Interleukin 1 gene expression in adult T cell leukemia.

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.     

Transactivation of the transforming growth factor beta 1 (TGF-beta 1) gene by human T lymphotropic virus type 1 tax: a potential mechanism for the increased production of TGF-beta 1 in adult T cell leukemia

We examined the effect of the human T lymphotropic virus type 1 (HTLV-I) Tax gene product on the human transforming growth factor beta 1 (TGF-beta 1) promoter. Transfection of deleted constructs of the TGF-beta 1 promoter revealed regions homologous with AP-1 binding sites that were required for Tax-induced transactivation of the TGF-beta 1 promoter. In addition, we examined the expression and secretion of TGF-beta in fresh leukemic cells isolated from patients with adult T cell leukemia (ATL) and in HTLV-1-infected T cell lines. We report that fresh leukemic cells from ATL patients constitutively produce high levels of TGF-beta 1 mRNA and secrete TGF-beta 1 but not TGF-beta 2 into the culture medium. In addition, long-term ATL cell lines expressed significant amounts of TGF-beta 1 mRNA as well as detectable levels of TGF-beta 1 protein. These results suggest a role for Tax in the upregulation of TGF-beta 1 in HTLV-I-infected cells.     

Elevated serum levels of soluble interleukin-2 receptors in HTLV-I--associated myelopathy

Using an enzyme-linked immunosorbent assay, we measured the level of soluble interleukin-2 receptors (sIL-2Rs) in the serum of 50 normal controls, 48 human carriers of T cell leukemia virus type I (HTLV-I) antibody who had no symptoms, 11 patients with HTLV-I-associated myelopathy (HAM), and 39 patients with adult T cell leukemia (ATL) (four smoldering, 10 chronic, nine lymphoma, and 16 acute type). The highest levels of sIL-2R were observed in patients with acute and lymphoma-type ATL, as opposed to those with chronic and smoldering-type ATL. The levels of sIL-2R in patients with HAM were roughly between those of smoldering ATL and healthy HTLV-I carriers. Serum sIL-2R levels in healthy carriers were also elevated compared with those in normal controls. These observations suggest that the measurement of sIL-2R levels in patients with ATL can be useful as a noninvasive measure of tumor burden and should aid in the understanding of the natural history of HTLV-I infection leading to the development of ATL.     

Origin of human T-lymphotrophic virus I-positive T cell lines in adult T cell leukemia. Analysis of T cell receptor gene rearrangement

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. From a patient with chronic ATL, whose leukemic cells proliferated in vitro in response to IL-2, we repeatedly established leukemic T cell clones having the same rearrangement profile of the T beta chain gene as the leukemic cells. By contrast, established cell lines from acute ATL patients had different beta chain gene rearrangements from those of the leukemic cells. These HTLV-I+ T cell lines might not be the direct progeny of the leukemic cells, but that of T cells infected either in vivo or in vitro. These IL-2-reactive nonleukemic T cells might have been selected in vitro, because their leukemic cells failed to respond to IL-2, despite the expression of IL-2 receptor. The analysis of the T cell receptor gene rearrangement may give a new approach for the elucidation of the mechanism of leukemogenesis and the origin of the HTLV-I+ T cell lines in ATL.     

Adult T-cell leukemia/lymphoma in the Middle East: first report of two cases from Lebanon

BACKGROUND: Adult T-cell leukemia/lymphoma (ATL) is an aggressive lymphoproliferative disorder caused by human T-cell leukemia virus type I (HTLV-I). HTLV-I is endemic in southern Japan, the Caribbean, Central and South America, certain areas of Africa, and the southeastern United States. In the Middle East, North East Iran, particularly the region of Mashhad, has been recognized as an endemic region.
CASE REPORTS: In this report, the first two cases of ATL diagnosed in Lebanon are described. The first patient of Lebanese origin presented with acute ATL. The second patient of Romanian origin developed acute ATL in early relapse after autologous transplantation for ATL. Both patients had lymphocytosis, severe hypercalcemia, and CD25+ T-cell immunophenotype on peripheral blood. In both patients, HTLV-I serology was positive by enzyme-linked immunosorbent assay and confirmed by Western blot and HTLV-I oncoprotein Tax expression was documented in the leukemic cells. Upon screening, seven direct family members of the first patient were HTLV-I positive; four of them were regular blood donors.
CONCLUSIONS: Screening blood donors for HTLV-I seropositivity is not currently performed in Lebanon. A large screening study in Lebanon is needed to confirm whether South Lebanon is a new endemic region for HTLV-I infection and to recommend mandatory screening of blood donors for HTLV-I infection.     

