Interleukin 1 gene expression in adult T cell leukemia.

Abstract

The adult T cell leukemia (ATL)' is a usually fatal T cell malignancy produced by human T lymphotropic virus type I (HTLV-I) infection of T3' and T4' lymphocytes (helper/in- ducer phenotype) (1-3). These leukemic T cells are often characterized by the abnormal constitutive expression of mem- brane receptors for interleukin 2 (IL-2) (4, 5). Clinically, this leukemia may present in acute, chronic, or smoldering forms (6). The acute form of this disease, and the development of a leukemic crisis in the other less common forms, is frequently associated with hypercalcemia (6-8), evidence of increased bone turnover or osteolysis. Several investigators have reported that HTLV-I-infected primary leukemic T cells pro- duce osteoclast-activating factor (OAF) or OAF-like sub- stance(s) that promote bone resorption and may contribute to the development of hypercalcemia (8-12). However, this ATL-associated OAF has not been purified and remains poorly characterized. Recently, Dewhirst et al. ( from mitogen and phorbol ester-activated peripheral blood mono- nuclear cells (PBMC) and unexpectedly found that its NH2terminal amino acid sequence was identical to that of inter- leukin Il# (IL-18) (14, 15). This finding, coupled with the rec- ognized ability of IL-1 to induce IL-2 receptor gene expression