B16F10/ESAT-6-GPI-IL-21瘤苗安全性及抗肿瘤效应研究

目的:评估B16F10/ESAT-6-GPI-IL-21瘤苗用于C57BL/6小鼠的安全性及其诱导的抗肿瘤免疫效应。方法:应用免疫荧光、FCM检测瘤苗细胞ESAT-6-GPI的表达情况;以Western blot方法检测瘤苗细胞IL-21的表达情况;动物实验检测瘤苗体内应用的安全性;制备荷瘤鼠术后免疫模型,评价瘤苗免疫效果。结果:B16F10/ESAT-6-GPI-IL-21瘤苗细胞表面有靶抗原ESAT-6-GPI表达,并分泌IL-21。于C57BL/6小鼠皮下接种2×105个B16F10/ESAT-6-GPI-IL-21瘤苗细胞,60天内未见致瘤,但能够诱导小鼠产生有效的抗肿瘤免疫效应。结论:B16F10/ESAT-6-GPI-IL-21瘤苗致瘤性明显下降,低剂量应用具有安全性,能够诱导小鼠产生有效的抗肿瘤免疫效应。     

表达ESAT-6-gpi和IL-21的B16F10瘤苗的构建及其活性鉴定

为构建膜表达糖基化磷脂酰肌醇(GPI)锚定的结核杆菌早期分泌靶抗原6 kD(ESAT-6)和分泌IL-21的B16F10瘤苗并鉴定其活性,利用重叠PCR法构建pIRES-ESAT-6-gpi/IL-21重组质粒,以脂质体转染重组质粒到B16F10细胞,G418筛选出阳性克隆,用RT-PCR、免疫荧光、FCM和Western blot检测瘤苗细胞靶抗原表达,用瘤苗细胞培养上清刺激小鼠CD8+T细胞,检测瘤苗所分泌IL-21的生物学活性。结果表明,pIRES-ESAT-6-gpi/IL-21重组质粒DNA测序正确,B16F10-ESAT-6-gpi/IL-21瘤苗细胞目的基因ESAT-6表达于瘤苗细胞表面,增殖能力未受外源基因导入影响,分泌的IL-21具有生物学活性,为研究膜表达ESAT-6和分泌表达IL-21瘤苗的抗瘤效应奠定了基础。     

糖基化磷脂酰肌醇修饰的小鼠IL-21瘤苗抗肿瘤效应及其机制初探

目的 构建糖基化磷脂酰肌醇(glycosyl phosphafidylinositol,GPI)修饰的小鼠IL-21瘤苗,并对此瘤苗的抗肿瘤效应及其机制作初步探讨.方法 通过重叠PCR方法获得IL-21-GPI融合基因并将其插入空载体pcDNA3.1.将鉴定过的重组载体以脂质体法转染B16F10细胞制成瘤苗,细胞间接免疫荧光法及流式细胞仪检测转染瘤细胞膜表面IL-21的表达,通过对小鼠脾细胞的增殖作用鉴定表达的IL-21的生物学活性.将瘤苗接种小鼠后,通过观察小鼠肿瘤体积和生存率分析瘤苗的抗瘤性,并检测了瘤苗免疫鼠的细胞免疫活性.结果 正确构建了pcDNA3.1/IL-21-GPI重组载体,膜表达的IL-21有良好的生物学活性,制备的瘤苗能发挥抗肿瘤效应,其机制与免疫鼠细胞免疫活性增强有关.结论 成功构建了具有抗肿瘤活性的GPI修饰的IL-21瘤苗,为其进一步抗肿瘤免疫治疗研究奠定了基础.     

