Microbiology Fundamentals ch 13
Which of the following are correctly matched?
CD4—Helper T cells CD8—Cytotoxic T cells
Which of the following cells is/are capable of specifically responding to a nearly infinite number of epitopes?
- B cells - Plasma cells - T cytotoxic cells
An antibody molecule is a composite of _______ polypeptide chains, including _______ heavy chains and _______ light chains. (Insert numbers.)
4; 2; 2
______ immunity occurs when an individual receives an antigen that activates B and T cells, causing the body to produce immune substances such as antibodies.
Active
MHC-I molecules are located on what types of cells?
All nucleated cells
Superantigens are processed by antigen-presenting cells.
FALSE
T or F: Cytotoxic T cells directly kill the viruses found inside of infected cells.
FALSE
Toxic shock syndrome is a mild disease similar to other mild allergic reactions.
FALSE
Which antibody fragment binds to receptors on the membranes of many different cells?
Fc
Helper T cells ________.
function in both cell-mediated and humoral immunity
The adaptive immune response ________.
involves memory of antigens from previous exposure Correct
T and B lymphocytes migrate to separate areas of the _______ organs after maturation.
lymphoid
Herd immunity involves _______.
maintaining a certain level of immunized individuals in a society to prevent a pathogen from circulating through the population
Protection against ______ diseases can be achieved through vaccination.
many, but not all
Mature B cells and T cells ______.
migrate in and out of lymphoid tissues
B cells differentiate into ________, which make antibodies.
plasma cells
The antibody producing progeny cells of a B-cell clone are called ________.
plasma cells
The effect of Fc binding to a cell's Fc receptor depends on the cell's _______.
role; function; or type
The effect of an antibody's Fc fragment binding to an Fc receptor on a cell depends on ______.
the cell's role
Which of the following are antigen-presenting cells?
Macrophages and B cells
MHC-II molecules are located on what types of cells?
Macrophages, dendritic cells, and B cells
Intravenous immunoglobulin (IVIG) contains immunoglobulins extracted from ______.
the pooled blood of many human donors
Superantigens are produced by ________.
Staphylococcus aureus in toxic shock syndrome
Only ________ cells require antigen to be presented on MHC class molecules.
T
______ lymphocytes require antigen presented with MHC molecules.
T
A person deficient in cytotoxic T cells may be more susceptible to cancer.
TRUE
MHC-I molecules normally display "self" proteins, those that are normally produced by a cell.
TRUE
Vaccinations depend on the anamnestic response to successfully protect a person from infection.
TRUE
That interaction is involved in the stimulation of a helper T cell?
The interaction of the T cell receptor with processed antigen and the binding of CD4 to the MHC II molecule.
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 is true for vaccines that have been approved and licensed for general use in preventing diseases?
The vaccines may show adverse outcomes, known as complications.
________ classes of major histocompatibility complex (MHC) genes have been identified.
Three
What is the purpose of booster shots?
To stimulate a secondary or anamnestic response
A measure of antibody level in a patient's serum is called ________.
titer
Which type of immunity occurs when an individual is stimulated by an antigen that activates the T and B cell response?
active immunity
The two arms of an antibody that bind the antigen are called _____.
antigen binding fragments
Helper T cells interact with target cells by recognizing ________.
antigen-MHC protein complexes
Which term refers to a special type of antibody that neutralizes bacterial exotoxins?
antitoxin
T cells ________.
are responsible for cell-mediated immunity
T or F: A basic immunoglobulin molecule is composed of four polypeptide chains: two heavy chains and two light chains.
true
Immune serum globulin contains immunoglobulins extracted from the pooled ______ of many human donors.
blood
B cell maturation occurs in the _______ _______.
bone marrow
In humans, B cells mature in the _______ and T cells mature in the ________.
bone marrow; thymus
Helper T cells secrete ________ to stimulate the proliferation of B cells.
cytokines
Cytotoxic T cells kill target cells by ________.
exposing them to chemicals which induces apoptosis
All mature T lymphocytes express ______ coreceptors. T cells also express ______ coreceptors.
CD3; CD4 or CD8
All of the following cells have class II MHC receptors on their surface EXCEPT ________.
red blood cells
T or F: B and T cells can only recognize and bind antigen that has been processed and presented on MHC molecules.
FALSE
T or F: Both antigen-presenting cells and B cells have class II MHC receptors on their surface.
FALSE
T or F: In a subunit vaccine, the subunit must come from the outer surface of the pathogen.
FALSE
T or F: T cells, but not B cells constantly recirculate in blood and lymphatics.
