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Flashcards in Chapter 10.2 quiz Deck (55):
1

Which of the following statements is incorrect regarding memory B cells?

a. Memory B cells are maintained for life.

b. In secondary responses, the number of pathogen-specific B cells is about 10Ð100-fold that seen in primary responses.

c. The sensitivity of memory B cells is improved compared with naive B bells because affinity maturation has occurred.

d. Memory B cells express lower levels of MHC class II and B7 than do naive B cells.

e. Memory B cells differentiate into plasma cells more rapidly than do naive B cells.

d. Memory B cells express lower levels of MHC class II and B7 than do naive B cells.

2

What would be the outcome if a naive B cell were to bind to pathogen coated with specific antibody made by an effector B cell in a primary immune response using Fc?RIIB1, and simultaneously bind to the same pathogen using its B-cell receptor?

a. a positive signal leading to the production of low-affinity IgM antibodies

b. a positive signal leading to isotype switching and the production of IgG, IgA, or IgE antibodies

c. a positive signal leading to somatic hypermutation and the production of high-affinity IgM antibodies

d. a negative signal leading to inhibition of the production of low-affinity IgM antibodies

e. a negative signal leading to apoptosis

d. a negative signal leading to inhibition of the production of low-affinity IgM antibodies

3

Which of the following explains why the first baby born to a RhDÐ mother and a RhD+ father does not develop hemolytic disease of the newborn?

a. Fetal erythrocytes do not cross the placenta and therefore do not stimulate an antibody response.

b. The antibodies made by the RhDÐ mother during the first pregnancy are predominantly IgM and have low affinity for the Rhesus antigen.

c. Maternal macrophages in the placenta bind to anti-Rhesus antibodies and prevent their transfer to the fetus.

d. Hemolytic disease of the newborn is a T-cell-mediated disease and maternal T cells do not cross the placenta during pregnancy.

e. The Rhesus antigen is not immunogenic and does not stimulate an antibody response.

b. The antibodies made by the RhDÐ mother during the first pregnancy are predominantly IgM and have low affinity for the Rhesus antigen.

4

By which process are fetal erythrocytes destroyed in hemolytic anemia of the newborn?

a. lysis of erythrocytes by cytotoxic T cells

b. lysis of erythrocytes by complement activation

c. clearance of antibody-coated erythrocytes by macrophages in the fetal spleen

d. lysis of erythrocytes by NK cells via antibody-dependent cell-mediated cytotoxicity

e. cytotoxicity caused by major basic protein released from eosinophils

c. clearance of antibody-coated erythrocytes by macrophages in the fetal spleen

5

When a naive B cell binds to an IgG:antigen complex on its cell surface using Fc?RIIB1, while simultaneously binding to the same antigen using membrane-bound IgM, _____.

a. the IgG:antigen complex is endocytosed

b. the B cell becomes anergic

c. the B cell will switch isotype to IgG

d. the B cell undergoes affinity maturation

e. the B cell secretes large amounts of IgM before becoming a memory B cell

b. the B cell becomes anergic

6

ÒOriginal antigenic sinÓ is best described as a phenomenon in which _____.

a. a highly mutable virus gradually escapes from immunological memory and interferes with compensatory immune responses.

b. latent viruses periodically activate effector T cells specific for the original antigen recognized in the primary immune response.

c. the persistence of antigen is necessary to sustain maintenance of immunological memory.

d. memory T cells no longer express the same profile of adhesion molecules and cytokine receptors compared with the original profile of the naive precursor T cell.

a. a highly mutable virus gradually escapes from immunological memory and interferes with compensatory immune responses.

7

Imagine a situation in which an individual who has a latent cytomegalovirus (CMV) infection receives a hematopoietic stem-cell transplant. Which of the following is likely to occur?

a. The memory T cells present at the time of transplantation would inhibit activation of newly generated naive T cells.

b. The CMV viral load would increase exponentially, overcoming the host and causing death.

c. The transplant-derived naive T cells would be activated and give rise to memory T cells that would persist and control viral load.

d. There would be a rapid increase in CMV viral load and expansion of T cells bearing CD45RA.

c. The transplant-derived naive T cells would be activated and give rise to memory T cells that would persist and control viral load.

