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.     

人白血病细胞株重组激活基因表达及T细胞受体基因重排的检测

背景:淋巴细胞特异性重组激活基因编码的重组激活基因1与重组激活基因2蛋白是参与V(D)J重排机制的重要的重组酶。除参与V(D)J重排以外,近年的研究结果表明重组激活基因介导的转位作用可能与染色体易位及淋巴性恶性肿瘤的发生有关,但迄今尚未有明确定论。目的:检测重组激活基因、DNA修复因子Ku70/Ku80和末端脱氧核苷转移酶mRNA表达以及T细胞受体基因重排在人白血病和淋巴瘤细胞株的发生情况。设计:重复测量实验。单位:南方医科大学生物技术学院分子免疫研究所。材料:T淋巴白血病细胞株Jurkat和6T-CEM购自上海细胞生物研究所;T淋巴白血病细胞株Molt-4,皮肤T细胞淋巴瘤细胞株HuT102,Burkitt’s淋巴瘤细胞株Raji和Daudi以及原髓细胞白血病细胞株HL-60和慢性髓原白血病细胞株K562均由本实验室保存。细胞用含有体积分数0.1胎牛血清的RPMI1640培养基于37℃,体积分数0.05CO2条件下培养。方法:实验于2005-10/2006-01在南方医科大学生物技术学院分子免疫研究所完成。采用反转录聚合酶链反应检测重组激活基因1,重组激活基因2,非同源末端连接装置途径中的DNA修复因子Ku70/Ku80,以及末端脱氧核苷转移酶mRNA表达;采用巢式、半巢式聚合酶链反应、连接介导的聚合酶链反应等方法检测T细胞受体重排删除DNA环和T细胞受体β链重组信号序列两端的断裂点。了解参与V(D)J重排过程的基因表达和T细胞受体基因重排中间体的产生情况。主要观察指标:重组激活基因、DNA修复因子Ku70/Ku80和末端脱氧核苷转移酶mRNA表达以及T细胞受体基因重排在人白血病和淋巴瘤细胞株的发生情况。结果:反转录聚合酶链反应检测结果显示:重组激活基因1mRNA在4种T细胞株中均被检测到,在两种B细胞株和两种髓性白血病细胞株中未检测到;重组激活基因2和末端脱氧核苷转移酶mRNA表达仅在Jurkat,Molt-4和6T-CEM3种T细胞株中检测到,但在6T-CEM表达较弱;除HL-60细胞未检测到Ku80表达外,所有细胞株均检测到Ku70和Ku80表达。对4种T细胞株T细胞受体重排中间体检测结果表明:仅在Jurkat细胞中检测到Dβ2-Jβ2sjTRECs与Dβ25’端和3’RSS断点,表明Jurkat细胞发生T细胞受体基因重排。同时发现JurkatTCRDβ2-Jβ2重排删除环结合区具有明显的多样性特征。结论:重组激活基因可能与T细胞白血病具有更为密切的关系。Jurkat细胞有可能成为研究重组激活基因与T细胞淋巴性肿瘤的一个潜在的细胞模型。     

