T lymphocytes are part of the immune system and develop from stem cells in the bone marrow. They help protect the body from infection and may help fight cancer. Also called T cell and thymocyte. Enlarge. Blood cell development.
T lymphocytes play a central role in regulation of antigen-specific immune responses, by modulating the function of antigen-presenting cells, B lymphocytes, and other T lymphocytes, both through contact with (receptor binding) and secretion of cytokines and by direct killing of target cells.T cells (thymus cells) and B cells (bone marrow- or bursa-derived cells) are the major cellular components of the adaptive immune response. T cells are involved in cell-mediated immunity, whereas B cells are primarily responsible for humoral immunity (relating to antibodies).T cells originate in the bone marrow and mature in the thymus. In the thymus, T cells multiply and differentiate into helper, regulatory, or cytotoxic T cells or become memory T cells.