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The interleukin-2 receptor: a target for monoclonal antibody treatment of human T-cell lymphotrophic virus I-induced adult T-cell leukemia.

Adult T-cell leukemia (ATL) is a malignancy of mature lymphocytes caused by the retrovirus human T-cell lymphotrophic virus-I (HTLV-I). It is an aggressive leukemia with an overall mortality rate of 50% within 5 months; no conventional chemotherapy regimen appears successful in inducing long-term disease-free survival in ATL patients. However, ATL cells constitutively express high-affinity interleukin-2 receptors (IL-2Rs) identified by the anti-Tac monoclonal antibody, whereas normal resting cells do not. To exploit this difference in receptor expression, we administered anti-Tac intravenously (IV) to 19 patients with ATL. In general the patients did not suffer untoward reactions, and in 18 of 19 cases did not have a reduction in normal formed elements of the blood. Seven patients developed remissions that were mixed (1 patient), partial (4 patients), or complete (2 patients), with partial and complete remissions lasting from 9 weeks to more than 3 years as assessed by routine hematologic tests, immunofluorescence analysis, and molecular genetic analysis of T-cell receptor gene rearrangements and of HTLV-I proviral integration. Furthermore, remission was associated with a return to normal serum calcium levels and an improvement of liver function tests. Remission was also associated in some cases with an amelioration of the profound immunodeficiency state that characterizes ATL. Thus the use of a monoclonal antibody that blocks the interaction of IL-2 with its receptor expressed on ATL cells provides a rational approach for treatment of this aggressive malignancy.

Adult↗

Inhibitory effect of interleukin 4 on production of interleukin 6 by adult T-cell leukemia cells.

Freshly isolated leukemic cells from patients with adult T-cell leukemia (ATL) produce high levels of interleukin 6 (IL-6), which is suggested to play an important role in thrombocytosis, elevation of C-reactive protein, and hypercalcemia in ATL. In this study, we investigated the effects of T-cell growth factors such as interleukin 2 (IL-2) and interleukin 4 (IL-4) on IL-6 production by ATL cells in vitro. Although IL-2 and/or IL-4 enhanced the cell proliferation of freshly isolated ATL cells from seven of nine patients, IL-2 did not affect the IL-6 release in most cases. In contrast, another T-cell tropic factor, IL-4 markedly inhibited the release of IL-6 in the conditioned medium in all cases. This IL-4-mediated inhibition of IL-6 release was completely abrogated by the addition of anti-IL-4 monoclonal antibody. Time course experiments demonstrated that IL-4 reduced the secretion of IL-6 for a prolonged period of time (more than 72 h). By Northern analysis, IL-4 reduced the transcription level of IL-6 mRNA. Furthermore, by flow cytofluorometry with the use of anti-human IL-4 receptor monoclonal antibody, ATL cells showed the significant level of IL-4 receptor on their cell surfaces without any stimulation. These data suggest that IL-4 may play an important regulatory role in the production of IL-6 in ATL.

Aged↗

Primary adult T cell leukemia of bone: two patients with primary bone lesion showing monoclonal integration of HTLV-I proviral DNA.

Adult T cell leukemia (ATL), a neoplasm of mature helper T lymphocytes is etiologically associated with human T lymphotropic virus type-I (HTLV-I). ATL cells infiltrate various organs, the lung, skin, central nervous system, gastrointestinal tract, and bone, causing various clinical manifestations. Two unusual cases of ATL, in which lytic bone lesion was the primary site of ATL, are described. One patient had multiple lytic lesions in bones without any involvement of other organs, and the other patient had a bone lesion in the right radius, which disappeared after chemotherapy. In both cases, monoclonal integration of HTLV-I provirus was demonstrated in the genomic DNA from each bone lesion. Although their clinical courses and pathological findings were different, ATL in both patients began as a bone lesion, showing that primary lymphoma of bone can be manifested in ATL cases.

