B-cell lymphocyte - definition
What is B-cell lymphocyte and Definition
A type of white BLOOD cell (LEUKOCYTE) responsible for ANTIBODY-MEDIATED IMMUNITY (also called humoral immunity). B-cell lymphocytes are so named because they come to maturity in the BONE MARROW (in contrast to T-cell lymphocytes, which come to maturity in the THYMUS). B-cell lymphocytes produce antibodies in reaction to the presence of antigens. The bone marrow generates millions of B-cell lymphocytes each day. Each B-cell lymphocyte is specific for a unique ANTIGEN.
B-cell lymphocytes may be memory B-cells, which “remember” specific antigens to mobilize a rapid IMMUNE RESPONSE upon detecting their presence, and PLASMA cells, which produce antibodies.
- Plasma cells generate antibodies in response to the presence of antigens.
- Memory B-cells remain in the circulation of the blood and LYMPH, carrying inactive antibodies. Each memory B-cell has antibodies specific to a particular antigen the immune response has previously encountered. When the memory Bcell encounters the antigen again, it immediately begins producing antibodies.
Health conditions that affect B-cell lymphocytes include cancers, such as certain types of LEUKEMIA and lymphoma, and acquired immune and AUTOIMMUNE DISORDERS.
For further discussion of B-cell lymphocytes within the context of the structures and functions of the immune system, please see the overview section “The Immune System and Allergies.”
See also CELL-MEDIATED IMMUNITY; HIV/AIDS; T-CELL LYMPHOCYTE.