8

Which of the following are not a component of immunological memory?

a. effector B cells

b. memory T cells

c. memory B cells

d. long-lived plasma cells

a. effector B cells

9

The efficiency and specificity of adaptive immune defenses and immunological memory improve each time a particular pathogen is encountered because _____.

a. of protective immunity

b. effector memory T cells outnumber central memory T cells

c. the half-life of antibodies made in secondary and tertiary immune responses exceeds that of antibodies made in primary immune responses

d. of affinity maturation

d. of affinity maturation

10

Unlike naive lymphocytes, memory lymphocytes _____.

a. do not recirculate between the blood and secondary lymphoid organs

b. do not require the receipt of survival signals through their antigen receptors in order to persist

c. are immortal and continue to divide throughout the lifetime of an individual

d. secrete antibody continuously, although at a much lower rate than plasma cells

e. do not express CD27

b. do not require the receipt of survival signals through their antigen receptors in order to persist

11

All of the following are ways in which plasma cells differ from memory cells except _____.

a. plasma cells lack surface immunoglobulin

b. cellular morphology

c. plasma cells are CD27-negative

d. plasma cells have undergone isotype switching

e. plasma cells are short-lived

d. plasma cells have undergone isotype switching

12

During a secondary immune response, high-affinity IgG antibodies are produced. Which of the following best explains why low-affinity IgM antibodies are not made?

a. Naive pathogen-specific B cells are suppressed by negative signaling through Fc?RIIB1.

b. Naive pathogen-specific B cells isotype switch and hypermutate much more quickly during secondary immune responses.

c. Memory B cells outnumber naive B cells.

d. Low-affinity IgM antibodies are made only when antigen concentration is exceedingly high.

a. Naive pathogen-specific B cells are suppressed by negative signaling through Fc?RIIB1.

13

Which of the following molecules is not elevated on the surface of memory B cells compared with naive B cells?

a. MHC class II molecules

b. CD45RA

c. antigen receptor

d. CD27

e. co-stimulatory molecules

b. CD45RA

14

_____ accounts for the production of different isoforms of the CD45 protein observed in naive, effector, and memory T cells.

a. Isotype switching

b. Affinity maturation

c. Alternative splicing

d. Somatic hypermutation

e. Recirculation to peripheral tissues

c. Alternative splicing

15

RhoGAM is administered to pregnant RhDÐ women so as to _____.

a. stimulate only anti-RhD IgM antibody

b. cause selective removal of anti-RhD memory B cells from the maternal circulation

c. inhibit a primary immune response to RhD antigen and prevent hemolytic anemia of the newborn

d. block transcytosis of IgG to fetal circulation by interfering with FcRn function

c. inhibit a primary immune response to RhD antigen and prevent hemolytic anemia of the newborn

16

Identify the mismatched pair.

a. variolation: smallpox

b. Salk vaccine: killed poliovirus

c. vaccinia virus: cowpox

d. rotavirus: segmented DNA virus

e. Sabin vaccine: TVOP

d. rotavirus: segmented DNA virus

17

Recombinant DNA technology has been especially useful for the production of _____ that are used in subunit vaccines.

a. viral proteins

b. viral nucleic acids

c. mutated viruses

d. viral polysaccharides

e. infectious particles

a. viral proteins

18

With reference to RotaTaq, identify the incorrect statement.

a. It is an attenuated vaccine derived from a human rotavirus, and it is nonpathogenic in humans unless a genetic reversion occurs.

b. It has been genetically engineered to express a variety of human VP4 and VP7 glycoproteins.

c. It is a mixture of five cattle rotaviruses.

d. Standard tissue culture methods are used for its production.

e. It took decades of research to develop this vaccine to an adequate standard.

a. It is an attenuated vaccine derived from a human rotavirus, and it is nonpathogenic in humans unless a genetic reversion occurs.