Adult↗

[Clinical significance of soluble interleukin-2 receptor levels in the cerebrospinal fluid in patients with adult T-cell leukemia complicated with meningeal infiltration].

We measured soluble interleukin-2 receptor (sIL-2R) levels in the cerebrospinal fluid (CSF) of patients with hematological malignancies especially, adult T-cell leukemia (ATL) and non-Hodgkin's lymphoma (NHL) with or without meningeal infiltration. CSF levels of sIL-2R were significantly higher in patients with ATL and NHL with meningeal infiltration than in patients with both diseases without meningeal infiltration. The sIL-2R levels in CSF were elevated in 4/4 ATL patients (100%) and 3/13 NHL patients (23%) with meningeal infiltration. CSF levels of sIL-2R from ATL patients with meningeal infiltration had a tendency to elevate in correlation with numbers of mononuclear cells and lactic dehydrogenase (LDH) in CSF. However, these had no correlation with serum levels of sIL-2R. Therefore, sIL-2 levels in CSF may be useful in the diagnosis of meningeal infiltration in patients with ATL, are probably specific markers for meningeal infiltration of ATL.

Adolescent↗

[Adult T-cell leukemia complicated with intestinal tuberculosis].

We report a patient with adult T-cell leukemia (ATL) complicated with intestinal tuberculosis. A 57-year old man was admitted to our hospital because of fever and dyspnea. He was diagnosed as ATL by leukocytosis [leukocyte count 18,200/microliters with 56% of abnormal lymphocytes which express CD4(+) and CD25(+)] and seropositive result of anti-HTLV-1 antibody. Combination chemotherapy for ATL improved his serum LDH level and peripheral lymph nodes, but fever was still persistent. He had an emergency operation because of perforation of the cecum during the chemotherapy. Histological examination of the resected cecum revealed caseous necrosis and numerous mycobacterium, which induced a diagnosis of intestinal tuberculosis. Although there have been several reports on pulmonary tuberculosis in patients with ATL, this is the first report of intestinal tuberculosis in ATL as far as we know. We conclude that if the patients with ATL have persistent fever of unknown origin, we should take account of intestinal tuberculosis as one of differential diagnosis.

Fever of Unknown Origin↗

Distribution of human leukocyte antigens in a population of black patients with human T-cell lymphotrophic virus type I-associated adult T-cell leukemia/lymphoma.

Human leukocyte antigens (HLAs) play an important role in regulating the immune response to infectious agents and determinants of malignant transformation. We compared the HLA frequencies of 25 black patients with adult T-cell leukemia/lymphoma (ATL) referred to the National Cancer Institute for therapy with a racially similar, asymptomatic control population of human T-cell lymphotrophic virus, type I (HTLV-I)-seropositive individuals (n = 45). Serological typing was performed for MHC class I and II antigens. Antigen frequencies were calculated, and corresponding gene frequencies were estimated using the maximum likelihood method. Comparisons between the ATL and control group were made with chi 2 or Fisher's exact test. Three antigens (A36, B18, and DR53) were found to have a higher frequency in the ATL patients than in the controls (uncorrected two-tailed P < 0.05). The gene frequencies for these antigens also were statistically significant in the uncorrected analysis. However, only A36 approached statistical significance after correction of the P value for multiple comparisons (P = 0.08). The results of this pilot study indicate that black patients with ATL may have increased frequencies of certain class I HLA when compared with a racially similar HTLV-I-positive reference population. This suggests that either these antigens may represent markers for a population at greater risk of developing ATL once infected with HTLV-I or that they were acquired at some point in the process of malignant transformation or progression from the carrier state to onset of ATL. These antigens should be targeted in larger studies to confirm or refute these findings.

Adult↗

SFA-1/PETA-3 (CD151), a member of the transmembrane 4 superfamily, associates preferentially with alpha 5 beta 1 integrin and regulates adhesion of human T cell leukemia virus type 1-infected T cells to fibronectin.

