Use of cell-free retroviral vector preparations for transduction of cells from the marrow of chronic phase and blast crisis chronic myelogenous leukemia patients and from normal individuals.

Marrow cells were exposed to the LNL6 or G1N safety-modified variants of the N2 retrovirus, which contain the G418 bacterial resistance gene neo. The frequency of acquisition of the G418 resistance phenotype following exposure to LNL6 or G1N was compared among hematopoietic progenitor cells from the marrow of patients with chronic phase chronic myelogenous leukemia (CML), blast crisis CML, or from nonleukemic individuals. Under the conditions of our experiments, the myeloid committed progenitor cells from 3 of 6 nonleukemic individuals, 9 of 18 chronic-phase CML patients, and 2 of 4 blast crisis CML patients acquired resistance to at least 1 mg/ml G418 following incubation with cell-free supernatants from the PA317 LNL6 or PA317 G1N producer cell lines. Ten of the 32 colonies growing up in 0.8 mg/ml G418 from chronic-phase marrow exposed to LNL6 were shown to contain the neo gene by polymerase chain reaction (PCR) assay of DNA. These results were consistent with estimates of the transduction frequency based on acquisition of resistance to G418 as the number of colonies growing under G418 selection was always greater at 0.8 mg/ml G418 than at higher concentrations of G418 (1.0-1.4 mg/ml). The average transduction frequency at each G418 concentration (1.0, 1.2, and 1.4 mg/ml) in cells from blast crisis CML cells ranged from 2 to 14%, as measured by acquisition of G418 resistance. Chronic-phase CML showed slightly lower average frequencies of transduction (0.6-2.8% of the colonies are G418 resistant). The average transduction frequency of cells from nonleukemic marrow was as high as that seen from the marrow of chronic-phase CML individuals.(ABSTRACT TRUNCATED AT 250 WORDS)     

Retrovirus-mediated gene transfer as an approach to analyze neuroblastoma relapse after autologous bone marrow transplantation.

Disseminated neuroblastoma is a malignancy of children often treated by intensive chemotherapy/radiotherapy followed by autologous bone marrow transplantation (ABMT). A high proportion of those treated subsequently relapse. It is unknown if relapse is a consequence of residual disease in the patient or of contaminating malignant cells remaining in the infused marrow, which, of necessity, is harvested and stored prior to ablative chemotherapy/radiotherapy. The assumption that residual cells in the infused marrow contribute to relapse has lead to the adoption of marrow purging prior to reinfusion. However, neither the necessity nor the efficacy of the procedure have been established. We now show how retroviral-mediated gene transfer using the LNL6 vector may resolve this issue. Clonogenic neuroblastoma cells in patient marrow can be transduced and the NEOR gene detected by observing individual neuroblastoma cell colony growth in G418, and by polymerase chain reaction (PCR) of individual colonies. Efficiency of transduction is between 0 and 13.5%. If marrow is exposed to LNL6 prior to infusion and marked cells are detected at the time of relapse, this would demonstrate that infused marrow contributed to disease recurrence. The technique could then be used to analyze the efficacy of marrow purging techniques. Since normal progenitor cells from these patients are also marked, the technique can be used to study factors that modify reconstitution and transducibility of infused marrow. Clinical studies using this approach have now begun.     

L-histidinol provides effective selection of retrovirus-vector-transduced keratinocytes without impairing their proliferative potential.