19

Which of the following is(are) example(s) of a subunit vaccine(s)?

a. hepatitis B vaccine and Bexsero¨

b. Bacille CalmetteÐGu rin (BCG) vaccine

c. trivalent oral polio vaccine

d. influenza vaccine

a. hepatitis B vaccine and Bexsero¨

20

All of the following are examples of adjuvants, except _____.

a. alum

b. MF59

c. inactivated Bordetella pertussis

d. virosomes

e. RhoGAM

e. RhoGAM

21

A newly identified antigen protein of Neisseria meningitidis called fHbp increases virulence by _____.

a. interfering with the alternative pathway of complement activation

b. binding to host-derived heparin

c. increasing the adhesiveness of the bacterium

d. inhibiting phagocytosis

e. inducing inflammation

a. interfering with the alternative pathway of complement activation

22

_____ is the approach that mines a pathogenÕs genome to reveal potential antigens and derives clues about cellular location, function, and ability to stimulate protective antibodies based on nucleotide sequence.

a. Conjugation

b. Attenuation

c. Reverse vaccinology

d. Herd immunity

e. Neutralization

c. Reverse vaccinology

23

The reason that vaccines against influenza must be administered annually, unlike vaccines against measles, is _____.

a. the antigens that stimulate protection against influenza virus are inside the virion and not on the surface

b. influenza is an RNA virus with a higher mutation rate

c. influenza stimulates T-independent responses that fail to generate memory cells

d. the polysaccharide antigens of influenza stimulate poor immune responses.

b. influenza is an RNA virus with a higher mutation rate

24

When a subpopulation of unvaccinated individuals are protected against a pathogen because the vast majority of individuals in the overall population are vaccinated, this is called _____.

a. reverse vaccinology

b. subunit vaccination

c. partial immunization

d. combined immunity

e. herd immunity

e. herd immunity

25

After a campus outbreak of Neisseria meningitidis (meningococcal serogroup B), a devastating bacterial disease, which affected at least eight students at Princeton University, the US Food and Drug Administration approved the use of Bexsero to prevent the development of additional cases on that campus. Bexsero is considered to provide broader protective coverage than the US-licenced vaccines conventionally used against this disease. Which of the following methodologies was used to develop Bexsero?

a. conjugation of neisserial capsular polysaccharide to tetanus toxoid

b. reverse vaccinology

c. formalin treatment of secreted toxins

d. production of a combination vaccine that includes DTP plus a meningococcal polysaccharide diphtheria toxoid conjugate

e. engineering a nonpathogenic cattle strain of N. meningitidis to express antigens associated with pathogenic human strains.

e. engineering a nonpathogenic cattle strain of N. meningitidis to express antigens associated with pathogenic human strains.

26

The measles virus is a relatively invariant pathogen that has little, if any, antigenic change. Antibodies made by memory B cells will be just as effective in a recall response as those made in a primary challenge. In fact, antibodies made in secondary immune responses by memory B cells will be more effective because of isotype switching and somatic hypermutation. In contrast, the influenza virus is highly mutable; as a result, new strains emerge each year bearing new epitopes that have not previously stimulated a primary response. Memory response and the suppression of naive B cells restrict antibody production to only those epitopes shared by the infecting strain and the original strain. Over time, the influenza virus will express only a limited number of epitopes that are able to activate memory B cells, and the new epitopes will lack the capacity to stimulate naive B cells.

a. True

b. False

a. True

27

Inactivated virus vaccines are made of virus particles that are not able to replicate because they have been chemically or physically treated (for example by heat) in a way that inactivates the nucleic acid. Examples are Salk polio vaccine, rabies vaccine, and influenza vaccine.

