Adaptive Immunity (MasteringMicro)

The antibody found in breastmilk and coating mucous membranes is a) IgA. b) IgD. c) IgE. d) IgG. e) IgM.

a) IgA

Which of the following is/are (a) mechanism(s) through which antibodies increase phagocytosis? Select all true statements. a) Opsonization b) Agglutination c) Precipitation d) Neutralization

a) Opsonization b) Agglutination c) Precipitation

Which statement is NOT true about T cell subclass differentiation? a) Regardless of which T helper cell subclass develops during an immune response, the humoral response is not impacted. b) T cell subclass differentiation is caused by the release of cytokines that is influenced by the antigen's nature and the amount present. c) Particular combinations of cytokines will favor the development of some T cell subclasses over others. d) Which specific T helper cell subclass that develops may impact the progression and outcome of an infectious disease. e) Each subclass will include both effector and memory cells.

a) Regardless of which T helper cell subclass develops during an immune response, the humoral response is not impacted.

Which of the following statements concerning the secondary response is true? a) The secondary response results in production of antibodies with a higher affinity for the antigen. b) The secondary immune response is stronger than the primary immune response due to the increased production of IgM antibody from plasma cells. c) The secondary immune response is slower than the primary immune response. d) In order to stimulate an immune reaction, the secondary immune response requires a higher concentration of antigen than the primary immune response.

a) The secondary response results in production of antibodies with a higher affinity for the antigen.

How is the immune system able to recognize a limitless number of different antigens and epitopes? a) While each lymphocyte carries receptors that recognize only one type of epitope, the immune system produces a wide variety of lymphocytes each of which carries unique receptors. b) Each lymphocyte is coated with many different receptors, each of which recognizes a different epitope AND the immune system produces a wide variety of lymphocytes. c) Each lymphocyte is coated with many different receptors, each of which recognizes a different epitope. d) If a lymphocyte encounters an antigen it does not recognize, it immediately switches receptors until it finds one that is a match. e) A genetic "memory" of the pathogens your parents encountered (and their parents and so on) is passed on to each generation, increasing the number of possible responses over time.

a) While each lymphocyte carries receptors that recognize only one type of epitope, the immune system produces a wide variety of lymphocytes each of which carries unique receptors.

T-independent antigens a) are usually polysaccharides and able to bind multiple B cell receptors on a given B cell. b) are usually polysaccharides. c) are usually proteins. d) may be polysaccharides or proteins, and are not able to bind multiple B cell receptors on a given B cell. e) are able to bind multiple B cell receptors on a given B cell.

a) are usually polysaccharides and able to bind multiple B cell receptors on a given B cell.

All the following apply to T cells EXCEPT a) coordinate the humoral response by making antibodies. b) originate in the bone marrow. c) mature in the thymus. d) reside in the lymphoid tissue. e) have the capacity to recognize virtually any type of antigen.

a) coordinate the humoral response by making antibodies.

While not a hard-and-fast rule, molecules may be ranked from more immunogenic to less immunogenic. Which shows the correct ranking form more immunogenic to less immunogenic? a) proteins > polysaccharides > lipids > haptens b) polysaccharides > lipids > proteins > haptens c) haptens > proteins > lipids > polysaccharides d) haptens > lipids > polysaccharides > proteins e) Only haptens are less immunogenic; lipids, polysaccharides, and proteins have about equal immunogenicity.

a) proteins > polysaccharides > lipids > haptens

What is the role of B cell receptors (BCRs) and T cell receptors (TCRs) in the immune response? a) to recognize specific epitopes of an antigen b) to release chemicals which destroy pathogens c) to release the cytokines needs for immune cell stimulation d) to combine with haptens so they can stimulate an immune response e) to communicate with lymphocytes and other white blood cells

a) to recognize specific epitopes of an antigen

(T/F) A patient with a high antibody titer to a pathogen for which there is no vaccination indicates that this person is currently infected with the pathogen or was infected in the past.

true

(T/F) An antigen may consist of multiple epitopes, each of which recognized by different lymphocytes.

true

(T/F) Both the light and the heavy chains of an antibody are involved with epitope recognition and binding.

true

(T/F) The humoral immune response can enhance phagocytosis by either direct interaction of antibodies with their antigen, or though antibody activation of the complement cascade.

