The immune system, which is made up of special cells, proteins, tissues, and organs, defends people against germs and microorganisms every day. In most cases, the immune system keeps people healthy and prevents infections. But sometimes, problems with the immune system can lead to illness and infection.
A foreign substance that invades the body is called an antigen. When an antigen is detected, several types of cells work together to recognize and respond to it. These cells trigger the B lymphocytes to produce antibodies. Antibodies and their responding antigens fit together like a key and a lock.
Antibodies as a part of the immune system
Once the B lymphocytes have produced antibodies, these antibodies continue to exist in a person’s body. If the same antigen is presented to the immune system again, the antibodies are already there to do their job. This principle forms the basis of immunizations. The immunization introduces the body to the antigen in a way that does not make a person sick, but it does allow the body to produce antibodies that will then protect that person from future attack.
Although antibodies can recognize an antigen and lock onto it, they are not capable of destroying it without help. That is the job of the specific T cells, also called “killer cells”. The T cells are part of the system that destroys antigens that have been tagged by antibodies or cells that have been infected or somehow changed. T cells are also involved in helping signal other cells of the immune system to do their jobs.
Antibodies can also neutralize toxic substances produced by different organisms. Lastly, antibodies can activate a group of proteins called complement that are also part of the immune system. Complement assists in killing bacteria, viruses, or infected cells.