成纤维细胞介导的G-CSF基因疗法促进化疗后造血功能恢复的实验研究

利用RT-PCR方法克隆到包括有全部编码序列和部分5′、3′端非编码序列的人G-CSF cDNA,并通过核苷酸测序得到证实。将其定向克隆至逆转录病毒载体pLXSN,构建成人G-CSF的重组逆转录病毒表达载体pLGSN。体外经CRE和CRIP细胞的两次包装,病毒滴度达到了临床应用的水平(1.1×10~6CFU/ml)。hG-CSF逆转录病毒感染NIH3T3小鼠成纤维细胞后,分泌G-CSF达168U/ml,Southern分析表明hG-CSF基因已整合至NIH3T3-G-CSF细胞的基因组中,Northern和Western分析分别从mRNA和蛋白质水平证实了人G-CSF在NIH3T3-G-CSF细胞的表达。将NIH3T3-G-CSF细胞植入同系小鼠体内,能从血清中检测到持续表达的G-CSF活性。本研究为开展人G-CSF基因治疗奠定了基础。     

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。     

G-CSP基因治疗对大剂量化疗后结肠癌小鼠中性粒细胞数量和功能的影响

中性粒细胞作为一种重要效应细胞在机体抗肿瘤过程中发挥重要的作用。为了探讨G-CSF基因治疗及大剂量化疗后对荷瘤小鼠中性粒细胞的影响以及G-CSF基因治疗后中性粒细胞在抗肿瘤中所起的作用,我们对G-CSF基因治疗后荷瘤小鼠中性粒细胞的数量和功能进行了研究。结果发现,G-CSF基因治疗与重组G-CSF(rhG-CSF)注射疗法相比,能更明显地提高结肠癌小鼠中性粒细胞的数量、中性粒细胞的吞噬功能、杀伤C-26细胞的活性以及分泌IL-1、TNF、NO水平。对大剂量化疗后的结肠癌小鼠,仍能明显提高中性粒细胞数量、吞噬功能、杀伤C-26结肠癌细胞的活性以及分泌IL-1、TNF、NO水平。表明G-CSF基因治疗比rhG-CSF注射疗法更有效地纠正并提高由于大剂量化疗后引起的外周血中性粒细胞的降低,增强中性粒细胞的杀伤活性,促进中性粒细胞分泌IL-1等细胞因子,发挥直接或间接的抗肿瘤作用。     

IL-2和IL-12基因联合治疗小鼠头颈鳞癌的实验研究

目的观察白细胞介素-2(IL-2)基因与白细胞介素-12(IL-12)基因联合治疗小鼠头颈鳞癌的疗效. 方法建立小鼠头颈鳞癌动物模型,在荷瘤部位将脂质体包裹的IL-2基因和IL-12基因直接注入肿瘤中,观察肿瘤大小变化,并检测此两种基因在肿瘤细胞中的蛋白表达情况、小鼠脾脏自然杀伤细胞(NK)和细胞毒T淋巴细胞(CTL)活性. 结果 IL-2基因和IL-12基因联合治疗组,肿瘤生长明显受抑制,疗效显著优于单独治疗组和对照组(P<0.01).在注射有IL-2、IL-12基因的肿瘤组织中,其相对应的IL-2、IL- 12蛋白水平明显升高,小鼠脾细胞NK活性和CTL杀伤活性增强. 结论 IL-2、IL-12基因治疗可抑制小鼠头颈鳞癌生长,提高机体的抗肿瘤免疫应答.二者联合应用,可产生协同效应并加强其抗肿瘤效果.     

G-CSF基因治疗对大剂量化疗后结肠癌小鼠中性粒细胞数量和功能的影响

中性粒细胞作为一种重要效应细胞在机体抗肿瘤过程中发挥重要的作用。为了探讨G-CSF基因治疗及大剂量化疗后对荷瘤小鼠中性粒细胞的影响以及G-CSF基因治疗后中性粒细胞在抗肿瘤中所起的作用．我们对G-CSF基因治疗后荷瘤小鼠中性粒细胞的数量和功能进行了研究。结果发现．G-CSF基因治疗与重组G-CSF(rhG-CSF)注射疗法相比．能更明显地提高结肠癌小鼠中性粒细胞的数量、中性粒细胞的吞噬功能、杀伤C-26细胞的活性以及分泌IL-1、TNF、NO水平。对大剂量化疗后的结肠癌小鼠．仍能明显提高中性粒细胞数量、吞噬功能、杀伤C-26结肠癌细胞的活性以及分泌IL-l、TNF、NO水平。表明G-CSF基因治疗比rhG-CSF注射疗法更有效地纠正并提高由于大剂量化疗后引起的外周血中性粒细胞的降低．增强中性粒细胞的杀伤活性．促进中性粒细胞分泌IL-1等细胞因子．发挥直接或间接的抗肿瘤作用。     

