移植GM—CSF基因修饰的骨髓细胞对小鼠造血恢复的影响

探索粒-巨噬细胞集落刺激因子(GM-CSF)基因修饰的骨髓细胞促进照射鼠骨髓移植后造血功能恢复的可行性。通过基因转移造血细胞进行骨髓移植的小鼠模型动态观察移植鼠外周血细胞数量、肝脾及骨髓形态学,CFU-S,CFU-GM及血清GM-CSF活性的变化。结果表明,实验组小鼠外周血白细胞与中性粒细胞计数,CFU-S及脾脏CFU-GM明显高于对照组(P<0.05),而各组间骨髓CFU-GM计数无显著性差异(P>0.05);组织学显示实验小鼠肝脾造血组织明显增多,而各组间骨髓象改变不大,并且血清GM-CSF活性也较对照组明显升高(P<0.01)。结论提示,给γ射线照射小鼠移植GM-CSF基因修饰的骨髓造血细胞能显著加快造血恢复的过程。     

异基因骨髓移植小鼠联合输注IL-3/IL-6双基因转导的骨髓基质细胞促进造血恢复

探讨用逆转录病毒载体转入IL 3和IL 6双基因的骨髓基质细胞系QXMSC1IL 3/IL 6对异基因骨髓移植小鼠造血功能的促进作用。用逆转录病毒载体 (含小鼠IL 3cDNA ,人IL 6cDNA)分别转导到骨髓基质细胞系QXMSC1(H 2 d) ,构建骨髓基质细胞系QXMSC1IL 3/IL 6。供体小鼠BALB/c(H 2 d)骨髓去除骨髓中T细胞 ,受体小鼠C57BL/6(H 2 b)经γ射线致死量照射后 ,输入去除T细胞的供体骨髓 (1× 1 0 7/鼠 )的同时输入骨髓基质细胞QXMSC1IL 3/IL 6(5× 1 0 5/鼠 )。在骨髓移植后 2 0和 40天 ,分别检测骨髓移植小鼠外周血RBC ,WBC和骨髓有核细胞数及骨髓中CFU S ,CFU GM ,CFU E和CFU GEMM数。结果 :异基因骨髓移植共输入QXMSC1IL 3/IL 6基质细胞系可使异基因骨髓移植小鼠外周血RBC ,WBC数明显恢复 ,骨髓中有核细胞数 ,CFU S ,CFU GM ,CFU E和CFU GEMM明显增加。基质细胞系QXMSC1可作为有效的基因载体促进骨髓移植后造血功能重建。结论 :基质细胞转入细胞因子IL 3或IL 6基因可以进一步促进骨髓移植后造血功能重建 ,联合转导IL 3和IL 6有协同作用     

转染IL-3基因的骨髓基质细胞促进骨髓移植小鼠造血功能重建

为了探讨可调控表达IL 3基因的骨髓基质细胞系对异基因骨髓移植小鼠造血功能重建的促进作用 ,建立了可诱导表达IL 3基因的工程化骨髓基质细胞系QXMSC1tet on +IL 3,加入多西环素 (Dox)诱导骨髓基质细胞系表达IL 3并检测其活性。C5 7BL/ 6 (H 2 b)小鼠经γ射线致死剂量照射后 ,输入供体BALB/C(H 2 d)小鼠去除T细胞的骨髓细胞 1× 10 7/只 ,同时输注骨髓基质细胞QXMSC1tet on +IL 35× 10 5/只 ,并灌服多西环素诱导IL 3表达。在第 30天 ,6 0天检测骨髓移植小鼠外周血红细胞 ,白细胞数 ,骨髓有核细胞数 ,骨髓CFU S ,CFU GM ,CFU E和CFU GEMM数。结果表明 :成功建立可诱导表达IL 3基因的骨髓基质细胞系QXMSC1tet on +IL 3,异基因骨髓移植共输注基质细胞系QXMSC1tet on +IL 3可使异基因骨髓移植小鼠外周血红细胞、血小板、白细胞明显恢复 ,骨髓中有核细胞数 ,CFU S ,CFU GM ,CFU E ,CFU GMEE明显增加。结论 :输注基因工程化基质细胞 ,并诱导细胞因子IL 3基因表达可以进一步促进异基因骨髓移植小鼠造血功能重建     

