Adult T-cell leukemia (ATL) cells have been shown to express the receptor for IL-2 by studies using anti-CD25 monoclonal antibody, but these cells usually show no or only a weak proliferative response to IL-2.
Adult T cell leukemia (ATL) is an aggressive malignancy that is associated with HTLV-I infection and characterized by constitutive expression of the high-affinity interleukin-2 receptor.
Interleukin 2 (IL 2) receptor (IL 2-R) is constitutively expressed on T cell lines established from the patients with adult T cell leukemia (ATL), which is a human T cell leukemia lymphoma virus (HTLV-1)(+) T4(+)-leukemia endemic in Japan, the United States, and other countries.
Interleukin-2 increases production and secretion of parathyroid hormone-related peptide by human T cell leukemia virus type I-infected T cells: possible role in hypercalcemia associated with adult T cell leukemia.
A long-term T-cell line, termed SP+, was developed from a human T-cell leukemia virus type I (HTLV-I)-infected patient with adult T-cell leukemia that is dependent on exogenous IL-2 for growth.
A novel interleukin-2 (IL-2)-dependent T-cell line, WHN2, was established from a patient with adult T-cell leukemia (ATL) not associated with human T-cell leukemia virus type I (HTLV-I).
Analysis of RNA from HTLV-I-infected cells established from patients with adult T cell leukemia (ATL) as well as tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM) and both IL-2-dependent and IL-2-independent HTLV-I-infected cell lines by RNase protection has confirmed the existence of all of the alternatively spliced messages in each cell line analyzed.
As is the case with adult T cell leukemia (ATL)-derived human T cell lines transformed by HTLV-I, these rat cell lines unequivocally expressed interleukin 2 (IL-2) receptor, as determined by radiolabeled IL-2 binding.
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.
Cell line PER-117 provides a model to investigate the requirements for induction of IL-2 receptors in a cell expressing the first T-cell-specific marker and may help to elucidate the role of IL-2 during thymic differentiation and in the uncontrolled proliferation of T-cell leukemias.
Collectively, these results suggest that immune activation in HAM/TSP, in contrast to ATL, is virally driven by the transactivation and coordinate expression of IL-2 and IL-2R alpha.
Deregulation of interleukin-2 receptor expression occurs in T-cell leukemias produced by the human T-lymphotropic retroviruses types I and II (HTLV-I and -II) and has been causally linked to the action of the trans-activator (taf) gene of these viruses.
Exposure to 10(-6) to 10(-10) M bexarotene or Panretin for 48 hours was associated with increased expression of both the p55 and p75 subunits of the IL-2R in T-cell leukemias and p75 in B-cell leukemias.
Flow cytometric analysis demonstrated the expression of the IL-2R beta chain on granular lymphocytes (GLs) from all eight patients with granular lymphocyte proliferative disorders (GLPDs), on adult T-cell leukemia (ATL) cells from all three patients with ATL, and on T-cell acute lymphoblastic leukemia (T-ALL) cells from one of three patients with T-ALL.
Here, we report that IL-2-dependent ATL cell lines also express IL-4Ralpha and respond to IL-4, which was verified by the activation of cytoplasmic transcriptional activator Stat6 protein.
High rate of chromosomal abnormalities in HTLV-I-infected T-cell colonies derived from prodromal phase of adult T-cell leukemia: a study of IL-2-stimulated colony formation in methylcellulose.
However, clonality analysis based on T cell receptor gene rearrangement profiles and the site of HTLV-I provirus integration revealed IL-2-dependent growth in leukemic cells in four patients with ATL.
HTLV-I transformed T-cell lines and fresh ATL cells are characterized by constitutive activation of the interleukin-2 receptor (IL-2R) signaling pathway however, the mechanism(s) responsible for constitutive IL-2R activation are unknown.