Lecture 9 Flashcards
When the body makes its own antibodies or T cells against a pathogen, it is exhibiting what type of immunity?
active
what are the 3 characteristics of innate immunity?
1) local
2) nonspecific
3) lacking memory
what are 3 characteristics of adaptive immunity?
1) systemic effect
2) specificity
3) memory
what are the different ways to classify adaptive immunity?
cellular (cell-mediated) immunity vs. humoral (antibody-mediated) immunity
natural vs. artificial active immunity
natural vs. artificial passive immunity
what is cellular (cell-mediated) immunity?
employs lymphocytes that directly attack and destroy foreign cells or diseased host cells
what is humoral (antibody-mediated) immunity?
employs antibodies that don’t directly destroy pathogens but tag them for destruction
what is natural active immunity?
natural exposure to antigen causes production of one’s own antibodies or T cells
what is artificial active immunity?
vaccination causes production of one’s own antibodies or T cells
what is natural passive immunity?
temporary immunity that results from acquiring antibodies produced by another person
ex. fetus from mother’s placenta or baby during breast-feeding
what is artificial passive immunity?
temporary immunity that results form injection of an immune serum abstained from another person or from animals that have antibodies against a certain pathogen
T or F:
natural active immunity –> a person develops resistance to a virus picked up from a drinking fountain
T
T or F:
artificial active immunity –> a person is given an attenuated smallpox virus and develops resistance
T
T or F:
natural passive immunity –> a baby acquires resistance to a virus thru antibodies obtained thru breast milk
T
T or F:
artificial passive immunity –> an antibody is injected into a person who has been bitten by a snack. The antibody infers resistance.
T
When the body acquires antibodies from another person or an animal that has developed its own immunity to the pathogen, this type what type of immunity?
passive
differentiate passive immunity from active immunity
passive – obtain antibodies from another person or animal –> temporary
active – your body makes its own antibodies against pathogens
What is any large molecule capable of triggering an immune response called?
antigen
Cellular immunity is mediated mainly by ______ cells, while humoral immunity is mediated mainly by ______ cells.
T, B
The body makes its own antibodies or T cells against a pathogen is natural ___ immunity
active
The region of the antigen which stimulates an immune response is the ___
epitope (antigenic determinants)
What is artificial active immunity?
Acquiring one’s own immunity against an attenuated pathogen
An incomplete antigen is also known as a ______.
hapten
In artificial ___ immunity, the body is injected with antibodies from another person or an animal.
passive
which area of an antibody determines its class?
structures of their C region
Any large molecule capable of triggering an immune response is called a(n) ___
antigen
Choose all the processes through with the great diversity in the specificity of antibody molecules is produced.
- somatic hypermutation
- anergy
- clonal selection
- somatic recombination
somatic hypermutation
somatic recombination
what is somatic recombination?
forms new combinations of DNA base sequences in somatic (nonreproductive) cells
what is somatic hypermutation?
B cells in germinal centers of lymphatic nodules undergo exceptionally high rates of mutation
not just recombining preexisting DNA but creating wholly new DNA sequences
B cells are the primary cell of ______ immunity and T cells are the primary cell of ______ immunity.
humoral
- B cells –> plasma cells –> antibodies –> tags pathogens for destruction
cell-mediated
- T cells –> directly attack and destroy foreign cells or diseased host cells
where do T cells mature?
thymus
What is the region of an antigen that stimulates an immune response?
epitope
B cells or T cells that are mature and are capable of recognizing antigens presented by APCs are described as ___
immunocompetent
Which is too small to be antigenic by itself, but can induce an immune response when bound to a larger molecule?
hapten
To function properly, T cells must have which two traits?
a lack of reactivity to self peptide fragments
the ability to recognize self MHC proteins
which area of an antibody determines specificity?
antigen-binding site on variable (V) region
The type of recombination whereby several hundred DNA segments are shuffled and combined in various ways to produce antibody genes unique to each clone of B cells is ______ recombination.
somatic
What is a mature T-cell that has not been activated by an antigen called?
naive
Which lymphocytes originate in the red bone marrow and then finish maturation in the thymus?
T
Cells that phagocytize antigens and display antigenic fragments on their surface are called ___-presenting cells
antigen
What is it called when mature T-cells become capable of recognizing antigens presented by APCs?
immunocompetence
The proteins on the surface of APCs that function to present antigens to other cells are called the ______.
MHC proteins
During which of the following are self reacting T cells eliminated?
negative T cell selection
which area of an antibody determines its class?
constant (C) region
Which class of cytokines promotes the development and differentiation of T, B, and hematopoietic cells?
interleukins
A T cell which has undergone positive and negative selection but has not become activated by an antigen is said to be ___
naive
immunocompetent
Which cell phagocytizes an antigen and displays fragments of it on its surface?
antigen-presenting cell
Which T cells carry out attacks on foreign cells?
cytotoxic
Choose all that describe MHC proteins.
- MHC proteins are identical in members of the same species
- MHC proteins function as self identity markers
- MHC proteins present endogenous antigens
- MHC proteins present exogenous antigens
MHC proteins function as self identity markers
MHC proteins present endogenous antigens
MHC proteins present exogenous antigens
To function properly, T cells must have which two traits?
- the ability to become anergic
- a lack of reactivity to self peptide fragments
- the ability to react to self proteins
- the ability to recognize self MHC proteins
a lack of reactivity to self peptide fragments
the ability to recognize self MHC proteins
T cells that perform a central coordinating role in both humoral and cellular immunity are called ___ T cells.
helper or CD4
True or false: Interleukins are a class of cytokines secreted by a variety of cells which function to promote the development and differentiation of T, B, and hematopoietic cells.
true
Which T cell inhibits multiplication and cytokine secretion by other T cells and thus limits immune responses?
regulatory T cell
What is a mature T-cell that has not been activated by an antigen called?
naive
T cells that are descended from the cytotoxic T cells and are responsible for memory in cellular immunity are called ___ T cells.
memory
T cells that attack foreign cells are ___ T cells
cytotoxic
Which MHC class of proteins occur on all nucleated somatic cells and may trigger a cytotoxic T cell response if displaying a viral protein?
