For almost 20 years, Dr. Richard Burt has taught at the Feinberg School of Medicine at Northwestern University in Chicago, Illinois. Now a full professor, Dr. Richard Burt studies the use of stem cells in the human immune system, which is the body’s defense against foreign bodies that cause infections and diseases.
One essential component of the immune system consists of proteins called antibodies. These are categorized into five classes (or isotopes), listed below with their purposes. Each group name begins with “Ig,” which stands for immunoglobulin:
- IgG, the antibody best known to the public, is associated with immunizations that destroy some kinds of infections and toxins.
- IgA is present in areas that secrete mucus, such as the mouth and the vagina. Breast milk, tears, and saliva also contain IgA. This antibody triggers inflammation, although it can also target the wrong areas and lead to conditions such as celiac disease.
- IgM responds in the preliminary stages of an infection. It binds tightly with its target and sometimes attacks recurring infections, such as herpes. IgM is also found when a disease returns that the patient has had before.
- IgE creates allergic responses, also known as histamine attacks. This antibody also goes to work against parasitic worms.
- IgD works in a less obvious way. Rather than working directly on diseased or infected cells, it signals other cells to fight them.
