Exam 2: Dr. Pharr Principles of Adaptive Immunity

Question 1

What is adaptive immunity’s focus?

Answer 1

Defense mechanisms onto the pathogen itself

Question 2

What do lymphocytes of adaptive immunity express?

Answer 2

Antigen receptors that recognize specific features of a microorganism

Question 3

What does the recognition of specific features of microorganisms allow the adaptive system to do?

Answer 3

Distinguish between different microorganisms

Question 4

What is immune memory?

Answer 4

A second encounter with the same pathogen that will induce a more rapid and efficient adaptive immune response

Question 5

How do effector cells eliminate pathogens from the body?

Answer 5

Effector function

Question 6

What is a pathogen?

Answer 6

A microbe that has a disease causing function or antagonist to the animal

Question 7

Why are all non-self microbes harmful?

Answer 7

They can replicate

Question 8

What is a B cell receptor referred to as?

Answer 8

Immunoglobulin

Question 9

What are the soluble forms if B cell receptors referred to as?

Answer 9

Antibodies

Question 10

What does the surface of T lymphocytes/cells express?

Answer 10

T cell receptor

Question 11

What are the regions that make up B cell and T cell receptors?

Answer 11

Variable region

Constant region

Question 12

What happens in the variable region?

Answer 12

Antigen binding

Question 13

What does the constant region do?

Answer 13

Anchors the receptor to the cell membrane

Question 14

What does the constant region determine when the BCR is secreted as an antibody?

Answer 14

The effector function of the antibody

Question 15

Where do B cells develop? T cell?

Answer 15

Bone marrow

Thymus

Question 16

What do antigen receptors recognize?

Answer 16

Protein, carbohydrates, and lipids

Self-proteins, self-carbohydrates, and self-lipids

Question 17

Why do B cells and T cells recognize different forms of the same antigen?

Answer 17

Because of their particular effector functions

Question 18

What do BCRs recognize?

Answer 18

The native form of an antigen

Question 19

What do TCRs recognize?

Answer 19

Peptides derived from the proteolytic degradation of the antigen

Question 20

Where does T cell recognition of antigen occur?

Answer 20

Secondary lymphoid tissues

Question 21

Where are dendritic cells present?

Answer 21

In the tissues with macrophages

Question 22

How do dendritic cells activate adaptive immunity?

Answer 22

In a situation where the innate response is overwhelmed, DCs engulf the pathogen at the site of infection and migrate in afferent lymphatic vessels to lymph nodes

Question 23

Where do DCs enter? Where do the migrate to?

Answer 23

Enter lymph node

Migrate to the capillaries where lymphocytes enter

Question 24

Because DCs enter the lymph node and migrate to capillaries, what can naive T cells do?

Answer 24

Enter the lymph node and survey the antigens displayed on the surface of DCs

Question 25

What does antigen do?

Answer 25

Causes specific T cells to be activated to proliferate and then differentiate into effector T cells

Question 26

After T cells have been differentiated into effector T cells due to antigen, what happens to effector T cells?

Answer 26

Migrates to the lymph node to the site of infection and display their effector function

Question 27

What are the effector functions of effector T cells?

Answer 27

Activate macrophages to kill pathogens that have been taken up by phagocytosis (helper T cells) Kill infected cells (cytotoxic T cells)

Question 28

Where are the 2 zones of the lymphocyte? Where are the zones located?

Answer 28

B cell zone–located in the medulla | T cell zone–located in the outer cortex

Question 29

What do some of the effector T cells (helper T cells) remain in the lymph node for?

Answer 29

To provide activation signals to antigen specific B cells

Question 30

What do DCs do?

Answer 30

Antigen processing | Antigen presentation

Question 31

What is the major histocompatibility complex (MHC)?

Answer 31

A complex of immune system genes that encode membrane potentials which are involved in presenting peptides to T cells

Question 32

What do T cells recognize? How?

Answer 32

An infection | By detecting peptide fragments derived from the pathogen

Question 33

What happens to the peptides recognized by T cells?

Answer 33

They are captured by MHC proteins and expressed on the surface of cells

Question 34

What are MHC proteins like?

Answer 34

They have a broad specificity and can bind peptides derived from many different pathogens

Question 35

Where is MHC class I expressed?

Answer 35

On the surface of most nucleated cells in the body

Question 36

What is MHC class I recognized by?

Answer 36

Cytotoxic T cells which express the co-receptor protein CD8

Question 37

Where is MHC class II expressed?

Answer 37

On the surface of DCs, macrophages, and B cells

Question 38

What is MHC class II recognized by?

Answer 38

Helper T cells which express the co-receptor protein CD4

Question 39

What is the function of MHC class I proteins in protection against intracellular pathogens?

Answer 39

Many proteins in a cell are degraded into short peptides after performing their function and pumped into the endoplasmic reticulum

Question 40

What happens to peptides in the ER?

Answer 40

They are bound by newly synthesized MHC class I protein and then transported to the cell surface

Question 41

What happens to some of the viral proteins during a viral infection

Answer 41

They will be degraded in cytoplasm and transported to the ER for binding to MHC class I

Question 42

Where are naive cytotoxic T cells activated?

Answer 42

Secondary lymphoid tissues by dendritic cells

Question 43

What do effector cytotoxic T cells do after activation?

Answer 43

Enter the circulation and are recruited to the site of viral infection

Question 44

What is the effector function of cytotoxic T cells?

Answer 44

Recognize and eliminate infected host cells

Question 45

What is the function of MHC class II proteins in protection against extracellular pathogens?

Answer 45

Naive helper T cells are activated in secondary lymphoid tissue by DCs Effector helper T cells are recruited to the site of infection and will activated the effector function of other leukocytes responding to the infection

Question 46

What do effector helper T cells do to kill intracellular bacteria?

Answer 46

Activate macrophage production of powerful reactive oxygen species

Question 47

What does antigen binding to the B cell receptor facilitate?

Answer 47

Internalization of the antigen for processing and presentation by MHC class II

Question 48

What will activation of B cells by effector helper T cells induce?

Answer 48

B cell proliferation and differentiation to plasma cells

Question 49

What do plasma cells do?

Answer 49

Synthesize and secrete the original antigen receptor as antibody

Question 50

What are the 2 signals required for lymphocyte activation?

Answer 50

1. Recognition of antigen | 2. Delivered by another cell

Question 51

What do antigen-activated T cells require a second signal from?

Answer 51

DCs

Question 52

What do antigen-activated B cells require a second signal from?

Answer 52

Effector helper T cells