a. True

b. False

a. True

28

Live-attenuated virus vaccines are made of viruses that have lost their pathogenicity and ability to reproduce efficiently in human cells through mutations accumulated as a result of growing the virus in non-human cells. Examples are Sabin polio vaccine (oral), measles vaccine, mumps vaccine, yellow fever vaccine, BCG and Salmonella typhi vaccine, and varicella vaccine.

a. True

b. False

a. True

29

Subunit vaccines are composed only of particular antigenic pathogen components known to induce protective immune responses. Recombinant DNA technology enables the production of antigenic proteins in the absence of other pathogen gene products. Examples are hepatitis B vaccine and Bexsero vaccine.

a. True

b. False

a. True

30

Toxoid vaccines are made from chemically inactivated toxins purified from pathogenic bacteria. Toxin activity is eliminated but antigenic activity is not, so an immune response is generated in the absence of pathological damage. Examples are diphtheria vaccine and tetanus vaccine.

a. True

b. False

a. True

31

Conjugate vaccines are made by covalently coupling antigenic polysaccharide found in bacterial capsules to a carrier protein (often a toxoid). This converts the otherwise T-independent bacterial polysaccharide antigen into a T-dependent antigen. T cells respond to an epitope on the protein carrier, whereas B cells respond to epitopes on the polysaccharide portion of the conjugate. This ensures that T-cell help is provided to B cells making anti-capsule antibodies. Examples include vaccines against Neisseria meningitidis, Haemophilus influenzae and Streptococcus pneumoniae.

a. True

b. False

a. True

32

Combination vaccines consist of components that stimulate protective immunity against more than one pathogen. DTP (diphtheria, tetanus, pertussis) vaccine is an example.

a. True

b. False

a. True

33

Bacterial vaccines differ from viral vaccines in that only in bacterial vaccines are _____ used.

a. subunit components

b. toxoids, capsular polysaccharides, and capsule:carrier protein conjugates

c. whole infectious components

d. capsular monosaccharides

e. capsule:carrier amino acid conjugates

b. toxoids, capsular polysaccharides, and capsule:carrier protein conjugates

34

Reasons complicating the development of vaccines to combat chronic diseases include all below, except_____.

a. evasion of the hostÕs immune system by the pathogen

b. the polymorphic diversity of MHC class I and class II molecules

c. the generation of inappropriate immune responses that do not eradicate the pathogen

d. survival of the infectious agent for long periods inside the host

e. low mutation rates in the pathogen

e. low mutation rates in the pathogen

35

On an otherwise uneventful sunny Sunday afternoon, an extremist group enters your city in a large van and drives to the front entrance of the Convention Center, where the annual flower show is taking place. The occupants unload large crates resembling flats of assorted flowers, and then drive off. Within minutes the crates explode, showering the visitors with an opaque powder. Medical teams are called to the scene to care for the injured, and CDC officials wearing levelÊ4 containment suits arrive in a few hours to test the contents of the powder for human pathogens using multiplex PCR methodology (a rapid method for identifying pathogens by their DNA). Which of the following potential bioterrorism agents would pose the most serious threat to those exposed?

a. Bacillus anthracis (anthrax)

b. Corynebacterium diphtheriae toxin (diphtheria)

c. Yersinia pestis (plague)

d. variola major (smallpox)

e. Clostridium botulinum toxin (botulism)

d. variola major (smallpox)

36

In which ways do memory B cells active in a secondary immune response differ from the naive B-cell population activated in a primary immune response?

a. The antibody produced is of higher affinity in a secondary immune response; the level of somatic hypermutation is higher in a secondary immune response; and memory B cells express higher levels of MHC class II molecules.

b. The frequency of antigen-specific B cells is lower in a secondary immune response.

c. Higher levels of IgM are produced in secondary immune responses.

d. B cells do not require T-cell help in secondary immune responses.

e. Naive B cells express higher levels of co-stimulatory molecules.

a. The antibody produced is of higher affinity in a secondary immune response; the level of somatic hypermutation is higher in a secondary immune response; and memory B cells express higher levels of MHC class II molecules.

