Transformation of normal bone-marrow cells by a leukaemic cell line associated with a presumptive new human virus

Characteristics of a cell line established from a child with familial acute myeloid leukaemia

The properties of an unusual new cell line from a child with acute myeloid leukaemia (AML) is described. The patient, his mother and grandmother all died within 2 years of AML. Karyotypic analysis suggests that the cells which grow in vitro represent a proliferation of the child's leukaemic cells. The presence of myeloid alkaline phosphatase in these cells suggests that they represent a proliferation of malignant myeloblasts. During the first year in culture a significant percentage of the cells formed E-rosettes, but the cells failed to react with monoclonal anti-T-cell antibodies. The cells are SmIg, Fc, C3 and EBNA negative. Ultrastructural examination of the cells revealed cytoplasmic inclusion bodies which contained virus-like particles. These inclusion bodies and particles were similar to those observed by us in two other human leukaemic cell lines and not unlike those in fresh human leukaemic cells, as reported by others.

Phenotypic characterization of a virus producing line established from a patient with leukaemia/lymphoma: comparison with T-lymphoblastic and myeloblastic lines

The properties have been studied of a haemic cell line established from a patient with longstanding non-Hodgkin's lymphoma after transformation to acute leukaemia. The cells are EBNA, Fc, C3 and SmIg and Ia-like antigen negative. The continuous in vitro proliferation and karyotype abnormalities suggest malignancy. The cells contain only the lymphoid type of alkaline phosphatase and a high level of terminal deoxynucleotidyl transferase and as they formed E-rosettes during the first year in culture they may be of T-cell lineage. Since the patients' leukaemic cells have not been studied it is impossible to know whether the cultured cells represent an in vitro proliferation of the patient's malignant cells or an outgrowth of a subpopulation of cells. In the cytoplasm of many cells inclusion bodies containing virus-like particles, similar to those observed in fresh human leukaemia cells, were often seen. As this new virus is biologically active, infection of the cells by virus may explain their continuous proliferation in vitro.