Classes of Immunoglobulins Flashcards
Predominant in healthy humans
IgG
Provides immunity to newborn
IgG
How does IgG provides immunity to newborn?
IgG is the smallest Ig which makes them easily cross the placenta
Subclass(es) of IgG that can cross placenta
IgG1 and IgG3
One function of IgG is fixation of complement. Arrange IgG based on the potency from greatest to least: IgG1, IgG2, IgG3.
IgG3 –> IgG1 –> IgG2
What are the molecules that enhances phagocytosis?
Opsonin
This enhances the phagocytosis by facilitating the linking or cross-bridging of phagocytes and target antigen
Opsonization
Type of immunity that provides immunity to the newborn from the maternal antibody
Acquired Natural Passive Immunity
This immunoglobulin is predominant antibody in the Secondary or Anamnestic Response
IgG
This immunoglobulin is a monomer and has no J Chain
IgG
This immunoglobulin is the best precipitating antibody
IgG
This immunoglobulin participates in agglutination and precipitation reaction
IgG
The four (4) subclasses of IgG are differentiated based on: (2)
- Concentration in the serum
- number of disulfide bonds
Concentration and number of disulfide bonds: IgG1
66%
2 disulfide bonds
Concentration and number of disulfide bonds: IgG2
23%
4 disulfide bonds
Concentration and number of disulfide bonds: IgG3
7%
15 disulfide bonds
Concentration and number of disulfide bonds: IgG4
4%
2 disulfide bonds
This immunoglobulin is predominant in primary immune response
IgM
This immunoglobulin First antibody displayed on B cell Surface
IgM
This immunoglobulin first to appear in phylogeny and last to leave in senescence
IgM
This immunoglobulin first to appear after a primary antigenic stimulus
IgM
Best antibody in terms of fixing the Complement
IgM
Biggest antibody – Composed of 5 monomers (Pentameric Antibody)
IgM
Functions of IgM (4)
▪ Complement Fixation
▪ Agglutination
▪ Opsonization
▪ Toxin neutralization
Best agglutinating antibody
IgM
This immunoglobulin exists as monomer or dimer
IgA
IgA is a monomer in:
Plasma
IgA is a dimer in:
Secretion
Responsible for mucosal immunity
IgA
Immunoglobulin that is predominant in secretion/body fluids
IgA
Only antibody with secretory component
IgA
Responsible in maintaining the structure of antibody by preventing the
enzymatic degradation of the structure
Secretory component
plays a role in the binding of IgA to the Epithelial mucosal surface
Secretory component
Function is still unknown but believes to play a role in
immunoregulation
IgD
Postulated to be an anti-idiotypic antibody
IgD
Least abundant Ig in the healthy serum
IgE
IgE is abundant in which type of parasitic infection?
Helminthic
IgE is present in which type of hypersensitivity
Type 1 Hypersensitivity
IgE is present in which type of hypersensitivity
Type 1 Hypersensitivity
Only Ig that binds strongly to mast cell and Basophil
receptor
IgE
Why can IgE bind to mast cells and basophil?
It has specific receptor to mast cells and basophil
Mediator of allergic reaction
Histamine
Site for histamine receptor
Basophil and Mast Cell
Mast cells are found in:
Tissues
Basophils are found in:
Circulation
Molecular weight of IgG
150 T
Molecular weight of IgA
160 - 400 T
Molecular weight of IgM
900 T
Molecular weight of IgD
180 T
Molecular weight of IgE
190 T
Half life of IgG
21-23 days
Half life of IgA
5-6 days
Half life of IgM
5 days
Half life of IgD
2-3 days
Half life of IgE
2-3 days
Other name for IgG
Serum Ig
Other name for IgA
Secretory Ig
Other name for IgM
Pentameric Ig
Other name for IgE
Reagenic Ig
Which complement does IgA activate?
Alternative Pathway only