In this study we have analyzed the adhesion molecules associated with and the biologic function of SFA-1/PETA-3 (CD151) in human T cell leukemia virus type 1 (HTLV-1)-infected T cells and in freshly isolated adult T cell leukemia (ATL) cells using an anti-CD151 mAb. The anti-CD151 mAb coprecipitated alpha 5 beta 1 integrin from HTLV-1-infected T cells. Conversely, an anti-alpha 5 integrin mAb coprecipitated CD151. The anti-CD151 mAb inhibited the adhesion of HTLV-1-infected T cells to fibronectin but did not have any effect on their adhesion to laminin, collagen type I, or collagen type IV. Moreover, antisense CD151 oligonucleotide-treated HTLV-1-infected T cells showed significant inhibition of adhesion to fibronectin. These findings showed that the CD151 molecule was associated with the alpha 5 beta 1 integrin molecule and that it enhanced alpha 5 beta 1 integrin-mediated adhesion to fibronectin. In addition, the expression levels of CD151, alpha 4 beta 1 integrin, and alpha 5 beta 1 integrin on ATL cells from lymph nodes of lymphoma-type ATL patients were significantly higher than those on circulating ATL cells from leukemia-type ATL patients. This suggests that the increased expression of these integrins may contribute to lymphoma formation through the adhesion of ATL cells to the extracellular matrix and dendritic cells, rather than contributing to transmigration.

Animals↗

Risk factors for adult T-cell leukemia among carriers of human T-lymphotropic virus type I.

The presence of circulating "flower cells" and a low prevalence of antibody to Tax regulatory protein of human T-lymphotropic virus type I (HTLV-I) are characteristics of adult T-cell leukemia (ATL). To examine the predictability of levels of HTLV-I antibodies and of flower cell-like abnormal lymphocytes (Ably) for the risk of ATL among asymptomatic HTLV-I carriers, we prospectively evaluated the levels of viral markers of five HTLV-I carriers who developed ATL and 38 age-, sex-, and screen-matched HTLV-I-positive controls in the Miyazaki Cohort Study. After accounting for matching factors, Ably level was slightly, but not significantly, higher among cases than among controls (P =.13). Anti-HTLV-I (odds ratio [OR] = 1.6 per twofold dilution; 95% confidence interval [CI] 0.94, 3.8) was associated with ATL diagnosis, but antibody to Tax regulatory protein (anti-Tax) was not (OR = 0.78; 95% CI 0.26, 1.7). Anti-Tax level was low for all ATL cases for up to 10 years preceding their diagnosis, independent of the level of anti-HTLV-I titer. HTLV-I carriers with a higher anti-HTLV-I titer and a lower anti-Tax reactivity may be at greatest risk of ATL.

Adult↗

Eosinophilia associated with adult T-cell leukemia: role of interleukin 5 and granulocyte-macrophage colony-stimulating factor.

To clarify the mechanism of eosinophilia in adult T-cell leukemia (ATL), we studied three ATL patients having marked eosinophilia. Eosinophil-predominant colony-stimulating activity was detected in the serum of one patient and in the conditioned media (CM) from cultured ATL cells from two patients. Soluble interleukin 5 (IL-5), but no interleukin 3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF), was detected in sera from all patients. On the other hand, GM-CSF was produced in vitro by ATL cells from all cases, whereas detectable IL-3 and IL-5 was produced by cells from only one, suggesting that in the other two cases, the serum IL-5 was produced by the normal reacting lymphocytes. The fact that no patient showed marked neutrophilia supports the possibility that IL-5 may have a leading role in the development of eosinophilia, with GM-CSF produced by ATL cells playing a complementary role.

Aged↗

A study of adult T-cell leukemia/lymphoma incidence in central Brooklyn.

