水流动力学注射介导的IL-12基因在小鼠体内的高效表达

目的:评估水流动力学注射法转移表达小鼠白细胞介素12(mIL-12)质粒pCMV-mIL-12的有效性,以及质粒DNA重复注射后转基因的表达情况.方法:通过小鼠尾静脉大体积快速注射pCMV-mIL-12质粒后取血及主要器官,应用ELISA、PCR、RT-PCR及免疫组织化学染色等方法,检测质粒在组织器官中的分布与表达.为了研究重复注射质粒后mIL-12的表达,分别在首次注射后第7天、第14天和第30天二次注射相同剂量的质粒.每次注射前及注射后均取血检测mIL-12的表达及其诱导产生的IFN-γ及NO.结果:注射后10小时血清中的mIL-12蛋白水平最高,第7天恢复到基线值,其表达呈DNA剂量依赖性.IFN-γ及NO的表达高峰均出现在注射后第3天.首次注射后第14天及第30天重复注射可获得mIL-12的再次高效表达.结论:水流动力学注射方法是一种简便、有效的体内IL-12基因转移方式.重复应用水流动力学注射方法体内转移表达mIL-12的裸DNA后,可以获得转基因的再次高效表达,两次注射间隔时间至少为14天.     

小鼠体内RU486诱导的及肝脏特异性的IL-12基因表达

目的 研究含有RU486调控系统质粒的可诱导能力.方法 通过水流动力学注射的方法,将含有RU486调控系统、肝脏特异性启动子以及转基因IL-12的质粒pRS22注射到小鼠体内,质粒注射后不同时间点腹腔注射RU486.通过ELISA试剂盒检测血清中IL-12表达水平,通过PCR、RT-PCR以及免疫组织化学染色的方法,在DNA、RNA及蛋白质水平测试质粒pRS22在小鼠体内的可诱导性表达.结果 为了确定质粒pRS22活性的持续时间,在水流动力学注射10μg质粒后,每7天给小鼠注射1次RU486(250μg/kg),发现尽管每次诱导后血清中IL-12的水平逐渐下降,但直到质粒注射后第15周,仍然可以被诱导表达.为了测试不同诱导方式对IL-12表达趋势的影响,5μgpRS22被注射到小鼠体内后,在6d内分别每天或每两天给小鼠注射1次RU486.结果每两天诱导1次后IL-12表达呈波浪形,而每天诱导1次则可获得持续的IL-12表达.PCR和RT-PCR结果显示,无论有无RU486诱导,都能在肝脏检测到pRS22质粒及GLp65调节子mRNA的表达,但是仅能够在接受RU486的小鼠肝脏中观察到IL-12 p35亚基mRNA表达.免疫组织化学染色结果提示,IL-12蛋白只有在RU486作用下才会在肝细胞中表达.结论 在肝脏特异性启动子TTR控制下,RU486调控系统能够在时间和空间上精确控制转基因IL-12的表达.     

结核分枝杆菌Ag85A基因DNA疫苗的构建及其联合人IL-12表达质粒诱导的小鼠细胞免疫应答观察

目的:构建编码结核分枝杆菌Ag85A分泌蛋白重组真核表达质粒,研究其与hIL-12联合免疫小鼠后的细胞免疫应答。方法:(1)构建质粒:采用PCR法从H37Rv菌株中扩增Ag85A编码基因,用限制性内切酶消化后,插入克隆载体PMD20-T中,经酶切鉴定与序列测定证实后,以亚克隆法构建于真核表达载体PCDNA3.1的相应酶切位点。(2)动物实验:50只C57BL/6N小鼠随机分为:①Ag85A基因疫苗+hIL-12质粒组(联合免疫组);②重组Ag85A基因疫苗组;③卡介苗BCG组(阳性对照);④空载体组(阴性对照);⑤PBS组(空白对照)。基因疫苗、空载体和PBS经肌内注射法免疫各组小鼠,每隔3周免疫1次,共免疫3次,BCG组经尾部皮下注射1×106CFU BCG免疫1次,约0.3 ml/只。第三次免疫小鼠后28天,处死各组小鼠,分离脾细胞,ELISA法检测脾细胞培养上清液中IFNγ-、IL-2、IL-4水平;乳酸脱氢酶释放法检测脾细胞杀伤活性;分离的脾细胞经TB-PPD刺激后,XTT比色法检测脾淋巴细胞增殖活性。结果:(1)成功构建结核分枝杆菌Ag85A基因DNA疫苗。(2)联合免疫组能诱导较强烈的抗原特异性Th1型细胞免疫应答,免疫小鼠脾细胞培养上清液IFN-r和IL-2水平显著高于Ag85A基因疫苗组,与BCG组相当,IL-4分泌减少;特异性CTL杀伤活性明显增强;淋巴细胞增殖活性也明显高于其他组别。结论:hlL-12表达质粒能够增强结核分枝杆菌Ag85A基因DNA疫苗所诱导的小鼠免疫应答。     

