chapter 33

Which of the following statements is correct about the production of antibodies after stimulation of B cells by antigen?

Class switching occurs when a cell secreting IgM changes the constant region of its antibody molecules, producing a different antibody class (IgG, IgA, or IgE).

Which of the following can lead to cytotoxic T lymphocyte activation?

A TH0 cell differentiates into a TH1 cell after stimulation by the MHC II/antigen complex and secretes IL-2.

Adaptive immunity refers to the type of specific immunity that ________.

All of the choices are correct.

Which of the following is not a function of the Fc portion of the immunoglobulin molecule?

Binding to the antigen

Major histocompatibility complex (MHC) proteins are coded for by a region on chromosome 6 known as the ____________ complex.

human leukocyte antigen

artificially acquired active immunity

intentional exposure to a foreign material, tetanus vaccine

The only immunoglobulin class with members able to cross the placental barrier is _________.

lgG

Which of the following types of immunoglobulins is most abundant in serum?

lgG

They also populate secondary ________ tissue sites once they mature.

lymphoid

All _____ T cells, whether CD4+ or CD8+ cells, require two signals to be activated into effector cells.

naive

The transfer of antibodies in breast milk is a good example of ________.

naturally acquired passive immunity

Interactions with the T cell cause the B cell to proliferate and differentiate into a ________ cell, which starts producing antibodies.

plasma

Once B cells have differentiated into _______ cells, antibody is secreted and can be detected.

plasma

The secondary response has a shorter lag phase and a more rapid log phase, persists for a longer __________ period, attains a higher IgG titer, and produces higher-affinity antibodies.

plateau

The immunoglobulin receptor molecules on the B-cell surface associate with other proteins known as the ________.

Ig-alpha/Ig-beta heterodimer proteins

What type of antibody is produced first after the initial exposure to antigen?

IgM

Which of the following function(s) as the B-cell antigen receptor?

Monomeric IgM

Which of the following statements about the acquisition of immunity is correct?

Naturally acquired active immunity occurs when an individual's immune system contacts an antigen such as a pathogen that causes an infection.

Clusters of differentiation (CDs) molecules are used to differentiate, classify, and name different cells of the immune system. Where are these molecules located?

Plasma membrane

Little Suzie has antibodies that bind specifically to the virus that causes mumps. Check all of the scenarios that could have provided her with the antibodies.

Suzie's mother's antibodies crossed the placenta during gestation. Suzie developed mumps, recovered, and now has a population of B memory cells. Suzie was vaccinated against mumps as an infant.

Which enzyme inserts nucleotides at the V-J junction to add further diversity?

Terminal deoxynucleotidyl transferase

Which of the following statements about activation of B cells is correct?

The T-independent antigens tend to be polymeric; that is, they are composed of repeating sugars or amino acids, and the resulting antibody generally has a relatively low affinity for antigen.

Which of the following statements is correct about the types of molecules that can serve as antigens?

The ability of a molecule to function as an antigen depends on its size, structural complexity, chemical nature, and degree of foreignness to the host.

Which of the following statements is correct about antigen presentation by class I and class II MHC molecules?

The class I MHC molecule is presented on the surface together with its endogenous antigen, enabling the host cell to present the antigen to a subset of T cells known as cytotoxic T lymphocytes.

All of the following events occur during T-dependent activation of a B cell EXCEPT _________.

There are no exceptions. All of these events occur during T-dependent activation of B cells.

What determines the cell type that a given CD4+ TH0 cell will differentiate into?

Type of cytokine exposure

The secondary immune response is typically stronger than the primary response because ________ during the secondary response.

a larger population of lymphocytes reactive to antigen has developed

artifically acquired passive immunity

administration of botulinum, introduction of antibodies or lynphocytes from one host into another

Class I MHC proteins are found on _______________ and their presence distinguishes almost every cell in the body as "self".

all nucleated cells

The variable domain of antibody molecules _________.

binds target antigen

Mature B cells and T cells are induced to elicit an ______ response when a foreign, nonself material is detected.

effector

In humans, the antigen-presenting cells include all of the following EXCEPT _________.

eosinophils

When a pathogen has been phagocytosed by an antigen presenting cell, __________ antigen processing results in fragments being displayed on the surface of the cell in conjunction with ________ MHC molecules. These antigen/MHC complexes are bound by ________ cells, which become activated.

exogenous, class II, T-helper

When a presented antigen fragment interacts with the T-cell receptor of a T-helper cell, the coreceptor that must also participate to finalize recognition is _________.