Retroviral vectors carrying the neomycin phosphotransferase (neo) gene have been shown to confer G418 resistance to canine keratinocytes at relatively high frequency. To investigate the usefulness of keratinocytes as potential target cells for gene therapy, we used a retroviral vector (LASN) that contains both human adenosine deaminase (hADA) and neo genes. We show here that LASN-transduced canine keratinocytes expressed high levels of hADA, a human protein of therapeutic relevance. Selection of LASN-transduced keratinocytes in medium containing G418 resulted in a population of cells that expressed even higher levels of hADA, about 80-fold higher than the endogenous canine ADA level. However, the G418-selected cells had a reduced proliferative potential and altered morphology indicative of terminal differentiation. To test whether L-histidinol is more beneficial for selection of keratinocytes than G418, we constructed two retroviral vectors that contain both the neo and the histidinol dehydrogenase (hisD) genes. Cocultivation of primary keratinocytes with lethally irradiated PA317 retrovirus packaging cells that produce these vectors gave rise to 12-53% drug-resistant colonies in either G418 or L-histidinol. In contrast to G418, selection of transduced keratinocytes in L-histidinol had no apparent effect on the proliferative potential or morphology of drug-resistant cells containing the vectors. Given the utility of this selection system, two hisD-based generic constructs containing cloning sites for cDNA expression from either the retroviral promoter or from an internal human cytomegalovirus immediate early promoter were constructed. Our results suggest that hisD will be a useful selectable marker for use in studies of keratinocyte differentiation and for transfer of genes into keratinocytes for the purposes of gene therapy.     

稳定表达bcr-abl融合基因片段的鼠SP2/0细胞系的建立

为了建立稳定表达bcr-abl融合基因片段的SP2/0细胞系,从重组克隆载体pGEMbcr-abl中酶切出bcr-abl融合基因片段,并将其亚克隆进逆转录病毒载体pLXSN中。脂质体介导重组逆转录病毒载体pLXSNbcr-abl转染包装细胞PT67,采用G418筛选后获得稳定产病毒的包装细胞。收集病毒感染NIH/3T3细胞,加G418筛选后进行逆转录病毒滴度的测定,计算病毒效价为2×107CFU/ml。结果表明,收集病毒上清感染SP2/0细胞(H-2d),经G418筛选获得了稳定表达bcr-abl融合基因片段的SP2/0细胞株。经特异性PCR扩增和RT-PCR反应扩增,从基因组整合和基因表达水平证实获得了能稳定表达bcr-abl融合基因片段的鼠SP2/0细胞系。结论:成功建立了表达bcr-abl融合基因的鼠SP2/0细胞系,这一肿瘤细胞模型可作为研究bcr-abl基因疫苗的有效实验工具,为检验bcr-abl基因疫苗激发小鼠CTL应答的研究奠定物质基础。     

Simultaneous use of two retroviral vectors in human gene marking trials: feasibility and potential applications.

Two Moloney murine leukemia virus (Mo-MLV)-based neoR retroviral vectors--LNL6 and G1Na--were used to transduce various human tumor-infiltrating lymphocytes (TIL) populations. These groups included bulk CD(8+)- and CD(4+)-enriched TIL from human renal cell carcinomas and melanomas. Transduction efficiencies averaged 5% for single 4-hr supernatant infections. Integrated provirus could be detected for up to 4 weeks of in vitro culture. LNL6 provirus could be distinguished from G1Na provirus using specific polymerase chain reaction (PCR) primers. A single neomycin phosphotransferase (neoR) gene copy could be detected in 10(5) TIL. Using quantitative PCR, the relative ratio of LNL6 to G1Na copies in the same sample could be determined even at low copy numbers. These preclinical studies demonstrate the feasibility of using two retroviral marking vectors in human gene therapy efforts.     

逆转录病毒介导转导的人粒-巨噬系集落刺激因子基因在哺乳动物细胞中的表达(英文)

利用多聚酶链反应(PCR)方法,从活化的人外周血单个核细胞中克隆了人粒-巨噬系集落刺激因子(GM-CSF)的cDNA。DNA序列测定证实此片段为完整的GM-CSF cDNA。应用DNA重组技术,将此cDNA重组于逆转录病毒载体pDORneo上,以Lipofectin介导转染病毒包装细胞PA317,用NIH3T3细胞测定病毒滴度。选取高滴度病毒上清感染中国仓鼠卵巢(CHO)细胞,经G418筛选获抗性克隆,PCR方法鉴定重组载体整合于CHO细胞的基因组DNA中。用CFU-GM集落形成实验检测GM-CSF活性,证实转染后的CHO细胞有GM-CSF的稳定、高效表达。     

