Talk 3
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Transcript of Talk 3
Talk 3
Antibody
Structures of Five Classes of Igs
Classes and Subclasses of Igs from Human and Animals
Species
Horse
Cattle
Sheep
Pig
Dog
Cat
Chicken
Mouse
Human
IgG
Ga, Gb, Gc, G(B), G(T)a, G(T)b
G1, G2(G2a,G2b)
G1(G1a?), G2, G3
G1, G2a, G2b, G3, G4
G1, G2, G3, G4
G1, G2, G3, (G4?)
G1, (G2a?), (G3?)
G1, G2a, G2b, G3
G1, G2, G3, G4
IgA
A
A
A1, A2
A1, A2
A
A1, A2
A
A1, A2
A1, A2
IgM
M
M
M
M
M
M
M
M
M
IgE
E
E
E
E
E1,E2
E
E
E
E
IgD
?
-
-
-
D
?
?
D
D
Antibody Structure
Polymeric Structure of Antibodies
Isotypes of Immunoglobulins
IgG IgA
The genes for isotypic variants are present in all healthy members of a species. For examples, the genes forγ1, γ2,γ3,γ4, , α1,α2, δ, , and c
hains are all present in the human genome and therefore isotypes.
Allotypes of Immunoglobulins
IgG IgG
Genetic variation between individuals within a species, involving different alleles at a given locus. Allotypes occur mostly as variants of H chain C region.
Idiotypes of Immunoglobulins
IgG IgG
Variation in the variable domain, particularly in the hypervariable regions, produces idiotypes, which determine the binding specificity of the antigen-binding site. Idiotypes are usually specific for individual B-cell clone (private idiotypes ), but are sometimes shared between different B-cell clones (public, cross-reactin
g or recurrent idiotypes)
Properties of Human Igs
Functions of Antibody(Direct Neutralization)
Functions of Antibody(opsonization)
Functions of Antibody(ADCC Killing)
Functions of Antibody(complement activation)