What is an antibody?


What Is An Antibody?

Our body is pretty remarkable. It protects us in ways that we don’t visually see day-to-day. One such way is through antibodies, but what are antibodies? How do antibodies work?

First, let’s start with what an antibody actually is. They are specialized Y-shaped proteins that bind to foreign invaders in the body. It could be anything from viruses, bacteria, fungi or parasites. They are the immune system’s search team hunting down these invaders.

What is the job of antibodies? Once they find an invader, the antibodies bind to it. This then triggers a cascade of actions to vanquish the invader. They are part of the body’s adaptive immune system helping it to learn to recognize and eliminate specific pathogens.

What Do Antibodies Do?

What are antibodies and what do they do? Antibodies help to eliminate disease-causing microbes from the body. They will either destroy them or block them from infecting cells. They work in a very specific way. If the body encounters a microbe for the first time, the immune cells produce antibodies that specifically recognize proteins associated with that particular microbe.

If you recover from an infection or you receive a vaccine, a small number of these antibody producing immune cells usually remain in the body as memory cells. They help to provide immunity to future infections when the body encounters the same bug.

So when the body encounters that same microbe, the immune response will be much faster and it can stop the infection.

What Are The 5 Functions of Antibodies?

But what else do antibodies do? Antibodies have five main functions resulting in searching for microbes, recognizing them and defending the body (1).

Neutralization Of Infectivity

Antibodies are secreted into the blood and mucosa, where they work to block infections by pathogens (bacterial, viruses, parasites and fungi), inactivate or neutralize foreign substances such as toxins. Neutralization occurs as a result of interfering with an organism’s attachment to host issues.

Phagocytosis (fa-gow-sai-tow-suhs)

This process is called opsonization (op·​son·​iza·​tion) and occurs when antibodies engulf other cells or particles. Inside the phagocyte (fa-guh-sait), the pathogen becomes the target of various destructive processes including oxidative damage, enzymatic digestion and membrane disrupting effects of antibacterial peptides.

Antibody-Dependent Cellular Cytotoxicity (sahy-toh-tok-sis-i-tee) (ADCC)

This process occurs when the antibody forms a bridge between an infected target cell (such as the virus infected cells of the host) and a PcR-bearing effector cell, particularly natural killer (NK) cells.

The result of this interaction is the death of the target cell.

Complement-Mediated Lysis Of Pathogens Or Of Infected Cells

Certain antibodies (such as IgM and most IgG subclasses) activate the complement system which can result in the lysis of organisms or of infected cells.

Transcytosis (tran-scy-to-sis), Mucosal (mee-you-co-sahl) Immunity And Neonatal Immunity

Certain types of antibodies can cross over during pregnancy through the placenta to the fetus providing a protective endowment against pathogens. This often occurs during the third trimester of pregnancy.

What Is An Antigen And Antibody?

Oftentimes people have heard the terms antigen and antibody and may be confused about what each one actually is. While there are some similarities, there are some specific differences between the two.


Antigens are molecules capable of stimulating an immune response. Each antigen has specific features also known as epitopes that result in specific responses. It’s basically a substance that induces a specific immune response. They originate within the body or externally.


Antibodies are the Y shaped proteins produced by B cells of the immune system that occur in response to exposure to antigens. Each antibody recognizes the specific epitopes (eh-puh-towps) on an antigen. It then acts like a lock and key binding mechanism to help eliminate the antigen from the body.


Both antigens and antibodies play a role in vaccinations. Vaccines often contain antigens to stimulate the B lymphocytes of the immune system to respond by producing plasma cells that secrete disease specific antibodies. Some of these B cells become memory B cells, which will then recognize future exposure to the disease. 

This will then result in a faster and more intense production of antibodies that work effectively to eliminate the disease by binding to the antigens.

What Is The Structure Of An Antibody?

An antibody is a Y shaped structure of equal-sized portions loosely connected by a flexible tether. It consists of four polypeptides. Two of those are heavy chains and two are light chains. This structure allows the antibody molecules to carry out their dual functions, which are antigen binding and biological activity mediation.

Each of these tasks is carried out by separable parts of the molecule. There are the fragment antigen-binding (Fab fragment) and the fragment crystallizable region (Fc region).

The fab fragment region on an antibody binds to the antigen. It’s composed of one constant and one variable domain of each of the heavy and light chains

What Is The Role Of Antibodies In The Immune System?

Antibodies work with the immune system in a few crucial ways:

  • Preventing pathogens from entering or damaging cells by binding to them in a process known as neutralization.
  • Stimulating removal of pathogens by macrophages and other cells in a process known as opsonization.
  • Triggering destruction of pathogens by stimulating other immune responses such as a complement pathway.

Simply put, antibodies recognize an invader and work to stop the invader from resulting in an infection or illness.

It is important to know that each antibody recognizes one specific type of antigen. For example, an antibody that recognizes the mumps virus cannot recognize the measles virus. This is known as antibody specificity.

So while pathogens can produce millions of harmful factors, an antibody can only protect against the one specific antigen. While that may sound scary, it’s important to know that there are tens to hundreds of millions of different types of B cells (antibody cells) circulating in the body. This helps to make sure every antigen is recognized.

Our body also has immunological memory to recognize microbes to provide protection from the same viruses or bacteria.

What Increases Antibody Production?

So we know that we have antibodies working to constantly protect us from microbes. But are there any ways to increase antibody production? The best way is to bolster your immune system. This can be achieved through:

Eating Healthy

Include plenty of protein either from lean cuts of meat like beef or pork as well as from beans, soy and seafood. Many foods high in protein also have other immune-boosting nutrients like zinc, which can help increase the production of infection-fighting white blood cells.

Make sure to also include plenty of fresh fruits and vegetables too which are chocked full of crucial nutrients like vitamins and minerals.


Even a simple 10 minute walk a few times a day can really add up to some immune-boosting abilities. Exercise helps to get antibodies and white blood cells moving through the body faster so illnesses could get detected sooner.

Reducing Stress

Find ways that you like to reduce your stress. This could be anything from listening to music, doing yoga or even playing with your dog.

Limiting Alcohol

One or two drinks are usually okay, but any more than that and you could be suppressing your immune system.

It’s also important to know that once antibody production begins, it will continue for several days until all antigen molecules are removed. The antibodies will actually remain in circulation for several months as well to provide further immunity against that particular antigen (2).

Supplements Can Help

While our body naturally has antibodies available to fight antigens, it’s important we fuel it right so it can do its job more effectively. This comes not only from eating healthy and exercising, but also making sure we are getting the right vitamins, minerals and supplements.

One such supplement is spermidine. While we cannot claim to heal or cure any illnesses, it’s important to understand the positive impact spermidine has on your cells.

Our body consists of cells. Over time, some of these components can become damaged. This leads to an increased risk of illnesses and premature aging. Fortunately, our body has a way to recycle those damaged cellular components through a process known as autophagy. Autophagy can also help destroy antigens. 

Spermidine assists with that process by helping to induce autophagy. It may also help support immunological memory to further increase the effectiveness of the cell’s defenses. When cells are healthy, our body is healthy.


  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4159104/
  2. https://www.britannica.com/science/antibody#:~:text=Antibodies%20are%20produced%20by%20specialized,identical%20cells%20called%20a%20clone.


  • Don Moxley - Director of Applied Science

    Don Moxley is the Director of Applied Science at Longevity Labs. Moxley draws upon his career as an athlete, a sports scientist, and an instructor to lead and educate on the science of autophagy and longevity.