Lecture 11

Question 1

What event occurs after the binding of a CD40 protein on a B cell to a CD40 ligand on a T cell?

A) internalization of antigen bound by B-cell receptors
B) release of perforins and granzymes from the T cell
C) release of IL-4 and IL-6 from the T cell
D) initiation of heavy chain class switching in the B cell.

Answer 1

D) initiation of heavy chain class switching in the B cell

Question 2

Which two events are required to activate a cytotoxic T cell?

A. IL-2 is released by a TH1 cell to be bound by a cytotoxic T cell.
B. Class I MHC molecules presents intracellular antigen for binding on a complementary cytotoxic T cell receptor.
C. IL-4 is released by a TH1 cell to be bound by a cytotoxic T cell.
D. Class II MHC molecules present extracellular antigen for binding on a complementary cytotoxic T cell receptor

Answer 2

A. IL-2 is released by a TH1 cell to be bound by a cytotoxic T cell.

B. Class I MHC molecules presents intracellular antigen for binding on a complementary cytotoxic T cell receptor.

Question 3

Which of the following is the most antigenic?

A) Lipids
B) Carbohydrates
C) Nucleic acids
D) Proteins

Answer 3

D) Proteins

Question 4

____ are the strongest antigens because they form a variety of shapes, they maintain tertiary structures, and they are made of amino acids in different combinations

Answer 4

Proteins

Question 5

____ and ____ tend to be weaker antigens because they are more flexible and their subunits are relatively uniform.

Answer 5

Lipids; nucleic acids

Question 6

All (nucleated) cells in a human body normally have:

A) Class I MHC molecules.
B) Class II MHC molecules.
C) CD8 surface antigens.
D) CD4 surface antigens.

Answer 6

A) Class I MHC molecules.

Question 7

Class ____ molecules are found on the surface of all nucleated cells

Answer 7

I MHC

Question 8

Class ____ molecules are found on the surface of antigen-presenting cells (dendritic cells, macrophages, and B cells)

Answer 8

II MHC

Question 9

MHC molecules are used to present ____ to ____ cells.

Answer 9

antigen; T

Question 10

Breast milk and colostrum provide passive immunity to infants in the form of ______. Hint: mucosal antibodies

A) IgE
B) IgG
C) IgM
D) IgA

Answer 10

D) IgA

Question 11

____ is secreted across mucosal surface and is found in tears, breast milk, and saliva.

Answer 11

IgA

Question 12

____ immunity occurs when babies receive IgG through the placenta and IgA through breast milk.

Answer 12

Passive

Question 13

In which of the following scenarios would you expect capping to occur?

A) A B-cell contacts a soluble protein with many different epitopes.
B) A T-cell recognizes antigen bound to the surface of an antigen-presenting cell.
C) A B-cell contacts a microbe with multiple copies of the same epitope.
D) A T-cell recognizes antigen bound to the surface of a B-cell.

Answer 13

C) A B-cell contacts a microbe with multiple copies of the same epitope.

Question 14

____ occurs when adjacent B-cell receptors bind adjacent epitopes on a microbe

Answer 14

Capping

Question 15

Capping is ____ cell independent and leads to activation of the ____ cell.

Answer 15

T, B

Question 16

Jamal is vaccinated against varicella, also known as chicken pox, as a young child. If he has subsequent exposure to the varicella virus as an adult, what would you expect to occur?

A) He would rapidly secrete much higher levels of IgM than he did after vaccination.
B) Class switching would lead to a switch from IgG production to IgM production.
C) He would develop varicella because vaccines only stimulate low levels of antibodies.
D) His titer levels of IgG would be much higher than they were after vaccination.

Answer 16

D) His titer levels of IgG would be much higher than they were after vaccination.

Question 17

Vaccination stimulates a ____ immune response.

Answer 17

primary

Question 18

During a secondary immune response, subsequent exposure would lead to class switching from ____ production to ____ production

Answer 18

IgM; IgG

Question 19

During a secondary immune response, ____ antibodies would be secreted at much higher levels.

Answer 19

IgG

Question 20

Patients who have functioning T cells but dysfunctional B cells will retain:

A) the ability to produce plasma cells.
B) cell-mediated immunity.
C) the ability to produce antibodies.
D) humoral immunity.

Answer 20

B) cell-mediated immunity.

Question 21

____ cells are responsible for the production of antibodies during a humoral immunity response

Answer 21

B

Question 22

The specific cells that secrete antibodies are differentiated B cells known as ____ cells.

Answer 22

plasma

Question 23

____ cells are responsible for cell-mediated immunity.

Answer 23

T

Question 24

T cells capable of activating cytotoxic T cells are known as ______.

A) TH2 cells
B) TH0 cells
C) TH1 cells
D) Treg cells

Answer 24

C) TH1 cells

Question 25

The major function of TH1 cells is activation of ____.