CD4

Cytotoxic T lymphocytes are distinguished from other lymphocytes by the presence of _________.

CD8

Which of the following statements about cluster of differentiation (CDs) molecules is correct?

CDs have both biological and diagnostic significance. They can be measured in situ and from peripheral blood, biopsy samples, or other body fluids.

Which of the following statements about antigen-presenting cells is correct?

Dendritic cells are particularly adept at presenting foreign peptides to T cells and stimulating them to become activated T cells.

Class II major histocompatibility complex molecules are found on all of the following types of cells EXCEPT ________.

red blood cells

Which of the statements about haptens is correct?

Haptens are usually small organic molecules.

The class of immunoglobulin transferred from mother to infant during breastfeeding is _________.

IgA

Which of the following prevents some bacteria from adhering to mucosal surfaces?

IgA

During the primary antibody response, IgM appears first, then switches to another antibody class, usually _____.

IgG

What antibody predominates during secondary antigen exposures?

IgG

The humoral immune response differs from the cell-mediated immune response in that only in the humoral immune response is there _________.

secretion of antibody

The immune system normally discriminates between ________ antigens.

self and non-self

Signal 1 occurs when an antigen fragment, presented in an _____ molecule of an antigen presenting cell (APC), fills the appropriate T-cell receptor.

MHC

Which of the following statements is true about clonal selection of lymphocytes?

Once a lymphocyte has been released from its primary development site and is exposed to its specific antigen, it proliferates to form a clone (a population of identical cells derived from a single parent cell).

What types of antigens are most susceptible to the action of precipitins?

Soluble antigens

Superantigens cause _________.

stimulation of T cells to overproduce cytokines.

Assess the following statements and classify them according to whether they refer to T-cell receptors or B-cell receptors.

T cell- 6 accessory polypeptides, heterodimeric a/b polypeptides, cytoplasmic tails interact with CD3 polpeptides b cell- transmembrane immunoglobulins, lga/lgb heterodimers, monomeric lgM and lgD

Which of the following statements is correct about the development of T cells?

T cells differentiate into progenitor cells destined to become (1) natural T regulatory (Treg) cells, (2) natural killer T (NKT) cells, (3) gamma/delta T cells, and (4) alpha/beta T cells.

Antigens that elicit a response with the aid of T cells are called _____ antigens.

T-dependent

In most cases, B cells that are specific for a given epitope on an antigen cannot develop into plasma cells that secrete antibody without the collaboration of __________ cells.

T-helper

A few specific antigens can trigger B cells into antibody production without T-cell cooperation; they are called _______ antigens, and their stimulation of B cells is known as T-independent antigen triggering.

T-independent

Which of the following statements about the function of T helper cells is correct?

TH1 cells promote cytotoxic T lymphocyte activity, activate macrophages, and mediate inflammation by producing interleukin (IL)-2, interferon (IFN)-gamma, and tumor necrosis factor-beta.

The ability to recognize a specific antigen and remember it in the future is a characteristic of the ________.

adaptive immune response

The humoral immune response defends against ________.

all of the choices are correct

Which of the following is (are) true about monoclonal antibodies?

all of the choices are correct

Which of the following is a characteristic associated with secondary antibody responses?

all of the choices are correct

Upon secondary _______ challenge, B cells mount a heightened secondary response.

antigen

B cells are more effective than macrophages in presenting antigens to activate T cells when _________.

antigen concentrations are low

All of the following might bring about the removal or destruction of bacteria by binding to antigens on bacterial surfaces EXCEPT _________.

antitoxins

Botulinum antitoxin produced in a horse and given to a human suffering from botulism food poisoning is an example of ________.

artificially acquired passive immunity

The T-cell progenitors initially leave the bone marrow and migrate to the ______, where they develop into at least four subsets of T cells.

thymus

Antibodies ________.