Adult T-cell leukemia/lymphoma (ATL), a rare outcome of infection with human T-lymphotropic virus (HTLV-I), is endemic in central Brooklyn, which has a large Caribbean migrant population. Previous studies have suggested that HTLV-I prevalence in central Brooklyn may be similar to that recorded in the Caribbean islands. We established a pilot 1-year surveillance program to identify cases of ATL in 7 of 10 hospitals serving the residents of 18 zip codes of central Brooklyn with a combined population of 1,184,670. Of the 6,198 in-patient beds in the catchment area, approximately 83% were covered. Twelve incident cases of ATL were ascertained, all among persons of Afro-Caribbean descent, indicating an annual incidence in African-Americans in this community of approximately 3.2/100,000 person-years. Unexplained hypercalcemia was the most useful screening method, identifying 3 of 5 patients not referred for possible ATL by a local hematologist. The female:male ratio was 3:1. The age pattern was different from that reported in the Caribbean Basin and closer to the pattern seen in Japan. Our study supports evidence that HTLV-I infection and ATL are endemic in central Brooklyn and suggests that a more intensive surveillance program for this disease coupled with intervention efforts to reduce HTLV-I transmission are warranted.

Adult↗

Prognostic significance of the proportion of Ki-67-positive cells in adult T-cell leukemia.

The authors examined peripheral blood samples from patients with adult T-cell leukemia (ATL) using the monoclonal antibody Ki-67 which detects a nuclear antigen present in actively proliferating cells. In patients with chronic ATL, the percentage of Ki-67-positive cells was significantly lower than in acute ATL patients (median values, 3.3% versus 18.9%, P less than 0.001). Furthermore, there was a significant inverse correlation between the percentage of Ki-67-positive cells and the length of survival (P less than 0.001). Serum lactic dehydrogenase (LDH) levels also showed a significant inverse correlation with survival, but this was less strong than that for Ki-67 (0.01 less than P less than 0.02). Thus, Ki-67 positivity appears to indicate the aggressiveness of ATL, and can possibly be used for the clinical classification of ATL patients as well as for the prediction of prognosis.

Antigens, Neoplasm↗

Spontaneous regression in adult T-cell leukemia/lymphoma.

BACKGROUND: Spontaneous regression of adult T-cell leukemia/lymphoma (ATL) is considered to be extremely unusual. Of the 82 patients with ATL who the authors saw between 1981 and 1991, spontaneous regression occurred in 3 (3.7%), 2 of whom were previously untreated and one who had been previously treated. Surgical excisional biopsy triggered the spontaneous regression in these patients. METHODS: In two of these patients with spontaneous regression, gene analysis studies of human T-cell leukemia virus type I (HTLV-I) proviral DNA, and T-cell receptor (TCR) were carried out by Southern blot analysis in lymph node cells or peripheral lymphocytes before regression and after recurrence. RESULTS: One patient exhibited monoclonal integration of HTLV-I proviral DNA and the rearranged band of the TCR-beta gene at the same positions both before regression and after recurrence. The other patient showed them at the different positions before regression and after recurrence. CONCLUSIONS: The authors' studies indicated heterogeneity in ATL patients with spontaneous regression. Temporary spontaneous regression could occur in typical ATL and might be associated with a longer survival time than that for prototypic ATL.

Blotting, Southern↗

Discordance between phenotype and function of Japanese adult T cell leukemia cells.

Phenotypes of cells from 12 patients with ATL were analysed by means of a fluorescence-activated cell sorter by utilizing a panel of monoclonal antibodies. A majority of the cells from peripheral blood coexpressed the antigens against MAbs CD2, CD3, CD4, CD5, Ti (WT31), CD25, CD38, CD45, and CD29, but did not express the antigens against CD1, CD13, CD14, CD33, CD36, CD10, CD19, CD20, CD21, CD24, CD41, CD42, CD45RA, CD56, and CD57. The expression of antigen for TQ-1 or Leu8 was variable. Surface immunoglobulins were not detected. Phenotypes of cultured cells established by utilizing recombinant interleukin II were similar to those of the uncultured peripheral blood lymphoid cells except for the lack of expression of CD8. By means of two-color fluorescence, the ATL cells possessing CD4 in peripheral blood and culture coexpressed CD29, but did not express CD45RA. The suppression of PWM-induced B-cell immunoglobulin synthesis by normal T and B cells was found in five cases in the presence of ATL cells. The ATL cells demonstrated helper T-cell phenotypes (CD4+, CD29+) with suppressor function, paradoxically. We conclude that the phenotype of the ATL cells was CD4+, CD29+, and CD45RA- but that the function of these cells was of suppressor T-cells. Our results inevitably suggest the possible existence of suppressor T-cells with CD4+, CD29+ phenotype in persons without evidence of any underlying hematologic disorder.

