B Cells and T Cells

Lymphocytes are one of the five kinds of white blood cells or leukocytes), circulating in the blood. Mature lymphocytes look alike, but they are very diverse in their functions. The most abundant lymphocytes are:

• B lymphocytes (often simply called B cells) and
• T lymphocytes (likewise called T cells).

B cells are not only produced in the bone marrow but also mature there.

However, the precursors of T cells leave the bone marrow and mature in the thymus (which accounts for their designation).

Each B cell and T cell is specific for a particular antigen. What this means is that each is able to bind to a particular molecular structure. Antigens are macromolecules that elicit an immune response in the body. The most common antigens are proteins and polysaccharides. B lymphocytes ("B cells") produce antibodies against an antigen.

• View some images of lymphocytes and the T and B cells.
• More details on T and B cells