antibody
Americannoun
plural
antibodies-
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
-
antibodies of a particular type collectively.
noun
-
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.
-
Also called immunoglobulin
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.
Etymology
Origin of antibody
Compare meaning
How does antibody compare to similar and commonly confused words? Explore the most common comparisons:
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The AAP advocates starting the vaccine sooner, as younger immune systems produce more antibodies.
From Los Angeles Times
In early testing, the antibody slowed the growth of primary tumors, reduced the spread of cancer to the lungs, and revived immune cells that normally attack cancer.
From Science Daily
Detecting antibodies to flagellin years before symptoms appear suggests that this immune response may help trigger the disease rather than simply result from it, Dr. Croitoru said.
From Science Daily
The team also developed an experimental antibody that blocks this deceptive signal and allows immune cells to recognize the cancer again.
From Science Daily
Treatments like checkpoint inhibitors, CAR T-Cells and antibody conjugates have improved survival for metastatic cancers.
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
