VMC 221: Veterinary Immunology and Serology (1+1)

Characteristic of Immunoglobulins

CHARACTERISTICS OF IMMUNOGLOBULINS

 

	IgG	IgM	IgA	IgE	IgD
Molecular weight	180,000	900,000	360, 000	190,000	180,000
Sub units	1	5	2	1	1
Heavy chain	γ	μ	α	ε	δ
Sedimentation coefficient	7S	19 S	7 S to 11S	8S	7S
Electrophoretic mobility	γ	β	β- γ	β- γ	γ
Carbohydrate percentage	3	12	7	12	12
Mainly synthesized in	Spleen and lymph nodes	Spleen, bone marrow and lymph nodes	Intestinal and respiratory tracts	Intestinal and respiratory tracts	Spleen and lymph nodes
Biological property	Major Ig in serum. Provides the majority of antibody based immunity against invading pathogens. Moderate complement fixer (IgG3) can cross placenta.	First response antibody. Expressed on the surface of B cells and in a secreted form with very high avidity. Eliminates pathogens in the early stages of B cell mediated immunity before there is sufficient IgG.	Most produced Ig. Found in mucosal areas, such as the gut, respiratory and urogenital tract, and prevents their colonization by pathogens. Resistant to digestion and is secreted in milk.	Binds to allergens and triggers histamine release from mast cells and is involved in allergy. Also protects against parasitic worms.	Function unclear. Works with IgM in B-cell development; mostly B cell bound