Establishment and cytological characteristics of two in vitro T‐cell lines derived from a child with acute lymphatic leukemia and a man with adult T‐cell leukemia in Japan

Two permanent T-cell leukemia lines designated KH-1 and KH-2 were established from the peripheral blood of a 9-year-old boy with acute lymphoblastic leukemia and a 47-year-old man with adult T-cell leukemia (ATL). No T-cell growth factor was used. KH-1 cells grew as single cells and KH-2 cells formed clusters in suspension culture. E-rosette formation, the absence of immunoglobulin determinants and Epstein-Barr-virus-associated nuclear antigen, and the presence of T-cell antigens revealed by monoclonal antibodies were characteristics of these cell lines as in other established T-cell leukemia lines. Chromosome analysis at the beginning revealed mosaic presence of cells with 46, XY, t (8q+; 15q-) and 46, XY which was later completely replaced by the latter karyotype in KH-1, and abnormal karyotype, 47, XY, +3, t (8q-; 10p+) was maintained throughout the period of in vitro passage in KH-2. The donor patient of KH-2 formerly lived in the south-western part of Japan where ATL is considered endemic and numerous type-C virus particles were detected electron microscopically, in KH-2 cell pellets.