FALSE
T or F: The third line of defense can be summarized in four stages; I—antigen binding to T helper cells, II—antigen binding to B cells, III—phagocytosis of antigen by B and T lymphocytes, IV—killing of antigen.
FALSE
T or F: There are no antigens that can stimulate B-cells directly.
FALSE
T or F: There are only two major subsets of T cells.
FALSE
T or F: Vaccination is the process of inoculating one individual with the dried pus from the pustules of a smallpox patient.
FALSE
The fragment of an antibody that serves as the effector portion of the molecule as it binds to receptors on the membranes of many different cells is the _______ fragment.
Fc
The fragment of the antibody molecule that binds to phagocytes when antibodies opsonize an antigen is the _______ fragment.
Fc
In addition to perforins, which chemical(s) is/are also secreted by cytotoxic T cells?
Granzymes
Why are CD4 cell counts an important measure in determining the progression of HIV disease to AIDS?
Helper T cells, which possess the CD4 markers are important in the activation or efficiency of both adaptive and innate defenses.
CD8 markers bind to MHC class _____ molecules.
I
In the case of cancer or viral infection, which MHC class is involved with displaying abnormal proteins to cytotoxic T cells as a signal for destruction?
I
Helper T cells require antigen processing and presentation by MHC-_____ molecules.
II
The primary B-cell receptor is _______.
IgD
Early in the primary response, most of the antibodies are the ________ type.
IgM
A conceptual explanation for the development of lymphocyte specificity and variety during immune system maturation is known as the clonal _____ theory.
selection
The process by which the B or T cell with an antigen-specific receptor is activated by that incoming antigen is called clonal ______.
selection
Antigen-presenting cells release what cytokine to activate helper T cells?
Interleukin-1
A substance used for passive immunization that contains immunoglobulin extracted from the pooled blood of many human donors, sometimes called gamma globulin, is also referred to as _______ _______ (IVIG).
Intravenous Immunoglobulin
What is the set of genes that encodes human cell receptors that play a role in recognition of self by the immune system called?
MHC
After final maturation, T and B lymphocytes migrate to ____ areas in the ____ organs.
separate; lymphoid
_______ with antigen fragments displayed on their surfaces are known as antigen-presenting cells (APCs).
Macrophages
________ can quickly respond upon second exposure to the eliciting antigen.
Memory T cells
A toxoid would best be described as an example of which type of vaccine?
Subunit vaccine
Most B cells must interact with cells that bear receptors for epitopes on the same antigen to become functional. What type of cell would this be?
T helper
T or F: A helper T cell must be activated before it can stimulate a B cell to produce antibodies.
TRUE
T or F: An attenuated vaccine usually provides better immunity than a killed or inactivated one.
TRUE
T or F: In addition to apoptosis of infected host cells, apoptosis of lymphocytes also occurs during embryonic development.
TRUE
T or F: One plasma cell will secrete antibodies of various classes but the antibodies will all have different specificity.
TRUE
T or F: Proteins generally are T-cell dependent antigens.
TRUE
T or F: Self-proteins of infected cells are not recognized by cytotoxic T cells.
TRUE
T or F: Vaccines approved for human use may still potentially cause complications in a small percentage of patients.
TRUE
During lymphocyte development, the major histocompatibility complex (MHC) plays a role in ________.
the recognition of self by the immune system and rejection of foreign tissue Correct
________ causes an immediate immune response upon entry of the pathogen in the body.
Vaccination
The process of inoculating one individual with the dried pus from the pustules of a smallpox patient is called _______.
Variolation
When considering pathogenic microbes, ______.
there are many that lack a vaccine
Each individual mature B and T cell has the capacity to respond to ______.
a single unique antigen
By the time T and B cells reach the lymphoid tissues, each one is already equipped to respond to ______.
a single, unique antigen
For the major histocompatibility complex, classes of MHC genes have been identified.
three
MHC genes can be grouped into ______ classes.
three
Specific immunity is ______ meaning that it is acquired after a(n) ______ event.
adaptive; immunizing
A child with a genetic disorder that does not allow immature B cells to develop would therefore not be able to make ________.
antibodies
Phagocytes, such as dendritic cells, process and present ________.
antigen
Phagocytic cells such as dendritic cells process and present _______ to T cells.
antigen
The principal activity of an antibody is to immobilize, call attention to, or neutralize the _______ that is complementary to its receptor.
antigen
The Fab fragment of an antibody molecule, with a site that recognizes the antigen, is termed the _______ _______ fragment.