慢性粒细胞白血病患者胸腺输出功能与bcr-ab1 mRNA水平的关系

本研究了解慢性粒细胞白血病（chronic myelogenous leukemia，CML）患者体内T细胞受体重排删除环（T cell receptor rearrangement excision circles，TREC）的含量与bcr-ab1 mRNA水平的关系，进而明确CML患者的胸腺近期输出功能测定对疾病预后判断的意义。实时定量PCR检测15例CML—CP患者外周血TREC含量及bcr-ab1融合基因转录本的水平，并追踪检测6例患者bcr—ab1水平的变化。结果发现：在CML初发时患者外周血TREC含量与bcr—ab1融合基因水平无明显的相关性；随访2年后，TREC含量高的患者bcr—ab1水平下降幅度更大，而在接受造血干细胞移植的2例患者中，移植前TREC含量相对较高者，移植1年后连续3次均检测不到bcr—ab1，另1例则检测到低水平的bcr—ab1。结论：CML患者胸腺输出功能较高者，可能对机体抵抗残留CML细胞有一定的帮助。     

定量检测bcr-abl mRNA在慢性粒细胞白血病患者异基因造血干细胞移植后的意义

本研究确切了解CML患者异基因造血干细胞移植后bcr-abl mRNA的变化情况,为临床诊断早期复发提供实验依据。用实时荧光定量PCR方法检测15例慢性粒细胞白血病(CML)患者异基因造血干细胞移植前后78份外周血和骨髓标本的bcr-abl mRNA水平。结果表明,移植前患者的bcr-ablmRNA水平较高,中位数为29.303%;移植后1个月时检测bcr-abl mRNA水平较移植前大幅度降低,中位数为0;移植后1年内,连续多次检测bcr-abl mRNA水平,变化模式不一致,但6个月后的总体水平较6个月前明显降低,移植1年以上的受者绝大多数bcr-abl mRNA检测不到,或偶可检测到,但水平极低(0.007%、0.004%和0.021%),所检测受者的骨髓和外周血像均正常;同期骨髓与外周血bcr-abl水平无明显差异,且变化趋势一致。结论:CML患者移植后早期bcr-abl水平变化起伏较大,连续动态检测可明确其变化趋势,有助于判断移植效果、指导临床治疗,但6个月前检测到bcr-abl存在并不提示疾病复发;检测外周血bcr-abl或许更适于临床上对患者的随访。     

CD3AK/iNOS细胞对慢性粒细胞原代细胞白血病体外净化效应

本研究旨在探讨免疫细胞性一氧化氮供体CD3AK/iNOS细胞对慢性粒细胞白血病(CML)原代白血病 细胞的体外净化效应。培养并扩增PA317/iNOS细胞并用G418筛选;用NIH3T3细胞测定病毒滴度,分离外周血 单个核细胞并用抗CD3单克隆抗体激活;病毒感染靶细胞CD3AK及用G418筛选,用逆转录-聚合酶链反应 (RT PCR)检测CD3AK/iNOS中iNOScDNA的转录;用硝酸还原酶法检测CD3AK/iNOS细胞培养上清中NO含 量以及iNOS活性;用系列稀释半定量巢式RT PCR检测CML患者白血病原代细胞经CD3AK/iNOS细胞净化后 bcr/abl融合基因的表达水平。结果表明,PA317/iNOS细胞能稳定合成并分泌重组逆转录病毒颗粒;NIH3T3细胞 测定病毒滴度为1.0×105CFU/ml;RT PCR检测发现CD3AK/iNOS细胞中有iNOScDNA的转录;CD3AK/iNOS 细胞培养上清中NO含量和iNOS活性较CD3AK细胞明显升高。上述两项指标,经统计学检验,均有显著性差异 (P<0.001,P<0.001)。系列稀释半定量RT PCR检测发现,经CD3AK/iNOS细胞净化后CML患者白血病细胞 bcr/abl融合基因的表达明显下调。实验结果统计分析表明,CD3AK/Neo细胞组净化后与CD3AK/iNOS细胞组净 化后bcr/ablmRNA表达的比较具有显著性差异(P<0.001)。结论:逆转录病毒可介导iNOS基因转入CD3AK细 胞,成功地构建了CD3AK/iNOS;CD3AK/iNOS能明显地增加NO含量和iNOS活性,应用CD3AK/iNOS可能成 为一个有效的AHSCT体外净化方法。     