Answer 25

cytotoxic T cells

Question 26

The major function of Treg cells is ____.

Answer 26

anti-inflammatory

Question 27

The major function of TH2 cells is ____.

Answer 27

helping B cells

Question 28

The major function of TH0 cells is differentiation into ____.

Answer 28

TH1 or TH2 cells

Question 29

The binding of the T-cell receptor (TCR) of a TH0 cell to an antigen-MHC complex is not enough to activate the TH0 cell. A second activation signal involves an interaction between: A) a CD40 molecule on the T cell and a CD4 molecule on the antigen-presenting cell. B) a CD28 molecule on the T cell and a B7 molecule on the antigen-presenting cell. C) a B7 molecule on the T cell and a CD28 molecule on the antigen-presenting cell. D) a CD4 molecule on the T cell and a CD40 molecule on the antigen-presenting cell.

Answer 29

B) a CD28 molecule on the T cell and a B7 molecule on the antigen-presenting cell.

Question 30

Two interactions must occur for TH0 cells to become activated. The first interaction involves linking a T-cell receptor to an ____ on antigen-presenting cell (APC). The second interaction involves linking a ____ to a B7 protein on the APC surface.

Answer 30

antigen-MHC II complex; CD28 on the T-cell surface

Question 31

The step leading directly to the binding of CD40 and CD40 ligand is ____.

Answer 31

the binding of a T-cell receptor to an antigen-MHC II complex on a B-cell

Question 32

What is the first molecular signal required for TC cell activation? A) secretion of the cytokine IL-2 from a TH1 cell B) binding of a T-cell receptor to an antigen-MHC I complex on an antigen-presenting cell C) secretion of the cytokine IL-1 from a TH0 cell D) binding of a CD28 molecule on the T cell to a B7 protein on an antigen-presenting cell

Answer 32

B) binding of a T-cell receptor to an antigen-MHC I complex on an antigen-presenting cell

Question 33

Two molecular signals are required for activation of Tc cells. The first signal involves binding of the ____. CD8 molecules on the Tc cell allow this binding to class I MHC on the APC occur. The second signal is the secretion of the ____.

Answer 33

T-cell receptor (TCR) to an antigen-presenting cell (APC); cytokine IL-2 from TH1 cells.

Question 34

Which of the following is considered a "professional" antigen-presenting cell (APC)? A) epithelial cell B) fibroblast C) macrophage D) chondrocyte

Answer 34

C) macrophage

Question 35

Macrophages, dendritic cells, mast cells, and B cells are considered ____.

Answer 35

"professional" APCs.

Question 36

Antibodies are produced by _____. a. plasma cells b. T cells c. bone marrow d. Macrophages

Answer 36

a. plasma cells

Question 37

Cellular adaptive immunity is carried out by ______. a. B cells b. T cells c. bone marrow d. neutrophils

Answer 37

b. T cells

Question 38

single antigen molecule may be composed of many individual _____. a. T-cell receptors b. B-cell receptors c. MHC II d. epitopes

Answer 38

d. epitopes

Question 39

Which class of molecules is the most antigenic? a. polysaccharides b. lipids c. proteins d. carbohydrates

Answer 39

c. proteins

Question 40

MHC I molecules present ____. ``` a. processed foreign antigens from proteasomes. b. processed self-antigens from phagolysosome. c. antibodies. d. T cell antigens. ```

Answer 40

a. processed foreign antigens from | proteasomes.

Question 41

MHC II molecules present ____. a. processed self-antigens from proteasomes. b. processed foreign antigens from phagolysosomes. c. antibodies. d. T cell receptors.

Answer 41

b. processed foreign antigens from | phagolysosomes.

Question 42

Which type of antigen-presenting molecule is found on all nucleated cells? a. MHC II b. MHC I c. antibodies d. B-cell receptors

Answer 42

b. MHC I

Question 43

Which type of antigen-presenting molecule is found only on macrophages, dendritic cells, and B cells? a. MHC I b. MHC II c. T-cell receptors d. B-cell receptors

Answer 43

b. MHC II

Question 44

What is a superantigen? a. a protein that is highly efficient at stimulating a single type of productive and specific T cell response b. a protein produced by antigen-presenting cells to enhance their presentation capabilities c. a protein produced by T cells as a way of increasing the antigen activation they receive from antigen-presenting cells d. a protein that activates T cells in a nonspecific and uncontrolled manner

Answer 44

d. a protein that activates T cells in a | nonspecific and uncontrolled manner

Question 45

To what does the TCR of a helper T cell bind? a. antigens presented with MHC I molecules b. antigens presented with MHC II molecules c. free antigen in a soluble form d. haptens only

Answer 45

b. antigens presented with MHC II molecules

Question 46

Cytotoxic T cells will bind with their TCR to which of the following? a. antigens presented with MHC I molecules b. antigens presented with MHC II molecules c. free antigen in a soluble form d. haptens only