Resistance to Fas-mediated Apoptosis of Peripheral T Cells in Human T Lymphocyte Virus Type I (HTLV-I) Transgenic Mice with Autoimmune Arthropathy

Transgenic mice carrying the env-pX region of human T lymphocyte virus type I (HTLV-I) develop autoimmune arthropathy in high incidence. Adopting the approach that Fas-mediated apoptosis has a critical function in the elimination of self-reactive T cells, we examined the involvement of this apoptosis in the induction of autoimmunity in HTLV-I transgenic mice. Splenic T cells derived from the transgenic mice were more resistant to apoptosis induced by anti-Fas mAb than those of the nontransgenic mice, whereas no appreciable difference in apoptosis was detected for thymocytes from either mouse's type. The resistance of transgenic T cells may be due to Tax coded in the pX region, since Tax mediates the inhibition of anti-Fas– induced apoptosis in mature T cell line, Jurkat. Among the transgenic mice, the extent of the resistance to Fas-mediated apoptosis was further enhanced in transgenic T cells with disease. These results suggest that the escape of self-reactive T cells from Fas-mediated apoptosis in the periphery, is critical for the development of autoimmune arthropathy in HTLV-I transgenic mice.     

Interleukin-2 receptor (Tac antigen) expressed on adult T cell leukemia cells.

We studied the expression of the interleukin-2 (IL-2) receptor and the proliferative response to exogenous IL-2 of peripheral blood leukemic cells from patients with adult T cell leukemia (ATL) in order to see whether IL-2 receptor expressed on ATL cells is different from normal IL-2 receptor and whether it plays a role in the neoplastic growth in ATL. Peripheral blood leukemic cells from 42 patients with ATL examined expressed IL-2 receptors that were detected by anti-Tac monoclonal antibody when examined immediately after the separation of cells or after the culture for 24 or 48 h. The number of anti-Tac binding sites ranged from 3,100 to 11,400 in fresh cells and from 3,600 to 96,000/cell in short-term cultured leukemic cells, whereas phytohemagglutinin-P (PHA-P)-stimulated normal T cells exhibited 6,900-35,000 anti-Tac binding sites per cell. ATL-derived and human T cell leukemia/lymphoma virus, type I (HTLV-I)-infected cell lines such as MT-1 and Hut102 expressed a much higher number of anti-Tac binding sites. Leukemic cells from 15 patients with ATL examined showed no or very poor proliferative response to various concentrations of immunoaffinity-purified IL-2, although they expressed Tac antigen (Ag). Radiolabeled IL-2 binding experiments demonstrated that ATL leukemic cells could bind IL-2, and they expressed both high and low affinity IL-2 receptors, although the number of high affinity IL-2 receptor was much less than that of low affinity IL-2 receptor and that of anti-Tac binding sites. In contrast, leukemic T cells from a patient with T cell chronic lymphocytic leukemia (CLL), in whom HTLV-I infection was not demonstrated, responded as well as PHA-P-stimulated normal T cells, and their IL-2 receptors, unlike ATL cells, were modulated (down regulated) by anti-Tac antibody. No differences were noted between ATL cells and normal activated T cells in one-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis of the IL-2 receptor. Thus, leukemic cells in ATL spontaneously and continuously express IL-2 receptor, which appears to be abnormally regulated and unresponsive to IL-2. These results, taken together with those on normal IL-2 receptors on HTLV-I-negative T-CLL cells, suggest that abnormal expression of the IL-2 receptor in ATL is closely associated with HTLV-I infection and may play a role in the neoplastic growth of ATL cells.     

Clinico-pathological aspects of adult T-cell leukemia/lymphoma(ATL)

Adult T-cell leukemia/lymphoma(ATL) was first discovered and reported in Japan, where it has a high incidence in the southwestern region of the country. The retrovirus human T-cell leukemia virus type I(HTLV-I) is considered to be related to its etiology. ATL shows divers clinical features. It can be divided into four types of smoldering, chronic, acute, and lymphoma. ATL cells originate from the CD4-positive subset of peripheral T cells showing a characteristic notch in the nucleus and a tendency for lobulation. A definit diagnosis of ATL is made by documenting the presence of HTLV-I proviral DNA in the DNA of leukemic or lymphoma cells. Crinico-Pathological aspects of ATL are more complexed than other types of lymphoma because of the verity of the disease type, state of immunodeficiency, hypercalcemia, cytokine activation, and so on.     

