Lymphocyte

A motile cell formed in tissues such as the lymph nodes, that functions in the development of immunity.

A cell present in the blood and lymphatic tissue.

(LIM-foh-site) A type of white blood cell. Lymphocytes have a number of roles in the immune system, including the production of antibodies and other substances that fight infections and other diseases.

Leukocyte with a large round nucleus and usually a small cytoplasm. Specialized types of lymphocytes have enlarged cytoplasms and produce antibodies. Other specialized lymphocytes are important in cellular immune responses.

White blood cells that are important components of the immune system of vertebrates. See: B cell, T cell.

A small white blood cell that plays a major role in defending the body against disease. There are two main types of lymphocytes: B cells, which make antibodies that attack bacteria and toxins, and T cells, which attack body cells themselves when they have been taken over by viruses or become cancerous. See also cancer, cell