both can bind to an immunogen and can target the immunogen for destruction

The major histocompatibility complex directs the production of proteins called ________.

both class I and class II

The antibody _______, which is a measurement of serum antibody concentration, then rises logarithmically to a plateau during the second, or log, phase.

titer

For CD8+ cells to be activated, an endogenous antigen is presented in _________ molecules on the APC, and the CD8 coreceptor on the T cell interacts with the antigen-bound MHC molecule on the APC to induce CTL function.

class I MHC

When a cell is infected by a pathogen, the foreign peptides are processed and presented on the surface of the cell in conjunction with ________ MHC molecules. These foreign peptides are known as _____________ antigens and are presented to _________.

class I, endogenous, CTLs

In the case of T-helper (TH) cells, antigen is presented by _________ MHCmolecules, which triggers CD41 coreceptors on the TH cell to interactwith the antigen-bound MHC molecule.

class II

In addition to the first signal, both naïve CD4+ and CD8+ cells require a second, _________ signal to become activated.

co-stimulatory

Thus B cells, like T cells, require two signals: antigen-BCR interaction (signal 1) and T-cell ___________ (signal 2).

cytokines

Antigen presented within Type I MHC molecules will activate T _______ cells, while antigens presented within Type II MHC molecules will activate T _______ cells.

cytotoxic; helper

Class II MHC proteins are found on certain leukocytes, primarily B cells, macrophages, and __________; the cells that present foreign antigens to T cells.

dendritic cells

The protein chains in a complete antibody molecule are connected to each other by ________ bonds.

disulfide

A successful response either eliminates the ______ material or renders it harmless to the host.

foreign

The major histocompatibility complex (MHC) is a collection of _________ that code for the self/non-self recognition potential of an animal.

genes

naturally acquired active immunity

immune system responds to an infection, measles infection

Innate and adaptive immunity differ from one another in that __________.

innate immunity involves general barriers and mechanisms in effect regardless of the nature of the antigen, whereas adaptive immunity is a targeted response to a specific antigen

During activation of a T cell, the cytokine it produces to stimulate its own proliferation is _________.

interleukin 2

When an individual is exposed to an antigen, there is an initial lag phase, or _______ period, before an antibody response is mounted.

latent

Examples include bacterial ____________ and antibodies against other antibodies.

lipopolysaccharides

naturally acquired passive immunity

transfer of antibodies through placenta to fetus, passage of antibodies through breast milk

The _________ regions of antibodies have different amino acid sequences, and these regions fold together to form the antigen-binding sites.

variable

The inability of a virus to bind to its target cell as a result of antibody binding to the virus is referred to as _________.

viral neutralization

The primary antibody response primes the immune system so that it produces clones of __________ B cells.

memory

The B-cell receptor is comprised of __________.

monomeric IgM or IgD as well as Ig-α/Ig-β heterodimer proteins

Tumor cells of the immune system that produce large quantities of antibodies and can be readily cultivated are called _________.

myeloma cells

When an individual's immune system responds to an appropriate antigenic stimulus during the course of daily activities, this is called ________.

naturally acquired active immunity

Which type(s) of antigen-presenting cell can activate T cells?

All of the choices are correct.

An immune complex resulting from an interaction of antibody with cells or particles that becomes large enough to settle out of solution is called a(n) ________.

precipitation reaction

To begin, B- and T-cell _________ develop in the embryonic bone marrow and relocate to specialized tissue sites, called microenvironments, for maturation.

progenitor cells

Which of the following statements describes how antibody-binding brings about the removal of antigens?

Antibodies tag antigens for destruction, either via phagocytes or via complement activation.

The _____ relocate to microenvironments within the bone marrow, leaving to seed secondary tissue sites when they arefully mature.

B cells

The most important second signal seems to be the ______ protein on the surface of an APC, which binds to the CD28 receptor on the T cell.

B7 (CD80)

Which of the following statements is true about the susceptibility of antigens to antibody action?

Because antibodies have at least two antigen-binding sites and most antigens have at least two epitopes, cross-linking can occur, producing large aggregates termed immune complexes.

Which of the following is correct about the activity of antibodies?

Binding of antibody to biologically active materials (such as bacteria, toxins, or viruses) causes their inactivation or neutralization.