转IL-3基因骨髓基质细胞对异基因骨髓移植后小鼠造血重建的促进作用

目的　探讨转IL 3基因的小鼠骨髓基质细胞系QXMSC1对异基因骨髓移植 (allo BMT)小鼠造血功能的促进作用。方法　用重组逆转录病毒载体 (含小鼠IL 3cDNA)感染骨髓基质细胞系QXMSC1(H 2 d) ,构建骨髓基质细胞系QXMSC1IL 3,挑选表达量最高的骨髓基质细胞系QXMSC1IL 3用于以后实验。供体小鼠BALB c(H 2 d)骨髓用抗T细胞单抗anti Thy1.2加补体去除骨髓中T细胞。受体小鼠C5 7BL 6 (H 2 b)经γ射线致死量照射后 ,输入供体骨髓细胞 (1× 10 7 只 )的同时输入QXMSC1IL 3(5× 10 6 只 )细胞。在骨髓移植后第 2 0 ,4 0天 ,分别检测受体小鼠外周血红细胞、白细胞、骨髓有核细胞数 ,CFU S、CFU GM、CFU E和CFU GEMM数以反映骨髓移植后受体小鼠的造血功能。结果　QXMSC1IL 3细胞系可稳定分泌IL 3。allo BMT同时输入QXMSC1IL 3细胞可使allo BMT小鼠外周血红细胞、白细胞明显恢复 ,骨髓中有核细胞数、CFU S、CFU GM、CFU E、CFU GEMM明显增加。结论　基质细胞QXMSC1可作为有效的基因载体进一步促进allo BMT小鼠造血功能重建。     

Drug selection of MDR1-transduced hematopoietic cells ex vivo increases transgene expression and chemoresistance in reconstituted bone marrow in mice

The MDR1 (multidrug resistance) gene, transferred to hematopoietic cells, is expected to protect them from anticancer chemotherapy and may serve as a selectable marker, restoring gene expression in vivo. Appropriate selection strategies, however, need to be established. To investigate whether preselection ex vivo affects chemoresistance, murine bone marrow cells were retrovirally transduced with high-titer or, as a model for suboptimal gene expression, low-titer retroviruses and exposed to daunomycin or colchicine for 48-96 h. Selection significantly increased chemoresistance of clonogenic progenitor cells. In tissue culture, the entire target population was rendered highly drug resistant after MDR1 transfer with high-titer viruses. If transduction was performed under suboptimal conditions, drug selection increased the frequency of chemoresistant colonies up to 40% over the number of unselected cells. Colchicine and daunomycin were equally efficient in increasing drug resistance ex vivo, but colchicine-preselected cells rescued lethally irradiated mice under conditions where daunomycin-selected bone marrow cells failed to do so. Hence, while hematopoietic cells can be protected by MDR1, the selection strategy is critical for repopulation of bone marrow with transduced cells. Preselection in culture before transplantation significantly increased P-gp expression and chemoresistance in vivo in mice reconstituted with transduced bone marrow cells. This study may help to facilitate the use of MDR1 as a selectable marker in gene therapy of the hematopoietic system. Gene Therapy (2000) 7, 348-358.     

Adenoviral transfer of a single donor-specific MHC class I gene to recipient bone marrow cells can induce specific immunological unresponsiveness in vivo

We investigated the delivery of a donor-specific MHC class I gene, H-2K(b), using a newly constructed replication-defective recombinant adenovirus (AdSV40K(b)) to recipient tissue before transplantation as a means of inducing donor-specific immunological unresponsiveness. AdSV40K(b) was able to transduce both a fibroblast cell line and freshly isolated bone marrow cells (BMCs) resulting in cell surface expression of H2-K(b) protein. Intravenous infusion of AdSV40K(b)-transduced syngeneic CBA/Ca (H-2(k)) BMCs into CBA recipient mice treated with an anti-CD4 monoclonal antibody 27 days before transplantation of a fully MHC-mismatched, C57BL/10 (H-2K(b+)), cardiac allograft resulted in significant long-term graft survival when compared with mice receiving the same dose of syngeneic BMCs transduced with a control adenovirus, AdRSVbetagal. Despite the induction of H-2K(b)-specific hyporesponsiveness following pretreatment with AdSV40K(b)-transduced CBA BMCs, persistence of H-2K(b) mRNA in central or peripheral tissues could not be demonstrated by RT-PCR. This result was in contrast to the observed persistence of K(b) mRNA both in the periphery and thymus following the infusion of transgenic CBK (H-2(k) + K(b)) BMCs. We conclude that ex vivo adenoviral gene transfer of a single donor MHC class I gene to recipient BMCs in combination with transient depletion of CD4(+) cells is sufficient to induce long-term graft survival of a fully allogeneic cardiac graft. In addition, detectable microchimerism is not a prerequisite for graft survival.     

