Immunoglobulin IsotypesDefinition - Antigenic determinants that

characterize the classes and subclasses of heavy chains and types and subtypes of light chains

Immunoglobulin Isotypes

OccurrenceImportance

Ig levels

• Definition

• Location

IgM (kappa)IgG1 (kappa)

• Definition - Antigenic determinants specified by allelic forms of the Ig genes

• Location

• Occurrence

– Source of anti-allotypic Abs

IgG1 (kappa)

Person 2

IgG1 (kappa)

Person 1

• Nomenclature– G1m(3)– Km(1)

Chain Domain Allotype Amino Acid

Position

CH1 G1m(f) = (3) Arg 214

CH1 G1m(z) = (17) Lys 214

IgG1

CH3 G1m(a) = (1) Arg, Asp,Glu, Leu

355-358

CL Km(1) Val, Leu 153, 191lightchain CL Km(3) Ala, Val 153, 191

- G2m(23)

• IgG – 25 Allotypes• IgA2 – 2 Allotypes• k (L) – 3 Allotypes

Immunoglobulin IdiotypesDefinition - Unique antigenic determinants

present on individual antibody molecules or on molecules of identical specificity

Immunoglobulin IdiotypesDefinitionLocation

IgG1 (kappa)

Person 1

anti-B

IgG1 (kappa)

Person 1

anti-A

Immunoglobulin IdiotypesDefinitionLocation Importance

V region markerRegulation of immune responses

Immunoglobulin IdiotypesDefinitionLocation Importance

V region markerRegulation of immune responsesVaccines

Ag Id anti-Id

+

-

Anti-Idiotype Vaccines

Ag Id anti-Id

+

Anti-Idiotype Vaccines

Ag + Ab Ag / Ab

+Ab = Ag Anti-Id-Ab Vaccine