[Il9 and its Receptor - Involvement in T-cell Oncogenesis]

IL9 is a cytokine produced by activated T cells and particularly from the Th2 subset. This protein shows pleiotropic activities on various cell types such as T and B lymphocytes, mast cells, erythroid and myeloid precursors and neuronal cell lines. The IL9 receptor is a member of the hematopoietin receptor superfamily and associates with the gamma chain of the IL2 receptor to transduce the signal inside the cells. IL9 transgenic mice, constitutively expr essing large amounts of this cytokine, are highly susceptible to the development of thymic lymphomas after irradiation or injection of a chemical mutagen. In the human, constitutive IL9 expression has been found in cell lines and lymph nodes from patients with Hodgkin disease or large cell anaplastic lymphomas and an IL9-mediated autocrine loop has been demonstrated for one Hodgkin cell line in vitro