B lymphocytes
The definitions used in this glossary of terminology either have been provided by the authors of the articles, or have been extracted wholly or in part, or paraphrased from the following sources: The American Medical Association Encyclopedia of Medicine, Charles B. Clayman, MD, Medical Editor, Random House, New York, 1989; Biotechnology from A to Z, 2d Edition, William Bains, Oxford University Press, New York, New York, 2002; A Dictionary of Genetics, 6th Edition, Robert C. King and William D. Stansfield, Oxford University Press, New York, New York, 2002; Dorland's Illustrated Medical Dictionary, 29th and 30th Editions, W. B. Saunders Company, Philadelphia, 2000, 2003; Genes VII, Benjamin Lewin, Oxford University Press, New York, New York, 2000; The Gale Encyclopedia of Genetic Disorders, Volumes I and II, Stacey L. Blachford, Ed., Thomson Learning, New York, New York, 2002; The Merriam-Webster Dictionary, Merriam-Webster, Inc., Springfield, Massachusetts, 1997; Molecular Biology of the Cell, 3rd Edition, Bruce Alberts, et al., Garland Publishing, 1994; The Random House Dictionary of the English Language, Unabridged Edition, 1966; Webster's Ninth New Collegiate Dictionary, 1991.
DEFINITION:
- B lymphocytes
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B cells; bursa-dependent lymphocytes and their counterparts in nonavian vertebrates, the cells primarily responsible for humoral immunity, the precursors of antibody-producing cells (plasma cells). In birds B cell maturation takes place in the bursa of Fabricius; the hypothesized analogous tissue in other vertebrates was termed the "bursa-equivalent" tissue. It now appears that B cell maturation occurs primarily in the bone marrow in mammals. B cells are characterized by the presence of surface immunoglobulin, monomeric IgM or IgD, which constitutes the B-cell antigen receptors. When stimulated by antigen, a process that requires the cooperation of helper T cells and macrophages, B cells proliferate and differentiate into plasma cells and memory B cells. The entire clone of cells descended from a single activated B cell produces immunoglobulins having the same antigen combining site as that in the antigen receptors of the original cell; thus all of the antibody produced and all of the memory cells are specific for the antigen that induced their formation.
Used in 12 Term definitions
Used in 12 Term definitions