Antibodies, Monoclonal↗

Genetic and epigenetic inactivation of tax gene in adult T-cell leukemia cells.

To clarify the status of tax gene, we analyzed human T-cell leukemia virus type-I (HTLV-I) associated cell lines and fresh adult T-cell leukemia (ATL) cells. We compared 2 types of HTLV-I associated cell lines: one was derived from leukemic cells (leukemic cell line) and the other from nonleukemic cells (nonleukemic cell line). Although all nonleukemic cell lines expressed Tax, it could not be detected in 3 of 5 leukemic cell lines, in which nonsense mutation or deletion (60 bp) of tax genes, and DNA methylation in 5'-LTR were identified as the responsible changes. We found such genetic changes of the tax gene in 5 of 47 fresh ATL cases (11%). The tax gene transcripts could be detected in 14 of 41 fresh ATL cases (34%) by RT-PCR. In ATL cases with genetic changes that could not produce Tax protein, the tax gene was frequently transcribed, suggesting that such cells do not need the transcriptional silencing. Although DNA methylation of 5'-LTR was detected in the fresh ATL cases (19 of 28 cases; 68%), the complete methylation associated with transcriptional silencing was observed only in 4 cases. Since partial methylation could not silence the transcription, and the tax gene transcription was not detected in 27 of 41 cases (66%), the epigenetic change(s) other than DNA methylation is considered to play an important role in the silencing.

Acetylation↗

Identifying progression-associated genes in adult T-cell leukemia/lymphoma by using oligonucleotide microarrays.

Adult T-cell leukemia/lymphoma (ATL) is associated with human T-lymphotropic virus type-1 (HTLV-1). To understand the changes in expression that occur in the progression of chronic phase of ATL to acute crisis, the gene expression profiles of fresh ATL cells were compared in 4 pairs of samples (progression of chronic to acute phase in 3 patients, as well as 1 typical chronic phase sample vs. 1 typical acute phase sample) using high-density oligonucleotide DNA arrays. We identified 203 genes that were commonly upregulated in acute vs. chronic phase samples including ribosomal proteins, proteosome subunits, eukaryotic translation factors, immunophilins, heat shock proteins and genes important for DNA replication. Additionally, we identified 91 commonly downregulated genes including immune molecules related to MHC and a phosphatase. Several of the genes were previously identified to be associated with the Tax protein of HTLV-1. Some of the upregulated genes were located in amplified regions identified by comparative genomic hybridization in the corresponding chronic/acute ATL sample. Using real-time quantitative PCR, we confirmed the array-results in those specimens analyzed by microarray. These results demonstrated that distinct sets of genes that are known to be critical in cellular transformation and/or activation are up- or down-regulated during the transition to the acute phase of ATL.

Biomarkers, Tumor↗

Curcumin (diferuloylmethane) inhibits constitutive active NF-kappaB, leading to suppression of cell growth of human T-cell leukemia virus type I-infected T-cell lines and primary adult T-cell leukemia cells.

