph nodes?

Answer 26

pick up antigens in tissues and migrate to lymph nodes

Question 27

What allows for blood to enter spleen and allow sampling of antigens?

Answer 27

antigen presenting cells

Question 28

Where do activated T cells migrate to and what do they do there?

Answer 28

Activated T cells migrate to tissues to eliminate microbes

Question 29

What is the organization of the mucosal immune system (gut)?

Answer 29

similar organization as lymph nodes (tonsils, Peyer’s patch)
- 25% of lymphocytes here

Question 30

How is movement of T and B cells coordinated to go to their own zones?

Answer 30

chemokine and chemokine receptors

Question 31

What are B cells attracted to?

Answer 31

attracted in follicles around periphery
(CXCR5–> CXCL5)

Question 32

What are T cells attracted to?

Answer 32

attracted outside but adjacent to follicles (paracortex)
(CCR7–> CCL19)

Question 33

What are the cells involved in innate immunity?

Answer 33

epithelial barriers, phagocytes (neutrophils, monocytes, macrophages), dendritic cells, plasma proteins, and natural killer cells

Question 34

What are the cells involved in adaptive immunity?

Answer 34

Naive B cell to become antibodies
Naive T cell (involved in antigen recognition) to become effector T cells

Question 35

T/F: Repeated antigen exposure mounts larger and more effective responses

Answer 35

True!

Question 36

What cells are involved in specific recognition of antigens?

Answer 36

• B lymphocytes: mediators of humoral immunity
• T lymphocytes: mediators of cell-mediated immunity

Question 37

What cells are involved in capturing antigens for display to lymphocytes (antigen presenting cells)?

Answer 37

• Dendritic cells: initiation of T cell responses
• Macrophages: effector phase of cell-mediated immunity
• Follicular dendritic cells: display of antigens to B lymphocytes in humoral immune responses

Question 38

What cells are involved in elimination of antigens (effector cells)?

Answer 38

• T lymphocytes: activation of phagocytes, killing infected cells
• Macrophages: phagocytosis and killing of microbes
• Granulocytes: killing microbes

Question 39

Where are the lymphocytes located?

Answer 39

blood/lymphoid organs

Question 40

Where are the antigen presenting cells located?

Answer 40

tissues/lymphoid organs

Question 41

Where are the effector T cells located?

Answer 41

blood to the infection site
(naive T cells circulate through lymphoid organs)

Question 42

What cell’s main function is to produce antibodies

Answer 42

B lymphocyte

Question 43

Where do B and T cells arise from?

Answer 43

bone marrow but mature in different places

Question 44

T/F: The thymus grows as we age.

Answer 44

False!
The thymus shrinks as we age so producing less naive T cells but our memory T cells increase

Question 45

What is the difference between primary and secondary lymphoid organs?

Answer 45

• primary: bone marrow and thymus that allow for maturation
• secondary: lymph nodes, spleen, appendix, and Peyer’s patch that allow for activation

Question 46

Which tissue has the most number of lymphocytes?

Answer 46

lymphocytes

Question 47

What are the phases of adaptive immune response?

Answer 47

1) antigen recognition
2) clonal expansion
3) differentiation in effector cells
4) contraction via apoptosis
5) memory cells

Question 48

What do antigen presenting cells present to?

Answer 48

They capture and antigens and concentrate them in lymphoid organs and then present it to T cells

Question 49

Describe the steps of T lymphocytes in tissues

Answer 49

• mature in primary lymphoid organ: thymus
• get in circulation when matured
• go through high endothelial venue
• get activated in secondary lymphoid organ
• once activated: become effector T cells
• proliferate and leave by the efferent lymphatic vessel to go to infected site
• once in tissue, can eliminate microbe