人白血病细胞株重组激活基因表达及T细胞受体基因重排的检测

背景：淋巴细胞特异性重组激活基因编码的重组激活基因1与重组激活基因2蛋白是参与V（D）J重排机制的重要的重组酶。除参与V（D）J重排以外，近年的研究结果表明重组激活基因介导的转位作用可能与染色体易位及淋巴性恶性肿瘤的发生有关，但迄今尚未有明确定论。目的：检测重组激活基因、DNA修复因子Ku70／Ku80和末端脱氧核苷转移酶mRNA表达以及T细胞受体基因重排在人白血病和淋巴癌细胞株的发生情况。设计：重复测量实验。单位：南方医科大学生物技术学院分子免疫研究所。材料：T淋巴白血病细胞株Jurkat和6T-CEM购自上海细胞生物研究所；T淋巴白血病细胞株Molt-4，皮肤T细胞淋巴癌细胞株HuT102，Burkitt’s淋巴癌细胞株Raji和Daudi以及原髓细胞白血病细胞株HL-60和慢性髓原白血病细胞株K562均由本实验室保存。细胞用含有体积分数0．1胎牛血清的RPMI1640培养基于37℃，体积分数0．05C02条件下培养。方法：实验于2005-10／2006-01在南方医科大学生物技术学院分子免疫研究所完成。采用反转录聚合酶链反应检测重组激活基因1，重组激活基因2，非同源末端连接装置途径中的DNA修复因子Ku70／Ku80。以及末端脱氧核苷转移酶mRNA表达；采用巢式、半巢式聚合酶链反应、连接介导的聚合酶链反应等方法检测T细胞受体重排删除DNA环和T细胞受体B链重组信号序列两端的断裂点。了解参与V（D）J重排过程的基因表达和T细胞受体基因重排中间体的产生情况。主耍观察指标：重组激活基因、DNA修复因子Ku70／Ku80和末端脱氧核苷转移酶mRNA表达以及T细胞受体基因重排在人白血病和淋巴癌细胞株的发生情况。结果：反转录聚合酶链反应检测结果显示：重组激活基因1mRNA在4种T细胞株中均被检测到，在两种B细胞株和两种髓性白血病细胞株中未检测到；重组激活基因2和末端脱氧核苷转移酶mRNA表达仅在Jurkat，Molt-4和6T-CEM3种T细胞株中检测到，但在6T-CEM表达较弱；除HL-60细胞未检测到Ku80表达外，所有细胞株均检测到Ku70和Ku80表达。对4种T细胞株T细胞受体重排中间体检测结果表明：仅在Jurkat细胞中检测到DB2-J132 sjTRECs与DB25’端和3’Rss断点，表明Jurkat细胞发生T细胞受体基因重排。同时发现Jurkat TCR Dβ2-Jβ2重排删除环结合区具有明显的多样性特征。结论：重组激活基因可能与T细胞白血病具有更为密切的关系。Jurkat细胞有可能成为研究重组激活基因与T细胞淋巴性肿瘤的一个潜在的细胞模型。     

T cell receptor alpha-chain gene rearrangements in B-precursor leukemia are in contrast to the findings in T cell acute lymphoblastic leukemia. Comparative study of T cell receptor gene rearrangement in childhood leukemia.

We have analyzed T cell receptor alpha-chain gene configuration using three genomic joining (J) region probes in 64 children with acute lymphoblastic leukemia (ALL). 11 out of 18 T-ALLs were T3 positive; alpha-chain gene rearrangements were demonstrated in only two of 18, indicating that the majority of T-ALLs would have rearrangements involving J alpha segments located upstream of these probes. In contrast, 15 out of 46 B-precursor ALLs showed rearrangements of the alpha-chain gene and J alpha segments located approximately 20-30 kb upstream of the constant region were involved in 13 of these patients. Nine of 15 B-precursor ALLs with rearranged alpha-chain genes had rearrangements of both gamma- and beta-chain genes, whereas the remaining six had no rearrangements of gamma- and beta-chain genes. These findings indicated that alpha-chain gene rearrangement is not specific for T lineage cells and gamma- and/or beta-chain gene rearrangement does not appear essential for alpha-chain gene rearrangement, at least in B-precursor leukemic cells.     

HTLV-1 infection promotes excessive T cell activation and transformation into adult T cell leukemia/lymphoma