Answer 46

a. antigens presented with MHC I molecules

Question 47

Name the T helper cell subset involved in antibody production. a. TH1 b. TH2 c. TH17 d. CTL

Answer 47

b. TH2

Question 48

Which of the following would be a T-dependent antigen? a. lipopolysaccharide b. glycolipid c. protein d. carbohydrate

Answer 48

c. protein

Question 49

A patient is bitten by a dog with confirmed rabies infection. After treating the bite wound, the physician injects the patient with antibodies that are specific for the rabies virus to prevent the development of an active infection. This is an example of: a. Natural active immunity b. Artificial active immunity c. Natural passive immunity d. Artificial passive immunity

Answer 49

d. Artificial passive immunity

Question 50

A patient gets a cold, and recovers a few days later. The patient's classmates come down with the same cold roughly a week later, but the original patient does not get the same cold again. This is an example of: a. Natural active immunity b. Artificial active immunity c. Natural passive immunity d. Artificial passive immunity

Answer 50

a. Natural active immunity

Question 51

This class of antibody is the only one that can cross the placenta

Answer 51

IgG

Question 52

This class of antibody is the first to appear after activation of B cells

Answer 52

IgM

Question 53

This class of antibody is involved in the defense against parasitic infections and involved in allergic responses

Answer 53

IgE

Question 54

This class of antibody is found in very large amounts in mucus secretions

Answer 54

IgA

Question 55

This class of antibody is not secreted by B cells but is expressed on the surface of naïve B cells

Answer 55

IgD

Question 56

There are two critically important aspects of adaptive immunity. The first is specificity, while the second is _____.

Answer 56

Memory

Question 57

____ immunity involves the production of antibody molecules that bind to specific antigens.

Answer 57

Humoral

Question 58

The heavy chains of an antibody molecule contain _____ region segments, which help to determine its class or isotype.

Answer 58

Constant

Question 59

The variable regions of the heavy and light chains form the _____ sites of an antibody.

Answer 59

Antigen-binding

Question 60

MHC molecules are used for antigen _____ to T cells.

Answer 60

Presentation

Question 61

A _____ T cell will become activated by | presentation of foreign antigen associated with an MHC I molecule

Answer 61

Cytotoxic

Question 62

A ____T cell will become activated by presentation of foreign antigen in association with an MHC II molecule.

Answer 62

Helper

Question 63

Both ____ and effector T cells are produced during differentiation of activated T cells

Answer 63

Memory

Question 64

____ antigens can stimulate B cells to become activated but require cytokine assistance delivered by helper T cells.

Answer 64

T-dependent

Question 65

____ immunity occurs when antibodies from one individual are harvested and given to another to protect against disease or treat active disease.

Answer 65

Artificial passive

Question 66

Adaptive immunity is an acquired defense | against foreign pathogens that is characterized by ____ and ____.

Answer 66

specificity and memory

Question 67

Adaptive immunity is a dual system involving ____ immunity (antibodies produced by B cells) and ____ immunity (T cells directed against intracellular pathogens).

Answer 67

humoral; cellular

Question 68

A single antigen possesses smaller ____, each capable of inducing a specific adaptive immune response.

Answer 68

epitopes

Question 69

____ is a collection of genes coding for glycoprotein molecules expressed on the surface of all nucleated cells.

Answer 69

Major histocompatibility complex (MHC)

Question 70

____ molecules are expressed on all nucleated cells and are essential for presentation of normal “self” antigens.

Answer 70

MHC I

Question 71

____ molecules are expressed only on the surface of antigen-presenting cells (macrophages, dendritic cells, and B cells).

Answer 71

MHC II

Question 72

____ cells primarily ingest pathogens by phagocytosis

Answer 72

Antigen-presenting cells (APCs)

Question 73

____ cells differentiate into TH1, TH2, TH17, or memory T cell subtypes.

Answer 73

Activated helper T cells

Question 74

B lymphocytes or B cells produce antibodies involved in ____ immunity.

Answer 74

humoral

Question 75

Protein antigens are called ____ antigens because they can only activate B cells with the cooperation of helper T cells.

Answer 75

T-dependent

Question 76

All nucleated cells in a human body normally have ____ molecules.

Answer 76

Class I MHC

Question 77

What is the first molecular signal required for Tc activation? A) secretion of the cytokine IL-2 from a TH1 cell B) secretion of the cytokine IL-1 from a TH0 cell C) binding of a T-cell receptor to an antigen–MHC I complex on an antigen-presenting cell D) binding of a CD28 molecule on the T cell to a B7 protein on an antigen-presenting cell

Answer 77

C. binding of a T-cell receptor to an antigen–MHC I complex on an antigen-presenting cell

Question 78

A child receives her first diphtheria vaccine when she is 5 years old. Four weeks later she receives a booster dose. One week later her physician checks her serum titer. Which of the following would indicate a normal response? A) Elevated levels of both IgM and IgG B) IgG levels near zero and elevated IgM C) Low levels of both IgG and IgM D) IgM levels near zero and elevated IgG

Answer 78

A) Elevated levels of both IgM and IgG

Question 79

Lymphocytes that are capable of killing infected host cells are known as____.

