Maintenance and Characterization of an Epstein Barr Virus‐infected CD56‐negative T Cell Lymphoma

T cell lymphoma carrying Epstein Barr virus (EBV(+)TL) is very rare among Western countries while it is much more common among Japanese. Here we report an EBV(+)TL which has been maintained for years by the use of mice with severe combined immune deficiency (SCID) mice. Lymphoma was obtained from a 55‐year‐old male suffering from oculomotor nerve palsy and lymphadenopathy. A small piece of biopsied tumor was transplanted into SCID mice and the lymphoma has been maintained for over 3 years with passages every 2–3 weeks. The maintained lymphoma, termed as TMS24, and the original lymphoma cells showed identical phenotype and genotype, including diffuse medium‐sized cell morphology lacking granules, suppressor/cytotoxic immunophenotype and identical T cell receptor β‐chain gene rearrangement mode. Further, both were shown to carry an identical EBV clone in terms of the number of terminal repeats and the latency II‐type restricted gene expression profile. Cytogenetically, TMS24 retained two characteristic chromosomal translocations of t(l;18)(q32;q21) and t(6;12)(p21;q24). Since only one cell line with such characters has been reported previously, TMS24 should be useful for detailed analysis of EBV(+)TL.