bcr—abl融合基因及其检测

bcr-abl融合基因位于染色体t(9;22)(q34;q11),由位于9号染色体上的细胞原癌基因abl部分序列从其正常位置易位至22号染色体的BCR区而形成。在绝大多数病例中,断裂点集中在5.8 kb的M-BCR区,主要形成b2a2和b3a2二种形式的转录物及蛋白质,二者差异仅为75个碱基及25个氨基酸。bcr-abl融合基因及其表达的检测对CML有重要的诊断与预后价值。用Southern印迹杂交、间期或中期染色体原位杂交等方法检测DNA,发现Ph阴性或变异型Ph病人存在bcr-abl融合基因,检测到许多新的融合类型,并确认异基因BMT后白血病的复发是源于自身MRL。用优化的RT-PCR,定量RT-PCR或RNA原位杂交检测RNA,可精确定位罕见或混合的接合型,还发现正常人中bcr-abl基因有低量表达且有随年龄增长而增加的趋势。用Western印迹或酶联免疫反应检测,发现BCR-ABL蛋白与C-ABL蛋白之比在外周血与骨髓中相似且与Ph染色体重排率有线性关系,还发现如果P190继P210之后出现,则CML的预后很差。     

实时定量RT-PCR监测慢性粒细胞白血病患者造血干细胞移植后bcr-abl mRNA水平

目的评价实时定量RT—PCR（Q—PCR）技术用于监测慢性粒细胞白血病（CML）患者异基因造血干细胞移植（HSCT）疗效的意义。方法采用基于TaqMan探针的Q—PCR技术检测112例CML患者HSCT后不同时间共316份骨髓标本bcr—abl mRNA的表达。bcr—abl mRNA水平以内参基因abl进行归一化。采用荧光原位杂交法（FISH）评估HSCT后是否达细胞遗传学完全缓解（CCyR）。结果Q-PCR实验可重复敏感度为5个拷贝。abl及bcr—abl基因CT值的批内差及批问差均〈2．0％。HSCT后1个月开始持续处于CCyR状态的101例患者，中位跟踪时问为12（6—60）个月的289份标本表现为HSCT后各时间段均有一定数量患者可检测出bcr-abl mRNA，总体上随着HSCT时间延长，中位水平逐渐降低。HSCT后1个月中位bcr—abl水平为0．035％（0～0．406％），较本室资料初治CML慢性期患者中位水平降低3个对数级，3个月时为0．006％（0～0．683％），6个月开始降至0％（0—0．225％），移植6个月后标本最高bcr—abl水平为0．068％。8例患者HSCT后未达CCyR或遗传学复发时bcr—abl水平为0．12％～13．45％，其中5例患者遗传学复发前的1份标本（复发前1—2个月）bcr—abl水平为0．09％-3．42％。9例持续CCyR患者bcr-abl水平曾经〉0．090％，但随后均下降至0。2例急变期患者HSCT后1．6和3个月内持续CCyR，但分别于1个月和1．5个月后进展为血液学复发，ber—abl水平亦从0及0．140％分别急剧增至46．900％和75．900％。结论Q—PCR技术精确、可靠，对CML患者HSCT后有必要定期系列监测ber—abl水平，以及时了解病情变化。对急变期患者需要更密切的监测。     

