Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

87 Cards in this Set

  • Front
  • Back
Result of exposure of a host to a foreign substance:
Active response
2 major categories of Active immune responses:
1. Innate
2. Adaptive
Main difference between adaptive and innate immunity:
Adaptive = specific
Innate = nonspecific
Innate immunity components (10)
Alternative complement pathway
Mannan, Toll-like (TLR) and C3b receptors
External barriers
Normal flora
Bile salts
Low pH
Adaptive immunity components (3)
-T lymphs
-B lymphs
5 components that are common to both adaptive and innate immunity:
-Classical complement pathway
-Dendritic cells
-Natural Killer cells
Timeframe over which Innate immunity operates:
0 to 12 hours
Timeframe over which Adaptive immunity operates:
1 to 5 days
What drives both the innate and adaptive immune systems?
Receptor ligand interactions
What do the receptors on cells of innate immunity recognize?
Patterns of macromolecules on microbe surfaces
What exactly are PAMPs?
The identical ligands present on different microbes that are recognized by innate immune cells
Where are receptors for both innate and adaptive immunity encoded?
In germline DNA
What happens to generate the specificity of the receptors in the adaptive immune cells?
Gene rearrangement during cell differentiation
So the 2 classes of Cell Surface Receptors are:
1. Those encoded by rearranged genes (adaptive)
2. Those encoded by non-rearranged genes (innate)
2 types of receptors that belong to the rearranged, adaptive category:
1. Tcell receptors for antigen
2. Antibody molecules (Igs)
7 types of receptors that belong to the nonrearranged, immune category:
1. Mannose receptor
2. LPS receptor
3. Glucan receptor
4. Scavenger receptor
5. Complement receptor
6. TLR
7. Fc Receptor
What is innate immunity specific for?
Structures shared by classes of microbes - molecular patterns
What is Adaptive immunity specific for?
Structural DETAIL of microbial molecules - antigens
What is the distribution of innate receptors?
-Identical receptors on all cells of the same lineage
What is the distribution of adaptive receptors?
-Different clones have receptors specific for different antigens
Does innate immunity have discrimination of self and non?
Does adaptive?
What are the 4 main principles of adaptive immunity?
1. Spcfc recgnitn of Ag by cell surface receptors on lymphs
2. Spcfc recgnition of Ag by Ag binding receptors on antibodies
3. Activation of 2ndary mechanisms
4. Memory
What are the 2 types of adaptive immunity?
1. Humoral
2. Cell-mediated
What are the microbes combated by humoral immunity?
What lymphocyte responds for humoral immunity?
B lymphs
What is the effector mechanism for humoral immnity?
Secreted antibody
What are the microbes combated by cell-mediated immunity?
-Phagocytosed microbes in macrophages
-Intracellular microbes replicating within infected cells
What are the cells that respond in cell mediated immunity?
-Helper T cells
-Cytotoxic T cells
What do Thelper cells respond to?
Macrophages containing phagocytosed microbes
What do Tcytotoxic cells respond to?
Cells infected with viruses
What is the function of a Thelper cell binding to antigen presented on a macrophage?
It activates the macrophage to kill the phagocytosed microbes.
What is the function of a Tcytotoxic cell binding to antigen on a cell?
It kills the infected cell and eliminates reservoirs of infection
Why is Specificity significant for immunity to microbes?
The body can recognize and respond to many different microbes
Why is Memory significant for immunity to microbes?
Because the body has enhanced responses to recurrent or persistent infections
Why is Specialization significant for immunity to microbes?
Because the body's responses to DISTINCT microbes are optimized for defense against these microbes.
Why is Nonreactivity to Self Antigens significant for immunity to microbes?
Because it prevents injurious immune responses against host cells and tissues.
List the 5 phases of the Adaptive immune response:
1. Recognition phase
2. Activation phase
3. Effector phase
4. Decline (homeostasis)
5. Memory
What happens during the recognition phase?
