重组腺病毒抗小鼠移植瘤生长

目的:研究携带细胞因子基因hIL-2、hTNF-a的重组腺病毒对小鼠移植瘤生长抑制作用。方法:将分别携带有hIL-2基因、hTNF-a基因的重组腺病毒感染人肺腺癌Anip973细胞系,应用ELISA试剂盒检测转染后的细胞IL-2、TNF-α的分泌量;通过肿瘤局部注射重组腺病毒的方法观察其在小鼠体内的抗肿瘤作用。结果:转基因的肿瘤细胞生长能力、克隆形成率等无明显变化。24h细胞培养上清IL-2的分泌量为50pg/2×105细胞,TNF-α的分泌量为20pg/2×105细胞。体内实验表明注射重组腺病毒后小鼠肿瘤生长缓慢,体积明显小于对照组(P<0.05),存活期显著延长。结论:瘤内注射重组腺病毒具有明显抗肿瘤作用。     

腺病毒介导IL-2基因转染的瘤苗体内抗肿瘤作用

目的 :探讨重组腺病毒介导的 IL- 2基因转染的瘤苗的体内抗肿瘤作用及其免疫学机制。方法 :应用腺病毒介导的鼠 IL- 2基因转染 CT2 6小鼠结肠癌细胞 ,灭活后用作瘤苗治疗荷瘤小鼠 ,观察皮下肿瘤生长及其存活期。采用乳酸脱氢酶释放法检测荷瘤小鼠脾细胞 CTL、L AK、NK细胞的杀伤活性。结果 :鼠 IL- 2基因转染瘤苗治疗能显著抑制荷瘤小鼠皮下肿瘤生长并明显延长其存活期 (P<0 .0 1)。体内免疫功能检测表明 ,鼠 IL- 2基因转染疫苗治疗组小鼠脾细胞 CTL 活性、L AK活性和 NK活性显著高于对照组 (P<0 .0 1)。结论 :腺病毒介导鼠 IL- 2基因转染的瘤苗体内具有较强的抗肿瘤效应 ,其机制可能是提高了荷瘤小鼠特异性和非特异性抗肿瘤免疫反应     

IL—2和（或）IL—3基因治疗对大剂量化疗后小鼠免疫功能恢复的影响

目的探讨ＩＬ－２、ＩＬ－３对化疗后小鼠免疫功能恢复的影响。方法正常小鼠腹腔注射大剂量环磷酰胺２４小时后,直接腹腔注射ＩＬ－２重组腺病毒（Ａｄ－ＩＬ－２）和（或）ＩＬ－３重组腺病毒（Ａｄ－ＩＬ－３）,观察小鼠腹腔巨噬细胞数量、杀伤活性、Ｉａ抗原表达、脾细胞增殖及ＮＫ细胞杀伤活性。结果腹腔注射Ａｄ－ＩＬ－３组小鼠,腹腔巨噬细胞数量明显增加,杀伤活性及Ｉａ抗原表达显著增强。腹腔注射Ａｄ－ＩＬ－２组小鼠,脾细胞增殖能力显著升高,ＮＫ细胞杀伤活性增强,但对小鼠腹腔巨噬细胞无激活作用。联合应用Ａｄ－ＩＬ－２及Ａｄ－ＩＬ－３组小鼠,腹腔巨噬细胞、脾细胞、ＮＫ细胞均被激活。结论腹腔直接注射Ａｄ－ＩＬ－２和Ａｄ－ＩＬ－３可促进化疗后小鼠免疫功能的恢复。     

腺病毒介导的IL-24对人大细胞肺癌NCI-H460细胞的体外抑制效应

目的研究腺病毒介导的IL-24基因表达对NCI-H460肺癌细胞抑癌增效作用及分子机制。方法将Ad-IL-24重组腺病毒感染NCI-H460细胞。以Western blot法鉴定IL-24基因在NCI-H460细胞中的表达;MTT法检测重组腺病毒对NCI-H460细胞的生长抑制作用;经Annexin-V-PE/7-AAD染色后流式细胞术（FCM）检测细胞凋亡率变化;RT-PCR检测NCI-H460细胞中bax、caspase-3、bcl-2、survivin等因子的表达。结果腺病毒介导的IL-24基因在NCI-H460细胞中能够有效表达;Ad-IL-24组对NCI-H460细胞的生长具有明显的抑制作用, Ad-IL-24能够上调bax、caspase-3等因子的表达,下调bcl-2、survivin等因子的表达,诱导细胞凋亡。结论腺病毒介导的IL-24 基因在体外可明显抑制人肺癌细胞NCI-H460的生长,诱导其凋亡,其分子机制可能与上调bax、caspase-3等促凋亡因子的表达,下调bcl-2、survivin等凋亡抑制因子的表达有关。     

