One of the two major classes of lymphocytes. During infections, these cells are transformed into
plasma cells that produce large quantities of antibody directed at specific pathogens. This transformation occurs through interactions with various types of
T cells and other components of the
immune system. In persons with
AIDS, the functional ability of both the B and the
T lymphocytes is damaged, with the
T lymphocytes being the principal site of
infection by the HIV
virus. See also
Lymphocyte;
T Cells.