Close association between interleukin 2 receptor mRNA expression and human T cell leukemia/lymphoma virus type I viral RNA expression in short-term cultured leukemic cells from adult T cell leukemia patients.

Human T cell leukemia/lymphoma (T-lymphotropic) virus type I (HTLV-I) infection has been considered to be closely associated with the leukemogenesis of adult T cell leukemia (ATL), in which interleukin 2 (IL-2) receptors are abnormally expressed. In this study, however, Southern blot analysis revealed no gross rearrangement or obvious amplification of the IL-2 receptor gene in ATL leukemic cells, indicating that abnormal IL-2 receptor expression in ATL is not due to the structural change of its gene. Hence, we studied the expression of the IL-2 receptor and HTLV-I at the RNA level during short-term cultures of leukemic cells from 9 ATL patients. Cytoplasmic dot hybridization and Northern hybridization revealed that fresh leukemic cells from seven of nine patients expressed a small amount of IL-2 receptor mRNA but HTLV-I RNA was undetectable in all cases. After cultures for up to 7 d, both IL-2 receptor mRNA and HTLV-I RNA (including pX message) expression concomitantly increased, whereas the amounts of other cellular genes, except for beta-actin, did not. The increases in their RNA expression were inhibited by early addition (within 12 h after the beginning of the culture) of cycloheximide, indicating that these increases are mediated by newly synthesized protein(s). These results strongly suggested that IL-2 receptor expression is closely associated with HTLV-I expression in leukemic cells from ATL patients.     

Adult T cell leukemia/lymphoma (ATL)

Adult T cell leukemia/lymphoma(ATL) is an aggressive, fatal malignancy associated with human T-lymphotropic virus type I(HTLV-I). The median survival time of acute- and lymphoma-type ATL is 6 and 10 months, respectively. According to recent reports, nearly half of the ATL patients who received allogeneic hematopoietic stem cell transplantation could survive without disease for over 3 years. However, the population of patients who are eligible for conventional transplantation is extremely limited. Therefore, a reduced-intensity allogeneic stem cell transplantation(RIST) is applied to ATL patients and a multi-center phase I clinical trial is now underway. In our institute, 5 patients, who received RIST, are all alive, with 1 case relapsed after 6 months. Thus, RIST is considered very promising.     

NIK-333 inhibits growth of human T-cell leukemia virus type I-infected T-cell lines and adult T-cell leukemia cells in association with blockade of nuclear factor-kappaB signal pathway

Adult T-cell leukemia (ATL) is caused by human T-cell leukemia virus type I (HTLV-I) and remains incurable. NIK-333, a novel synthetic retinoid, prevents the recurrence of human hepatoma after surgical resection of primary tumors. We explored the effects of NIK-333 on HTLV-I-infected T-cell lines and ATL cells. NIK-333 inhibited cell proliferation, induced G1 arrest, and resulted in massive apoptosis in all tested HTLV-I-infected T-cell lines and ATL cells, whereas little effect was observed on normal peripheral blood mononuclear cells. NIK-333 treatment decreases the levels of cyclin D1, cyclin D2, cIAP2, and XIAP proteins. Further analysis showed that NIK-333 inactivated nuclear factor-kappaB in HTLV-I-infected T-cell lines. In animal studies, treatment with NIK-333 (100 mg/kg given orally every other day) produced partial inhibition of growth of tumors of a HTLV-I-infected T-cell line transplanted s.c. in severe combined immunodeficient mice. Our results indicate that NIK-333 is a potentially useful therapeutic agent for patients with ATL.     