true

Your pediatric patient recently received a DTaP vaccination, providing immunity to diphtheria, tetanus, and pertussis. If your patient is exposed to pertussis a few weeks following this vaccination, which of the results would you expect to receive when measuring the patient's antibody titers? a) A rapid decline in the proportion of IgE antibody b) A rapid surge in the production of IgG antibody c) A sharp decline in the production of IgD antibody d) A sharp increase in the proportion of IgM antibody

b) A rapid surge in the production of IgG antibody

Which of the following statements is/are true regarding T cytotoxic cell antigen elimination? Select all true statements. a) Released interferons by cancer cells or infected cells increases production of MHC II, increasing the likelihood that cytotoxic T cells will "seek and destroy" these cells. b) Following apoptosis by cytotoxic T cells, macrophages and natural killer cells clear the dead cells. c) Interferons released by infected or cancer cells attract and activate cytotoxic T cells, while cytokines released by the cytotoxic T cells attract natural killer cells and macrophages. d) Once the threat has been detected by the T cell receptor, the cytotoxic T cell releases perforins that form pores in the target cell and granzymes, which enter through pores to trigger apoptosis.

b) Following apoptosis by cytotoxic T cells, macrophages and natural killer cells clear the dead cells. c) Interferons released by infected or cancer cells attract and activate cytotoxic T cells, while cytokines released by the cytotoxic T cells attract natural killer cells and macrophages. d) Once the threat has been detected by the T cell receptor, the cytotoxic T cell releases perforins that form pores in the target cell and granzymes, which enter through pores to trigger apoptosis.

Which statement does NOT apply to haptens? a) Haptens are generally too small to be immunogenic on their own. b) Haptens are any nonpathogenic substance, rather than a microorganism, which can stimulate an immune response. c) Antibiotics such as penicillin are often haptens. d) Haptens must bind to a more complex molecule to stimulate an immune response. e) Haptens are also known as incomplete antigens.

b) Haptens are any nonpathogenic substance, rather than a microorganism, which can stimulate an immune response.

Your patient has an anaphylactic response to bee venom. Which of the following classes of antibodies would you expect to be elevated in the patient's serum, based on this hypersensitivity? a) IgA b) IgE c) IgD d) IgM

b) IgE

Which of the following statements regarding B lymphocytes is/are true? Select all true statements. a) B lymphocytes are found in high concentration at various sites throughout the body, including the lymphatic system and the bloodstream. b) Once activated, B lymphocytes have the ability to produce antibodies. c) B lymphocytes are both produced and mature in the bone marrow. d) B lymphocytes carry out cell-mediated immunity.

b) Once activated, B lymphocytes have the ability to produce antibodies. c) B lymphocytes are both produced and mature in the bone marrow.

Your patient is born without a thymus (a genetic defect known as DiGeorge Syndrome). Which of the following statements would you expect to be true for this patient? a) This patient's immune system would be able to respond to both T-independent and T-dependent antigens. b) This patient's immune system would not be able to respond to T-dependent antigens, but would have an immune response to T-independent antigens. c) This patient's immune system would not be able to respond to T-independent antigens, but would have an immune response to T-dependent antigens. d) This patient's immune system would not be able to respond to either T-independent nor T-dependent antigens.

b) This patient's immune system would not be able to respond to T-dependent antigens, but would have an immune response to T-independent antigens.

Which of the following statements accurately differentiates the adaptive immune system and the innate immune system? Select all true statements. a) Unlike the innate immune system, the adaptive immune system is able to respond immediately to a pathogen. b) Unlike the innate immune system, the adaptive immune system includes both a cellular and humoral response. c) Unlike the innate immune system, the adaptive immune system has the ability to distinguish self from foreign antigens. d) Unlike the innate immune system, the adaptive immune system is characterized by memory and specificity.

b) Unlike the innate immune system, the adaptive immune system includes both a cellular and humoral response. d) Unlike the innate immune system, the adaptive immune system is characterized by memory and specificity.

Antibodies do all the following EXCEPT a) activate the complement cascade. b) activate killing by T cytotoxic cells. c) increase phagocytosis by agglutination of antigens. d) neutralize antigens to prevent binding to host cells. e) increase phagocytosis by opsonization.

b) activate killing by T cytotoxic cells.