联合自杀基因与IL-2基因转移疗法的抗肿瘤效果及其抗肿瘤免疫应答的诱导作用

单用自杀基因疗法或单用细胞因子基因疗法抗肿瘤效果不理想,本研究中我们观察了大肠杆菌胞嘧啶脱胺酶(CD)基因与白细胞介素2(IL-2)基因联合转移对荷瘤小鼠的治疗效果及其对抗肿瘤免疫的诱导作用。复制荷瘤小鼠模型后在荷瘤部位注射表达CD基因的重组腺病毒(AdCD)及表达小鼠IL-2基因的重组腺病毒(AdIL2),并连续10天、每天1次腹腔注射5氟胞嘧啶(5FC)对荷瘤小鼠进行治疗。结果表明,AdCD/5FC/AdIL2联合基因治疗能显著抑制荷瘤小鼠皮下肿瘤的生长,并明显延长其生存期(P<0.01)。联合基因治疗组小鼠肿瘤细胞发生明显的坏死,瘤内及瘤周有大量的炎性细胞浸润,瘤内CD4~ 和CD8~ T细胞明显增加,脾细胞NK和CIL杀伤活性明显高于单用AdCD/5FC、对照病毒AdLacZ/5FC或PBS组。实验结果表明,联合应用自杀基因与细胞因子基因治疗可更有效诱导机体的抗肿瘤免疫反应,从而更显著地抑制荷瘤小鼠肿瘤的生长。     

IL-3基因修饰的骨髓基质细胞辅助大剂量化疗后造血功能恢复

为研究基因治疗在造血功能损伤后恢复中的应用,本课题以携带小鼠IL-3基因的复制缺陷型重组腺病毒载体转染骨髓基质细胞,对大剂量化疗后的小鼠进行脾内移植观察造血功能的恢复情况.结果表明,缺陷型腺病毒载体能有效地转染小鼠原代骨髓基质细胞,转染效率在80%以上(MOI=10);基因修饰的骨髓基质细胞体外分泌IL-3的水平可达110U/ml/10~6细胞/24小时;在大剂量环磷酰胺治疗后脾内移植IL-3基因修饰的基质细胞能有效地升高实验小鼠外周血白细胞总数;病理检测发现IL-3基因修饰的基质细胞治疗组小鼠脾脏和骨髓中细胞增生较其它组明显活跃;经IL-3基因修饰的基质细胞治疗组小鼠脾淋巴细胞对ConA反应明显增强.结果提示IL-3基因修饰的骨髓基质细胞体内移植对大剂量化疗后机体造血与免疫功能的恢复都有较好的促进作用.     

瘤体内/瘤周注射TNF重组腺病毒和/或IL-2重组腺病毒对肝癌小鼠的治疗作用研究

选择两种具有协同免疫调节作用的细胞因子进行联合基因治疗是提高肿瘤细胞因子基因治疗的有效途径之一.目前对IL-2/TNF-α联合基因方案,特别是瘤体内注射途径的抗肿瘤研究尚未见报道.IL-2与TNF-α具有协同作用.因此我们分别将携带TNF-α基因和IL-2基因的腺病毒(Ad-TNF,Ad-IL-2)联合或直接注射于BALB/c小鼠肝癌内,观察其抗瘤效果,并探讨其抗肿瘤免疫机制.结果表明:1.TNF治疗组脾细胞NK、LAK、CTL活性及Mφ杀伤活性明显高于对照组,诱生的细胞因子包括IL-2、GM-CSF、IFN-γ、TNF和IL-     

IL-2基因与自杀基因联合转移对小鼠红白血病的治疗作用

用腺病毒作为载体,将大肠杆菌胞嘧啶脱氨酶(CD)基因体外转染小鼠红白血病FBL-3细胞,结果CD基因转移后该细胞对5-氟胞嘧啶(5-FC)的敏感性提高了近1000倍,FBL-3细胞有明显的凋亡发生,且观察到明显的旁观者效应.小鼠体内接种FBL-3红白血病细胞后3天,肿瘤局部注射小鼠白细胞介素2(IL-2)基因的表达载体(Ad-IL-2)和Ad-CD腺病毒载体,然后连续10天给予5-FC 300mg/kg行治疗.结果FBL-3皮下肿瘤的生长明显受到抑制,部分小鼠肿瘤消失.联合治疗小鼠的存活期明显大于单用Ad-IL-2治疗组和单用自杀基因CD与5-FC治疗组.体内免疫功能检测表明,经小鼠自杀基因与IL-2联合基因治疗后小鼠脾细胞的CTL杀伤     

