Antibody

Antibody, also called immunoglobulin, is a protective  

protein produced by the immune system in response to the presence of a foreign substance, called an antigen. 

✅A wide range of substances are regarded by the body as antigens, including disease-causing organisms and toxic materials. 

✅Antibodies recognize and attack onto antigens in order to remove them from the body.

▪️ Different Types of Antibodies

 

🔸IgG

✅ It is the main antibody in blood and it has a powerful ability to bind to bacteria and toxins, and thus it takes on an important role in the biological defense system.

✅ It is the only isotype that can pass through the placenta, and IgG transferred from the mother’s body protects a newborn.

 

🔸IgM

✅It is constructed of five units of basic Y-shaped structures and is mainly distributed to the blood. 

✅ Produced first upon pathogen invasion by B cells, IgM has a key role in the initial immune system defense for protecting the body. 

✅The B-cell, also called B-lymphocyte, is a type of white blood cell that plays a significant role in protecting your body from infection.

🔸 IgA

✅ While in blood, IgA is mainly present as monomers (the shape of a single Y), but it forms dimers (a combination of 2 Ys) in secretions such as bowel fluid, nasal discharge, and saliva, to prevent bacterial invasion from a mucous membrane.

✅ It is also present in breast milk and protects the gastrointestinal tract of newborns from bacterial and viral infection. 

🔸 IgD

✅ It is present on the surface of B cells and it is reported to play a role in the induction of antibody production and the prevention of respiratory tract infections. 

🔸IgE

✅ It is believed that IgE was originally related to immunity reactions to parasites. 

✅ By binding to mast cells, IgE is believed to be involved in allergies such as pollinosis.