慢性粒细胞白血病异基因造血干细胞移植后bcr-abl动态监测对低复发患者筛选的意义

目的 寻找慢性粒细胞自血病(CML)患者异基因造血干细胞移植(allo-HSCT)后早期bcr-abl的动态变化规律,以识别不需要十预的低复发患者.方法 2004年11月至2006年11月在我院接受allo-HSCT的CML患者149例.移植前后采用实时定量PCR方法定期监测骨髓bcr-abl转录本的水平,计算未干预组患者各时间点的bcr-abl中位值,并采用Mann-Whitney U比较同一时间点不同移植模式下的bcr-abl水平.采用Kaplan-Meier曲线计算复发率、生存率和移植物抗宿主病(GVHD)发生率.结果 149例患者2年总生存率为86.0%(CI:82.9%～89.1%),累积血液学复发率为3.5%(CI:1.7%～5.3%).未干预组患者102例,bcr-abl水平中位值:移植前25.800%(0.067%～96.100%),+1个月0.025%(0～3.583%),+2个月0.011%(0～0.425%),+3个月0.002%(0～0.610%),+4个月为0(0～0.056%).本组患者至随访结束无一例复发.未干预组患者HLA配型不合组、配型相合组和非血缘关系移植组分别于移植后3、4和5个月bcr-abl下降至不能检测出其水平.结论 CML患者allo-HSCT后bcr-abl的动态监测有助于筛选出无须干预的CML患者.     

Role of Dok-1 and Dok-2 in myeloid homeostasis and suppression of leukemia

Dok-1 and Dok-2 are closely related rasGAP-associated docking proteins expressed preferentially in hematopoietic cells. Although they are phosphorylated upon activation of many protein tyrosine kinases (PTKs), including those coupled with cytokine receptors and oncogenic PTKs like Bcr-Abl, their physiological roles are largely unidentified. Here, we generated mice lacking Dok-1 and/or Dok-2, which included the double-deficient mice succumbed to myeloproliferative disease resembling human chronic myelogenous leukemia (CML) and chronic myelomonocytic leukemia. The double-deficient mice displayed medullary and extramedullary hyperplasia of granulocyte/macrophage progenitors with leukemic potential, and their myeloid cells showed hyperproliferation and hypo-apoptosis upon treatment and deprivation of cytokines, respectively. Consistently, the mutant myeloid cells showed enhanced Erk and Akt activation upon cytokine stimulation. Moreover, loss of Dok-1 and/or Dok-2 induced blastic transformation of chronic phase CML-like disease in mice carrying the bcr-abl gene, a cause of CML. These findings demonstrate that Dok-1 and Dok-2 are key negative regulators of cytokine responses and are essential for myeloid homeostasis and suppression of leukemia.     

PY20抗体检测bcr-abl阳性细胞内磷酸化酪氨酸的临床应用

目的探讨酪氨酸磷酸化抗体 PY20检测 bcr-abl 阳件细胞的特异性及其可能的临床应用。方法采用多色直接免疫荧光标记方法,同时标记膜 CD45和胞质 PY20抗体,应用流式细胞术检测 bcr-abl 阳性细胞系(K562、MEG-01)和阴月性细胞系(Jurkat、MCF-7)的酪氨酸磷酸化水平。并利用bcr-abl 蛋白酪氨酸磷酸化特异性阻断剂伊马替尼作用 K562细胞和 MEG4-01细胞,观察 PY20抗体的特异性。检测了49例白血病患者和3名正常人的骨髓细胞,包括慢性粒细胞白血病(CML)、Ph~+急性淋巴细胞白血病(Ph~+ ALL)、Ph~- ALL、急性髓系白血病、慢性淋巴细胞白血病。PY20~+细胞占白血病细胞群的10%以上定义为阳忡。以阳性细胞的平均荧光强度(MFI)表示其酪氨酸磷酸化水平。结果bcr-abl 阳性细胞系、10例初诊 CML 和8例 Ph~+ALL 患者 PY20抗体均为阳性,而 bcr-abl 阴性细胞系、20例 bcr-abl 阴性白血病患者和3名正常人 PY20抗体均为阴性。伊马替尼作用后 K562细胞和MEG-01细胞的酪氨酸磷酸化水平随作用时间的延长逐渐下降。10例初诊和9例伊马替尼治疗有效的 CML 患者 PY20~+细胞占有核细胞的比例分别为(54.20±19.82)%和(14.84±6.17)%(P<0.05),而2例伊马替尼耐药者 PY20~+细胞比例分别为64.3%和57.2%。2例伊马替尼耐药患者和9例伊马替尼治疗有效患者的 CML 细胞的 MFI 分别为99.42±4.87和46.41±4.67(P<0.01)。结论酪氨酸磷酸化抗体 PY20对 bcr-abl 阳性细胞具有相对特异性,有可能应用于 bcr-abl 阳性疾病如 CML 和Ph~+ALL 的早期快速辅助诊断,同时有可能作为判断该类疾病对伊马替尼敏感性的一个辅助指标。     