37

The production of CD45RO results from the removal of _____ during _____ processing.

a. domain A; post-translational

b. domain A; post-transcriptional

c. exons A, B, and C; post-translational

d. exons A, B, and C; post-transcriptional

e. exon A; post-transcriptional

d. exons A, B, and C; post-transcriptional

38

Effector memory cells enter _____, whereas central memory cells enter _____.

a. B-cell follicles; T-cell zones of secondary lymphoid tissues

b. T-cell zones of secondary lymphoid tissues; B-cell follicles

c. secondary lymphoid tissues; primary lymphoid tissues

d. T-cell zones of secondary lymphoid tissues; inflamed tissues

e. inflamed tissues; T-cell zones of secondary lymphoid tissues

e. inflamed tissues; T-cell zones of secondary lymphoid tissues

39

_____ involves deliberate stimulation of the immune system and induction of protective immunity to a particular disease-causing pathogen by mimicking infection in the absence of disease.

a. Variolation

b. Attenuation

c. Vaccination

d. Conjugation

e. Herd immunity

c. Vaccination

40

Inactivation of viruses for vaccine use can be achieved by _____.

a. irradiation, heat treatment, and formalin treatment

b. cold treatment

c. mutation

d. neutralization

e. ethanol treatment

a. irradiation, heat treatment, and formalin treatment

41

The Salk polio vaccine is an inactivated virus vaccine, whereas the Sabin polio vaccine is a live-attenuated virus vaccine. The Salk vaccine should be used for immunocompromised individuals. Live attenuated vaccines carry a risk of mutational reversion in an immunocompromised host to a more virulent, disease-causing strain. This occurs because the virus is able to replicate at higher levels and acquire a significant number of mutations, some of which may lead to reversion to a pathogenic strain.

a. True

b. False

a. True

42

Variolation and vaccination are both procedures used to confer immunological protection against the smallpox virus, variola. They both use live virus and stimulate humoral and cell-mediated immune responses against the smallpox virus. Variolation, a method used for only a short period in the 18th and 19th centuries because of the risk of developing smallpox, used dried pustules derived from humans exhibiting relatively mild symptoms of smallpox infection. Vaccination, a safer alternative causing only mild infection, used dried pustules from cows infected with cowpox.

a. True

b. False

a. True

43

Vaccinia and variola have some viral surface antigens in common. Some of the antibodies made against cowpox surface antigens during immunization are able to bind to shared surface antigens also expressed on the surface of the smallpox virus. Through neutralization, these anti-cowpox antibodies are able to bind to and prevent the entry of smallpox into host cells if the host is infected naturally with the smallpox virus.

a. True

b. False

a. True

44

Example(s) of inactivated virus vaccine(s) is(are) _____.

a. Sabin polio vaccine

b. influenza and rabies vaccines

c. mumps vaccine

d. hepatitis B vaccine

b. influenza and rabies vaccines

45

For a viral subunit vaccine to be effective, except _____.

a. B cells must be activated

b. cytotoxic T and NK cells must be activated

c. neutralizing antibodies must be induced

d. CD4 TFH cells must be activated

e. it must be derived from viral surface components.

b. cytotoxic T and NK cells must be activated

46

A conjugate vaccine is one that couples _____ to _____ so as to stimulate T-dependent antibody responses.

a. polysaccharide; a protein carrier

b. a protein carrier; irradiated DNA

c. protein carrier; toxoids

d. adjuvant; toxoids

e. polysaccharide; filamentous hemagglutinin

a. polysaccharide; a protein carrier

47

_____ vaccines are the most effective at evoking memory responses against a virus in an immunized host.

a. Conjugate

b. Subunit

c. Killed

d. Live-attenuated

e. Toxoid

d. Live-attenuated

48

Which of the following vaccines is least likely to pose a risk in an individual with an immunodeficiency?

