Microbio: Ch. 15
Mature T cells express ______.
CD4 coreceptors CD8 coreceptors
Either --------- or -------- coreceptors are expressed on mature T cells.
CD4; CD8
Upon activation, this T cell type mounts a direct attack on target cells.
CD8
The CD8 coreceptor is found on the surface of which cell type?
Cytotoxic T cells
The nursing baby receives IgA from the mother's milk which is critical for protection because ______.
- IgA protects the gastrointestinal tract from enteric pathogens - natural intestinal barriers are not yet developed - the infant is not yet producing IgA
Looking at the structure of an antibody, you will find ______.
2 identical heavy chains constant regions 2 identical light chains
When activated by antigen, CD----- T cells directly attack and kill the target cell.
8
HIV infects T helper cells and severely reduces their number. Which of the following do you expect as a result of this?
A reduced ability of cytotoxic T cells to be activated A reduced ability of B cells to be activated
In most specific immune responses, antigen must be processed and presented by which of the following?
APC's
T-cell dependent antigens, which are usually protein based, require recognition steps between the following cells and substances.
Antigen Lymphocytes Antigen presenting cells
MHC class II molecules are found on which of the following host cells?
B lymphocytes Dendritic cells Macrophages
Which is NOT a characteristic of the structure of an antibody?
four different polypeptide chains
Microbes enter the human body most frequently through the ________ and ________ mucosa.
gastrointestinal; respiratory
The CD4 coreceptor is expressed on T ----- cells.
helper
The antigen binding sites on an antibody molecule are ______.
highly variable
Which of the following are principal activities of antibodies with respect to their specific antigens?
immobilize neutralize unite with (bind) call attention to
Any clinical process that produces immunity in an individual is called a(n) ________.
immunization
------ is the ability of the body to react to a myriad of foreign substances.
immunocompetence
The ability of the body to react to a myriad of foreign substances is termed ________.
immunocompetence
---- are the chemical class of proteins to which antibodies belong.
immunoglobins
The class of proteins to which antibodies belong are ________.
immunoglobins
B cells are activated by chemical signals called ______ produced by macrophages and T cells.
interleukins
The three main antigen presenting cells are --------, as well as -------- and B cells.
macrophages; dendritic
Antigen-presenting cells that both process and present antigenic determinants on their surfaces include B-cells, ------- and dendritic cells.
macrophanges
Chemical signals produced by ----- and T cells called interleukins can activate B cells.
macrophanges
One set of genes that codes for human cell receptors and plays a role in recognition of self by the immune system is the ---------- ---------- ------------ (MHC).
major histocompatibility complex
---- T or B cells remain for long periods to be ready to respond to the same antigen encountered at a later time.
memory
Some specific immune cells can differentiate into --------- cells, which persist long after a pathogen has been cleared and can reactivate during re-infection.
memory
The ______ response to previously seen antigens is the basis for the success of vaccinations.
memory
The basis of immunization is using antigen to produce immunologic ----- to that antigen.
memory
These cells remain in circulation for long periods of time and are ready to respond to a specific antigen should it be encountered again.
memory cells
Which of the following is a cell type that remains in the body long after a pathogen has been cleared, and can quickly respond if the body ever re-encounters the same pathogen?
memory cells
After an initial exposure to antigen, which of the following is not a typical time period for the generation of a secondary immune response?
minutes
----- immunity is acquired from infection or through breastfeeding from the mother; this immunity is acquired through normal life experiences.
natrual
Any immunity that is acquired during the normal biological experiences of an individual, such as infection or through breast feeding is known as ________ immunity.
natrual
After recovery from an infectious disease, the resistance to reinfection is called ________ immunity.
natural active
Recovery from infectious disease results in ------ --------immunity.
natural active
______ immunity can last from a few months to a lifetime.
natural active
Prenatal and postnatal mother and child relationships result in ----------- -------- acquired immunity.
natural passive
Which of the following is LEAST likely to show a similar combination of class I MHC genes?
neighbors from unrelated families
After antigen stimulation, B cells produce antibodies to ______ antigens.
neutralize inactivate target
T-cell dependent antigens do NOT require recognition steps between which of the following cells or substances?
neutrophils
The coating of nonself molecules with antibodies to increase their rate of phagocytosis is called ------
opsonization
---- immunity is the acquisition of premade antibodies either from the mother or via injection of immune serum.