Human T cell leukemia virus type 1 (HTLV-1) mainly infects CD4⁺ T cells and induces chronic, persistent infection in infected individuals, with some developing adult T cell leukemia/lymphoma (ATL). HTLV-1 alters cellular differentiation, activation, and survival; however, it is unknown whether and how these changes contribute to the malignant transformation of infected cells. In this study, we used single-cell RNA-sequencing and T cell receptor–sequencing to investigate the differentiation and HTLV-1–mediated transformation of T cells. We analyzed 87,742 PBMCs from 12 infected and 3 uninfected individuals. Using multiple independent bioinformatics methods, we demonstrated the seamless transition of naive T cells into activated T cells, whereby HTLV-1–infected cells in an activated state further transformed into ATL cells, which are characterized as clonally expanded, highly activated T cells. Notably, the greater the activation state of ATL cells, the more they acquire Treg signatures. Intriguingly, the expression of HLA class II genes in HTLV-1–infected cells was uniquely induced by the viral protein Tax and further upregulated in ATL cells. Functional assays revealed that HTLV-1–infected cells upregulated HLA class II molecules and acted as tolerogenic antigen-presenting cells to induce anergy of antigen-specific T cells. In conclusion, our study revealed the in vivo mechanisms of HTLV-1–mediated transformation and immune escape at the single-cell level.     

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.     

Functional and phenotypic studies of Japanese adult T cell leukemia cells.

The cell surface marker profile and functional analysis of peripheral blood lymphocytes from 11 Japanese adult T cell leukemia patients were studied. The phenotypic analysis of Japanese adult T cell leukemia (ATL) cells by a series of 13 monoclonal antibodies showed that all ATL cells are anti-T4 reactive but some differ in their expression of T3, T11, and T12 antigens. Thus, considerable phenotypic heterogeneity exists in these populations of leukemia cells. When analyzed in functional assays, ATL cells were suppressive when added to a pokeweed mitogen- (PWM) driven Ig synthesis system. However, the suppression mechanism seemed to be more complex than originally conceived. ATL cells examined in this study seem to function mainly as an inducer of suppressor cells, and as such, activate normal T8 precursors of suppressor cells rather than function as suppressor effector cells. In addition, no evidence was obtained to suggest that suppression of PWM-stimulated IgG synthesis was mediated by natural killer (NK) activity of ATL cells. Rather, ATL cells seem to be markedly deficient in NK activity. These studies suggest that the majority of ATL cells tested are representative of and seem to be the leukemic counterparts of the T4+ suppressor inducer subset.     

Identification of the human T cell lymphoma virus in B cell lines established from patients with adult T cell leukemia.

Cell lines were established from the peripheral blood of two patients with adult T cell leukemia. In contrast to our previous experience, where all such lines expressed T cell markers, these two cell lines expressed B cell antigens and Ig light chains (kappa on CF-2, lambda on HS). Human T cell lymphoma proviral (HTLV) sequences were demonstrated in both cell lines. Since only a portion of the cells in culture expressed Ig light chains, experiments were carried out to exclude the possibility that the cultures were not a mixture of B and T or non-B cells. Cells that expressed kappa- or lambda-light chains were separated by cell sorting from kappa- or lambda-negative cells and replaced in culture. Light chain negative cells reexpressed light chains after time in culture. After 5-azacytidine treatment of the cell lines, all cells expressed Ig light chains. These studies show that the human retrovirus HTLV, which has been demonstrated to be associated with certain T cell malignancies, can infect B cells or B cell precursors.     

Interleukin 1 gene expression in cultured human keratinocytes is augmented by ultraviolet irradiation.

Interleukin 1 (IL-1) is a family of polypeptides initially found to be produced by activated monocytes and macrophages that mediate a wide variety of cellular responses to injury and infection. Epidermal epithelial cells (keratinocytes) produce "epidermal cell-derived thymocyte activating factor" or ETAF, which has been recently shown to be identical to IL-1. Human epidermis is normally exposed to significant amounts of solar ultraviolet radiation. Certain ultraviolet wavelengths (UVB, 290-320 nm) are thought to be responsible for most of the immediate and long-term pathological consequences of excessive exposure to sunlight. In this study, we asked whether exposure to UVB irradiation induced IL-1 gene expression in cultured human keratinocytes. Cultured human keratinocytes contain detectable amounts of IL-1 alpha and beta mRNA and protein in the absence of apparent stimulation; these levels could be significantly enhanced 6 h after exposure to 10 ng/ml of 12-O-tetradecanoyl-phorbol-13-acetate (TPA). Exposure to UVB irradiation with an emission spectrum comparable to that of sunlight (as opposed to that of an unfiltered artificial UV light source) significantly increased the steady state levels IL-1 alpha and beta mRNA in identical populations of human keratinocytes. This was reflected in the production of increased IL-1 activity by these cultures in vitro. In the same cell population, exposures to UVB irradiation did not alter the level of actin mRNA; therefore, the effect of UV irradiation on IL-1 represents a specific enhancement of IL-1 gene expression. Local increases of IL-1 may mediate the inflammation and vasodilation characteristic of acute UVB-injured skin, and systemic release of this epidermal IL-1 may account for fever, leukocytosis, and the acute phase response seen after excessive sun exposure.     

