13th Page Flashcards
IgA
provides natural passive immunity
predominant in body secretions such as tears, saliva, colostrum, milk, and intestinal fluids.
What are the subclasses of IgA?
IgA1, which is a monomer found in serum
IgA2, which is a dimer found in secretions, held together by a J chain.
How does IgA protect itself during transport?
IgA binds to a glycoprotein (secretory component)
Protects IgA from digestion by proteolytic enzymes and facilitates its transport to mucosal surfaces
Secretory component
IgM
largest antibody (megastar)
primary response antibody.
IgM
What are the forms of IgM?
monomer or a pentamer
IgM has how many antigen binding sites that are available for effector functions due to steric hindrances
5-6
IgM reacts at what temperature?
COLD
first antibody formed by the fetus
IgM
IgM
IgM is the first antibody to appear during an immune response and is the last to leave in senescence.
IgM
most efficient antibody that activates the complement system.
Agglutinating Ig
IgM
Cold-reacting Ab
IgM
Acute Infection Ig
IgM
Has the longest hinge region
IgD
IgD
found on the surface of mature and naive B cells in association with IgM.
What role does IgD play in B cells?
antigen recognition by B cells and signals B cells for antibody production.
Extremely susceptible to proteolysis
IgD
Drive B cells to produce antibody for immunoregulation
IgD
Antibody for hypersensitivity
IgE
Antibody that defense against parasitic worm?
IgE
IgE
least abundant immunoglobulin in the serum.
IgE
most heat labile antibody
Reaginic antibody
IgE
IgE
binds strongly to receptors on mast cells and basophils, mediating the release of histamine and heparin.
IgE
IgE mediates some types of hypersensitivity reactions, allergies, and anaphylaxis.
Generally responsible for immunity to invading pararsites (IL-4)
IgE
greatest plasma concentration
IgG
body secretions (saliva, tears)
IgA
mega (largest)
IgM
activates complement easily
IgM
pentaMer
IgM
Drive B cells
IgD
Allergy
IgE
Lag phase
No antibody is detectable.
This phase is known as the ‘1a9 phase’.
Log phase
The antibody titer increases logarithmically.
This indicates a rapid increase in antibody levels.
Plateau phase
The antibody titer stabilizes.
This phase is characterized by a steady level of antibodies.
Decline phase
The antibody is catabolized.
This phase marks the decrease in antibody levels.
What defines the primary antibody response?
It is the first immune response to the first encounter with a specific immunogen.
This includes a longer lag phase and lower antibody titer.
Initial challenge of the immune system
Primary antibody
Characteristics of the primary antibody response?
- Predominant antibody produced: IgM
- Longer lag phase
- Decrease/low antibody titer
Secondary (anamnestic) antibody response?
It is the immune response to subsequent exposure to the same antigenic stimulus.
This response is faster and stronger.
Characteristics of the secondary antibody response?
- Predominant antibody produced: IgG
- Shorter lag phase
- Longer stationary/plateau phase
- More gradual decline phase
- Increase in antibody titer
- Faster and stronger response
Most abundant Ab in the body
IgA
Most abundant Ab in serum
IgG
Ratio of IgG to IgA in serum
10:1
Least abundant Ab in the serum
IgE
Most effective in complement fixation
IgM
Longest hinge region
IgD
Longest hinge region in IgG classes
IgG3
Incomplete or non-agglutinating Ab
IgG
Significant Ab type often implicated in HTR and HDN
IgG
IgG that cannot cross the placenta
IgG2
IgG that is most efficient in complement fixation
IgG3
IgG that CANNOT fix complement
IgG4
IgGs that have high affinity to Fc receptors of phagocytic cells, increasing efficiency of phagocytosis
IgG1 and IgG3
An excellent neutralizing Ab
IgG
The only Ab with secretory components
IgA
Major Ab found in the colostrum in the mother’s milk
IgA
Ab most often formed in response to Gram (-) bacteria
IgM
Last to leave in senescence
IgM
First Ab that is formed by the fetus
IgM
First Ab to appear during an immune response
IgM
Abs in the membrane of B cells
IgM, IgD
Most heat-labile Ab
IgE