携带反义c-myc的重组腺病毒安全性研究

目的　研究携带反义c myc的重组腺病毒 (Ad ASmyc)潜在的副作用 ,评价其安全性 ,为其进一步进入临床试验提供依据。方法　用Ad ASmyc感染HeLa细胞 ,制备细胞提取液后反复两次感染HeLa细胞 ,观察Ad ASmyc的繁殖、扩增 ,以及对HeLa细胞的作用 ,RT PCR检测其DNA的转录 ;确定Ad ASmyc对作为正常细胞的人胚肺二倍体细胞 2BS的感染能力 ,绘制细胞生长曲线 ,观察Ad ASmyc对正常细胞的毒性 ;给Balb/c小鼠腹腔注射重组腺病毒后 ,每日观察一般状况 ,化验肝、肾功能 ,PCR检测Ad ASmyc在重要脏器中的分布 ,显微镜观察重要脏器的病理学变化。结果　Ad ASmyc是一复制缺陷型腺病毒 ,它能高效感染 2BS细胞 ,但并不影响其生长 ,小鼠体内应用后 ,无急性毒性症状发生 ,在肝、肾、胃、脾内可检测到腺病毒的分布。但在注射 10 9pfu第 6天、第 12天的小鼠肝组织内可观察到轻微炎症。结论　Ad ASmyc应用是安全的 ,可以进入临床试验。     

TβR-Ⅱ-RANTES融合基因重组腺病毒的抗肿瘤作用

目的构建表达融合基因TGF-βⅡ型受体(TβR-Ⅱ)胞外区及活化T细胞表达和分泌的调节因子(RANTES)重组腺病毒载体,并观察其抗肿瘤作用。方法RT-PCR扩增小鼠TβR-Ⅱ胞外区和RANTES基因,重叠PCR扩增融合基因TβR-Ⅱ胞外区-RANTES。采用adMax adenovjrus vector creation试剂盒构建表达融合基因重组腺病毒。体外感染小鼠肺腺痛LA795细胞系,绘制细胞生长曲线。采用Western blot法检测感染后细胞融合基因的表达;酶联免疫吸附试验(FLISA)法检测其培养上清的蛋白含量;Annexin V-FITC法检测感染后细胞的凋亡;并观察感染后细胞培养上清对小鼠脾细胞的趋化作用。将感染后的细胞(1×105个)接种于T739小鼠,观察成瘤时间和生存时间;1×1010pfu的重组腺病毒局部注射荷瘤小鼠,观察肿瘤的大小变化,并统计肿瘤的重量和计算抑瘤率。结果经测序证实,RT-PCR正确扩增小鼠TβR-Ⅱ胞外区和RANTFS基因,重叠PCR正确扩增融合基因TβR-Ⅱ胞外区-RANTES。重组质粒pDC316-融合基因经酶切鉴定正确,与pJM17双质粒共转染获得表达融合基因重组腺病毒,病毒滴度为8×1010pfu/ml。Western blot结果表明,感染后的LA795细胞有融合蛋白的特异性条带出现;培养上清中,游离TGF-β1的水平显菩减低,而RANTES的水平显著升高。感染融合基因重组腺病毒的细胞生长速度明显减低,凋亡率为16.9%;培养上清可趋化小鼠脾细胞,与对照组之间差异均有统计学意义。感染融合基因重组腺病毒组与对照组相比,体内成瘤时间和生存时间明显延长;局部注射融合基因重组腺病毒可显著抑制肿瘤的生长,抑瘤率为37.6%。结论成功构建表达融合基因TβR-Ⅱ胞外区-RANTES重组腺病毒可有效结合TGF-β1,显著逆转TGF-β介导的免疫抑制状态,高水平表达RANTES强化肿瘤局部的免疫功能,具有显著的抗肿瘤作用。     

EFFICIENT ACTIVATION OF ANTITUMOR IMMUNITY BY IL-6 GENE-MODIFIED LEUKEMIA VACCINE IN COMBINATION WITH LOW DOSE CYCLOPHOSPHAMIDE AND LOW DOSEIL-2

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Dynamics of leukemic and normal stem cells in leukemic RFM mice.