BP1基因在成人急性白血病中的表达

目的　研究 β蛋白 1(BP1)基因在成人急性白血病中的表达并分析与急性白血病的关系。方法　用RT PCR方法分别检测 70例急性白血病患者、10名健康对照者及HEL细胞系中BP1基因的表达。结果　在正常人外周血、骨髓和完全缓解的患者骨髓中均没有检测到BP1基因的表达 ;在急性髓系白血病 (AML)中BP1表达阳性率为 5 7% (35例中 2 0例 ) ,在AML M5中阳性率高达 80 % (10例中 8例 ) ;在急性淋巴细胞白血病中无表达。结论　BP1与AML有一定的相关性 ,可作为AML的一种分子标志。     

Interleukin 2 upregulates expression of its receptor on a T cell clone

Stimulation of a class II-restricted, antigen-specific T cell clone with interleukin 2 (IL-2) resulted in substantial increases in both cell surface IL-2 receptor (IL-2-R) and cytoplasmic IL-2-R messenger RNA (mRNA), whereas no increase was observed for cell-surface expression of Thy-1 and L3T4 antigens, and only a modest increase in Thy-1 mRNA was observed. These experiments demonstrate that, after initial acquisition of the IL-2-R, IL-2 as well as antigen is able to directly upregulate both the level of IL-2-R mRNA and cell surface IL-2-R molecules.     

WT1基因表达对K562、HL-60细胞增殖作用的研究

目的：探讨ＷＴ１基因反义ＲＮＡ对髓系白血病细胞生长增殖和细胞凋亡的影响及作用机制。方法：用ＷＴ１基因反义ＲＮＡ培养Ｋ５６２、ＨＬ６０细胞，用氮蓝四氮唑盐染色、流式细胞仪检测、逆转录聚合酶链反应等方法观察细胞增殖、凋亡、细胞动力学和基因表达情况。结果：ＷＴ１反义ＲＮＡ可以特异性抑制Ｋ５６２细胞增殖，诱导Ｋ５６２、ＨＬ６０细胞凋亡；对ＨＬ６０细胞的增殖无影响，对ＷＴ１、ｂｃｌ２、ｍｄｍ２基因表达无显著影响。结论：ＷＴ１基因与白血病细胞的增殖、凋亡密切相关，对白血病细胞凋亡的影响与ｐ５３、ｂｃｌ２基因无关。     

Therapy-induced selective loss of leukemia-initiating activity in murine adult T cell leukemia

Chronic HTLV-I (human T cell lymphotropic virus type I) infection may cause adult T cell leukemia/lymphoma (ATL), a disease with dismal long-term prognosis. The HTLV-I transactivator, Tax, initiates ATL in transgenic mice. In this study, we demonstrate that an As(2)O(3) and IFN-α combination, known to trigger Tax proteolysis, cures Tax-driven ATL in mice. Unexpectedly, this combination therapy abrogated initial leukemia engraftment into secondary recipients, whereas the primary tumor bulk still grew in the primary hosts, only to ultimately abate later on. This loss of initial transplantability required proteasome function. A similar regimen recently yielded unprecedented disease control in human ATL. Our demonstration that this drug combination targeting Tax stability abrogates tumor cell immortality but not short-term growth may foretell a favorable long-term efficiency of this regimen in patients.