Term
| List the five immunoglobulin classes in order from highest serum concentration to lowest |
|
Definition
|
|
Term
| Are immunoglobulins immunogenic? |
|
Definition
| They can be, because they are high molecular weight globular proteins |
|
|
Term
| How are immunoglobulins often detected? |
|
Definition
By use of anti-antibody antibodies
(haha) |
|
|
Term
| What distinguishes the five classes of antibodies from each other? |
|
Definition
| Their constant regions of the heavy chain (γ, μ, δ, α, ε) to make (G, M, D, A, E) |
|
|
Term
| Which Ig classes have subclasses, and how many are there? |
|
Definition
IgG has 4 subclasses,
IgA has 2 |
|
|
Term
| How many different heavy chain isotypes of immunoglobulins exist? |
|
Definition
9
(4 classes of G, 2 classes of A, 1 M, 1D, and 1E) |
|
|
Term
| What are the two types of immunoglobulin light chains? |
|
Definition
|
|
Term
| How many light chain isotypes (subtypes) exist? |
|
Definition
7
1 class κ, 6 classes of λ |
|
|
Term
| How many possible immunoglobulin isotypes exist? |
|
Definition
63
9 possible heavy chains x 7 possible light chains |
|
|
Term
For any given cell, are the
a)heavy chains
b)light chains
c) variable regions
d) allotype
always the same? |
|
Definition
a) heavy chain can change via class switching
b)Light chain always the same
c) Variable region always the same
d) Allotype same, either maternal/paternal |
|
|
Term
| Which contributes more to secondary biological characteristics, the heavy chain or the light chain? |
|
Definition
| The heavy chain, so it is common to refer to only the class/subclass when speaking of antibody isotypes; i.e., IgG1, IgG2, IgG3, IgG4, IgA1, IgA2, IgM, IgD, and IgE |
|
|
Term
|
Definition
| Genetically-determined differences in the proteins (antigens) between individuals in the same species resulting from polymorphic (allelic) genes |
|
|
Term
How many allotypes are inherited by an individual?
How many allotypes will show up on a single cell? |
|
Definition
Individuals express all of the allotypes inherited from parents in their immunoglobulin pool
However, only a single allotype (maternal or paternal) is expressed on a cell/Ab |
|
|
Term
How different are the structural differences between different allotypes?
How does this effect their function? |
|
Definition
The structural differences between the different allotypes is usually one amino acid.
Allotypic variants have no effect on antibody function. |
|
|
Term
| Which light and heavy chains have allotype variants? |
|
Definition
G, A, E, and κ have variants
M, D, and λ do not |
|
|
Term
| What can allotype variation affect? |
|
Definition
Variation does not affect antibody function, but it can affect antibody immugenicity
Ex. Maternal reaction to fetus, blood transfusion response, anti-G Ab in arthritis |
|
|
Term
|
Definition
The unique composition of the variable region (VL + VH) in a monoclonal antibody is called the idiotype
Any specific epitope in the V-region |
|
|
Term
| How many antibody idiotypes does an individual express? |
|
Definition
| 10^6-10^8 different antibody specificities |
|
|
Term
| Define monoclonal antibodies |
|
Definition
| Antibodies produced by the progeny of a single cell— a clone |
|
|
Term
| What was the first monoclonal antibody used in human therapy? |
|
Definition
| MUROMONAB-CD3 (Orthoclone OKT-3® Ortho) |
|
|
Term
| What allows surface immunoglobulins to attach to B cells? |
|
Definition
| A transmembrane protein, a lipophilic carboxy-terminal peptide of about 40 amino acids |
|
|
Term
| What immunoglobulin classes are often found on B cell surfaces? |
|
Definition
| IgM and IgD (important for B cell activation) |
|
|
Term
| Give two examples of immunoglobulin reversibly to cells via the Fc binding sites |
|
Definition
IgE to basophils and mast cells
IgG to phagocytes |
|
|
Term
| What is the main function of an Fc receptor? |
|
Definition
| Fc receptors are important in binding of IgG and IgA to macrophages and neutrophils and IgE to mast cells and basophils. |
|
|
Term
| List biological properties of IgM |
|
Definition
-Pentameric (decavalent)
-Efficient in agglutination and complement activation
-Diffuses poorly into extravascular
-First to appear in immune response
-Major B cell surface receptor
-Natural antibody to blood types |
|
|
Term
| List biological properties of secretory IgA |
|
Definition
-Dimer, attached by J-chain
-Associated with large secretory piece |
|
|
Term
| What two proteins are associated with secretory IgA? |
|
Definition
1. J-Chain: Small glycopeptide (MW 15,000) associated with all Ig polymers
2. Secretory Piece: Large glycoprotein (MW 70,000) synthesized by epithelial cells and associated with SIgA. It may be largely responsible for the stability of SIgA. |
|
|
Term
| List biological properties of IgD |
|
Definition
-Trace serum Ig
-No known function
-Surface receptor on naive B cells |
|
|
Term
| List biological properties of IgE |
|
Definition
-Trace serum Ig best known for involvement in allergy
-Cytophilic for mast cells and basophils via Fc receptors
-May be involved in immunity against some parasites |
|
|
Term
| List biological properties of IgG |
|
Definition
-Longest serum half-life (20-25 days) except for G3
-Complement activator (G3 best and G4 nil)
-Transported across placental barrier except G2
-Opsonizing antibody — Fc receptors on phagocytes |
|
|
Term
Which IgG subtype is best at complement activation?
Which is worst? |
|
Definition
|
|
Term
| Which IgG subtype is the worst at being actively transported across the placental barrier? |
|
Definition
|
|
Term
| Which Ig classes have the longest half-life in serum? |
|
Definition
|
|
Term
| Which Ig has the largest molecular weight? |
|
Definition
|
|
