B cell

noun

: any of the lymphocytes that have antigen-binding antibody molecules on the surface, that comprise the antibody-secreting plasma cells when mature, and that in mammals differentiate in the bone marrow : b lymphocyte

The glycoproteins produced by B cells, called antibodies or immunoglobulins, recognize and bind free antigens and are responsible for humoral immunity …

—Haruo Saito et al.

… helper T cells that induce the proliferation of the antibody-producing B cells.

—N. A. Mitchison

… patients have no mature B cells circulating in the bloodstream and no antibodies to fight off infections.

—Jean Marx

compare t cell

Examples of B cell in a Sentence

Recent Examples on the Web

These B cells produce antibodies that can recognize a pathogen the body has previously been exposed to, and that gives you a better chance of fighting off dangerous viruses. —Abhimanyu Ghoshal, New Atlas, 24 June 2025

More than 20 years ago, scientists learned to target those rogue B cells with monoclonal antibodies, bulky proteins made in the lab, which bind to B cells and force their destruction. —Byjennifer Couzin-Frankel, science.org, 14 Nov. 2024

In fact, those who received the dual-adjuvant vaccine produced more than twice as many unique B cells than those mice who received a single-adjuvant vaccine. —Ian Randall, MSNBC Newsweek, 19 June 2025

Back in 2022, researchers at the University of Erlangen-Nuremberg in Germany showed that administering CAR T-cell therapy to five people with severe lupus could completely remove the aberrant B cells, sending all of the patients into remission. —Juergen Eckhardt, Forbes.com, 23 Apr. 2025

Word History

Etymology

B probably from bursa-derived (produced by the bursa of Fabricius)

First Known Use

1962, in the meaning defined above

Rhymes for B cell

• bel
• belle
• cel
• dell
• dwell
• el
• ell
• fel
• fell
• gel
• gell
• jell

Kids Definition

B cell

noun

ˈbē-ˌsel

: any of the lymphocytes that produce antigen-binding antibodies and that arise and mature in the bone marrow compare t cell

Medical Definition

B cell

noun

: any of the lymphocytes that have antigen-binding antibody molecules on the surface, that comprise the antibody-secreting plasma cells when mature, and that in mammals differentiate in the bone marrow

called also B lymphocyte

compare t cell