B cell

B cell or B lymphocyte is a type of white blood cell that plays a significant role in the immune system by producing antibodies. Named after the bursa of Fabricius, an organ in birds where they were first discovered, B cells are essential for adaptive immunity.

Origin and Development

B cells originate from hematopoietic stem cells (HSCs) in the bone marrow. They undergo a series of differentiation and maturation stages in the bone marrow, becoming fully mature B cells when they express a unique type of antigen receptor on their cell surface.

Function

The primary function of B cells is to produce antibodies against antigens, which are foreign substances in the body. When a B cell encounters its specific antigen, it proliferates and differentiates into plasma cells and memory B cells. Plasma cells are the antibody factories of the immune system, while memory B cells provide long-term immunity by remembering the same antigen for faster antibody production in future infections.

B Cell Subtypes

There are several subtypes of B cells, including follicular B cells, marginal zone B cells, and B1 cells, each with distinct functions and locations in the body.

Role in Disease

Abnormal B cell function can lead to various diseases. Overactive B cells can cause autoimmune diseases, while underactive B cells can result in immunodeficiency diseases. B cells also play a role in the development of lymphoma, a type of cancer.

See Also

• T cell
• Immune system
• Antibody
• Autoimmune disease
• Immunodeficiency