By which means of acquiring immunity is likely to produce the longest lasting protection? a) natural b) active c) artificial d) passive e) Active, artificial, natural, and passive all provide equally long-lasting protection.

b) active

Postexposure prophylaxis, a form of artificial passive immunity, is often given when a person is bitten by an animal that is suspected of having rabies, or if the rabies-status of the animal cannot be confirmed. What specifically, is being given to the patient in this type of treatment? a) antigens from the rabies virus b) antibodies harvested from a host who has developed an immune response to the rabies virus c) memory cells from a host who has developed an immune response to the rabies virus d) effector B and T cells from a host who has developed an immune response to the rabies virus e) antigen-presenting cells which increase the rate at which the rabies antigens can be presented to T cells for activation

b) antibodies harvested from a host who has developed an immune response to the rabies virus

IgE antibody, which is associated with allergic responses, a) is passed from mother to child through breastfeeding and may prevent the development of allergies in the child. b) encourages mast cells and basophils to release chemicals such as histamine and leukotrienes. c) is resistant to destruction by stomach acid. d) is usually found circulating in the bloodstream. e) can be found bound to B cells.

b) encourages mast cells and basophils to release chemicals such as histamine and leukotrienes.

What is the role of memory cells? a) suppress the cellular response once the infection has passed b) remain in the lymphoid tissue to rapidly proliferate and differentiate upon subsequent exposure to the same pathogen c) circulate in the body at elevated levels to maintain an active attack against any possible pathogen d) prevent an immune response against members of the normal microbiota e) provide immune protection specifically for central nervous system

b) remain in the lymphoid tissue to rapidly proliferate and differentiate upon subsequent exposure to the same pathogen

Each antibody molecule consists of a) a "light" protein chain. b) two light and two heavy protein chains. c) one light and one heavy protein chain. d) various combinations of light and heavy protein chains. e) a "heavy" protein chain.

b) two light and two heavy protein chains.

How does adaptive immunity differ from innate immunity? a) Adaptive immunity is specific to each pathogen. b) Adaptive immunity generates immunological memory. c) Adaptive immunity generates immunological memory and is specific to a pathogen. d) Adaptive immunity's effects are immediate upon exposure to a pathogen. e) Adaptive immunity generates immunological memory and its effects are immediate upon exposure to a pathogen.

c) Adaptive immunity generates immunological memory and is specific to a pathogen.

Which of the following scenarios would result in long-term immunity? Select all true statements. a) Administration of an anti-tetanospasmin antitoxin after stepping on a rusted nail b) A newborn receiving protective IgA anti-pertussis antibodies through her mother's breastmilk c) An otherwise healthy individual developing antibodies against Epstein-Barr virus following a case of mononucleosis d) A healthy individual receiving an MMR vaccination

c) An otherwise healthy individual developing antibodies against Epstein-Barr virus following a case of mononucleosis d) A healthy individual receiving an MMR vaccination

The antibody class which is involved in fighting parasites is a) IgA. b) IgD. c) IgE. d) IgG. e) IgM.

c) IgE

Which of the following statements is true regarding superantigens? a) Superantigens only activate T helper cells that recognize a specific epitope of the antigen. b) The life-threatening organ failure that can result from superantigens is due to the overwhelming humoral response. c) Superantigens trigger the release of high levels of inflammatory cytokines, such as tumor necrosis factor alpha and interferon gamma by CD4 T cells. d) Superantigens are first processed by antigen-presenting cells via an external antigen presentation route and then mixed with MHC II prior to presentation.

c) Superantigens trigger the release of high levels of inflammatory cytokines, such as tumor necrosis factor alpha and interferon gamma by CD4 T cells.

Which T cell class is INCORRECTLY matched with its description? a) Treg: ensures that immune responses subside once a threat subsides b) TH1: stimulate Tc cells c) Tc: attack other T cells during self-tolerance screening d) TH2: stimulate B cells to make antibodies e) TH: identified by the CD4 proteins on the cell surface

c) TC: attack other T cells during self-tolerance screening

Which of the following is NOT required for T cell activation? a) MHC I or II b) bound antigen c) antibody d) involvement of CD4 or CD8 e) co-stimulatory proteins

c) antibody

Pregnant women are usually advised to be vaccinated against influenza to protect themselves and the baby after birth. The mother will acquire ________ immunity from the vaccine while the baby will acquire ________ immunity. a) artificial passive; artificial passive b) artificial active; artificial passive c) artificial active; natural passive d) artificial active; artificial active e) natural active; natural passive

