Chapter 13
B
Cellular adaptive immunity is carried out by ________. A. B cells B. T cells C. bone marrow D. neutrophils
What is the purpose of Class I MHC, Class II MHC, and Class III MHC?
Class 1 MCH- code for self molecules Class 2 MCH- immune function Class 3 MCH- complement system
A
Cytotoxic T cells will bind with their TCR to which of the following? A. antigens presented with MHC I molecules B. antigens presented with MHC II molecules C. free antigen in a soluble form D. haptens only
ADCC: enhances killing of pathogen that are too large to be phagocytosed Uses natural killer cells or macrophages and eosinophils; brings them into close proximity with target pathogen and secretes powerful cytotoxins that kill pathogen
Describe the mechanism of antibody-dependent cell-mediated cytotoxicity.
True or False: One antibody can bind multiple types of antigens.
F
True or False: The actual bacterium causes the development of the symptoms seen in TSS.
F
Which of the following correctly describes Staphylococcus aureus?
Gram positive cocci arranged in clusters
Why are CD4 cell counts an important measure in determining the progression of HIV disease to AIDS?
Helper T cells which posses the CD4 makers are important in the activation or efficiency of both adaptive and innate defenses.
Early in the primary response, most of the antibodies are the _______ type.
IgM
Variolation
In the practice of _________, scabs from smallpox victims were used to immunize susceptible individuals against smallpox.
A
MHC I molecules present A. processed foreign antigens from proteasomes. B. processed self-antigens from phagolysosome. C. antibodies. D. T cell antigens.
B2 microglobulin
MHC II molecules are made up of two subunits (α and β) of approximately equal size, whereas MHC I molecules consist of a larger α subunit and a smaller subunit called ______.
B
MHC II molecules present A. processed self-antigens from proteasomes. B. processed foreign antigens from phagolysosomes. C. antibodies. D. T cell receptors.
Presentation
MHC molecules are used for antigen ________ to T cells.
_______ with antigen fragments displayed on their surfaces are known as antigen-presenting cells (APCs)
Macrophages
MHC-II molecules are located on what types of cells?
Macrophages, dendritic cells and B cells
Thymus
Peripheral tolerance mechanisms function on T cells after they mature and exit the _________.
A helper T-cell must be activated before it can stimulate a B-cell to produce antibody
T
An attenuated vaccine usually provides better immunity than a killed or inactivated one.
T
Both antigen-presenting cells and B-cells have class II MHC receptors on their surface
T
MHC-I molecules normally display "self" proteins, those that are normally produced by a cell.
T
Plasma cells are B cells that produce antibodies.
T
Proteins generally are T-cell dependent antigens.
T
Self proteins of infected cells are not recognized by cytotoxic T-cells.
T
True or False: An effective measles virus vaccine exists today.
T
Vaccinations depend on the anamnestic response to successfully protect a person from infection.
T
A toxoid would best be described as an example of which type of vaccine?
subunit vaccine
Repetitive
T-independent antigens can stimulate B cells to become activated and secrete antibodies without assistance from helper T cells. These antigens possess ___________ antigenic epitopes that cross-link BCRs.
Which of the following cells are needed for most B cells to become functional?
t helper cells
Constant
The heavy chains of an antibody molecule contain ________ region segments, which help to determine its class or isotype.
What 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 MCH II molecule
Antigen binding
The variable regions of the heavy and light chains form the __________ sites of an antibody.
Memory
There are two critically important aspects of adaptive immunity. The first is specificity, while the second is ________.
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
B
To what does the TCR of a helper T cell bind? A. antigens presented with MHC I molecules B. antigens presented with MHC II molecules C. free antigen in a soluble form D. haptens only
Which of the following is correct regarding antibodies?
they are proteins
D
What is a superantigen? A. a protein that is highly efficient at stimulating a single type of productive and specific T cell response B. a protein produced by antigen-presenting cells to enhance their presentation capabilities C. a protein produced by T cells as a way of increasing the antigen activation they receive from antigen-presenting cells D. a protein that activates T cells in a nonspecific and uncontrolled manner
Helper T cells: orchestrate humoral and cellular immunity, involved in activation of macrophages and NK cells Cytotoxic T cells: destroy cells infected with intracellular pathogens
What is the basic difference in effector function between helper and cytotoxic T cells?
Antigen: trigger adaptive immune defense/pathogen specific molecular structures Hapten: too small to be antigenic by self/ free epitopes not part of complex three dimensional structure of larger antigen- not associated with specific pathogen
What is the difference between an antigen and a hapten?
Humoral: mechanism of adaptive immunity that involve B cells and antibody production Cellular: targeting and destruction of intracellular pathogens by T cells
What is the difference between humoral and cellular adaptive immunity?
APCs presenting antigens associated with MHC II and APCs or infected nucealted cells presenting antigens associated with MHC I
What necessary interactions are required for activation of helper T cells and activation/effector function of cytotoxic T cells?