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     

氟胞嘧啶/胞嘧啶脱氨酶自杀基因疗法结合热休克蛋白-多肽复合物治疗小鼠胃癌

目的；研究氟胞嘧啶／胞嘧啶脱氨酶（5－FC／CD）基因疗法与热休克蛋白－多肽复合物（FSP70－PC）免疫疗法联合抗肿瘤效果。方法；将携带CD基因的重组腺病毒注射到小鼠MFC瘤体内，腹腔注射5－FC，同时皮下接种HSP70－PC。结果；经联合治疗后，70％荷瘤小鼠肿瘤体答缩小，消退，小鼠存活期延长，细胞毒T淋巴细胞（CTL）杀伤活性增高，CD4^ 及CD^8 T细胞浸润明显。结论：5－FC／CD基因疗法结合HSP－PC免疫疗法抗小鼠MFC瘤作用显著，具有临床应用前景。     

共刺激分子B7和肿瘤免疫

为了更好地使IL-3在体内发挥其造血促进作用和免疫增强作用，于本实验中建立了IL-3基因疗法的小鼠模型，并动态观察了其外周血细胞数量的变化．通过基因转染、G418抗性筛选、有限稀释及IL-3活性测定，从16株NIH3T3成纤维细胞克隆中选出一株分泌IL-3高达2416U／ml的克隆株。将其移植入小鼠腹腔后，实验小鼠血清可检测出一定水平的IL-3并维持至半个月之久。实验小鼠外周血自细胞，特别是中性粒细胞数量显著增加，血小板也有不同程度的升高。该实验结果表明成纤维细胞途径能将IL-3基因携至体内进行有效表达并发挥显著的生物学作用。     

低剂量环磷酰胺增强MHCⅠ类限制性肿瘤抗原多肽冲击致敏的树突状细胞的抗肿瘤转移效果

目的:研究低剂量环磷酸胺(Cy)联合MHC Ⅰ类限制性肿瘤抗原多肽Mutl致敏、白细胞介素2(IL-2)基因修饰的树突状细胞(DCs)对转移性肺癌小鼠的治疗作用及其免疫学机理.方法:制备小鼠骨髓来源的DCs,用转移性Lewis肺癌特异性多肽Mutl预激经IL-2基因修饰的DCs联合低剂量Cy治疗转移性肺癌小鼠.通过FACS分析其脾细胞内T淋巴细胞比例的变化,~51Cr释放法检测CTL和NK细胞杀伤活性.结果:肿瘤抗原多肽致敏、IL-2基因修饰的DCs与小剂量Cy联合后,能比单用DCs更有效地治疗转移性肺癌,小鼠脾细胞中CD8~+T细胞和NK1.1~+细胞明显比例升高,联合治疗组诱导出的CTL杀伤活性最高.结论:以肿瘤抗原多肽冲击致敏的IL-2基因修饰的DCs联合小剂量Cy能更有效地促进荷瘤宿主免疫应答,具有显著地体内抑制肺癌转移的效果.     

局部注射小鼠白细胞介素12逆转录病毒包装细胞对大鼠肝癌的治疗

目的:研究低剂量环磷酸胺(Cy)联合MHC Ⅰ类限制性肿瘤抗原多肽Mutl致敏、白细胞介素2(IL-2)基因修饰的树突状细胞(DCs)对转移性肺癌小鼠的治疗作用及其免疫学机理.方法:制备小鼠骨髓来源的DCs,用转移性Lewis肺癌特异性多肽Mutl预激经IL-2基因修饰的DCs联合低剂量Cy治疗转移性肺癌小鼠.通过FACS分析其脾细胞内T淋巴细胞比例的变化,~51Cr释放法检测CTL和NK细胞杀伤活性.结果:肿瘤抗原多肽致敏、IL-2基因修饰的DCs与小剂量Cy联合后,能比单用DCs更有效地治疗转移性肺癌,小鼠脾细胞中CD8~ T细胞和NK1.1~ 细胞明显比例升高,联合治疗组诱导出的CTL杀伤活性最高.结论:以肿瘤抗原多肽冲击致敏的IL-2基因修饰的DCs联合小剂量Cy能更有效地促进荷瘤宿主免疫应答,具有显著地体内抑制肺癌转移的效果.     