An APC presents antigen to the naive B and T lymphocytes
What happens during the Activation phase?
Expansion and differentiation of the mature T/B cells
What are the 2 important results of the Activation phase?
1. Antibody producing cells
2. Effector T lymphocytes
What happens during the Effector phase?
Elimination of antigens by Humoral and Cell-mediated immunity
What happens during the Decline phase?
What happens during the memory phase?
Surviving memory cells remain available for the next infection by the same pathogen
Where do lymphocyte clones mature?
In generative lymphoid organs in the ABSENCE of antigens
What are clones of naieve lymphocytes specific FOR? What happens to THEM?
Diverse antigens - they enter lymphoid tissues
What happens to antigen-specific clones of lymphocytes in lymphoid tissues if their appropriate Ag is present?
The clones are ACTIVATED (selected)
So lymphocyte activation is essential and necessary for:
Antigen-specific immune responses to occur.
What is REQUIRED for lymphocyte activation?
What is signal 1?
The microbial antigen binding to its antigen receptor on the lymphocyte
What is signal 2?
The costimulatory molecule produced or induced by the microbe
What are the 3 principal cells of the immune system?
1. Lymphocytes
2. APCs
3. Effector cells
What are the 3 varieties of lymphocytes?
-B cells
-T cells
-NK cells
What is the main principal function of lymphocytes?
Specific recognition of antigens
B lymphs mediate:
T lymphs mediate:
NK cells mediate:
B = humoral immunity
T = cell-mediated immunity
NK = innate immunity
4 types of APCs:
-Dendritic cells
-Follicular dendritic cells
-B cells
What is the principal function of APCs?
Capture of antigens for display to lymphocytes
Dendritic cells are responsible for the initiation of:
T cell responses
Macrophages are responsible for:
Initiation and the effector phase of cell-mediated immunity.
Follicular dendritic cells are responsible for:
The display of antigens to B lymphocytes in humoral immune responses
What are 3 types of Effector cells?
-T lymphocytes
What is the principal action of Effector cells?
Elimination of antigens
What are the 2 types of effector T lymphocytes?
-Helper T cells
-Cytotoxic T cells
Which granulocytes are effector cells?
Eos and Neuts
What cells are capable of capture and degradation of antigens for Induction of the Immune response?
-Dendritic cells
-B cells
What is required for presentation of degraded Ag to T lymphocytes?
What cells have MHC class I?
All nucleated cells
What does MHC I activate?
CD8 pos T cells (cytotoxic)
What cells have MHC class II?
Specialized cells
What does MHC II activate?
CD4 pos Thelper cells
What can cause "DIRECT" presentation of foreign MHC molecules?
-Transplantation reactions
What are the 3 main steps in the B lymph humoral immune response?
1. Binding native antigen to surface antibody
2. Activation via the Ag binding and cytokine signals from activated T cells
3. Differentiation into plasma cells to secrete Ab
What form of antigen do Bcells respond to?
What form of antigen do Thelper cells respond to?
Degraded + MHCII
What form of antigen do Tcytotoxic cells respond to?
Degraded + MHCI
What form of antigen do NK cells respond to?
Altered or no MHC I
How do T lymphocytes get from the circulation into lymph nodes?
Via high endothelial venules
What size of proteins are more immunogenic?
Large - larger than 2500 mw
What dose of antigen is most immunogenic?
What is the most immunogenic route of entry for antigens?
What is the least immunogenic route of entry for antigens?
Intravenous or intragastric
What type of protein composition is most immunogenic?
What is the most immunogenic form of protein?
Particulate and denatured
Does one protein consist of only one, or several epitopes?
What would be found in antiserum of an individual immunized with myoglobin which has four epitopes?
4 antibodies, one for each epitope
So when a person is immunized against the flu, for instance, will they develop antibodies and Tcells from only one clone?
No, they may develop several specific clones for a large number of epitopes