antibody

[an-ti-bod-ee]

noun

plural

antibodies 

1. any of numerous Y -shaped protein molecules produced by B cells as a primary immune defense, each molecule and its clones having a unique binding site that can combine with the complementary site of a foreign antigen, as on a virus or bacterium, thereby disabling the antigen and signaling other immune defenses. Ab

2. antibodies of a particular type collectively.

antibody

/ ˈæntɪˌbɒdɪ /

noun

1. any of various proteins produced in the blood in response to the presence of an antigen. By becoming attached to antigens on infectious organisms antibodies can render them harmless or cause them to be destroyed See also immunoglobulin

antibody

1. Any of numerous proteins produced by B lymphocytes in response to the presence of specific foreign antigens, including microorganisms and toxins. Antibodies consist of two pairs of polypeptide chains, called heavy chains and light chains, that are arranged in a Y-shape. The two tips of the Y are the regions that bind to antigens and deactivate them.

2. Also called immunoglobulin

Word History and Origins

Origin of antibody¹

First recorded in 1895–1900; anti- + body

A Closer Look

Like other vertebrates, humans possess an effective immune system that uses antibodies to fight bacteria, viruses, and cancer cells. Antibodies are complex, Y-shaped protein molecules. The immune system's B lymphocytes, which are produced by the bone marrow, develop into plasma cells that can generate a huge variety of antibodies, each one capable of combining with and destroying an antigen, a foreign molecule. Antibodies react to very specific characteristics of different antigens, binding them to the top ends of their Y formation. Once the antibody and antigen combine, the antibodies deactivate the antigen or lead it to macrophages(a kind of white blood cell) that ingest and destroy it. High numbers of a particular antibody may persist for months after an invasion, eventually diminishing. However, the B cells can quickly manufacture more of the same antibody if exposure to the antigen recurs. Vaccines work by “training” B cells to recognize and react quickly to potential disease molecules.

Example Sentences

“Vaccinating during pregnancy is incredibly helpful, because moms can make the antibodies and transfer those antibodies across the placenta,” Singh said.

From Los Angeles Times

Viruses can mutate to escape from antibodies, but the mRNA vaccines are not causing the emergence of more virulent strains, likely for at least two reasons.

From Salon

Finding a suitable donor — one with the proper blood type, antibody levels and geographic location — all play a role.

From Los Angeles Times

Then, the brain is sliced up and very thin sections are put on glass slides and stained with antibodies that help make abnormal proteins visible.

From Los Angeles Times

Unlike a vaccine, which prompts the body to create antibodies and takes a few weeks to be effective, nirsevimab gives immediate protection from RSV infection.

From BBC

Related Words

• bacterium 
• bug 
• disease 
• microbe 
• microorganism 
• pathogen 
• virus