Chapter 15

Which of the following represents the correct sequence in "combinatorial joining" of DNA segments that code the variable region of antibodies?

D and J regions are first connected together, V joins next, then an mRNA is formed with a specific C segment.

Early in the primary response, most of the antibodies are the ____type.

IgM

Superantigens are produced by

Staphylococcus aureus in toxic shock syndrome.

Helper T cells ___.

stimulate B cells and other T cells

Foreign antigens presented on class I MHC molecules

stimulate cell destruction by activated T cells.

A toxoid would best be described as an example of which type of vaccine

subunit vaccine

T/F: A person deficient in cytotoxic T cells may be more susceptible to cancer.

True

T/F: Both antigen-presenting cells and B cells have Class II MHC receptors on their surface.

True

T/F: Helper T cells interact with target cells by recognizing antigens that are complexed with MHC proteins.

True

T/F: In addition to apoptosis of infected host cells, apoptosis of lymphocytes also occurs during embryonic development.

True

T/F: Many different antibodies can be made against a single antigen.

True

T/F: Monoclonal antibodies have applications in cancer therapy and diagnostic microbiology.

True

T/F: Natural active immunity occurs when you get chickenpox from contact with an infected person.

True

T/F: Plasma cells are B cells that produce antibodies.

True

T/F: The basic principle behind vaccination is to stimulate a primary response that primes the immune system for future exposure to a virulent pathogen

True

T/F: The same B cell can produce IgG and IgM antibodies.

True

T/F: Vaccinations depend on the anamnestic response to successfully protect a person from infection.

True

T/F: Viruses and self-proteins are examples of antigens produced within the cell.

True

The major histocompatibility complex (MHC) plays a role in

the recognition of self by the immune system and rejection of foreign tissue.

Helper T cells interact with target cells by recognizing

antigen-MHC protein complexes.

A helper T cell becomes activated by a(n) _______.

antigen-presenting cell

Live chickenpox virus can be used in a(n) ___.

attenuated vaccine

Which of the following processes does NOT generate antibody diversity during B cell development?

combinatorial joining that adds different constant regions to the heavy chain

B cell differentiation is stimulated by

interleukins.

Antigen receptors on B lymphocytes (antibodies) consist of

two identical light chains and two identical heavy chains.

Cytotoxic T cells recognize ___.

viral antigens and Class I MHC

Please match the lymphocyte with the statements that most accurately describe them to test your understanding of the events in B cell and T cell maturation.

1. mature in the bone marrow - B cells 2. mature in the thymus - T cells 3. migrate to secondary lymphoid organs/tissues - both T cells and B cells 4. are fully activated at birth - neither T cells nor B cells

Please match the interleukins with the statements that most accurately describe them to test your understanding of the actions of interleukins in the early reactions of recognition and activation.

1. produced by the APC to activate the helper T cell - interleukin-1 2. produced by the helper T cell to stimulate a general increase in activity of committed B and T cells - interleukin-2

B cells differentiate into plasma cells and _______.

memory cells

Breast feeding is an example of

natural passive immunity.

Possible symptoms of toxic shock syndrome include -diarrhea -nausea and vomiting -shock -fever

All of these choices are correct.

The coating of pathogens by antibodies to enhance phagocytosis is referred to as _________.

opsonization

Cytotoxic T cells produce _______.

perforin, which makes holes in cell membrane of infected cells

Surface receptors on immune system cells function in ___. - cell development - communication - identification of self/non-self

All of these choices are correct

T/F: A helper T cell must be activated before it can stimulate a B cell to produce antibody.

True

Select the correct sequence for the processing of antigens originated outside of the cell after their ingestion by phagocytes

Proteins are broken into fragments within a vesicle, which fuses with a Golgi vesicle containing Class II MHCs, and this complex is transported to the plasma membrane.

Characteristics of good antigens include all of the following EXCEPT - whole cells - exotoxins - viruses

large, repetitive molecules

All of the following cells have Class II MHC receptors on their surface EXCEPT - dendritic cells - red blood cells. - macrophages. - B cells.

red blood cells.

Please select the goals for designing effective vaccines to test your understanding of factors that are involved in vaccine development.

- does not require numerous doses or boosters - has a low level of adverse side effects or toxicity - achieves long-term, lasting effects - inexpensive to produce

Please select all of the functions of immune receptors to test your understanding.