passive
Specific resistance that is acquired indirectly by donation of preformed immune substances (antibodies) produced in the body of another individual is called artificial ________ immunity.
passive
Which is NOT a B cell outcome following activation signals from a T cell?
phagocytosis
Upon antigen encounter, B lymphocytes differentiate into antibody producing cells called ----- cells and memory cells that can quickly react with the same antigen in a subsequent encounter.
plasma
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
The ----- immune response is the initial antibody response upon encountering antigen.
primary
The first response of the immune system when exposed to an antigen is called a ________ immune response.
primary
Different host cell surface receptors can be involved in a wide range of significant roles such as ______.
promoting recognition of self antigens attachment to foreign antigens receiving and transmitting chemical messages aiding in cellular development
A given host cell can express several different surface molecules called ________, each of which has a role in detection, recognition, and cell communication.
receptors
An APC and a T cell form a complex between their ________ that triggers T cell activation.
receptors
During T cell activation, the APC and the T cell form a complex between their ----- that triggers T cell activation.
receptors
Microbes enter the body most frequently through the ------ tract or the ------- tract.
respiratory; gastrointestinal
The ---- response, also called the anamnestic response, is the specific immune response generated upon subsequent exposure to a previously seen antigen and it is directed by memory cells.
secondary
The ______ immune response is advantageous because it is faster and more vigorous at clearing antigen.
secondary
The advantage of a(n) ----- immune response is that it is faster and more vigorous at clearing antigen than the primary immune response.
secondary
The rapid rise in antibody titer following a repeat exposure to an antigen that has been recognized from a previous exposure is called a(n) ________ immune response.
secondary
The specific immune response is highly ------ which means that a given antibody, B cell receptor, or T cell receptor only recognizes a specific antigen.
selective
MHC class I proteins allow for the recognition of ----- molecules.
self
A given host cell can express ______.
several types of receptors
The two features that characterize the specific immune response are ---- and --------
specificity; memory
Which of the following is NOT a feature that characterizes specific immunity:
speed
The overall structure of an antibody is a(n) ______ shape.
symmetrical Y
Specific immunity is highly selective which means that antibodies produced to a specific foreign protein antigen on a virus only recognize ______.
that specific antigen
Cytotoxic T cells (with CD8 receptors) recognize antigen presented with MHC class ------ molecules
I
Helper T cells (with CD4 receptors) recognize antigen presented with MHC class ---- molecules.
II
Which of the following is NOT a reason why IgA from mother's milk is critical for the protection of a nursing baby?
IgA is needed to stimulate the baby's immature B cells
----- is any clinical procedure that produces either passive or active immunity in a subject.
Immunization
After antigen-presenting cells process an antigen, it is moved to the surface and then bound to ------- molecules for presentation.
MHC
Host cell protein receptors involved in immune reactions recognize self proteins such as -------- molecules.
MHC
What is the name for molecules that, following antigen processing, bind the antigen fragment and display it on the surface of the cell?
MHC
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
Which type of protein must be complexed with peptide to activate CD8 T cells?
MHC class I protein
Which type of protein must be complexed with peptide to activate CD4 T cells?
MHC class II proteins
Which of the following are the main antigen-presenting cells?
Macrophages B cells Dendritic cells
Which of the following must be true if a newborn infant was found to have circulating antibodies against a pathogen it has never seen?
Mother's antibodies are able to cross the placenta
---- immunity is acquired from infection or through breastfeeding from the mother; this immunity is acquired through normal life experiences.
Natural
________ immunity occurs only as a result of prenatal and postnatal mother and child relationships.
Natural passive
______ enhances phagocyte recognition by coating the invader with antibodies so that they will be more readily recognized by phagocytes.
Opsonization
________ are differentiated B cells that produce and secrete large amounts of antibodies.
Plasma
------ cells are responsible for cell-mediated immunity.
T
Cytotoxicity is the ability for this type of lymphocyte to kill specific target cells.
T
____ cells are the "mediators" of cell-mediated immunity.
T
Which immune system cell assists in activating both B cells and T cells?
T helper cell
Assisting in the recognition steps of the T-cell response, which type of cell has a receptor that binds with the class II MHC receptor on the APC and with the antigen?
T helper cells
The CD4 coreceptor is found on the surface of which cell type?
T helper cells
Which cell types are needed to activate B cells in the absence of B cells activating independently?
T helper cells
Which of the following cell types does not express MHC class II molecules on its surface?
