What Antibodies Do: The Body’s Secret Weapon

The human body is always prepared to fight against the radicals that can cause diseases. In this regard, the immune system is the front line defense mechanism for our body. One of the critical components of the immune system is the antibody. In this article, we will dig deeper into the functions and types of antibodies in the human body.

What are Antibodies?

Antibodies are the proteins that the human immune system produces to protect it from invaders. They work by recognizing and binding to a specific antigen that they identify as foreign. Antibodies have a Y-shaped structure that consists of two heavy chains and two light chains connected by a disulfide bond.

What are the Functions of Antibodies in the Human Body?

Antibodies play a significant role in protecting us from harmful microbes, such as viruses and bacteria by recognizing and binding to foreign antigens. They help to neutralize viruses that enter the body, and they also recognize and signal to other immune cells to destroy invading bacteria.

Antibodies also serve as a marker for immune cells to identify cancerous cells and eliminate them. They can activate a process called complement fixation, in which a series of enzymes are activated to form a complex that destroys bacterial cell walls.

How Do Antibodies Work?

Antibodies are produced by B-cells, which are immune cells that mature in bone marrow. When the body encounters a foreign antigen, B-cells recognize it and engulf it, then present the antigen to T-cells that activate the B-cells to produce antibodies against it. Once produced, the antibodies circulate in the bloodstream and lymphatic system looking for matching antigens that they can destroy.

When the antibody encounters its match, it binds to the antigen and stimulates other immune cells to attack and destroy the invader. It also marks the cell with the antigen, making it more recognizable to the immune system in the future.

Types of Antibodies

IgM Antibodies

IgM antibodies are the first type of antibodies that the body produces in response to a new antigen. These antibodies are usually short-lived and do not cross the placenta.

IgG Antibodies

IgG antibodies are the most abundant and long-lasting antibodies in the body. They can cross the placenta and provide protection for the fetus during pregnancy. IgG antibodies are responsible for providing long-term immunity, making them helpful in vaccination.

IgA Antibodies

IgA antibodies are found in the lining of the mucous membranes, such as in the gut, respiratory tract, and the urinary tract. They play an essential role in protecting the body against pathogens that enter through mucosal surfaces.

IgE Antibodies

IgE antibodies are involved in allergic reactions and parasitic infections. They stimulate the release of histamine, which causes an allergic reaction.

IgD Antibodies

IgD antibodies are found on the surface of B-cells and play a role in activating them.

Testing for Antibodies

Antibody testing is a critical tool in identifying the presence of various diseases. The most common method of testing is the enzyme-linked immunosorbent assay (ELISA). ELISA tests measure the amount of antibodies in the blood or other fluids. In some cases, a person may not have symptoms of the disease but can still test positive for antibodies demonstrating that they have been previously exposed to the pathogen.


Antibodies are pivotal in keeping our immune system healthy. By recognizing and neutralizing foreign invaders, they protect our body from a range of diseases. We hope that this article has shed some light on the critical role that antibodies play in our immune system.


  • What are antibodies?
    Antibodies are protein molecules produced by the immune system to help protect against invading pathogens such as bacteria and viruses.
  • How do antibodies work?
    Antibodies bind to specific parts of a pathogen and can neutralize it directly or activate other immune cells to remove it from the body.
  • What types of antibodies are there?
    There are five main types of antibodies, including IgM, IgG, IgA, IgE, and IgD.
  • What is an ELISA test?
    An enzyme-linked immunosorbent assay (ELISA) test is a method used to detect the presence of antibodies in the fluid or blood of an individual.
  • Can antibodies protect against future infections?
    Yes, antibodies can protect against future infections by recognizing and neutralizing the invader.


1. “Antibody.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine, pubchem.ncbi.nlm.nih.gov/compound/Antibody.

2. “Antibodies.” HealthDirect, Australian Government’s Department of Health, 2020, healthdirect.gov.au/antibodies

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