B cell

1 of 2

noun (1)

: 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

B lymphocyte

2 of 2

noun (2)

: 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 cell

After contacting antigens, cells known as B lymphocytes mature and produce antibodies.

—David Baltimore and Carole Heilman

With lupus erythematosus, an autoimmune condition …, the B lymphocytes go out of control and begin producing all types of antibodies, which then begin to attack the body's immune cells.

—Betsy Sikora Siino

compare t lymphocyte

Examples of B cell in a Sentence

Recent Examples on the Web

Noun

Meanwhile, prototypic B cells made their own separate exit from the macrophage line. —Mrigakshi Dixit, Interesting Engineering, 25 May 2026

Patients also retain antibodies that their B cells made before the treatment, which provide residual protection for a few months. —Amber Dance, ArsTechnica, 17 May 2026

Noun

There are two types of lymphocytes: B and T. B lymphocytes protect the body by making proteins called antibodies to destroy bacteria, viruses, and fungi in the body. —Doru Paul, Health, 7 Dec. 2024

Word History

Etymology

Noun (1)

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

First Known Use

Noun (1)

1962, in the meaning defined above

Noun (2)

1971, 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