Electron microscopic study of cell lines established from adult T-cell leukemia--coexistence of adult T-cell leukemia virus and Epstein-Barr virus.

Six cell lines established from five patients with adult T-cell leukemia (ATL) were studied by electron microscopy. From one patient two cell lines were established, an interleukin 2-dependent line and a nondependent line. The interleukin 2-dependent T-cell line had only ATL virus (ATLV) particles. The interleukin 2-nondependent B-cell line had both ATLV particles and Epstein-Barr virus (EBV) particles. In two other B-cell lines and one undetermined cell line, both ATLV particles and EBV particles were seen. In one B-cell line only a few EBV particles were seen. These findings suggest that (1) interleukin 2 is necessary for the growth of leukemic T-cells from ATL tissue samples, and (2) ATLV can infect not only T-cells but also B-cells.