LAK细胞和活化NK细胞对小鼠骨髓造血功能影响的实验研究

目的 探讨淋巴细胞因子激活的杀伤细胞／ 活化自然杀伤细胞（ＬＡＫ 细胞／ 活化ＮＫ 细胞）与造血的关系及其对同基因骨髓移植小鼠造血重建的影响。方法 ①将同基因ＬＡＫ 细胞／ 活化ＮＫ 细胞与骨髓细胞一起置于体外半固体琼脂培养体系中,观察其对ＣＦＵＧＭ 形成的影响。②在小鼠同基因骨髓移植中, 联合注射同基因ＬＡＫ 细胞／ 活化ＮＫ 细胞, 观察其对移植后小鼠造血重建的影响。结果①当骨髓细胞置于有外源性集落刺激因子（ＣＳＦ） 的适宜培养体系中,同基因ＬＡＫ 细胞／ 活化ＮＫ 细胞抑制ＣＦＵＧＭ 形成;而当骨髓细胞置于无ＣＳＦ 不良培养体系中,同基因ＬＡＫ 细胞／ 活化ＮＫ 细胞促进ＣＦＵＧＭ 形成。②在小鼠同基因骨髓移植中,联合注射同基因ＬＡＫ 细胞／ 活化ＮＫ 细胞,能显著促进ＣＦＵＳ 和ＣＦＵＧＭ 增殖和显著升高白细胞和血小板数量。结论 ①同基因ＬＡＫ 细胞／ 活化ＮＫ 细胞对ＣＦＵＧＭ 形成有双向调节作用。②在小鼠同基因骨髓移植中,联合注射同基因ＬＡＫ 细胞／ 活化ＮＫ 细胞,能促进移植后小鼠造血重建。     

Methotrexate preconditioning allows sufficient engraftment to confer drug resistance in mice transplanted with marrow expressing drug-resistant dihydrofolate reductase activity

Methotrexate (MTX) is an effective antitumor agent that has been demonstrated to be particularly useful in the treatment of hematopoietic neoplasms but causes substantial hematologic and gastrointestinal toxicity. We previously demonstrated that transplantation with transgenic marrow expressing drug-resistant dihydrofolate reductase (DHFR) into animals preconditioned by irradiation substantially protected recipient mice from the toxic side effects of methotrexate administration. Here we test the use of methotrexate itself as a preconditioning agent for engraftment of drug-resistant transgenic marrow, subsequently conferring drug resistance upon recipient animals. Administration of methotrexate beginning 1 or 2 weeks prior to or on the same day as transplantation with drug-resistant DHFR transgenic marrow did not allow sufficient engraftment to confer drug resistance to most unirradiated recipients. A small number of animals were curiously protected from lethal MTX toxicity but exhibited extremely low hematocrits and were not engrafted with stem cells, as indicated by low engraftment levels assessed in secondary transplant recipients. However, we subsequently found that MTX preconditioning allowed sufficient engraftment of DHFR transgenic marrow to confer drug resistance if MTX administration was withdrawn at the time of bone marrow transplantation (BMT) and withheld until 2 weeks post-transplant. Quantitative molecular analysis of primary and secondary recipients indicated a stem cell engraftment level of approximately 1%, consistent with previous studies demonstrating that a low level of DHFR transgenic cell engraftment was sufficient to confer drug resistance in recipient animals. We conclude that MTX can be used as a preconditioning agent for subsequent engraftment of hematopoietic stem cells, in this case conferring resistance to MTX.     