Factors Secreted by Human T Lymphotropic Virus Type I (HTLV-I)–infected Cells Can Enhance or Inhibit Replication of HIV-1 in HTLV-I–uninfected Cells: Implications for In Vivo Coinfection with HTLV-I and HIV-1

It remains controversial whether human T lymphotropic virus type I (HTLV-I) coinfection leads to more rapid progression of human immunodeficiency virus (HIV) disease in dually infected individuals. To investigate whether HTLV-I infection of certain cells can modulate HIV-1 infection of surrounding cells, primary CD4⁺ T cells were treated with cell-free supernatants from HTLV-I–infected MT-2 cell cultures. The primary CD4⁺ T cells became resistant to macrophage (M)-tropic HIV-1 but highly susceptible to T cell (T)-tropic HIV-1. The CC chemokines RANTES (regulated on activation, normal T cell expressed and secreted), macrophage inflammatory protein (MIP)-1α, and MIP-1β in the MT-2 cell supernatants were identified as the major suppressive factors for M-tropic HIV-1 as well as the enhancers of T-tropic HIV-1 infection, whereas soluble Tax protein increased susceptibility to both M- and T-tropic HIV-1. The effect of Tax or CC chemokines on T-tropic HIV-1 was mediated, at least in part, by increasing HIV Env-mediated fusogenicity. Our data suggest that the net effect of HTLV-I coinfection in HIV-infected individuals favors the transition from M- to T-tropic HIV phenotype, which is generally indicative of progressive HIV disease.     

Rat lymphoid cell lines producing human T cell leukemia virus. II. Constitutive expression of rat interleukin 2 receptor

Three rat lymphoid cell lines (TARS-1, TARL-2, and TART-1) (12) transformed by human T cell leukemia/lymphoma virus I (HTLV-I) had rearrangement of the beta chain gene of the T cell antigen receptor, and had integrated proviral DNA from HTLV-I in their genomes. 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. By Scatchard plot analysis, one of the cell lines, TART-1, proved to have high affinity receptors (Ka = 1.3 X 10(11)/M and 8.8 X 10(9)/M). Rat IL-2 receptor, not human IL-2 receptor, was expressed on HTLV+ rat cell lines, as demonstrated by the fact that they expressed antigens reactive with monoclonal antibodies (ART-18) against rat IL-2 receptor, but not with anti-Tac antibodies. The collective evidence indicates that the endogenous IL-2 receptor gene is activated in human and rat lymphoid cell lines with HTLV-I production. The mechanism of abnormal IL-2 receptor expression in HTLV infection is discussed.     

Increased expression of human T lymphocyte virus type I (HTLV-I) Tax11-19 peptide-human histocompatibility leukocyte antigen A*201 complexes on CD4+ CD25+ T Cells detected by peptide-specific, major histocompatibility complex-restricted antibodies in patients with HTLV-I-associated neurologic disease

Human T lymphocyte virus type I (HTLV-I)-associated chronic inflammatory neurological disease (HTLV-I-associated myelopathy/tropical spastic paraparesis [HAM/TSP]) is suggested to be an immunopathologically mediated disorder characterized by large numbers of HTLV-I Tax-specific CD8+ T cells. The frequency of these cells in the peripheral blood and cerebrospinal fluid is proportional to the amount of HTLV-I proviral load and the levels of HTLV-I tax mRNA expression. As the stimulus for these virus-specific T cells are immunodominant peptide-human histocompatibility leukocyte antigen (HLA) complexes expressed on antigen-presenting cells, it was of interest to determine which cells express these complexes and at what frequency. However, until now, it has not been possible to identify and/or quantify these peptide-HLA complexes. Using a recently developed antibody that specifically recognizes Tax11-19 peptide-HLA-A*201 complexes, the level of Tax11-19-HLA-A*201 expression on T cells was demonstrated to be increased in HAM/TSP and correlated with HTLV-I proviral DNA load, HTLV-I tax mRNA load, and HTLV-I Tax-specific CD8+ T cell frequencies. Furthermore, CD4+ CD25+ T cells were demonstrated to be the major reservoir of HTLV-I provirus as well as Tax11-19 peptide-HLA-A*201 complexes. These results indicate that the increased detection and visualization of peptide-HLA complexes in HAM/TSP CD4+ CD25+ T cell subsets that are shown to stimulate and expand HTLV-I Tax-specific CD8+ T cells may play an important role in the pathogenesis of HTLV-I-associated neurological disease.     