IL-3基因疗法对骨髓移植后免疫功能重建的影响

以大剂量化疗后进行同基因骨髓移植小鼠为实验模型,动态观察了成纤维细胞介导的IL-3基因疗法对骨髓移植后小鼠免疫功能重建的作用。结果发现,IL-3基因疗法能显著加快骨髓细胞的淋巴细胞增殖反应的恢复,并能显著增强腹腔巨噬细胞的杀伤功能,提高巨噬细胞分泌IL-1、TNF及脾细胞分泌IL-2等细胞因子的水平,从而证明IL-3基因疗法对骨髓移植后机体免疫功能重建具有促恢复作用。     

联合应用成纤维细胞介导的G-CSF基因疗法及IL-2基因疗法对肿瘤的治疗作用

本实验观察了成纤维细胞介导的G-CSF基因疗法对大剂量化疗后造血功能损伤小鼠的恢复作用。结果发现:接受G-CSF基因治疗的实验小鼠外周血白细胞尤其是中性粒细胞降低程度明显减弱,恢复速度明显加快;并可明显促进血小板的恢复,但作用较缓;其脾脏和骨髓CFU-GM、CFU-MK、CFU-S水平显著地高于对照组,表明成纤维细胞介导的G-CSF基因疗法可显著降低大剂量化疗后造血损伤程度,并明显加速受损的造血功能的恢复。     

腺病毒介导的IL—2基因及B7—1基因联合转染G422细胞致瘤原性和免疫原性的变化

目的研究联合细胞因子基因转染的D422胶质母细胞瘤细胞体内致瘤原性和免疫原性的变化,为胶质瘤的免疫基因治疗打下基础.方法IL-2基因和B7-1基因转染的G422细胞1×105皮下和脑内接种,观察肿瘤生长速度和荷瘤小鼠的存活期,2周取脾脏,检测NK、LAK和CTL的杀伤活性.结果IL-2和B7-1基因联合转染的G422细胞,皮下接种后肿瘤生长明显减慢,脑内接种动物存活期明显延长,NK、LAK和CTL的杀伤活性增强.结论IL-2基因和B7-1基因联合转染的G422细胞,致瘤原性下降,免疫原性增强,能有效激活机体特异性与非特异性抗肿瘤免疫反应.     

Combination therapy of murine liver cancer with il-12 gene and HSV-TK gene

Interleukin-12 (IL-12), produced by antigen-presenting cell, is a heterodimeric cytokine that has multiple immune regulatory functions, various studies have shown that IL-12 has multiple anti-tumor effects and anti-metastatic properties for many tumors.[1] Suicide gene approaches are also widely investigated recently, the gene products are capable of converting the non-toxic pro-drug to the active cytotoxic agent. The most commonly used suicide gene and pro-drug is the herpes simplex virus th…     

G-Csf prevents the suppression of bone marrow hematopoiesis induced by IL-12 and augments its antitumor activity in a melanoma model in mice

Background: IL-12 has been successfully used in experimental tumor therapy. However, administration of this cytokine induces dose-dependent suppression of hematopoiesis that could potentially limit its use in clinical trials. We decided to examine whether the myelosuppressive activity of IL-12 could be corrected by the administration of G-CSF.Materials and methods: In the initial experiments the influence of IL-12 and/or G-CSF on bone marrow and spleen GM-CFC was evaluated. To examine whether G-CSF could influence the antitumor activity of IL-12 the combination therapy with these agents was carried out starting on day seven following inoculation of melanoma MmB16 cells into the footpads of B6D2F₁ mice. To obtain insight into the mechanism of the observed augmented antitumor activity of the combination therapy with IL-12 and G-CSF, the influence of these cytokines on macrophage activity (cytotoxicity and nitric oxide release) was analyzed.Results: In accord with our expectations, the application of G-CSF partially prevented the suppression of bone marrow myelopoiesis in IL-12-treated mice. Unexpectedly, G-CSF also showed potentiation of antitumor effects of IL-12 in this melanoma model. The augmented antitumor activity of combined IL-12/G-CSF immunotherapy could result from the enhanced stimulation of macrophage NO production and cytotoxicity.Conclusion: The simultaneous administration of IL-12 and G-CSF partially prevented suppression of bone marrow myelopoiesis in IL-12-treated mice. Moreover, treatment with these cytokines also results in potentiated antitumor effects in a murine melanoma model.     

