antibody

[ an-ti-bod-ee ]

noun

, plural an·ti·bod·ies.

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

/ ăn′tĭ-bŏd′ē /

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

Benralizamab is a monoclonal antibody which targets specific white blood cells, called eosinophils, to reduce lung inflammation.

From Science Daily

That study will also have to assess cost-effectiveness since monoclonal antibodies, like this therapy, are expensive drugs.

From BBC

He and colleagues tested a sample of people in California for SARS-COV-2 antibodies and, like others doing similar surveys, they found evidence that many infections with the coronavirus were mild.

From Science Magazine

In one CDC study, 7% of farmworkers had antibodies that suggested they had previously been infected with bird flu, which is far higher than the proportion of cases actually reported.

From Salon

The agency sampled blood from 115 people; eight — or 7% — had antibodies.

From Los Angeles Times

Related Words

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