GPI修饰的ESAT-6核酸疫苗的构建及其免疫功能初探

目的构建糖基化磷脂酰肌醇(GPI)修饰的结核杆菌早期分泌性抗原靶(ESAT-6)核酸疫苗,初步分析其免疫功能。方法利用重叠PCR法构建pIRES-ESAT-6-gpi重组体,转染B16F10细胞,G418筛选阳性克隆,用RT-PCR、免疫荧光检测转染细胞的ESAT-6抗原表达情况;采集ESAT-6核酸疫苗免疫鼠血清,分别检测抗体滴度和CDC效应,免疫磁珠法分选CD4+和CD8+T细胞,CFSE/7-AAD细胞毒实验分析CTL细胞毒活性。结果测序正确的重组体pIRES-ESAT-6-gpi转染细胞后,ESAT-6表达于细胞膜表面。ESAT-6核酸疫苗免疫血清和CD8+T细胞分别通过CDC效应和细胞毒作用杀伤膜表达ESAT-6的B16F10细胞。结论构建的GPI修饰的ESAT-6核酸疫苗能够诱导免疫鼠产生体液和细胞免疫反应,杀伤膜表达ESAT-6的B16F10细胞,为进一步基于该法构建B16F10瘤苗的抗肿瘤免疫效应及机制研究奠定了基础。     

IL-21 gpi和sGM-CSF共同修饰的瘤苗构建及其抗肿瘤效应

目的:构建膜锚定IL-21和分泌性GM-CSF(sGM-CSF)双表达瘤苗,并对其抗肿瘤效应及其机制作初步探讨.方法:用分子生物学方法构建双表达IL-21 gpi和sGM-CSF重组质粒,将鉴定过的重组质粒以脂质体转染B16F10细胞制成瘤苗,用流式细胞仪检测转染瘤苗IL-21 gpi和sGM-CSF的表达.以瘤苗治疗荷瘤鼠,经观察小鼠肿瘤体积、生存率来分析瘤苗的抗瘤性,并检测了瘤苗治疗鼠的细胞免疫活性.结果:正确构建了pRSC/IL-21 gpi-sGM-CSF重组质粒,转染细胞可很好地表达膜锚定IL-21和分泌性GM-CSF,制备的瘤苗能有效地发挥抗肿瘤效应,其机制与瘤苗治疗鼠的脾细胞增殖活性、NK细胞及CD8+细胞细胞毒活性增强有关.结论:成功构建了具有抗肿瘤活性的膜锚定IL-21和分泌性GM-CSF双表达瘤苗,为进一步抗肿瘤免疫治疗研究奠定了基础.     

小鼠IL-18基因修饰瘤苗的抗白血病作用研究

我们在前期工作中成功制备了IL-18基因修饰的白血病疫苗,为了探讨IL-18基因修饰瘤苗的体内抗白血病作用,实验采用L1210小鼠淋巴细胞白血病模型,在小鼠体内接种IL-18基因修饰瘤苗,观察瘤苗对L1210细胞致瘤性的影响及免疫保护作用,并进一步对其抗白血病作用机制进行了探索。结果显示,IL-18基因修饰瘤苗能够明显延长荷瘤小鼠存活时间,大部分小鼠达到长期生存,且长生存小鼠用野生型L1210细胞二次攻击后大多数仍能长期生存,表明IL-18基因修饰瘤苗有显著的抗白血病作用,并可诱导小鼠产生免疫记忆和免疫保护。机制探讨发现,接种IL-18基因修饰瘤苗后,小鼠脾脏淋巴细胞对L1210肿瘤细胞的CTL及NK细胞杀伤活性明显高于对照组(P<0.05),提示IL-18基因修饰瘤苗能够显著增强抗肿瘤CTL和NK细胞反应。接种瘤苗可使小鼠IFN-γ水平升高,但与对照相比无统计学意义,提示IFN-γ可能在IL-18基因修饰瘤苗诱导的抗肿瘤免疫应答中作用不大。     

IL—6基因转染的瘤苗体内诱导的抗肿瘤免疫功能与效果

经丝裂霉素C体外处理后,将IL-6基因转染的、高分泌的IL-6的B16黑色素瘤细胞制成瘤苗。结果发现,体内注射IL-6基因转染的瘤苗后,小鼠脾脏CTL活性、NK活性及IL-2诱导的LAK活性显著升高。经IL-6基因转染瘤苗体内治疗后,荷瘤小鼠的皮下肿瘤生长显著减慢、肺转移结节数显著降低、存活期显著延长,若同时合用低剂量IL-2,则上述治疗效果更好。可见IL-6基因转染的瘤苗能有效地通过诱导机体抗肿瘤免疫功能而发挥抗肿瘤作用,与低剂量IL-2合用后,IL-6基因转染的瘤苗的抗肿瘤效果更佳。     

