B cell

: A type of white blood cell and, specifically, a type of lymphocyte. Many B cells mature into what are called plasma cells that produce antibodies (proteins) necessary to fight off infections while other B cells mature into memory B cells. All of the plasma cells descended from a single B cell produce the same antibody which is directed against the antigen that stimulated it to mature. The same principle holds with memory B cells. Thus, all of the plasma cells and memory cells "remember" the stimulus that led to their formation. The maturation of B cells takes place in birds in an organ called the bursa of Fabricus. B cells in mammals mature largely in the bone marrow. The B cell, or B lymphocyte, is thus an immunologically important cell. It is not thymus-dependent, has a short lifespan, and is responsible for the production of immunoglobulins. It expresses immunoglobulins on its surface.

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B cell n 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

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1. beta c. (def. 1). 2. basophil (def. 3). 3. (in the pl.) see under lymphocyte.