RFM mice spontaneously develop a myelogenous leukemia that is transplantable into nonleukemic RFM mice. On transplantation, hemopoietic stem cells from leukemic mice (L-CFU-S) will seed in the spleen and grow as discrete colonies, as will hemopoietic stem cells from normal mice (N-CFU-S). As the leukemic cells used in these experiments have 39 chromosomes and normal murine cells have 40, it has been possible to estimate the numbers of N-CFU-S and L-CFU-S in RFM mice at weekly intervals after these mice had been given i.v. injections of 10(6) leukemic spleen cells (spleen cells from preterminal leukemic mice). At each study time, splenic weights, peripheral blood counts, and nucleated cell counts and colony forming units (CFU-S) of marrow, spleen, and blood were assayed. The karyotypes of dividing cells from and the histology of the resultant spleen colonies were also studied. Two weeks after the injection of leukemic spleen cells, the number of CFU-S in the marrow had increased to 3 to 10 times normal, that in the spleen to 100 times normal, and that in the blood was markedly increased. Three weeks after injection, the number of CFU-S in the marrow fell from the peak level at 2 weeks, the number in the spleen rose modestly, and the number in the blood continued to be markedly increased. A normal distribution of erythroid, myeloid, and megakaryocytic colonies was obtained from CFU-S assayed 1 week after injection of leukemic spleen cells, but from CFU-S assayed 2 or 3 weeks after injection of leukemic spleen cells, the colonies formed were comprised almost exclusively of myeloid cells. From spleen colonies formed from marrow or spleen cells obtained 1 week after the injection of leukemic spleen cells, all karyotypes contained 40 chromosomes, whereas from spleen colonies formed from marrow or spleen cells obtained 2 or 3 weeks after injection of spleen cells, almost all karyotypes contained 39 chromosomes. In contrast, most of the karyotypes found in spleen colonies formed from the injection of blood cells even 3 weeks after injection of leukemic spleen cells contained 40 chromosomes. All colonies containing cells with 39 chromosomes, leukemic colonies, contained only myeloid cells. We conclude that L-CFU-S differentiate only into the myeloid series. Early in the course of the disease there is an increase in both N-CFU-S and L-CFU-S in the spleen and marrow. As the disease progresses, the numbers of N-CFU-S in both spleen and marrow decline and, during the final week of the illness, the number of L-CFU-S in the marrow declines. The CFU-S in the peripheral blood are predominantly of normal type, even late in the disease when N-CFU-S are rare in the spleen and marrow.     

Effect of combination treatment with cyclophosphamide and isogeneic or allogeneic spleen and bone marrow cells in leukemic (l1210) mice

Generalized leukemia was observed on day 3 following intra-peritoneal inoculation of leukemic (L1210) ascites cells in CDF₁ mice. On day 3 after tumor implantation, residual viable leukemic cells were detected in the peritoneal cavities and spleens of leukemic mice 6 h following treatment with 180 mg/kg of cyclophosphamide. Mice receiving weekly intraperitoneal injections of X-irradiated leukemic (L1210) cells for 6 weeks were resistant to a challenge of tumor cells. When incubated in vitro, spleen and bone marrow cells of immune mice were able to inactivate viable leukemic cells, as evidenced by failure of tumor growth in mice inoculated with these cells. Leukemic mice injected with immune spleen or bone-marrow cells from isogeneic mice following treatment with cyclophosphamide survived a 60-day observation period. In one such experiment 90-day survivors were able to resist re-inoculation of tumor cells. Leukemic (DBA/2) mice inoculated with allogeneic spleen cells following cyclophosphamide treatment survived for longer periods than mice injected with isogeneic spleen cells.     

Interleukin-12 (IL-12) gene therapy of leukemia: immune and anti-leukemic effects of IL-12-transduced hematopoietic progenitor cells

Recombinant interleukin-12 (rlL-12) is a potent immunomodulatory cytokine that has been shown to exert strong antitumoral and antimetastatic activity against several mouse tumors grown as solid lesions. The therapeutic efficacy of rIL-12 against hematological tumors and the transfer of IL-12 genes into hematopoietic progenitor cells to deliver IL-12 to the bone marrow (BM) to treat residual leukemia has not been studied adequately. We have investigated the retroviral-mediated transduction of hematopoietic progenitor cells with IL-12 genes and the in vivo anti-leukemic activity of transduced cells against the murine myeloid leukemia cell line 32Dp210. We were able to efficiently transduce the IL-3-dependent 32Dc13 myeloid progenitor cell line and primary hematopoietic progenitor cells using an MFG-based polycistronic retroviral vector containing the cDNAs of p35 and p40 murine IL-12 genes. 32Dc13 myeloid progenitor cells expressing IL-12 genes (32DIL-12 cells) have stably secreted biologically active murine IL-12 for >9 months. Mice transplanted with 32DIL-12 cells transiently express the transgene in the BM and spleen, which is associated with a rapid elevation of interferon-gamma (IFN-gamma) in the circulation and with secretion of IFN-gamma by spleen cells in vitro. In addition, spleen and BM cells of mice injected with 32DIL-12 cells readily acquire the capacity to lyse natural killer cell-sensitive YAC-1 target cells and 32Dp210 myeloid leukemia cells. Furthermore, whereas mice challenged with leukemia cells suffered 100% mortality within 14 days, approximately 40% of mice coinjected with 32Dp210 leukemia cells and 32DIL-12 progenitor cells exhibited long-term, leukemia-free survival (>60 days). This study demonstrates that IL-12 can be stably expressed in hematopoietic cells; in addition, when transplanted, transduced cells induce IFN-gamma production and activation of natural killer cells, both of which may be involved in inhibiting the progression of leukemia in vivo.     

