Type C virus particles produced in human T-cell lines derived from acute lymphoblastic leukemia and a leukemic T-lymphoid malignancy.

Electron microscopy of four human T-cell lines revealed the production of type C virus particles in two T-cell lines: one derived from acute lymphoblastic leukemia and the other from a leukemic T-lymphoid malignancy. Virus particles isolated from these cells had reverse transcriptase activity and the major internal structural protein of 30,000 daltons (p30). The indirect immunofluorescence test of these virus-producing cells with sera of patients with adult T-cell leukemia (ATL) was negative. The data indicate that these retroviruses are different from adult T-cell leukemia virus (ATLV).