Development of a synthetic promoter for macrophage gene therapy

Macrophages have the potential to deliver therapeutic genes to many target tissues. Macrophage-specific synthetic promoters (SPs) generated by random ligation of myeloid/macrophage cis elements had activity up to 100-fold that of a native macrophage promoter in macrophage cell lines, but were minimally active in nonmyeloid cells. Mouse bone marrow cells (BMCs) transduced ex vivo with lentivectors expressing green fluorescent protein (GFP) driven either by an SP (SP-GFP) or a cytomegalovirus (CMV) promoter (CMV-GFP) were used for syngeneic transplantation of lethally irradiated mice. Blood leukocytes showed stable GFP expression for up to 15 months after transplantation. SP-GFP expression was selective for CD11b+ macrophages, whereas CMV-GFP expression was observed in erythrocytes, as well as in both CD11b+ and CD11b- leukocytes. Furthermore, SP-GFP expression was much stronger than CMV-GFP expression in CD11b+ macrophages. apoE-/- BMCs transduced with the lentiviral vector encoding human apoE were used to transplant apoE-/- mice. Macrophage expression of apoE from 10 to 26 weeks of age significantly reduced atherosclerotic lesions in recipient apoE-/- mice. Thus, the novel SPs, especially when combined with lentivectors, are useful for macrophage-specific delivery of therapeutic genes.     

致敏受体排斥异基因供体骨髓细胞的实验研究

目的 建立致敏动物模型,研究致敏对异基因骨髓细胞植入的影响及机制.方法 将C57 BL/6小鼠脾细胞经尾静脉注射到BALB/c小鼠体内建立致敏动物模型,应用二抗结合实验及补体依赖细胞毒性反应检测血清抗体.以非致敏或致敏BALB/c小鼠为受鼠,经照射预处理后予以1 ×10 7C57BL/6供鼠骨髓细胞.移植后于不同时间点(2、12和48 h)分离受鼠外周血、脾脏及骨髓等细胞,检测供鼠细胞在致敏受鼠体内各组织的分布.移植后记录各组受鼠的生存情况,监测造血重建与骨髓恢复情况.体外分离非致敏或致敏受鼠的血清及脾细胞,与异基因骨髓细胞相孵育,通过免疫实验计算细胞毒性指数.结果 二抗结合实验和补体依赖细胞毒性反应均证实致敏受鼠血清中含有高滴度的供鼠反应性抗体.骨髓移植归巢实验结果表明,与非致敏组相比,异基因骨髓细胞在致敏受鼠的外周血、脾脏及股骨的分布均明显减少.生存分析结果发现非致敏组小鼠于照射后能长期存活,而致敏组小鼠于照射后12～15 d全部死亡.移植后第14天,非致敏组受鼠外周血白细胞和股骨骨髓细胞计数分别为(3240±300)×106/L和(396±27)×106/股骨,而致敏组受鼠外周血白细胞和股骨骨髓细胞计数分别为(320±80)×106/L和(6±2)×106/股骨,两组差异有统计学意义(P＜0.01).移植后第7天,供鼠细胞在非致敏组和致敏组骨髓所占的百分比分别为(48.07±4.70)％和(0.77±0.11)％,两者差异有统计学意义(P＜0.01).体外通过补体依赖细胞毒性反应实验、细胞毒性淋巴细胞的杀伤作用和抗体依赖细胞介导细胞毒性作用实验表明,致敏组受鼠的细胞毒性指数均明显高于非致敏组.结论成功建立脾细胞输注致敏的小鼠动物模型,致敏受体完全排斥异基因供体骨髓细胞,作用机制与免疫损伤途径有关.     

Protection of bone marrow transplant recipients from lethal doses of methotrexate by the generation of methotrexate-resistant bone marrow

To develop a highly efficient means for generating methotrexate resistant (MTXr) hematopoietic cells in vivo, a recombinant retroviral genome was constructed that encodes a MTXr dihydrofolate reductase (DHFRr). Cell lines producing high titers of virus capable of transmitting the DHFR gene were generated and used to infect mammalian cells in vitro. Analysis of infected fibroblasts indicated that the DHFRr gene was transmitted intact and conferred a high level of MTXr upon cells. Based on these findings, DHFRr-containing virus was used to infect murine bone marrow cells in vitro. Following infection, the transduced cells were introduced into lethally irradiated recipients via bone marrow transplantation techniques. The presence of the proviral sequences in cells of the spleen and bone marrow of engrafted recipients was associated with significantly increased survival of mice treated with otherwise lethal doses of MTX.     