Dendritic cell immunotherapy with poly(D,L-2,4-diaminobutyric acid)-mediated intratumoral delivery of the interleukin-12 gene suppresses tumor growth significantly

A conventional DC-based immunotherapy has been tested clinically for treatment of patients with advanced cancer but requires modification to further improve the clinical results. In this study, we evaluated the in vivo antitumor effects of DC therapy, non-viral-mediated IL-12 gene therapy, and a combination of the two in a murine bilateral subcutaneous tumor model. DC therapy alone and IL-12 gene therapy alone suppressed tumor growth at the injected sites. However, the antitumor effect on the distant contralateral tumor was insufficient. When DC therapy and IL-12 gene therapy were carried out simultaneously, tumor growth was significantly suppressed bilaterally (P < 0.001). Cytolytic activity was augmented significantly in mice given the combination treatment compared to in mice treated with either DC or IL-12 gene therapy alone (P < 0.05). Microvessel density of both tumors was significantly lower in mice subjected to the combination therapy than in mice treated otherwise (P < 0.05). Furthermore, no side-effects were observed in the treated mice. DC therapy combined with non-viral-mediated intratumoral IL-12 gene delivery has a synergistic antitumor effect not only on targeted tumors but also on contralateral distant tumors and may be of great potential as a therapeutic treatment for patients with advanced cancer.     

Efficient inducation of local and systemic antitumor immune response by liposome-mediated intratumoral co-transfer of interleukin-2 gene and interleukin-6 gene.

Interleukin 2 (IL-2) expressing plasmid and interleukin 6 (IL-6)-expressing plasmid were encapsulated in liposome and administrated intratumoraly into tumor-bearing mice 4 days after subcutaneous inoculation of B16F10 melanoma cells. The results showed that treatment of tumor-bearing mice with IL-2 gene or IL-6 gene transfer inhibited the growth of subcutaneous tumor and prolonged the survival of tumor-bearing mice significantly when compared with the treatment of PBS or control gene transfer mediated by liposome (P < 0.01). Combined transfer of IL-2 gene and IL-6 gene was found to elicit inhibitory effects on the growth of B16F10 tumor more significantly and prolonged the survival period of tumor-bearing mice more obviously. We investigated the local immunity in tumor microenvironment and found that IL-2 and IL-6 gene transfer could significantly increase the expression of lymphocyte function-associated antigen-1 on tumor infiltrating lymphocytes (TIL) and MHC-I molecule on tumor cells freshly isolated from the tumor mass. The NK and CTL activity of TIL increased markedly after the combined transfer of these two cytokine genes. We also observed the systemic antitumor immune response in the tumor-bearing mice and demonstrated that NK and CTL activity of splenocytes and the production of IL-2, tumor necrosis factor and interferon-gamma from splenocytes increased obviously in mice after the combined transfer of IL-2 and IL-6 gene. In conclusion, local and systemic antitumor immunity of the tumor-bearing host could be induced efficiently after the combined gene transfer. The enhanced specific and non-specific antitumor immunity might be responsible for the more potent antitumor effects of the combined gene therapy.     

Responsiveness of experimental prostate carcinoma bone tumors to neutron or photon radiation combined with cytokine therapy

PURPOSE: To improve the outcome of radiotherapy for prostate carcinoma bone tumors, we investigated bone tumor irradiation with photons or neutrons followed by interleukin 2 (IL-2) therapy in a tumor model. METHODS AND MATERIALS: Implantation of PC-3 cells in nude mouse femur cavity induced a bone tumor that progressed to the formation of a palpable tumor, at the hip joint, by Day 20. Established bone tumors were irradiated with photons or neutrons, and a day later, mice were treated with IL-2 therapy for 3 weekly cycles. RESULTS: PC-3 bone tumors responded to radiation with photons or neutrons in a dose-dependent manner. Combination of photon or neutron radiation with IL-2 therapy increased tumor growth delay, compared to that with photons or neutrons alone. Radiation alone or combined with IL-2 significantly increased mouse survival compared to that with IL-2 or no treatment. After combined therapy, a complete inhibition of bone tumor growth was observed in 45% to 50% of the mice. Histologically, the combined therapy resulted in greater tumor destruction associated with fibrosis, new bone formation, and inflammatory infiltrates than that observed with each modality alone. CONCLUSIONS: The efficacy of tumor irradiation with neutrons or photons was enhanced by IL-2 therapy for the treatment of prostate carcinoma bone tumors.