- to perceive and attach to non-self or foreign antigens - to promote the recognition of self-antigens

Please match the type of T cells with the statements that most accurately describe them to test your understanding of the relationships between the types of T cells and their receptors.

1. antigen specific receptor - all T cells 2. CD4 - helper T cells 3. CD8 - cytotoxic T cells

Please match the statement to the term that it most accurately describes to test your understanding of the main categories of antigens, based on function.

1. cell surface markers and molecules that occur in some members of the same species but not in others - alloantigen 2. bacterial proteins that are potent stimuli for T cells - superantigen 3. evoke allergic reactions - allergens 4. molecules that escaped lymphocyte differentiation during which immune tolerance to self tissue developed - autoantigen

Please match the specific immune response phase with the statements that most accurately describe them to test your understanding of the overall phases in a specific immune response.

1. lymphocytes arise from the same stem cells but differentiate into two distinct cell types - antigen-Independent Development 2. foreign cells bear molecules that are recognized by B cells or engulfed by dendritic cells or macrophages - antigen Contact 3. involves production of antibodies by plasma cells - humoral Immunity 4. involves helper T cells and cytotoxic T cells - cell-Mediated Immunity 5. required for activation of T cells - antigen Presentation

Arrange the following in the proper order in which they occur during clonal selection. 1. Helper T cells are activated. 2. Macrophages ingest antigen. 3. B cells differentiate into plasma cells and memory cells.

2, 1, 3

T/F: A single monoclonal antibody can bind to several different sites on an antigen

False

T/F: Acellular vaccines are formaldehyde-inactivated bacterial exotoxins.

False

T/F: B and T lymphocytes develop in the bone marrow and mature in the thymus before moving into the circulatory system.

False

T/F: Cytotoxic T cells directly kill the viruses found inside of infected cells

False

T/F: Each B cell can react to many different types of antigens.

False

T/F: Fragments of foreign proteins are antibodies.

False

T/F: Helper T cells interact with Class I major histocompatibility complex (MHC) proteins.

False

T/F: In a subunit vaccine, the subunit must come from the outer surface of the pathogen

False

T/F: Innate immunity is the product of a dual system of unique leukocytes—the B and T lymphocytes.

False

T/F: One antibody can react with many different epitopes.

False

T/F: One plasma cell will secrete antibodies of various classes but the antibodies will all have different specificity.

False

T/F: Superantigens are processed by antigen presenting cells.

False

Which process involves a more rapid synthesis and greatly increased titer of antibody when the immune system is subsequently exposed to the same antigen?

anamnestic response

Interleukin I is secreted by _____ and activates _____.

antigen presenting cells, T helper cells

Helper T cells secrete ________ to stimulate the proliferation of B cells.

cytokines

Which of the following are antigen-presenting cells?

macrophages and B cells

An individual antibody is made against

one epitope on the bacterial cell.

An important difference between the primary response to an antigen and the anamnestic response is that

the anamnestic response has no latent period.

What is the purpose of booster shots?

to stimulate a secondary or anamestic response

Choose all the characteristics that are true about "active immunity."

- It protects the body against a new infection thanks to antibodies developed by the host during the first exposure to the antigen. - It requires several days to develop. - It can last for a relatively long time, sometimes for life.

Newer strategies for vaccine preparation include

- antigen synthesis - recombinant DNA technology - gene cloning

T/F: There are as many genes in the germ line DNA as there are types of antibodies possible.

False

____________ originate from activated plasma cells fused with tumor cells and have a single specificity for antigen. These can be used therapeutically to treat cancer and autoimmune disease.

Monoclonal antibodies

T/F: An attenuated vaccine usually provides better immunity than a killed or inactivated one.

True

T/F: Antigen receptors on lymphocytes include variable regions and diversity regions.

True

T/F: Proteins generally are T cell dependent antigens.

True

T/F: Self-proteins of infected cells are not recognized by cytotoxic T cells.

True

Please match the type of immunoglobulins with the statements that most accurately describe them to test your understanding of the basic functions of the five major types.

1. long-term immunity; memory antibodies; neutralizes toxins and viruses - IgG 2. secretory antibody on mucous membranes - IgA 3. produced at first response to antigen and can serve as B cell receptor - IgM 4. receptor on B cells for antigen recognition - IgD 5. antibody of allergy and worm infections - IgE

Please match the types of adaptive immunity with the statements that most accurately describe them to test your understanding of natural and artificial immunities and active and passive immunities.