Comparison of the effects of growth factors on retroviral vector-mediated gene transfer and the proliferative status of human hematopoietic progenitor cells

We have examined the ability of the recombinant hematopoietic growth factors (HGF) interleukin-3 (IL-3), IL-6, and granulocyte-macrophage colony-stimulating factor (GM-CSF) to increase retroviral vector-mediated gene transfer into human hematopoietic progenitor cells (HPC). The efficiency of neo gene transfer by the N2 vector into human HPC was enhanced by preculture with either GM-CSF or IL-3 (but not IL-6) and with each combination of the three factors. The combination of IL-3 plus IL-6 consistently produced significantly higher levels of G418-resistant colonies (50-60%) than any of the other combinations of HGF tested. Following preculture with HGF and transduction by N2, marrow was maintained in long-term bone marrow culture (LTBMC) for 2 months. The levels of G418-resistant HPC remained stable, and no apparent depletion of total HPC content resulted from the prior exposure to highly stimulatory doses of factors. The proliferative status of the HPC, following exposure to the HGF, was measured as the percentage of HPC that were inhibited from forming colonies by exposure to the S-phase-specific drug, hydroxyurea. The ability of the different HGF to increase the rate of gene transfer by N2 correlated significantly with the extent to which they stimulated HPC proliferation. These results suggest that the mechanism by which HGF increase rates of gene transfer into HPC is by stimulating cell proliferation. Techniques that produce high rates of gene transfer into long-lived human HPC will facilitate studies to quantitate expression of exogenous genes in hematopoietic cells and may be applicable to clinical gene therapy.     

Genetically modified donor leukocyte transfusion and graft-versus-leukemia effect after allogeneic stem cell transplantation

Seven patients with acute myeloid leukemia (AML) and two patients with chronic myelogenous leukemia (CML) were transplanted from HLA-identical sibling donors with CD34(+) cell-enriched stem cells (HSCTs) without further immunosuppression. The myeloablative standard transplantation protocol was adapted to include transfusion of gene-modified donor T cells after HSCT. Donor T cells were transduced with the replication-deficient retrovirus SFCMM-3, which expresses herpes simplex thymidine kinase (HSV-Tk) and a truncated version of low-affinity nerve growth factor receptor (ΔLNGFR) for selection and characterization of transduced cells. Transduced T cells were detectable in all patients during follow-up for up to 5 years after transfusion. Proteomic screening for development of acute graft-versus-host disease (aGvHD) was applied to five of the seven patients with AML. No positivity for the aGvHD grade II-specific proteomic pattern was observed. Only one patient developed aGvHD grade I. To date, three of the patients with AML relapsed; one responded to three escalating transfusions of lymphocytes from the original donor and is in complete remission. Two were retransplanted with non-T cell-depleted peripheral blood stem cells from their original donors and died after retransplantation of septic complications or relapse, respectively. In one patient with CML, loss of bcr-abl gene expression was observed after an expansion of transduced cells. Seven of nine patients are alive and in complete remission.     