C
Which class of molecules is the most antigenic? A. polysaccharides B. lipids C. proteins D. carbohydrates
B
Which of the following does not occur during the lag period of the primary antibody response? A. activation of helper T cells B. class switching to IgG C. presentation of antigen with MHC II D. binding of antigen to BCRs
D
Which of the following would be a BCR? A. CD4 B. MHC II C. MHC I D. IgD
C
Which of the following would be a T-dependent antigen? A. lipopolysaccharide B. glycolipid C. protein D. carbohydrate
B
Which type of antigen-presenting molecule is found on all nucleated cells? A. MHC II B. MHC I C. Antibodies D. B-cell receptors
B
Which type of antigen-presenting molecule is found only on macrophages, dendritic cells, and B cells? A. MHC I B. MHC II C. T cell receptors D. B cell receptors
T-dependent
________ antigens can stimulate B cells to become activated but require cytokine assistance delivered by helper T cells.
Humoral
________ immunity involves the production of antibody molecules that bind to specific antigens.
Artificial passive
________ immunity occurs when antibodies from one individual are harvested and given to another to protect against disease or treat active disease.
When first administered to a naïve individual (has not been exposed to measles virus), the measles vaccine will stimulate
a primary response
An individual successfully recovered from measles as a child. Now 35 years old, her toddler has the infection. What immune response is occurring in the woman's body at this time?
a secondary response
Antibodies are produced by which line of defense?
third
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
A helper T-cell becomes activated by a(n) ______.
antigen-presenting cell
Which of the following is a term that refers to a gamma globulin that can neutralize virulence factors secreted by Staphylococcus or Streptococcus strains, as in the case of TSS?
antitoxin
Characteristics of antigens include
are made up of many antigenic determinants (epitopes)
Live chickenpox virus can be used in a(n) _______.
attenuated vaccine
Antibiotics were used for treatment because Staphylococcus aureus is a ______.
bacterium
Superantigens
bind without antigen specificity to the outer portion of portion of T helper cells and antigen presenting cells (APCs)
Based upon the epidemiological evidence, the mode of transmission in this case was
direct contact
Epidemiologists determined that this outbreak could have been avoided if
everyone had been adequately vaccinated against measles
When activated by antigen-presenting cells, helper T-cells release what cytokine that activates B-cells and cytotoxic T-cells?
interleukin-2
Cytotoxic T-cells know that a cell is infected because
it has antigen from the disease-causing microbe on its surface
What is the purpose of booster shots?
to stimulate a secondary or anamestic response
Cytotoxic T-cells recognize
viral antigens and class I MHC
Measles is caused by a ______.
virus
CD8 markers bind to MHC class ___ molecules.
1
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?
1
Naturally Acquired
1. Active through infection 2. passive through antibodies to the newborn
artificially acquired
1. Active through vaccination 2. passive through antibodies by immunoglobulin injections
Name the 5 ways that antibodies tag antigens
1. Osponization- coating antigen with antibody 2. Agglutination-phagocytosis by grouping together antigens 3. Neutralization- blocks adhesion 4.Antitoxin- blocks toxin 5. interaction with complement- cytolysis MAC (membrane attack complex)
Helper T cells require antigen processing and presentation by MHC-___ molecules.
2
B-cells
mature in bone marrow Intercellular; bacteria
T-cells
mature in the thymus intracellular; virus
Variable
A TCR is a protein dimer embedded in the plasma membrane of a T cell. The ________ region of each of the two protein chains is what gives it the capability to bind to a presented antigen.
Cytotoxic
A ________ T cell will become activated by presentation of foreign antigen associated with an MHC I molecule.
Helper
A ________ T cell will become activated by presentation of foreign antigen in association with an MHC II molecule.
D
A ________ molecule is a glycoprotein used to identify and distinguish white blood cells. A. T-cell receptor B. B-cell receptor C. MHC I D. cluster of differentiation
A
A patient gets a cold, and recovers a few days later. The patient's classmates come down with the same cold roughly a week later, but the original patient does not get the same cold again. This is an example of: A. Natural active immunity B. Artificial active immunity C. Natural passive immunity D. Artificial passive immunity
D
A patient is bitten by a dog with confirmed rabies infection. After treating the bite wound, the physician injects the patient with antibodies that are specific for the rabies virus to prevent the development of an active infection. This is an example of: A. Natural active immunity B. Artificial active immunity C. Natural passive immunity D. Artificial passive immunity
D
A single antigen molecule may be composed of many individual ________. A. T-cell receptors B. B-cell receptors C. MHC II D. epitopes
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
Attenuated
A(n) ___________ pathogen is in a weakened state; it is still capable of stimulating an immune response but does not cause a disease.
B cells differentiate into plasma cells and _______.
memory cells
MHC-I molecules are located on what types of cells?
All nucleated cells
An antigen-presenting cell presents antigen to a helper T-cell
on its surface using a class II MHC
Which of the following statements characterizes clonal selection in the process of antibody production?
one B cell type is selected to produce one type of antibody
Cytotoxic T-cells produce
perforin, which makes holes in cell membrane of infected cell
B-cells differentiate into ______, which make antibodies.
plasma cells
A
Antibodies are produced by ________. A. plasma cells B. T cells C. bone marrow D. B cells
In the bloodstream, bacterial antigens will first bind to antibodies presented on _______.
B-cells
Memory
Both ________ and effector T cells are produced during differentiation of activated T cells.
Attenuated pros: stimulate comprehensive immune response than others con: associated with challenges with long term storeage and transport as well as potential for a patient to develop signs/symptoms of disease Inactivated pros: long term storeage stability and ease of transport: no risk of causing serve active infections Cons: immune response is weaker and less comprehensive: Multiple boosters
Briefly compare the pros and cons of inactivated versus live attenuated vaccines.