All Sources -
Updated Media sources (1) About encyclopedia.com content Print Topic
B cell (B lymphocyte) A lymphocyte that is derived from stem cells in the bone marrow but does not mature in the thymus (compare T cell); in birds it matures in the bursa of the cloaca (hence B cell). Each B cell has a unique set of receptor molecules on its surface, designed to recognize a specific antigen. Binding of the appropriate antigen to class II MHC receptors on the B cell (see histocompatibility) is recognized by helper T cells, which themselves bind to the antigen–receptor complex. This triggers the T cells to release lymphokines, which cause the B cell to undergo repeated division to form a clone of cells (i.e. clonal expansion). These mature into plasma cells, capable of producing large amounts of specific antibody (see immunoglobulin), which circulates in the blood and lymph and binds to the corresponding antigen. After a few days of antibody production the plasma cells die. However, some cells from the clone remain in the form of memory cells, which initiate a more rapid immune response on subsequent exposure to the same antigen. See also clonal selection theory.
More From encyclopedia.com
Basement Membrane , basement membrane (basal lamina) A thin sheet of fibrous proteins that underlies and supports the cells of an epithelium, separating this from underl… Schwann Cell , Schwann cell (neurilemma cell) A cell that forms the myelin sheath of a nerve fibre. Each cell is responsible for a single length of the fibre (calle… Adherens Junction , adherens junction A cell junction that is commonly observed in epithelial (see EPITHELIUM) cells (e.g. those lining the intestine and those in cardia… Cell Hybridization , Skip to main content Cell hybridization cell fusion (somatic cell hybridization) The technique of combining two cells from different tissues or speci… cell line , cell line A lineage or pedigree of cells that are related through asexual division. The cell line of an organ traces the course taken by cell divisio… Cell Death , Cell death Like all living things, the various types of cells in plants, animals, and the many different cell types in humans eventually die. Cell de…
You Might Also Like