Answer 79

Cytotoxic T cells

Question 80

The second signal required for T cell activation is ____. A) secretion of the cytokine IL-2 from a TH1 cell. B) binding of a CD8 molecule on the T cell to an antigen-MHC I complex on an antigen-presenting cell. C) secretion of the cytokine IL-1 from a TH0 cell.

Answer 80

B. binding of a CD8 molecule on the T cell to an antigen-MHC I complex on an antigen-presenting cell.

Question 81

How are antigens processed before binding to MHC class I molecules? A.They are digested in the cytoplasm of the cell by the proteosome. B. they are digested by enzymes in the endoplasmic reticulum. C.They are digested by enzymes in the endocytic vesicle.

Answer 81

C.They are digested by enzymes in the endocytic vesicle.

Question 82

The following are the steps for B-cell activation. The steps are in an incorrect order. 1. B cells display antigens in MHC class II receptors on the cell surface. 2. Antibodies released by plasma cells bind to antigen so they will be destroyed by other cells of the immune system. 3. B cells rearrange their DNA to create a unique B-cell receptor. 4. B cells become activated by interacting with helper T cells. 5. B cells undergo clonal expansion. 6. B cells digest antigens that bind to the antibodies on their surface.

Answer 82

3, 6, 1, 4, 5, 2

Question 83

Both MHC class I receptors and MHC class II receptors are synthesized on the rough ER. What keeps MHC class II receptors from binding to antigens while in the ER? a) The MHC class II receptor has its binding site covered by a protein called the invariant chain. Until that is removed, it is unable to bind to any antigens. b) There are no antigens in the ER compartment for MHC class II to bind. c) The MHC class II molecules are kept in a separate compartment of the ER so that they cannot mix with antigens yet. d) Any antigens bound to the MHC class II molecule are removed by enzymes in the Golgi complex.

Answer 83

a) The MHC class II receptor has its binding site covered by a protein called the invariant chain. Until that is removed, it is unable to bind to any antigens.

Question 84

What cytokine directs a cytotoxic response?

Answer 84

IL-2

Question 85

What occurs after a B cell binds to an epitope?

Answer 85

Clonal expansion of the activated B cell

Question 86

Why are lipids less immunogenic than proteins?

Answer 86

Lipids are more flexible than proteins.

Question 87

What is an APC?

Answer 87

Only macrophages, dendritic cells, & B lymphocytes have the ability to present antigens with the specific purpose of activating T lymphocytes

Question 88

Th (CD4) functions

Answer 88

1. Orchestrate humoral and cellular immunity 2. Involved in the activation of macrophages and NK cells 3. Formation of Tc cells, activate macrophages, produce cytokines, & formation of antibodies by B cells

Question 89

Tc (CD8) function

Answer 89

Destroy cells infected with INtracellular pathogens

Question 90

Th1 cell function

Answer 90

Stimulate cytotoxic T cells and produce memory cytotoxic T cells Stimulate macrophages and NK cells

Question 91

Th2 function

Answer 91

Stimulate B cell activation and differentiation into plasma cells and memory B cells

Question 92

Tc cell function

Answer 92

Differentiate into effector cytotoxic T cells that target pathogens for destruction or memory cells

Question 93

CD4 only interacts with MHC __.

Answer 93

MHC II

Question 94

IgG Fc binds to ____.

Answer 94

Phagocytes

Question 95

IgG functions

Answer 95

Neutralization, agglutination, complement activation, & opsonization

Question 96

IgM shape

Answer 96

Pentamer

Question 97

IgM functions

Answer 97

Neutralization, agglutination, & complement activation

Question 98

IgA function

Answer 98

Neutralization & trapping of pathogens in mucus

Question 99

IgD function

Answer 99

B cell receptor

Question 100

IgE function

Answer 100

Binds to basophils & mast cells against parasites and allergens

Question 101

Th (CD4) activated by MHC __.

Answer 101

MHC II

Question 102

Treg activated by MHC __.

Answer 102

MHC II

Question 103

Tc (CD8) activated by MHC __.

Answer 103

MHC I

Question 104

Tc (CD8) cells focus on INtracellular or EXtracellular infections?

Answer 104

INtracellular

Question 105

What immunoglobulins are present on the surface of naive B cells?

Answer 105

IgM and IgD

Question 106

All cells have MHC __ and therefore any cell can be killed by Tc cells.

Answer 106

MHC I