Adult T-cell leukemia (ATL) is a fatal malignancy of T lymphocytes caused by infection with human T-cell leukemia virus type I (HTLV-I) and remains incurable. Curcumin (diferuloylmethane), the major pigment of the spice turmeric, can be potentially effective by promoting cell apoptosis. Here we examined whether curcumin is effective in the treatment of ATL. Curcumin prevented cell growth of HTLV-I-infected T-cell lines and primary ATL cells but not of normal peripheral blood mononuclear cells. Curcumin induced cell cycle arrest by reducing the expression of cyclin D1, Cdk1 and Cdc25C and apoptosis by reducing the expression of XIAP and survivin. Most of these genes are known to be regulated by NF-kappaB, which plays a critical role in oncogenesis by HTLV-I. Curcumin suppressed constitutive active NF-kappaB of HTLV-I-infected T-cell lines and primary ATL cells by inhibiting phosphorylation of IkappaBalpha. Curcumin also inhibited Tax-induced NF-kappaB transcriptional activity. However, curcumin-induced suppression of cell growth did not correlate with Tax expression level. Curcumin inhibited the growth of HTLV-I-infected T-cell tumors implanted subcutaneously in SCID mice. Our results indicate that curcumin has tumor-suppressive activity against ATL.

Adult↗

Inhibition of heat shock protein-90 modulates multiple functions required for survival of human T-cell leukemia virus type I-infected T-cell lines and adult T-cell leukemia cells.

The molecular chaperone Hsp90 is involved in the stabilization and conformational maturation of many signaling proteins that are deregulated in cancers. The geldanamycin derivative 17-AAG is currently tested in clinical trials and known to inhibit the function of Hsp90 and promote the proteasomal degradation of its misfolded client proteins. ATL is a fatal malignancy of T lymphocytes caused by HTLV-I infection and remains incurable. Since Hsp90 is overexpressed in HTLV-I-infected T-cell lines and primary ATL cells, we analyzed the effects of 17-AAG on cell survival, apoptosis and expression of signal transduction proteins. HTLV-I-infected T-cell lines and primary ATL cells were significantly more sensitive to 17-AAG in cell survival assays than normal PBMCs. 17-AAG induced the inhibition of cell cycle and apoptosis. These effects could be mediated by inactivation of NF-kappaB, AP-1 and PI3K/Akt pathways, as well as reduction of expression of proteins involved in the G1-S cell cycle transition and apoptosis. Proteasome inhibition interfered with 17-AAG-mediated signaling proteins depletion. Collectively, our results indicate that 17-AAG suppresses ATL cell survival through, at least in part, destabilization of several client proteins and suggest that 17-AAG is a potentially useful chemotherapeutic agent for ATL.

Adult↗

Strong induction of ICAM-1 in human T cells transformed by human T-cell-leukemia virus type 1 and depression of ICAM-1 or LFA-1 in adult T-cell-leukemia-derived cell lines.

Sixteen human T-cell lines were studied for the expression of a cell-adhesion molecule ICAM-1 and its counter-receptor LFA-1. The cell lines included 3 human T-cell-leukemia-virus-type-I (HTLV-1)-negative cell lines derived from acute lymphoblastic leukemia (ALL) and 13 HTLV-1-positive cell lines, 7 of them established from cord- or peripheral-blood T cells by in vitro transformation with HTLV-1, 2 derived from HTLV-1 carriers, and 4 derived from patients with adult T-cell leukemia (ATL). In sharp contrast to a basal level of ICAM-1 in 3 HTLV-1-negative ALL cell lines, strong induction of ICAM-1 was seen in all HTLV-1-positive T-cell lines except for MT-1, one of the 4 ATL cell lines used in the present study. On the other hand, the expression of LFA-1 (CD11a and CD18) was more or less similar among the cell lines with and without HTLV-1. Interestingly, however, 3 out of 4 ATL cell lines (TL-Om1, H582, HUT102) revealed striking depression of LFA-1 expression. Several lines of evidence strongly argued against direct involvement of the viral transactivator p40tax or some autocrine cytokines in the induction of ICAM-1 in HTLV-1-positive T-cell lines. It was also found that ICAM-1 and LFA-1 were involved in syncytium formation induced in the co-culture of HTLV-1-positive and HTLV-1-negative human T-cell lines. Implications of constitutive expression of ICAM-1 for certain clinical manifestations of ATL and of depression of either ICAM-1 or LFA-1 during progression of ATL are discussed.

Animals↗