In vivo methotrexate selection of murine hemopoietic cells transduced with a retroviral vector for Gaucher disease.

The studies described were performed to investigate whether in vivo selection of retrovirus-transduced hemopoietic cells is feasible starting from a low percentage of transduced hemopoietic stem cells (PHSCs). The vector used is an amphotropic bicistronic retroviral vector carrying a cDNA for human lysosomal glucocerebrosidase (hGC) for treatment of Gaucher disease and a methotrexate (MTX) resistant mutant cDNA encoding human dihydrofolate reductase (DHFR). We tested the effect of MTX selection in mice that were either myeloablated or not before infusion of transduced cells. In addition, we determined whether repeated administration of transduced bone marrow cells has an additional effect on the percentage of hGC expressing cells. The results obtained have shown that, in myeloablated mice transplanted once with transduced bone marrow and treated twice weekly with 10 mg/kg of MTX for a total of 6 months, a two- to three-fold increased numbers of hGC expressing cells could be detected in both peripheral blood and bone marrow as compared with non-MTX treated mice. In mice transplanted with transduced bone marrow once every 2 weeks for a total of four times, percentages of hGC expressing cells were not significantly increased as compared with mice transplanted once. In non-ablated mice neither MTX selection nor multiple infusions of transduced bone marrow resulted in detection of hGC expressing cells 6 months after transplantation, indicating that the success of in vivo selection using MTX is highly dependent on the ratio of transduced hemopoietic stem cells transplanted versus residing and untransduced stem cells.     

IL—6基因转染的骨髓基质细胞系对骨髓移植小鼠造血功能恢复？…

目的：探讨白细胞介素６（ＩＬ－６）基因转染的骨髓基质细胞系ＱＸＭＳＣ１ＩＬ－６对骨髓移植后造血功能的重建作用。方法：将骨髓造血细胞和骨髓基质细胞系一起经尾静脉注射给同系小鼠，建立骨髓移植（ＢＭＴ）模型。小鼠的造血功能用脾结节（ＣＦＵ－Ｓ）、粒－单系祖细胞（ＣＦＵ－ＧＭ）、红系祖细胞（ＣＦＵ－Ｅ、ＢＦＵ－Ｅ）测定及外周血各项血液学指标来确定。结果：ＷＸＭＳＣ１ＩＬ－６转基因骨髓基质细胞可明显增强ＢＭ     

体内转染人突变DHFR原小鼠骨髓对致死量照射小鼠造血重建和 …

目的 将转染了人突变ＤＨＦＲ基因的小鼠骨髓移植给经致死剂量照射的小鼠,观察棋 对受者造血功能的重建和保护作用。方法 分离转染人突变ＤＨＦＲ基因小鼠骨髓有核细胞,移植给经致死剂量照射的同系小鼠,以甲氨蝶呤（ＭＴＸ）筛选．观察受体小鼠血象、生存率和ＣＦＵ－ＧＭ的改变,并用ＰＣＲ和Ｓｏｕｔｈｅｒｎ印迹杂交分析外源基因在小鼠染色体ＤＮＡ中的整合与表达情况。对照组以正常同系小鼠为供体。结果 在大剂量ＭＴＸ筛     

小鼠骨髓程序移植的实验研究

目的：探讨进一步提高骨髓移植效果的新方法。方法：以昆明种小鼠急性放射病为模型，进行了骨髓程序移植后小鼠活存率及造血重建、急性移植物抗宿主病（ＧＶＨＤ）的观察。结果：骨髓程序移植可使小鼠移植细胞数降至１０５数量级，活存率达３０％；骨髓程序移植４×１０６个细胞时，于照射后１７天小鼠外周血白细胞、骨髓有核细胞计数显著回升，ＣＦＵＥ、ＣＦＵＧＭ、ＣＦＵＳ、ＣＦＵＦ已达正常，ＧＶＨＤ较一次移植１×１０７骨髓细胞组轻，活存率达６０％，显著高于一次骨髓移植组（３０％）。结论：骨髓程序移植可能充分利用了每次腾出的“龛位”，增加干细胞植入，却减少了移植细胞数，减轻了ＧＶＨＤ，提高了移植效果，是一种较好的移植新方法     