c) artificial active; natural passive

You conduct an experiment to test the immunogenicity of penicillin. You note that when you inject penicillin into your patient, antibody titers are at baseline. However, once penicillin is degraded in the body, it is capable of reacting with albumin, producing an elevated IgE antibody titer. Based on this experiment, penicillin would best be described as a(n) ______. a) epitope b) complete antigen c) hapten d) antigenic determinant

c) hapten

CD8 T cell activation occurs through _______, involving presentation of antigen with _______. a) intracellular antigen presentation; MHC II molecule b) extracellular antigen presentation; MHC I molecule c) intracellular antigen presentation; MHC I molecule d) extracellular antigen presentation; MHC II molecule

c) intracellular antigen presentation; MHC I molecule

The human immunodeficiency virus (HIV) selectively infects any cell which carries the CD4 surface glycoprotein. Which immune function will be impaired? a) stimulation of Tc cells and destruction of virally-infected cells b) stimulation of B cells and antibody production c) stimulation of macrophage, B and Tc cells d) stimulation of B and Tc cells but not of macrophage e) stimulation of macrophage activity

c) stimulation of macrophage, B and Tc cells

Which of the following statements describes the purpose of gene shuffling? a) Gene shuffling allows an individual to switch from producing IgM antibody to IgG antibody. b) Gene shuffling allows for propagation of a specific lymphocyte whose receptor corresponds to the invading antigen. c) Gene shuffling eliminates lymphocyte clones that respond to autoantigens. d) Gene shuffling generates an enormous repertoire of antigen receptors during lymphocyte development.

d) Gene shuffling generates an enormous repertoire of antigen receptors during lymphocyte development.

The most abundant antibody class in the body, found in all body fluids, is a) IgA. b) IgD. c) IgE. d) IgG. e) IgM.

d) IgG

What is the role of MHC I in the immune response? a) MHC I presents a sample of cellular proteins, including those of any intracellular pathogens, to T cells. b) MHC I is found only on antigen-presenting cells. c) MHC I is found on all body cells except red blood cells. d) MHC I is found on all body cells except red blood cells and presents a sample of cellular proteins, including those of any intracellular pathogens, to T cells. e) MHC I is found only on antigen-presenting cells and presents a sample of cellular proteins, including those of any intracellular pathogens, to T cells.

d) MHC I is found on all body cells except red blood cells and presents a sample of cellular proteins, including those of any intracellular pathogens, to T cells.

Which of the following statements is true concerning cellular immunity? a) Cellular immunity includes antibodies and the cells that produce them. b) Cellular immunity allows for antigen elimination but does not involve creation of memory cells. c) Cellular immunity includes non-specific phagocytic cells. d) The cellular branch of adaptive immunity is mainly organized by T helper cells and carried out by T cytotoxic cells.

d) The cellular branch of adaptive immunity is mainly organized by T helper cells and carried out by T cytotoxic cells.

Which is NOT a step in the process of B cell activation by a T-dependent antigen? a) release of cytokines by the T helper cell provide the second activation signal for the B cell b) binding of the antigen to the B cell receptor c) interaction between co-stimulatory proteins on the B and T cells d) binding of the antigen to a T helper cell receptor e) processing and displaying the antigen with MHC II on the B cell

d) binding of the antigen to a T helper cell receptor

In contrast to a primary immune response, immunological memory a) generates antibodies with enhanced affinity for its antigen. b) provides a rapid reactivation of both cellular and humoral responses. c) provides a rapid reactivation of humoral responses only by generating higher antibody titers and antibodies with increased affinity for its antigen. d) provides a rapid reactivation of both cellular and humoral responses including generating higher antibody titers and antibodies with increased affinity for its antigen. e) generates higher antibody titers.

d) provides a rapid reactivation of both cellular and humoral responses including generating higher antibody titers and antibodies with increased affinity for its antigen.

Cytotoxic T cells eliminate pathogens by a) ingesting and digesting infected or cancerous cells. b) releasing chemicals which are toxic to cellular pathogens. c) ingesting and digesting cellular pathogens. d) releasing chemicals which cause infected or cancerous cells to undergo apoptosis. e) coordinating the activities of other immune cells.

d) releasing chemicals which cause infected or cancerous cells to undergo apoptosis.

The branches of adaptive immunity are... a) the cellular response, the humoral response, and the memory response. b) the antigen response and the memory response. c) the humoral response and the memory response. d) the cellular response and the humoral response. e) the cellular response and the memory response.

d) the cellular response and the humoral response.

