Two permanent T-cell leukemia lines designated KH-1 and KH-2 were established from the peripheral blood of a 9-year-old boy with acute lymphoblastic leukemia and a 47-year-old man with adult T-cell leukemia (ATL).No T-cell growth factor was used.
It was possible that T-cell depletion in acquired immune deficiency syndrome could be due to an impairment of TCGF synthesis and that adult T-cell leukemia could be due to unregulated production of TCGF.
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.
Using the clone-specific rearrangement of the T cell receptor gene as the genetic marker of the clonotype, we analyzed the clonal origin of the interleukin 2 (IL-2)-dependent human T-lymphotrophic virus I (HTLV-I)-positive T cell lines established from various adult T cell leukemia (ATL) patients.
Normal resting T-cells and most leukemic T-cell populations do not express IL-2 receptors; however, the leukemic cells of the 11 patients examined who had human T-cell lymphotropic virus-associated adult T-cell leukemia expressed the Tac antigen.
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.
The ability to culture target cells with T-cell growth factor and sensitive detection systems for the virally encoded polymerase reverse transcriptase permitted isolation of HTLV-I, which is strongly linked to the cause of adult T-cell leukemia and associated with other lymphoid malignancies in endemic areas.
The human T-lymphotropic viruses types I and II (HTLV-I and -II) have been etiologically linked with certain T-cell leukemias and lymphomas that characteristically display membrane receptors for interleukin-2.
The cellular interleukin-2 (IL-2) and its receptor (IL-2R), the latter of which is expressed on ATL leukemic cells, were shown to be transiently induced by transfection of plasmid pMTPX expressing pX in two T-cell lines, Jurkat and HSB-2, but not in other human T- or B-cell lines.
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.
To examine the possibility of heterogeneous mechanisms in the proliferation of adult T cell leukemia (ATL) cells, leukemic cells from 13 patients, nine acute-type and four chronic-type ATL, were examined for the production of interleukin 2 (IL 2) with or without mitogenic stimulation and their response to recombinant IL 2 when exogeneously added.
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.
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.
In HTLV-I transformed T-cell lines established from the patients with adult T-cell leukemia (ATL), there is a constitutive activation of the normal IL-2 receptor (IL-2-R) gene.
The constant display of large numbers of IL-2 receptors which may be aberrant in the ATL cells may play a role in the uncontrolled growth of these leukemic T cells.
Therapy of patients with human T-cell lymphotrophic virus I-induced adult T-cell leukemia with anti-Tac, a monoclonal antibody to the receptor for interleukin-2.
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.
The transforming activity of tax, possibly via a transcriptional deregulation of cell growth control, may play an important role in leukemogenesis of ATL in addition to its aberrant stimulation of the interleukin 2 system.
To determine whether the interleukin-2 receptor (IL-2R) beta-chain (p70-75) is expressed on leukemic cells from patients with adult T cell leukemia (ATL) as well as alpha-chain (p55, Tac), we performed radiolabeled interleukin-2 (IL-2) binding assay, chemical crosslinking of radiolabeled IL-2 and flow cytometric analysis using a newly-developed anti-IL-2R beta-chain antibody.