An animal model for anaplastic large cell lymphoma in the immunocompetent syngeneic C57BI/6 mouse

We report on the analysis of a murine anaplastic lymphoid cell line TS1G6, established recently by interleukin (IL)-9 transfection. TS1G6 revealed a h ighly characteristic pattern of large anaplastic cells with mononuclear, bi nuclear, or multinuclear cells resembling Hodgkin (H) or Sternberg-Reed (SR ) cells. This cell line is tumorigenous after injection of as few as 10(4) lymphoma cells into nude or immunocompetent C57Bl/6 mice and leads to death from progressive disease of all treated animals within a few weeks. The hi stological analysis of these tumors revealed a diffuse large cell malignant lymphoma that is morphologically almost identical to human anaplastic larg e cell lymphoma (ALCL). The lymphoma cells did not show overexpression of t he anaplastic lymphoma kinase (ALK) gene, which is found in about 50% of th e cases of human ALCL. Thus, this model may be an animal model for an impor tant subset of human ALCL. The cytokine profile, which is of the T helper 2 type, showed strong parallels to the human lymphoma counterpart. Mice suff ering from such lymphomas could not be cured with a regimen using high dose cyclophosphamide similar to many ALCL patients. Such an animal model for A LCL has not yet been recognized, but may provide the basis for investigatin g new antitumor immunotherapies in a fully immunocompetent host.