antigen

noun
an·​ti·​gen | \ ˈan-ti-jən How to pronounce antigen (audio) , -ˌjen\

Definition of antigen

: any substance (such as an immunogen or a hapten) foreign to the body that evokes an immune response either alone or after forming a complex with a larger molecule (such as a protein) and that is capable of binding with a product (such as an antibody or T cell) of the immune response

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Other Words from antigen

antigenic \ ˌan-​ti-​ˈje-​nik How to pronounce antigenic (audio) \ adjective
antigenically \ -​ni-​k(ə-​)lē How to pronounce antigenically (audio) \ adverb
antigenicity \ -​jə-​ˈni-​sə-​tē How to pronounce antigenicity (audio) \ noun

Did You Know?

An antibody is a protein produced by your immune system to fight outside invaders. Since the enemy substance actually triggers the production of antibodies, such substances are called antigens—anti- being short for antibody, and -gen meaning "producer". (In a similar way, an allergen produces an allergy, and a pathogen produces a pathology or disease.) Antigens are often rodlike structures that stick out from the surface of an invading organism—usually a bacterium or a virus—and allow it to attach itself to cells in the invaded body. But unfortunately for them, in doing so they let the immune system know they're present, and the body is flooded with an army of Pac-Man-like antibodies.

Examples of antigen in a Sentence

Recent Examples on the Web

One of them, called CAR-T (for chimeric antigen receptor T-cell therapy), removes a patient’s own immune cells and genetically re-engineers them to bind to a specific protein on the surface of the patient’s cancer cells. Ezekiel Emanuel, WSJ, "We Can’t Afford the Drugs That Could Cure Cancer," 20 Sep. 2018 Drug companies have spent big on chimeric antigen receptor T-cells, or CAR-T, cancer therapies. Charley Grant, WSJ, "Big Pharma’s Big Cancer Hope Is Fizzling," 8 Feb. 2019 Each of these antigens have an Rh factor, a positive or a negative. David Grossman, Popular Mechanics, "What Different Blood Types Mean (And How To Find Out Yours)," 28 Dec. 2018 These antigens may be unique to tumor cells, but usually, cancerous cells have more of the markers than normal cells do. Marie Mccullough, Philly.com, "Cracking the cancer code: Can immune therapy treat tumors?," 5 Apr. 2018 But everything has consequences, and for the medieval European strain of C. recurrenti, the price of a smaller genome was probably fewer antigen variants. Kiona N. Smith, Ars Technica, "Ancient DNA reveals the secrets of a devastating European disease," 26 Sep. 2018 And once the antigens are recognized, the immune system makes antibodies to fight them. Bartell Drugs, The Seattle Times, "It’s time to think about back-to-school vaccinations," 14 Aug. 2018 The variations change the shape of its antigens, allowing it to keep dodging the host’s immune responses. Kiona N. Smith, Ars Technica, "Ancient DNA reveals the secrets of a devastating European disease," 26 Sep. 2018 The Western Blot test measures your body’s antibody response to Borrelia antigens. Andrea K. Mcdaniels, baltimoresun.com, "Ask the expert: With Lyme disease on the rise, here's how you can protect yourself," 3 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'antigen.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of antigen

1908, in the meaning defined above

History and Etymology for antigen

German, from French antigène, from anticorps antibody + -gène -gen

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Last Updated

5 Apr 2019

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Time Traveler for antigen

The first known use of antigen was in 1908

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More Definitions for antigen

antigen

noun

English Language Learners Definition of antigen

medical : a harmful substance that causes the body to produce antibodies

antigen

noun
an·​ti·​gen | \ ˈant-i-jən How to pronounce antigen (audio) \

Medical Definition of antigen

: any substance (as an immunogen or a hapten) foreign to the body that evokes an immune response either alone or after forming a complex with a larger molecule (as a protein) and that is capable of binding with a product (as an antibody or T cell) of the immune response

Other Words from antigen

antigenic \ ˌant-​i-​ˈjen-​ik How to pronounce antigenic (audio) \ adjective
antigenically \ -​i-​k(ə-​)lē How to pronounce antigenically (audio) \ adverb

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More from Merriam-Webster on antigen

Spanish Central: Translation of antigen

Nglish: Translation of antigen for Spanish Speakers

Britannica English: Translation of antigen for Arabic Speakers

Britannica.com: Encyclopedia article about antigen

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