成人慢性髓性白血病骨髓细胞血管内皮生长因子的表达

血管生成出现于实体瘤生长的早期,抗血管生成可能成为治疗实体瘤的一个新的策略。血管内皮生长因子（vascular endothelial growth factor,VEGF）是人类实体瘤中主要的促血管生成细胞因子之一,其在慢性髓性白血病（chronic myelogenous leukemia,CML）病程进展中是否呈现过度表达尚不清楚。为此,本研究采用RT-PCR和ELISA方法对CML病人骨髓细胞及血浆VEGF的表达进行了研究。结果表明,多数CML细胞、白血病细胞系及正常人骨髓细胞均表达VEGF,CML病人VEGF mRNA检测阳性率（93.1%)高于骨髓移植后的CML病人（50%）及正常人（60%）;未治CML病人血浆VEGF浓度（380.6pg/ml）比CML骨髓移植后病人血浆的VEGF浓度（38.0%pg/ml)高9倍;未治CML骨髓细胞分泌的VEGF（499.8pg/ml)比正常人骨髓细胞分泌的（141.3pg/ml)多2.5倍,两之间有显性差异（P＜0.05)。研究结果说明VEGF在CML病人中确实存在过度表达,其在CML发病机制中的作用值得进一步深入研究。     

急性白血病患者HLA半倍相合骨髓移植后供者源复发2例

为了探讨半倍相合骨髓移植后急性白血病患者的复发情况，对2例接受半倍相合骨髓移植后出现白血病复发的急性白血病患者进行了外周血、骨髓检查、骨髓细胞形态观察及HLA基因型和染色体核型分析。结果发现。2例原发病分别为急性淋巴细胞白血病（普通细胞型）和急性巨核细胞白血病，且2例白血病细胞均有染色体畸变或癌基因突变、活化，2例骨髓移植后完全供者源造血重建，但2例复发后白血病细胞均来源于供者源，血型和HLA分型均为供者型，复发后2例诊断为急性淋巴细胞白血病（B细胞型）和急性巨核细胞白血病。这一结果提示，供者源复发可能与移植后应用大剂量免疫抑制剂有关，化疗、放疗以及受者本身造血微环境异常也可能参与了二次白血病的发生过程。异基因造血干细胞移植后供者源复发可能是研究人白血病发生的适宜模式。     

Generation of chronic myelogenous leukemia-specific T cells in cytokine-modified autologous mixed lymphocyte/tumor cell cultures.

Chronic myelogenous leukemia (CML) may be amenable to cell-based adoptive immunotherapy, as suggested by the graft-versus-leukemia effect of bone marrow transplantation and the therapeutic benefit of donor leukocyte infusions. Specific adoptive immunotherapy without bone marrow transplantation might be more effective and less cost-intensive. Professional antigen-presenting cells, the dendritic cells, from patients with CML are derived from the malignant clone and may stimulate antileukemia T-cell responses. Autologous T cells may also be able to recognize tumor antigens on CML cells directly. Here, the authors show that CD4 and CD8 T-cell responses to autologous CML cells can be generated in vitro rapidly and effectively by performing modified autologous mixed lymphocyte/tumor cell cultures (MLTC) in serum-free medium in the presence of cytokines known to support dendritic cell differentiation. MLTC-sensitized T cells secreted large amounts of the type 1 cytokine interferon-gamma, as well as interleukin (IL)-2. However, they also secreted a variety of other cytokines, including the type 2-subtype cytokine IL-13 but not the classic type 2 cytokines IL-4, IL-5, and IL-10. Monoclonal populations of CML-specific CD4 cells could be derived from these lines in limited numbers but showed markedly enhanced reactivity. This suggests that CML-specific T cells are relatively rare in these autologous MTLC-derived sensitized populations, but that their isolation and propagation would yield much more potent antitumor effector cells for use in adoptive immunotherapy without the need for bone marrow transplantation.