antigen binding
A helper T cell becomes activated by a(n) ________.
antigen-presenting cell
Which type of cell ingests and degrades a microbe, then processes and displays the microbe's antigens on its surface?
antigen-presenting cell
Substances known as _________ provoke a specific immune response so discriminating that only a single molecular fragment, called an __________, actually interacts with the lymphocyte's receptor.
antigens; epitope
A special type of antibody that can neutralize a bacterial exotoxin is called a(n) ________.
antitoxin
An antibody that can neutralize a toxin can also be referred to as a(n) _______.
antitoxin
Antigens ________.
are molecules that are recognized by B or T cells Correct
Live chickenpox virus can be used in a(n) ________.
attenuated vaccine
Superantigens ________.
bind without antigen specificity to the outer portion of T helper cells and antigen-presenting cells (APCs)
Human B cells mature in the ________.
bone marrow
The concentration of antibodies in serum is expressed as the _______.
titer
After maturation, B cells and T cells ______.
constantly recirculate through blood and lymphatics
After repeated exposure to foreign material, innate immunity ________.
continues to react the same way
The region of an antibody that does not bind to antigen, designated Fc, is called the _______ fragment.
crystallizable
In an antibody molecule, one light chain is bonded to one heavy chain, and the two heavy chains are bonded to one another with _______ bonds, creating a symmetrical Y-shaped arrangement.
disulfide
In an antibody molecule, the two heavy chains are bonded to one another through _____.
disulfide bonds
An important characteristic of an antigen is that it be perceived to be ________.
foreign
The important antigenic characteristic of whole microbes or their parts is that they are recognized as ______.
foreign
To become functional, most B cells must interact with T _______ cells that bear receptors for epitopes on the same antigen.
helper
B-cell differentiation is stimulated by ________.
interleukins
When activated by antigen-presenting cells, helper T cells release what cytokine that activates B-cells and cytotoxic T cells?
it has antigens from the disease-causing microbe on its surface
Characteristics of good antigens include all of the following EXCEPT ________.
large, repetitive molecule
Through ______, both a primary and memory response will occur so that if the pathogen enters the body, the immune response will be immediate, powerful, and sustained.
vaccination
Cytotoxic T cells recognize ________.
viral antigens and class I MHC
Select all of the statements that apply to B-cell maturation.
- B cells form and mature in the bone marrow - Naive B cells circulate for lymphatic organs where they come into contact with antigens
Mature T cells express ______ or ______.
- CD4 coreceptors - CD8 coreceptors
Antigen-presenting cells ________.
- Include dendritic cells - Engulf and present processed antigen on the surface - Include macrophages
Select all of the characteristics exhibited by effective vaccines.
- Little or no adverse side effects - Protect against exposure to wild-type, natural pathogens - Stimulate a B-cell or T-cell response - Relatively long shelf life
Which of the following cells can be a target for cytotoxic T cells?
- Viral-infected cells - Cancer cells - Transplanted cells
Possible symptoms of toxic shock syndrome include ________.
- fever - diarrhea - nausea and vomiting - shock
The principal activity of an antibody is to ______ the antigen for which it was formed.
- immobilize - call attention to - neutralize
Specific immunity ______.
- is adaptive - occurs only after an immunizing event such as an infection
Mature B and T lymphocytes migrate in and out of _______ organs.
lymphoid
Antigen-presenting cells process and present antigenic determinants on their surface and include B-cells, _______ and dendritic cells.
macrophages
The gene complex giving rise to a series of glycoproteins that are found on all cells except red blood cells and are important in the recognition of self by the immune system is called the ______ complex.
major histocompatibility
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
Like B cells, T cells also form _______ cells which can quickly respond upon secondary exposure to the eliciting antigen.
memory
The immune system responds more swiftly by making antibodies to an antigen after the first exposure because ________.
memory B cells are produced during the first response
Which type of T cell will be available to mount an immediate response upon subsequent contact with the same invader?
memory T cell
The aggregation (or clumping) by antibodies of whole cells or similar-size particles is called ________.
Agglutination
The aggregation formed by antibodies binding cellular antigens or large particles is called _______.
Agglutination
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
An antigen-presenting cell presents antigen to a helper T cell ________.
on its surface using a class II MHC
Cytotoxic T cells produce ________.
perforin, which makes holes in cell membrane of infected cells Correct
Antibodies are produced by ________.
plasma B cells
An antigen-_______ cell is a cell that ingests and degrades an antigen and subsequently places the antigenic determinant molecules on its surface for recognition by CD4 T lymphocytes.
presenting