Hsp70L1增强肿瘤细胞疫苗免疫原性的研究

目的:考察Hsp70L1对肿瘤细胞免疫原性的增强作用。方法:用RT-PCR的方法,从小鼠黑色素瘤B16细胞和C57BL/6小鼠脾脏中获得TRP2153-243及Hsp70L1基因。分别插入pcDNA3.1/V5-His真核表达载体,构建pHSP70L1、pTRP和pTRP2-Hsp3种表达载体。分别转染B16肿瘤细胞并制备坏死或凋亡瘤苗,免疫C57BL/6小鼠后移植B16肿瘤细胞,观察肿瘤生长曲线,采用流式细胞术(FCM)或微量细胞毒的方法检测荷瘤小鼠细胞因子INF-γ和CTL活性。结果:将经过HSP70L1、TRP2及TRP2-HSP基因修饰的坏死或凋亡的B16肿瘤细胞免疫正常小鼠后,观察到Hsp70L1及TRP2-Hsp基因修饰的坏死瘤苗可显著抑制荷瘤鼠肿瘤的生长,并显著促进荷瘤鼠脾脏淋巴细胞CTL活性和IFN-γ产生(P0.05,P0.01);HSP70L1免疫刺激作用在坏死瘤苗中更明显。结论:Hsp70L1可明显提高B16瘤苗的免疫原性,且对坏死细胞瘤苗的作用更显著。     

B7—1基因修饰的肿瘤细胞疫苗抗肿瘤的实验研究

目的：研究B7-1基因修饰的肿瘤细胞作为瘤苗的抗肿瘤作用。方法：通过逆转录病毒载体。将小鼠B7-1基因导入EL-4淋巴瘤细胞中,研究EL-4/B7-1在同系C57BL/6小鼠中的成瘤性及其诱导抗肿瘤免疫的效果。结果：转B7-1基因诱导了CD80的高表达,EL-4/B7-1细胞在小鼠中的成瘤性下降,在肿瘤生长的早期对实验性荷瘤小鼠进行治疗。基因修饰的瘤苗作用明显增强,EL-4/B7-1细胞能有效地保护野生型肿瘤细胞的攻击,射线灭活的EL-4/B7-1瘤苗作用减弱。结论：B7-1基因修饰的肿瘤疫苗可诱导体内的抗肿瘤免疫反应,导致肿瘤的部分根除,为基因修饰的肿瘤疫苗的临床应用提供了实验依据。     

人IL-6基因转染的小鼠黑色素瘤细胞B16-IL-6~ 致瘤性降低的实验研究

应用细胞因子基因转染的瘤苗治疗肿瘤是近年来肿瘤基因治疗的重要进展之一。本研究采用磷酸钙DNA共沉淀法将人IL-6基因转染入B16黑色素瘤细胞中,筛选出一株高分泌IL—6(240U/ml)克隆(B16—IL—6~ ),B16—IL-6~ 细胞体外生长能力减弱,小鼠皮下接种后肿瘤结节形成率降低,生长速度减慢,并对再次接种野生型B16细胞具有抵抗作用。小鼠静脉接种后形成的肺转移结节数显著减少,荷瘤小鼠存活期延长。结果表明IL-6基因转染的肿瘤细胞致瘤性显著下降。并能诱导机体产生抗肿瘤免疫功能。     