The amount of antibody present in the blood is termed the antibody ________. a) affinity b) specificity c) effector d) titer e) isotype

d) titer

Generally, the first antibody class made upon a primary antigen exposure is a) IgA. b) IgD. c) IgE. d) IgG. e) IgM.

e) IgM

A newly-generated T cell can recognize MHCs and is not self-reactive. What is its fate? a) It will migrate to the bone marrow for screening for the ability to make antibodies against self-antigens. b) It is signaled for destruction via apoptosis. c) It will undergo genetic shuffling to change its receptor to increase self-tolerance. d) It will become part of an autoimmune attack in the body's tissues at some time in the future. e) It will migrate to the lymphoid tissues to await activation by its antigen.

e) It will migrate to the lymphoid tissues to await activation by its antigen.

Which statement is NOT true about MHC II? a) When bound to antigen, MHC II serves a key role in activation of the appropriate T cells. b) MHC II interacts with the CD4 receptor on T helper cells. c) MHC II is present only on antigen-presenting cells. d) MHC II primarily displays extracellular antigens which have been phagocytized. e) MHC II interacts with both the CD4 and CD8 receptors on T helper and T cytotoxic cells.

e) MHC II interacts with both the CD4 and CD8 receptors on T helper and T cytotoxic cells.

Which statement provides the best explanation of the need for self-tolerance screening of lymphocytes? a) It is necessary to have some lymphocytes with receptors that are self-tolerant to respond to intracellular infections by viruses. b) The process which generates the vast array of diverse antigen receptors is a highly-controlled process, so the generation of receptors which can bind to the body's own tissues is a rare occurrence due to a genetic mutation. c) Lymphocytes which would attack the body's own tissues are never generated. d) Self-tolerance involves "self" lymphocytes which bind to and form a protective layer over all body tissues. e) The process which generates the vast array of diverse antigen receptors is a random process that could produce receptors which will bind to the body's own tissues.

e) The process which generates the vast array of diverse antigen receptors is a random process that could produce receptors which will bind to the body's own tissues.

A substance that may trigger an immune response, if presented in the right context is termed a(n) a) effector. b) hapten. c) antibody. d) cytokine. e) antigen.

e) antigen.

The difference between T cell activation by normal antigens and T cell activation by superantigens is that superantigens a) cause nonspecific activation of many T cells at once, including those that would not normally recognize the antigen. b) suppress cytokine release. c) are not processed and presented by APCs. d) cause nonspecific activation of many T cells at once, including those that would not normally recognize the antigen and suppress cytokine release. e) are not processed and presented by APCs and cause nonspecific activation of many T cells at once, including those that would not normally recognize the antigen.

e) are not processed and presented by APCs and cause nonspecific activation of many T cells at once, including those that would not normally recognize the antigen.

The cellular branch of adaptive immunity a) is based on antibody production. b) is organized by T cytotoxic cells and carried out by T helper cells. c) is based on the activity of both T and B cells. d) does not involve a memory function. e) is organized by T helper cells and carried out by T cytotoxic cells.

e) is organized by T helper cells and carried out by T cytotoxic cells.

All the following apply to B cells EXCEPT a) coordinate the humoral response by making antibodies. b) reside in the lymphoid tissue. c) mature in the bone marrow. d) originate in the bone marrow. e) play a critical role in both the cellular and humoral responses.

e) play a critical role in both the cellular and humoral responses.

Consider a genetic mutation which causes T helper cells to be unable to respond to stimulation by the cytokines which lead to TH2 differentiation. This mutation would cause a patient to be deficient in which activity? a) production of memory cells b) action of macrophage c) action of cytotoxic T cells d) decrease of the immune response once the pathogen is eliminated e) production of antibodies

e) production of antibodies

A patient antibody titer which shows an increasing level of IgM but very little IgG would likely indicate that a) the patient has nearly recovered from the infection. b) the patient is having an allergic reaction. c) the patient was vaccinated against this pathogen rather than having the infection. d) the patient is currently a nursing mother. e) the patient is in the early stages of developing an immune response.

e) the patient is in the early stages of developing an immune response.

(T/F) Both the cellular and humoral branches of adaptive immunity have the goal of eliminating an identified antigen, but only the humoral branch develops a memory of the antigen so that future responses are faster.

false