Transformation of Bloom syndrome T-lymphocytes by cocultivation with a lethally irradiated human T-cell line carrying type C virus particles.

The present study describes the establishment of T-cell lines from the peripheral blood of two Bloom syndrome (BS) patients and one healthy female by co-cultivation with a lethally irradiated human T-cell line (MT-2) carrying adult T-cell leukemia (ATL) virus (ATLV). The cell lines from normal and BS subjects exhibited cell surface markers compatible with T-cell origin, and BS T-cell lines retained the original cytogenetic characteristics of the syndrome. Even though phytohemagglutinin-stimulated BS lymphocytes from the two BS patients studied all showed high levels of sister chromatid exchange (SCE), one of the BS T-lines retained the high SCE level in 100% of the cells and the other BS T-line contained two populations, one with high SCE (70%) and the other with normal SCE (30%), at a relatively constant frequency over 6 months. Transformation of normal and BS cells by cocultivation with MT-2, which carries ATLV, did not cause karyotypic changes over 6 months. ATLV infection, chromosome instability, karyotypic abnormality and SCE in BS T-lymphocytes are also discussed.