表达前列腺特异性膜抗原的DNA疫苗对肿瘤细胞的抑制作用

目的构建表达前列腺特异性膜抗原（PSMA）的DNA疫苗，观察其在体外对肿瘤细胞的免疫攻击和在体内对肿瘤细胞攻击的免疫保护作用。方法通过稳定转染构建表达PSMA的小鼠黑色素瘤细胞系B16-PSMA，将DNA疫苗pCDNA3．1-PSMA通过肌肉注射导入C57BL／6小鼠体内，分离小鼠脾细胞，检测细胞毒性T淋巴细胞（cytotoxic T lymphocytes，CTL）反应。以B16-PSMA细胞攻击免骺小鼠，观察免疫动物的无瘤生存期和肿瘤体积增长情况，评价DNA疫苗的抗肿瘤作用。结果DNA疫苗可诱导小鼠脾淋巴细胞CTL活性，经过免疫后的小鼠成瘤率降低，无瘤生存期延长，肿瘤生长缓慢，肿瘤组织内有较多淋巴细胞浸润，表明产生较强的抗肿瘤反应。结论表达PSMA的DNA疫苗能够诱导小鼠产生特异性免疫反应，对表达PSMA的肿瘤细胞的攻击产生免疫保护作用，为前列腺癌的预防和免疫治疗提供了新的思路。     

肿瘤疫苗Ad-hDCT抑制黑色素瘤B16细胞在C57BL/6小鼠脑内增殖

目的 观察肿瘤疫苗Ad-hDCT预防接种对移植到C57BL/6小鼠脑实质内的黑色素瘤B16细胞增殖的抑制作用.方法 40只C57BL/6小鼠随机分为2组:Ad-BHG对照组(20只)和Ad-hDCT免疫接种组(20只).借助小鼠脑立体定位仪行B16细胞脑内注射;采用大体观察、流式细胞术、石蜡切片HE染色及冷冻切片CD...     

Antitumor efficacy of viable tumor vaccine modified by heterogenetic ESAT-6 antigen and cytokine IL-21 in melanomatous mouse

The goal of this study was to investigate whether glycosylphosphatidylinositol (GPI)-anchored 6?kDa early secreted antigenic target (ESAT-6) and IL-21-producing B16F10/ESAT-6-GPI-IL-21 viable vaccine would induce antitumor efficacy. Mice were immunized with B16F10/ESAT-6-GPI-IL-21 vaccine and challenged by B16F10 cells 2?weeks later. Antitumor efficacy and mechanisms of the vaccine were analyzed. Vaccination with the viable B16F10/ESAT-6-GPI-IL-21 vaccine resulted in an increase of IFN-γ level and the CD8(+)CTL cytotoxicity, a decrease in TGF-β generation and increase in the expression of miR-200c that serves as melanoma suppressor by directly targeting zinc-finger E-box binding homeobox 1 to inhibit epithelial-mesenchymal transition and block tumor metastasis. The vaccine significantly inhibited the melanoma growth, reduced the lung melanoma nodules, and prolonged the mouse survival compared with the controls. These findings highlighted IL-21 as an immune adjuvant in an engineered viable tumor vaccine to reinforce heterogenetic antigen ESAT-6 immune tolerance break to induce powerful antitumor efficacy in mice.     

Dual Role of Interleukin-10 in Murine Lyme Disease: Regulation of Arthritis Severity and Host Defense

In the murine model of Lyme disease, C3H/He mice exhibit severe arthritis while C57BL/6N mice exhibit mild lesions when infected with Borrelia burgdorferi. Joint tissues from these two strains of mice harbor similar concentrations of B. burgdorferi, suggesting that the difference in disease severity reflects differences in the magnitude of the inflammatory response to B. burgdorferi lipoproteins. Stimulation of bone marrow macrophages from C3H/HeN mice with the B. burgdorferi lipoprotein OspA resulted in higher-level production of the inflammatory mediators tumor necrosis factor alpha, nitric oxide, and interleukin-6 (IL-6) than that of macrophages from C57BL/6N mice. In contrast, macrophages from C57BL/6N mice consistently produced larger amounts of the anti-inflammatory cytokine IL-10 than did C3H/HeN macrophages. Addition of recombinant IL-10 suppressed the production of inflammatory mediators by macrophages from both strains. IL-10 was found to modulate B. burgdorferi-induced inflammation in vivo, since C57BL/6J mice deficient in IL-10 (IL-10-/-) developed more severe arthritis than wild-type C57BL/6J mice. The increase in arthritis severity was associated with a 10-fold decrease in the number of B. burgdorferi organisms present in ankle tissues from IL-10-/- mice. These findings suggest that in C57BL/6 mice, IL-10-dependent regulation of arthritis severity occurs at the expense of effective control of bacterial numbers.     