T lymphocytes
Antigen binding sites are considered to be highly ------- in amino acid sequence and thus shape.
variable
MHC class I molecules on host cells display unique characteristics of self which is important to the process of _____.
tissue recognition
An antibody has a symmetrical ----- shape.
Y
B and T lymphocytes provide protection against specific antigens as part of ------ immunity.
acquired
The third line of defense, also known as ________ immunity provides long-term protection against foreign antigens encountered through infection or vaccination.
acquired adaptive
Natural ----- immunity generates memory so it can last from a few months to a lifetime.
active
The result of the body's response to exposure to antigen is called ________ immunity.
active
----- immunity is the result of the body's response to antigen.
activite
---- is the process by which the crosslinking of antibodies and microbes renders the microbes immobile and enhances their phagocytosis.
agglutination
----- is the aggregation formed by antibodies binding cellular antigens or large particles.
agglutination
Crosslinking of antibody to microbes leads to ______, which renders microbes immobile and enhances their phagocytosis.
agglutination
The aggregation (or clumping) by antibodies of whole cells or similar-sized particles is called ________.
agglutination
A(n) ------- is a type of antigen that provokes an allergic response.
allergen
An antigen that provokes an allergic reaction is called a(n) ________.
allergen
Antigen binding sites are highly variable from one antibody to another. This is due to high variability of the ------ acid content that makes up the hypervariable region.
amino
The high level of variability in antigen binding sites of different antibodies is due to high variability of the ________ composition (sequence) that makes up the variable region.
amino acid
Activated B cells (plasma cells) secrete immunoglobulins otherwise known as -------
antibodies
Plasma B cells produce -----
antibodies
Plasma cells produce copious amounts of ________.
antibodies
Plasma cells secrete immunoglobulins called ________.
antibodies
While the newborn is developing its own specific immune response it is protected by ______.
antibodies obtained by nursing antibodies obtained in utero
Following stimulation by antigen, B cells differentiate either into plasma cells, which produce and secrete --------, or into ------- cells, which will react rapidly if the antigen is encountered at some point in the future.
antibodies; memory
A molecule that induces a specific immune response is known as a(n) __________.
antigen
Once naive B cells have homed in on and attached to secondary lymphoid tissues, they are able to come into contact with ________ that enters from circulation or fluids.
antigen
The principal activity of an antibody is to unite with, immobilize, call attention to, or neutralize the ----- which is complementary to its receptor.
antigen
In most specific immune responses, antigen must be processed and presented by ___________-__________ cells.
antigen-presenting
----- are foreign molecules that elicit a specific immune response.
antigens
--- immunity results when a person is given a vaccination or receives premade antibodies through medical intervention.
artificial
Immunity that is induced as a medical intervention, either by exposing an individual to an antigen or by administering an immune substance such as antiserum is called ________ immunity.
artificial
Immunotherapy is ----- passive immunization with antibodies.
artificial
Most antibodies are passed in utero, but ----- also provides milkborne antibodies.
breastmilk
The CD8 coreceptor is expressed on ------ T cells.
cytotoxic
---- is the ability of certain T cells to kill a specific target cell such as an infected cell or a cancer cell.
cytotoxicity
True or false: After B cells have homed in on secondary lymphoid tissues, they are available to bind antigens that enter from circulation or fluids.
true
Along with B cells, ______ can serve as APCs for T cell activation.
dendritic cells and macrophages
Antigens can be presented to T cells by B cells, ------ cells and -------
dendritic; macrophages
Activation signals received from the T cells cause the activated B cell to ______.
differentiate enlarge proliferate
A(n) ------- is any molecule or fragment of a molecule that has the potential to trigger a specific immune response.
epitope
The precise molecular group of an antigen that defines its specificity and triggers an immune response is called a(n) _____.
epitope
True or false: A given host cell can express only one type of receptor.
false
True or false: Maternal antibodies are unable to cross the placental barrier.
false
True or false: Immune system receptors are involved in binding to MHC molecules.
true
An important characteristic of an antigen is that it be perceived to be ________.
foreign
Antigens are ________ molecules that stimulate a specific immune response.
foreign
Due to individual differences in the inheritance of class I MHC genes, the cells of each individual express molecules that are -------- to other humans.
foreign
One important characteristic of an antigen is that it be perceived as -------- meaning that it is not a normal constituent of the body.
foreign
A secondary immune response can occur ______ after exposure to antigen.
years weeks months
