LEC 6 Intro to Immunology II Flashcards
1
Q
What are the two forms of antibodies?
A
- Cell surface antigen receptor on B cells
- Secreted antibody
2
Q
What is IgM?
A
- B cell receptor
- earlierst Ig produced
3
Q
What is IgD?
A
- Antigen receptor on B cells; co-expressed with IgM
4
Q
What is IgG?
A
- most prevalent in serum
- 4 subclasses: IgG1, IgG2, IgG3, IgG4
5
Q
What is IgA?
A
- Most prevalent in secretions
- 2 subclasses: IgA1, IgA2
6
Q
What is IgE?
A
- Immediate hypersensitivity
7
Q
When expressed on B cells, IgM is a what?
A
Monomer
8
Q
In its secreted form, IgM is a what?
A
Pentamer
9
Q
How many antigen binding sites are there in the secreted form of IgM?
A
10
10
Q
What holds the individual antibodies together in the pentamer form of IgM?
A
- Disulfide bonds
- J chain
11
Q
What is the major isotype of antibody secreted at mucosal surfaces?
A
IgA
12
Q
Where is IgA1 mostly found?
A
- serum
- and made by bone marrow b cells
13
Q
Where is IgA2 mostly found?
A
mucosal secretions, colostrum and milk and is made by B cells located in the mucosa
14
Q
IgA can exist as a what?
A
Monomer or dimer
15
Q
What is an isotype?
A
determined by differences in the constant regions of heavy and light chains
16
Q
What is an allotype?
A
- polymorphisms within the Ig isotype
- Minor variations within the constant regions
17
Q
What is an idiotype?
A
- differences based on variable regions and antigen binding specificity
- A monoclonal antibody has only one idiotype
- Antibodies specific for a single epitope may have multiple idiotypes
