title: Interleukin 1 gene expression in adult T cell leukemia.
abstract: The adult T cell leukemia (ATL) is a T cell neoplasm etiologically associated with human T lymphotropic virus type I (HTLV-I) infection. ATL cells often abnormally express interleukin 2 (IL-2) receptors, and ATL patients may show clinical evidence of hypercalcemia, osteolytic bone lesions, or increased bone turnover. Whereas interleukin 1 (IL-1) is not generally recognized as a product of T cells, this cytokine is capable of both altering IL-2 receptor expression and activating osteoclasts. Thus, we investigated the possibility that primary ATL leukemic T cells and HTLV-I-infected long-term ATL cell lines produce IL-1. S1 nuclease protection assays demonstrated that primary leukemic ATL cells from five out of six patients, as well as one patient with T4+ chronic lymphocytic leukemia, contained considerable quantities of IL-1 beta messenger RNA (mRNA) and small amounts of IL-1 alpha mRNA. These primary leukemic T cells also released biologically active IL-1 protein as evaluated in the murine thymocyte comitogenesis bioassay. In contrast to primary tumor cells, four out of six long-term ATL cell lines produced variable amounts of IL-1 alpha mRNA in the absence of detectable IL-1 beta mRNA as measured by S1 nuclease protection. These data demonstrate that IL-1 gene (especially IL-1 beta) expression occurs in many primary HTLV-I-infected leukemic T cells raising the possibility that this mediator may play a role in the pathological changes associated with this leukemia. Also, these studies show that the pattern of IL-1 alpha and IL-1 beta gene expression differs between primary ATL tumor cells and long-term cultured ATL cell lines, indicating an interesting biological difference in these two HTLV-I-infected cell populations.
mesh_terms: D000328:Adult; D002460:Cell Line; D006800:Deltaretrovirus Infections / Q000235:genetics; D005786:Gene Expression Regulation; D006801:Humans; D007375:Interleukin-1 / Q000235:genetics*; D007938:Leukemia / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008213:Lymphocyte Activation; D012333:RNA, Messenger / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism
chemical_list: D007375:Interleukin-1; D012333:RNA, Messenger