a. Sabin polio vaccine

b. measles vaccine

c. hepatitis B vaccine

d. vaccinia vaccine

e. yellow fever vaccine

c. hepatitis B vaccine

49

Approximately one-quarter of individuals infected with hepatitis C _____.

a. develop a chronic infection of hepatocytes

b. are at risk of developing liver cancer

c. experience episodes of liver destruction and regeneration

d. require a liver transplant

e. mount an effective immune response and eradicate the virus

e. mount an effective immune response and eradicate the virus

50

An adjuvant enhances the effectiveness of vaccines by inducing the expression of _____ on ________.

a. co-stimulatory molecules; dendritic cells

b. CD28; macrophages

c. MHC class II molecules; T cells

d. T-cell receptor; T cells

e. immunoreceptor tyrosine-based activation motifs; dendritic cells

a. co-stimulatory molecules; dendritic cells

51

Tim Smith, aged 16 years, was hit by a car while riding his motorcycle. At the hospital he showed only minor abrasions and no bone fractures. He was discharged later that day. In the morning he experienced severe abdominal pain and returned to the hospital. Examination revealed tachycardia, low blood pressure, and a weak pulse. He received a blood transfusion without improvement. Laparoscopic surgery confirmed peritoneal hemorrhage due to a ruptured spleen. In addition to a splenectomy, which of the following treatments would be administered?

a. plasmapheresis to remove autoantibodies (antibodies generated against self constituents)

b. regular intravenous injections of gamma globulin

c. vaccination and regular boosters with capsular polysaccharides from pathogenic pneumococcal strains

d. booster immunization with DTP (diphtheria toxoid, killed Bordetella pertussis, and tetanus toxoid)

e. regular blood transfusions

c. vaccination and regular boosters with capsular polysaccharides from pathogenic pneumococcal strains

52

Jenny Smith was five months pregnant when she stepped on a rusty piece of scrap metal while hauling rotted wood from a dilapidated shed in her garden. The sliver of metal cut through her sneaker and pierced her heel deeply. Her physician gave her a tetanus booster. When baby was born she decided to breastfeed. If the baby antibodies were tested for specificity to tetanus 2 months after birth, what would be the expected finding?

a. the presence of anti-tetanus toxoid IgA antibodies

b. the presence of anti-tetanus toxoid IgM antibodies

c. the presence of anti-tetanus toxoid IgG antibodies

d. the presence of IgM antibody specific for Clostridium tetani cell-wall components

e. the presence of IgG antibody specific for Clostridium tetani cell-wall components

c. the presence of anti-tetanus toxoid IgG antibodies

53

There is no link between vaccines and autism (or Autism spectrum disorder (ASD)). Some people have had concerns that ASD might be linked to the vaccines children receive, but studies have shown that there is no link between receiving vaccines and developing ASD. In 2011, an Institute of Medicine (IOM) reportÊon eight vaccines given to children and adults found that with rare exceptions, these vaccines are very safe.

a. True

b. False

a. True

54

Vaccine ingredients do not cause autism [or Autism spectrum disorder (ASD)]. One vaccine ingredient that has been studied specifically isÊthimerosal, a mercury-based preservative used to prevent contamination of multidose vials of vaccines. Research shows that thimerosal does not cause ASD. In fact, a 2004 scientific reviewÊby the Institute of Medicine (IOM) concluded that "the evidence favors rejection of a causal relationship between thimerosal-containing vaccines and autism." Since 2003, there have beenÊnine CDC-funded or conducted studiesÊthat have found no link between thimerosal-containing vaccines and ASD, as well as no link between the measles, mumps, and rubella (MMR) vaccine and ASD in children.

a. True

b. False

a. True

55

A 2013 CDC study added to the research showing that vaccines do not cause (or Autism spectrum disorder (ASD)). The study looked at the number of antigens (substances in vaccines that cause the body immune system to produce disease-fighting antibodies) from vaccines during the first two years of life. The results showed that the total amount of antigen from vaccines received was the same between children with ASD and those that did not have ASD.

a. True

b. False

a. True