T-Cell Transformation

**Semantic type:** Cell Function

**Definition:** Morphologic alteration of small T lymphocytes in culture into large blast-like cells able to synthesize DNA and RNA and to divide mitotically. It is induced by interleukins, mitogens such as phytohemagglutinins, and by specific antigens. It may also occur in vivo, as in graft rejection and chronic myelogenous leukemia, or the process that a normal T lymphocyte goes through when induced by a pathologic agent such as human T-lymphotropic virus 1 (HTLV-1) to become an adult T cell leukemia or other aggressive malignancy where neoplastic T cells apparently use IL-2 as an autocrine growth factor. (from Fundamental Immunology, 3rd ed., William Paul, ed., Raven Press, NY 1993, p.768)