I
The proteins on the surface of APCs that function to present antigens to other cells are called the ______.
MHC proteins
Which cells carry MHC class II proteins?
APCs
Which T cell plays an integral role in both humoral and cell mediated immunity?
helper T cell
The process called ___ selection results in the formation of a clone of identical T cells programmed against the same epitope.
clonal
T cells that inhibit multiplication and cytokine secretion by other T cells, and thus limit immune responses are called ___ T cells.
regulatory
Identical cells produced by mitosis from a single parent cell are called ______.
clones
Which T cells are descended from the cytotoxic T cells and responsible for subsequent immune responses to the same antigen?
memory T cells
What are the 4 substances that cytotoxic T cells secrete to attack and destroy target cells?
perforin
granzymes
interferons
tumor necrosis factor (TNF)
Where are type I MHC proteins found?
On all nucleated body cells
Which class of MHC proteins occur only on APCs?
II
Choose all the reasons why memory T cells allow for a faster immune response when the body is exposed to the same antigen again.
There are more of them.
There are fewer steps to activation.
Choose all the events that must occur to activate a T cell.
It binds to a foreign antigen presented on an MHC protein.
It is costimulated by other surface molecules.
Which type of immunity is mediated by B cells and the antibodies they secrete?
Humoral
Which describes a clonal population of T cells?
They are identical.
They are self-tolerant.
They react to the same antigen.
Which T cells attack and destroy target cells by secreting perforins and granzymes?
cytotoxic
Usually, a B cell requires costimulation from a ___ T cell to begin the process of clonal selection
helper
Which MHC class of proteins occur on all nucleated somatic cells and may trigger a cytotoxic T cell response if displaying a viral protein?
I
Once a B cell binds an antigen, it phagocytizes it and displays antigen fragments on what molecules?
MHC-II proteins
The T cell ______ response allows memory cells to mount a faster response upon exposure to the same pathogen later.
recall
Humoral immunity is mediated by ______ lymphocytes.
B
Which cells produce antibodies?
plasma cells
Identical cells produced by mitosis from a single parent cell are called ______.
clones
Choose of of the following ways antibodies function to render antigens harmless.
neutralization
complement fixation
agglutination
precipitation
Place the events of the humoral response in order beginning at the top.
1) immunocompetent B cells bind to an antigen
2) A B cell internalizes an antigen and displays it on MHC-II proteins to TH cells
3) TH cells secrete interleukins which activate the B cell
4) the B cell undergoes clonal selection
5) B cells differentiate into plasma cells and memory cells
6) plasma cells produce and secrete antibodies
Choose all that are required for activation of a B cell.
Usually, it must bind a helper T cell.
It must bind an antigen on several surface receptors.
Antibodies provide an important defense against bacteria when they bind two or more cells together. What is this immobilization called?
Agglutination
Choose all the reasons why memory T cells allow for a faster immune response when the body is exposed to the same antigen again.
There are more of them.
There are fewer steps to activation.
Choose all that are characteristics of a primary immune response.
IgM antibodies are formed first.
It occurs with the first exposure to an antigen.
Antibodies first appear 3-6 days after exposure, peaking at day 10.
cells that secrete antibodies are called ___ cells
plasma
What is the level of antibody present in the blood plasma called?
antibody tier
Molecules that function to render antigens harmless by neutralization, complement fixation, agglutination and precipitation are called ______.
antibodies
Usually, a B cell requires costimulation from a ___ T cell to begin the process of clonal selection.
helper
The clumping of cells by antibodies is called ______.
agglutination
Choose all that are characteristics of a secondary immune response.
Antibodies first appear within hours, peaking at day 3.
IgG antibodies are formed first.
It occurs after the second and subsequent exposures to an antigen.
To confirm exposure to an antigen what is measured to demonstrate that an immune response has occurred?
Antibody titer
Antibodies provide an important defense against bacteria when they bind two or more cells together. What is this immobilization called?
Agglutination
which type of antibody is formed first during primary immune response?
IgM
which type of antibody is formed first during primary immune response?
IgM
what are the 4 ways antibodies attack antigens?
(1) neutralization
(2) complement fixation
(3) agglutination
(4) precipitation
describe how antibody attacks antigens:
neutralization
antibody covers over pathogenic part of antigen
describe how antibody attacks antigens:
complement fixation
antibody binds complement proteins to enemy cell –> inflammation, phagocytosis, immune clearance, and cytolysis
IgM and IgG bind to enemy cells and change shape, exposing their complement-binding sites –> initiates binding of complement to the enemy cell surface and leads to inflammation, phagocytosis, immune clearance, and cytolysis
describe how antibody attacks antigens:
agglutination
antibody clumps enemy cells together –> immobilizes pathogens and prevents them from spreading –> allows neutrophils and macrophages to come and phagocytize clusters of bacteria
describe how antibody attacks antigens:
precipitation
antigen molecules (not whole cells) are clumped to antibodies –> form large Ag-Ab complexes –> can be removed by immune clearance or phagocytize by eosinophils
choose all of the substances that cytotoxic T cells secrete to attack and destroy target cells.
interferons
perforins
tumor necrosis factor
granzymes
process where antibodies make molecule insoluble and less mobile is an example of ___
precipitation