九例成人T淋巴细胞白血病的临床与实验研究

目的探讨成人Ｔ淋巴细胞白血病（ＡＴＬ）的临床、细胞学、免疫学、细胞遗传学、血清学及分子生物学等特征。方法采用间接免疫荧光法及酶联免疫吸附法检测血清ＨＴＬＶⅠ抗体,建立ＰＣＲ和液相杂交法检测前病毒基因序列,结合ＭＩＣ特征确诊ＡＴＬ。结果和结论确诊９例ＡＴＬ,其临床特征主要为淋巴结肿大,皮损及溶骨改变少见,外周血及骨髓出现典型的花瓣状核淋巴细胞,胞体大,核畸形,免疫表型为ＣＤ－１、ＣＤ＋２、ＣＤ３＋、ＣＤ４＋、ＣＤ－８,还表达ＣＤ２５等激活标记,染色体核型及ＨＬＡ分型未发现有规律性的变化。８例ＡＴＬ中有７例血清ＨＴＬＶⅠ抗体阳性,应用ＰＣＲ及液相杂交法可检出整合到宿主细胞ＤＮＡ中的ＨＴＬＶⅠ病毒序列,表明在我国ＨＴＬＶⅠ也是ＡＴＬ的病因。９例中１例为淋巴瘤型,１例为慢性型,７例为急性型ＡＴＬ,治疗效果及预后均不良     

Functional and phenotypic comparison of human T cell leukemia/lymphoma virus positive adult T cell leukemia with human T cell leukemia/lymphoma virus negative Sézary leukemia, and their distinction using anti-Tac. Monoclonal antibody identifying the human receptor for T cell growth factor.

Adult T cell leukemia (ATL) and Sézary leukemia are malignant proliferations of T lymphocytes that share similar cell morphology and clinical features. ATL is associated with HTLV (human T cell leukemia/lymphoma virus), a unique human type C retrovirus, whereas most patients with the Sézary syndrome do not have antibodies to this virus. Leukemic cells of both groups were of the T3, T4-positive, T8-negative phenotype. Despite the similar phenotype, HTLV-negative Sézary leukemic cells frequently functioned as helper cells, whereas some HTLV-positive ATL and HTLV-positive Sézary cells appeared to function as suppressors of immunoglobulin synthesis. One can distinguish the HTLV-positive from the HTLV-negative leukemias using a monoclonal antibody (anti-Tac) that appears to identify the human receptor for T cell growth factor (TCGF). Resting normal T cells and most HTLV-negative Sézary cells were Tac-negative, whereas all ATL cell populations were Tac-positive. The observation that ATL cells manifest TCGF receptors suggests the possibility that an abnormality of the TCGF-TCGF receptor system may partially explain the uncontrolled growth of these cells.     

The human OX40/gp34 system directly mediates adhesion of activated T cells to vascular endothelial cells

Fresh leukemic cells from patients with adult T cell leukemia (ATL) and some ATL-derived T cell lines show adhesion to human umbilical vein endothelial cells (HUVECs) mainly through E-selectin, but a proportion of this binding remains unaffected by the addition of combinations of antibodies against known adhesion molecules. By immunizing mice with one of such cell lines, we established monoclonal antibodies (mAbs), termed 131 and 315, that recognize a single cell surface antigen (Ag) and inhibit the remaining pathway of the adhesion. These mAbs did not react with normal resting peripheral blood mononuclear cells (PBMC) or most of the cell lines tested except for two other human T cell leukemia virus type I (HTLV-I)-infected T cell lines. After stimulation with phytohemagglutinin (PHA), PBMC expressed Ag 131/315 transiently, indicating that these mAbs define a T cell activation Ag. Western blotting and immunoprecipitation revealed that Ag 131/315 has an apparent molecular mass of 50 kD. Expression cloning was done by transient expression in COS-7 cells and immunological selection to isolate a cDNA clone encoding Ag 131/315. Sequence analysis of the cDNA indicated that it is identical to human OX40, a member of the tumor necrosis factor/nerve growth factor receptor family. We then found that gp34, the ligand of OX40, was expressed on HUVECs and other types of vascular endothelial cells. Furthermore, it was shown that the adhesion of CD4+ cells of PHA-stimulated PBMC to unstimulated HUVECs was considerably inhibited by either 131 or 315. Finally, OX40 transfectants of Kit 225, a human interleukin 2-dependent T cell line, were bound specifically to gp34 transfectants of MMCE, a mouse epithelial cell line, and this binding was blocked by either 315 or 5A8, an anti-gp34 mAb. These results indicate that the OX40/gp34 system directly mediates adhesion of activated T cells or OX40+-transformed T cells to vascular endothelial cells.