CD4- and CD56-positive T-cell line, MTA, established from natural killer-like T-cell leukemia/lymphoma

We have established a T-cell line, MTA, from the peripheral blasts of a patient with natural killer (NK)-like T-cell leukemia/lymphoma. The MTA cell displays a T-cell and NK-cell phenotype (CD2⁺, CD3⁺, CD4⁺, CD56⁺) identical to freshly isolated leukemic blasts from the patient. This cell line shows clonal T-cell receptor rearrangement and a distinguishable character by light microscopy with May-Grünwald Giemsa staining. G-banding analysis showed that the MTA cells had a karyotype of 94(4N), XXXX, add (1) (p36), del (5) (q14q23), add (17) (p11), add (19) (q13). However, unlike NK malignancy, we could not show a direct pathogenic role for Epstein-Barr virus (EBV) with EBV-encoded small RNA and polymerase chain reaction analysis. The MTA cell line is a novel cell line with which to study NK-like T-cell ontogenecity.