Disaggregation and invasion of ovarian carcinoma ascites spheroids

Background

In vivo studies have recently demonstrated that interleukin 21 (IL-21) enhances the anti-tumor function of T-cells and NK cells in murine tumor models, and the combined use of IL-21 and IL-15 has resulted in prolonged tumor regression and survival in mice with previously established tumors. However, the combined anti-tumor effects of IL-21 and low dose IL-2 have not been studied even though IL-2 has been approved for human use, and, at low dose administration, stimulates the proliferation of memory T cells, and does not significantly increase antigen-induced apoptosis or regulatory T cell (Treg) expansion. This study examined whether recombinant IL-21 alone or in combination with low-dose IL-2 could improve the in vivo anti-tumor function of naïve, tumor-antigen specific CD8⁺ T cells in a gp100_25–33 T cell receptor transgenic pmel murine melanoma model.

Methods

Congenic C57BL/6 (Ly5.2) mice bearing subcutaneous B16F10 melanoma tumors were sublethally irradiated to induce lymphopenia. After irradiation naive pmel splenocytes were adoptively transferred, and mice were immunized with bone marrow-derived dendritic cells pulsed with human gp100_25–33 (hgp100_25–33). Seven days after vaccination groups of mice received 5 consecutive days of intraperitoneal administration of IL-2 alone (20 × 10³ IU), IL-21 alone (20 μg) or IL-21 and IL-2. Control animals received no cytokine therapy.

Results

IL-21 alone and IL-2 alone both delayed tumor progression, but only IL-21 significantly augmented long-term survival (20%) compared to the control group. However, combination therapy with IL-21 and IL-2 resulted in the highest long-term (>150 days) tumor-free survival frequency of 46%. Animals that were tumor-free for > 150 days demonstrated tumor-specific protection after rechallenge with B16F10 melanoma cells. At peak expansion (21 days post vaccination), the combination of IL-21 plus IL-2 resulted in a 2- to 3-fold higher absolute number of circulating tumor antigen-specific pmel CD8⁺ T cells than was stimulated by IL-2 or IL-21 alone. Pmel CD8⁺ T cells were predominantly partitioned into central memory (CD62L⁺/CD127⁺) or effector-memory (CD62L^-/CD127⁺) phenotypes by day 28-post vaccination in IL-21 + IL-2 treated mice.

Conclusion

These observations support the potential use of IL-21 and low-dose IL-2 therapy in combination with a tumor-antigen vaccine and lymphopenic conditioning in future cancer clinical trials to maintain high numbers of anti-tumor memory CD8⁺ T cells with the potential to sustain long term tumor regression and survival.     

影响空弯菌抗原诱导自身免疫应答的因素

利用慢性粘膜免疫应答小鼠模型,研究在空弯菌抗原(CJ-S131菌苗)诱导下,不同品系、性别的小鼠的自身免疫应答。经肠道,持续用CJ-S131菌苗免疫16周后,用ELISA或CELISA检测小鼠体内的抗ds-DNA,ss-DNA,组蛋白,ENA和胸腺细胞抗体。在五个品系小鼠中,四个品系小鼠(BALB/C,ICR,KM和SMMC/B)均有一种或多种被测的自身抗体升高。其中SMMC/B和KM小鼠的EI值较高,BALB/C和ICR小鼠次之。C57BL/6和对照组无显著性差异,提示对空弯菌抗原诱导的自身免疫应答不敏感。在遗传背景的制约下,性别也影响自身抗体的产生,有三种可能:(1)自身抗体升高主要见于雌性小鼠,如雌性KM小鼠被测的各种自身抗体均有升高;(2)雌性,雄性小鼠均有一种以上自身抗体升高,如SMMC/B和BALB/C小鼠;(3)雌、雄性小鼠的自身抗体均无升高,如C 57BL/6。本文结果表明,空弯菌苗诱导的自身抗体种类和水平,受小鼠的遗传背景和性别两个因素的相互制约和影响。