1. occurs when an individual receives an immune stimulus that activates specific lymphocytes, causing an immune response such as production of antibodies - active immunity 2. occurs when an individual receives immune substances that were produced actively by the immune system of another human or animal donor - passive immunity 3. any immunity that is acquired during any normal biological experiences of an individual but not through medical intervention - natural immunity 4. protection from infection obtained through medical procedures - artificial immunity

Please select which of the following statements is true about antigen-presenting cells (APC)? - include dendritic cells - engulf and present processed antigen on the surface - include macrophages

All of these choices are correct

Which of the following cells can be a target for cytotoxic T cells? - cancer cells - transplanted cells - viral-infected cells

All of these choices are correct

Consider two IgG molecules, each of which reacts with a different epitope. Which of the following statements is FALSE? -They will have different amino acid sequences in the variable regions of their chains. -They will bind to two different antigenic determinants. -They will have the same amino acid sequence in the constant regions of their chains. -Each molecule consists of two light and two heavy chains.

All of these choices are correct.

______ are molecules that stimulate a response by T cells and B cells.

Antigens

T/F: T cell responses are considered cell-mediated immunities because they secrete molecules into circulation.

False

T/F: The primary response is also called the anamnestic response.

False

T/F: There are no antigens that can stimulate B cells directly.

False

Proteins are first broken into fragments during processing within a cell. Which of the following occurs next?

Fragments are transported to the rough endoplasmic reticulum, combined with Class I MHCs, move to the Golgi apparatus, then to the plasma membrane.

___________ may provoke overwhelming immune responses by large numbers of T cells regardless of specificity.

Superantigens

In creating a recombinant vaccine, a gene for an antigen can be spliced into a plasmid. What happens next?

The plasmid is placed into a host cell, such as yeast and the yeast will produce large quantities of the antigen.

Which of the following statements about the molecular structure of antigens is correct?

They are made up of many antigenic determinants (epitopes).

Which of the following statements about the interaction of superantigens with T cells is correct?

They bind without antigen specificity to the outer portion of T helper cells and antigen presenting cells (APCs).

Please choose the statement that best describes the complex structure of the bacterial cell surface in regards to immunity.

They have many different epitopes, which each bind to specific antibodies.

Molecules that can stimulate a response by T and B cells are called _________.

antigens

Please choose the term that describes a type of adaptive immunity occurring when a child gets the chickenpox vaccine.

artificial active immunity

Antivenin, given to people who have been bitten by rattlesnakes, consists of antibodies that bind to and inactivate the snake's venom. Antivenin is produced by injecting sheep with rattlesnake venom (which causes the sheep to produce antibodies) and then collecting the antibodies from the blood of the sheep, for later injection into humans. In this case, the sheep develops______________ immunity while the human experiences _____________________ immunity.

artificial active, artificial passive

An antibody which recognizes a measles virus will not recognize a chicken pox virus

because of the specificity of the antibody.

According to the _________________ theory, early undifferentiated lymphocytes in the embryo and fetus undergo a continuous series of divisions and genetic changes that generate hundreds of millions of different cell types, each carrying a particular receptor.

clonal selection

Which of the following cells attacks virally infected cells and cancer cells?

cytotoxic T cell

Please choose the answer that best fills in the blanks of this sentence in the correct order. A molecular fragment of an antigen that serves as the primary signal that the molecule is foreign is called a(n) ______, whereas a small foreign molecule that can only elicit an immune response when linked to another larger molecule is called a(n) ________.

epitope; hapten

Antigens such as proteins have several different sites that can react with antibodies. These sites are called

epitopes.

Please select which of the following statements is true about helper T cells?

function in both cell-mediated and humoral immunity Correct

In addition to perforins, which chemical(s) is/are also secreted by cytotoxic T cells?

granzymes

Vaccination is an effective method of establishing ____________,which makes it less likely that an unvaccinated member of the population will encounter the infectious agent.

herd immunity

The most direct source of monoclonal antibodies are ________ cells.

hybridoma

Passive immunization, in which a person is given antibodies, is a type of _________.

immunotherapy

Please choose the answer that best fills in the blanks of this sentence in order. The ______________ plays a vital role in recognition of self by the immune system and in rejection of transplanted tissues, and all nucleated cells possess Class ____ molecules.

major histocompatibility complex; I

An antigen-presenting cell presents antigen to a helper T cell _______.

on its surface using a Class II MHC

Antibodies are produced by

plasma B cells.

The progeny cells of a B cell clone are called _____.

plasma cells