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

Immunoglobulin E

IMMUNOGLOBULIN E (Ig E)

• It is synthesized by plasma cells located beneath body surfaces. It has two ε heavy chains and two light chains (either κ or λ).
• Constant region of heavy chain composed of four domains (C_H 1 to C_H4).
• It has sedimentation coefficient of 8S (molecule weight 190 KDa). IgE has about 12 % carbohydrate.
• The serum concentration is very low with shortest half-life.

Functions

• Reaginic antibody: Provide protection against microbes by degranulation of mast cells .IgE adhere to cell surface through C_H3 and C_H4 domains and release of inflammatory mediators (vesoreactive substances).
• It mediates immediate hypersensitivity reaction (Type-1) e.g. anaphylactic shock, hay fever, asthma etc.
• Provide immunity against parasitic worms.
• It does not fix complement components.