mdr—1和DHFR双基因共转染入CD^＋34细胞拓宽造血细胞耐药谱的体外研究

目的：探讨将多药耐药基因（mdr-1)和二氢叶酸还原酶基因（DHFR)同时导入人CD^ 34细胞,以拓宽造血细胞耐药谱,改善骨髓耐受联合化疗的可行性,方法：将以造血细胞中高表达的逆转录病毒载体FMCF为基本结构骨架,通过引入IRES序列构建获得含mdr-1和DHFR（L22Y）双耐药基因的塑转录病毒载体pSF－DIM,通过脂质体介导包装,单嗜性和双 包装细胞上清交叉感染提高病毒滴度,低温离心病毒上清转染人脐血CD^ 34细胞,用流式细胞仪检测P－gp的表达,基因组PCR检测外源性耐药基因的整合,CFU－GM培养药性变化,结果：逆转录病毒载体pSF-DIM转人脐血CD^ 34细胞后,P-gp的表达较未转基因组增加了10．98％,基因组PCR同时检测到两种外源性药基因的整合,与未转基因组比较,在48nmol/L甲氢蝶呤和10ng/ml及12ng/ml紫杉醇（商品名Taxol）浓度水平,CFU－GM集落形成显著培养（P＜0．05）。结论：重组双耐药基因逆转录病毒载体pSF-DIM可度水平,CFU－GM集落形成显著增加（P＜0．05）,结论：重组双耐药基因逆转录病毒载体pSF-DIM可以有效介导mdr-1和DHFR双耐药基因进入人脐血CD34^ 细胞并获得共表达,拓宽了造血细胞药谱。     

Transgene Expression Levels Determine the Immunogenicity of Transduced Hematopoietic Grafts in Partially Myeloablated Mice

We investigated whether transgene expression levels influence the immunogenicity of transduced hematopoietic grafts upon transplantation into partially myeloablated mice. To this aim, bone marrow cells (BMCs) transduced with retroviral vectors driving green fluorescent protein (GFP) expression either at high (high-EGFP) or low levels (low-EGFP) were transplanted into congenic recipients conditioned with sublethal doses of total body irradiation (TBI) or busulfan. Virtually all recipients showed evidence of donor engraftment 4 weeks after transplantation. However, as opposed to recipients receiving low-EGFP transduced grafts, the risk of rejecting the EGFP⁺ cells by 30 days after transplantation was significantly higher in mice conditioned with busulfan and receiving high-EGFP transduced grafts. Anti-EGFP cellular immune responses were demonstrated in high-EGFP-treated mice conditioned with busulfan by interferon-γ (IFN-γ), enzyme-linked immunospot assay (ELISPOT), and cytotoxic T lymphocyte (CTL) assays, in contrast to that observed in mice transplanted with low-EGFP BMC. These results show for the first time that transgene expression levels can be critical for the immunogenicity of gene-modified hematopoietic grafts, especially in immunocompetent or in partially immunosuppressed recipients. These results have profound implications in vector choice and in the design of gene therapy (GT) protocols.     

归芪猪蹄汤对骨髓抑制模型大鼠造血功能的影响

目的探讨归芪猪蹄汤对环磷酰胺致骨髓抑制模型大鼠造血功能的影响。方法应用环磷酰胺腹腔注射建立骨髓抑制模型大鼠,观察高、低剂量归芪猪蹄汤对模型大鼠外周血白细胞、脾结节计数、骨髓DNA含量及骨髓病理形态的影响。结果归芪猪蹄汤可显著提高骨髓模型大鼠血白细胞计数(P<0.05),其中高剂量组优于低剂量组。高剂量组可提高模型大鼠脾结节计数和骨髓DNA含量(P<0.05);归芪猪蹄汤对模型大鼠骨髓组织造血细胞及巨核细胞数的减少有不同程度的恢复作用,对脂肪组织的增加有一定的抑制作用,其中高剂量组疗效显著。结论归芪猪蹄汤可明显改善环磷酰胺致骨髓抑制大鼠的造血功能。