Differences in the pharmacokinetics of daunomycin in normal and leukemic rats

We compared the pharmacokinetics of daunomycin (7.5 mg/kg i.v. bolus injection) in normal and leukemic rats using a leukemia model which resembles acute myeloid leukemia in humans. Due to a more rapid decrease in plasma concentration, the area under the plasma concentration/time curve (AUC) for up to 2 h after drug injection was smaller (2.2 times) in the leukemic rats than that for normals. However, due to higher plasma levels during the drug elimination phase, the total AUC0----infinity was somewhat larger (1.3 times) in the leukemic rats. In the leukemia-infiltrated organs (spleen, liver, and lungs), significantly higher daunomycin concentrations (per gram wet weight) were found than in those obtained from normal rats. In contrast, femoral bone marrow from leukemic rats contained less daunomycin (per 10(9) nucleated cells) than did normal marrow. Quantification of the daunomycin uptake in vitro by flow cytometry showed that leukemic cells from bone marrow and spleen have an equal net drug uptake. Our data suggest that, in the presence of a high leukemic cell load, the intravenously injected daunomycin is rapidly taken up and retained by the leukemic tumor mass in, e.g., spleen, liver, and lungs, and that, as a consequence of this, the femoral marrow functions as a kind of pharmacological sanctuary.     

Effects of chemotherapy on bone marrow stroma in mice with acute myelogenous leukemia. Correlation with CFU-C and CFU-D

This study describes changes in bone marrow stroma in murine acute myelogenous leukemia (AML). The AML was induced in C57B1 mice by intravenous (i.v.) transfusion of C4198 myelogenous leukemic cells. In untreated leukemic mice, the colony-forming unit fibroblasts (CFU-F) were severely inhibited. In leukemic mice treated by three chemotherapy protocols of cytosine-arabinoside (Ara-C) and adriamycin there was a 200% increase in the life span as compared to untreated leukemic animals and marked reduction of marrow leukemic load. In these mice the stromal inhibition was temporarily relieved, expressed by peaks of CFU-F2-3 days following each protocol. In between the peaks, CFU-F decreased to subnormal levels, remaining low to the end of the disease. In normal mice administered a similar chemotherapy regimen, there were peaks of CFU-F activation after each protocol and normal levels in between the peaks. Granulocyte/macrophage progenitors (CFU-C) of leukemic-treated and normal-treated mice showed increased levels following each chemotherapy protocol. Whereas CFU-C decreased below normal levels in leukemic mice towards the end of the disease, the level of these progenitors remained high in normal mice receiving Ara-C and adriamycin. Colony-forming units in diffusion chamber (CFU-D) showed mild fluctuations in both leukemic and normal mice receiving three protocols of Ara-C and adriamycin. It is possible that despite treatment, the bone marrow stroma in leukemia becomes irreversibly deficient towards the end of the disease and cannot support the residual normal hematopoiesis.     

Improved prognosis in mice with advanced myeloid leukemia following administration of GM-CSF and cytosine arabinoside

Acute myeloid leukemia (AML) was induced in C57Bl mice through the i.v. innoculation of C-1498 cell line. One week later, i.e. at mid-term disease, the leukemic mice received an i.p. injection of 200 ng rmGM-CSF and 24 h later, two consecutive i.p. cytosine arabinoside (ara-C) injections at 6 h intervals (2 x 200 mg/kg). The leukemic mice received 3-4 weekly courses of combined therapy and survived 4-5 weeks following leukemia induction. Control mice received ara-C only and survived 2-3 weeks. Moreover, leukemic mice administered both GM-CSF and ara-C had a lower marrow leukemic load than mice treated with ara-C only. From these findings, we conclude that therapy of murine AML with combined rmGM-CSF and ara-C is more effective than ara-C only. Leukemic mice treated with GM-CSF and ara-C had a longer life expectancy and a smaller leukemic load than mice administered ara-C only.