How do antibodies work?

Antibodies are a special class of Y shaped proteins that help guard your body from invading viruses and bacteria. They do this by either neutralizing the dangerous substance or marking it for destruction.

Five classes of antibodies

There are five antibody types called IgA, IgG, IgM, IgE and IgD. Each antibody type is made up of two heavy chains and two light chains also known as an 'immunoglobulin'. Every antibody has a unique tip on its end known as the paratope which contains the key to fighting against invaders which could be a virus or bacterium. The middle section of the antibody is called the constant region which attaches itself to certain cells in order to rid them from these invaders.

Antibodies are a vital component of the immune system and help white blood cells, or leukocytes , fight disease.

For example, antibody type IgA is most abundant antibody found in body secretions such as saliva, nasal secretions and tears. In these locations IgA helps prevent microbes from entering your body by disrupting their outer membrane with its components anti bodies which causes them to rupture .

In contrast, antibody type IgE attaches itself to mast cells which causes increased white blood cell activity against a certain invader . This antibody type is present when your body comes into contact with something that you're allergic to such as pollen peanuts . If this antibody is over produced it causes a condition known as anaphylaxis where your throat swells and you have trouble breathing.

The antibody type IgG which is the most abundant antibody in our body, attaches to invading microbes. This antibody then activates other white blood cells that destroy these invaders.

IgM antibody shape

IgM on the other hand is made up of five antibody fragments instead of two found in all other antibody types . Once exposed to an invader IgM will form a pentamer which attracts virus-infected cells and carries them to lymph nodes where they are destroyed by macrophages .

Those suffering from immunodeficiency lack certain antibody types or produce antibodies with no effect to pathogens while those who make too many antibodies also experience problems such as autoimmune diseases where the antibody attaches to our own cell membranes such as thyroid.


  • immune system - immune defense system of vertebrates containing antibody proteins that specifically recognize and neutralize foreign molecules.
  • invader - organism that enters another's territory with harmful intent.
  • mast cells - white blood cells responsible for releasing histamine during inflammation, anaphylaxis, and allergic reactions.
  • macrophage - type of large white blood cell responsible for being a universal scavenger in the body searching out old or dying red blood cells, antibody-coated bacteria, digesting them up and destroying them through phagocytosis .
  • white blood cell - refers to leukocyte s which are produced by stem cells in the bone marrow that are involved in protecting the body from disease.
  • paratope - three dimensional antibody structure which contains amino acids that are crucial for antibody-antigen specificity.
  • constant region - antibody proteins responsible for binding complement and mediating cytotoxic effector functions of leukocytes, among other things .
  • immune response - sequence of steps triggering your immune system to protect you again a particular invader by destroying it with antibody s and T lymphocyte s (T cell receptor).
  • anaphylaxis - life threatening allergic reaction triggered by overreacting of immune system after exposure to an allergen such as nuts, shellfish or bee venom.
  • condition - medical condition; different from a disease which is an illness or sickness.
  • lymph node - spleen like organ that contains phagocytes and antibody-producing cells and filters blood as it makes white blood cells to help those who are sickest first .
  • histamine - chemical released by mast cell s during immune response for inflammatory responses such as inflammation, hay fever , watery eyes, runny nose .
  • universal scavenger - any of the large scavenger cells found in body tissues that have a non specific action against decaying material and pathogenic microorganisms.
  • stem cell - cell with the ability to produce more progenitor cells just like it, but not to produce more stem cells.
  • antibody - antibody protein with ability to attach itself to an antigen .
  • lipopolysaccharide (LPS) - endotoxin responsible for immune response problems in severe infections such as sepsis , toxic shock syndrome , and e coli infection s caused by the bacterium Salmonella enterica
  • phagocyte - cell that surrounds and digests microorganisms in order to destroy them.
  • inflammatory response - immune system response triggered when antibody attached themselves with invasive cells, substances or particles outside of our bodies in order to protect us from them.
  • allergen - substance capable of inducing an allergy in people who are hypersensitive towards it.
17th Jan 2022 Sean Mac Fhearraigh

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