乳腺直接注射质粒DNA的转基因暂时性表达研究进展

本综述了对动物乳腺直接注射质粒ＤＮＡ进行验证转基因动物乳腺表达载体正确性的进展，对所注射的质粒ＤＮＡ的制备方法，浓度及其动物乳腺表达的可能机制进行了讨论。     

两种HCV不同结构基因重组质粒DNA诱导免疫应答的比较研究

目的：探讨丙型肝炎病毒（HCV）包膜基因E1E2,对核心基因CDNA疫苗诱生的免疫应答有无增强作用。方法：构建包含HCVC或CE1E2基因片段的真有达载体pHCV-C和pHCV-CE1E2,分别接种于Balb/c小鼠股四头肌（以空载体pcDNA3作为对照）,每间隔2wk l次,用ELISA法检测免疫小鼠血清中抗HCVC特异性抗体的产生。以pHCV-C转染并表达HCcAg r S p2/0细胞为靶细胞,采用^51Cr翻译放试验检测特异性CTL的杀伤作用。结果,两个实验免疫的20只小鼠均产生抗HCV C特异性抗体,当前／靶细胞比例为100：1时,CTL的杀伤率均明显高于对照组（P＜0．01）;pHCV-CE1E2与pHCV-C组之间,无论是抗HCV C抗体的滴度还是CTL的杀伤率均无显著性差异（P＞0．05）。结论E1E2基因的加入,并没有增加HCV C基因DNA疫苗诱导的抗HCcAg特异性抗体的滴度和CTL的杀伤作用。     

登革病毒Ⅱ型NS1基因在小鼠体内诱导的DNA免疫

目的　研究含有登革病毒Ⅱ型NS1基因的重组质粒肌内注射小鼠后在其体内诱导的细胞和体液免疫。方法　用含有登革病毒NS1基因的真核表达质粒pCNX2 NS1于小鼠胫前肌注射并加强免疫 2次。然后定期处死 ,采集血液标本以及小鼠脾细胞 ,检测小鼠的体液和细胞免疫。结果　在末次免疫后 4周检测到小鼠抗NS1抗体 ,并且检测到小鼠CD4 、CD8 亚群的变化。结论　含有登革病毒NS1基因的真核表达质粒pCNX2-NS1免疫小鼠后 ,可以诱导小鼠产生针对NS1的稳定特异性体液、细胞免疫     

体内电穿孔在质粒介导的基因转移及DNA免疫中的应用

目的 研究体内电穿孔技术对于质粒DNA介导的体内基因表达以及HIV-1 Env DNA疫苗免疫效果的影响.方法 将携带荧光素酶Luciferase基因的表达质粒p1.0-Luc和携带HIV-1 CN54 env基因的DNA疫苗质粒p1.0-gp1455m通过单独肌肉注射或肌肉注射后加电穿孔两种不同方法 注射小鼠.用IVIS(R)活体成像系统实时检测Luciferase报告基因在体内的表达情况.用ELISA检测HIV-1 Env特异的抗体反应,用IFN-γ ELISPOT检测HIV-1 Env特异的T细胞免疫反应.结果 体内电穿孔技术可以显著提高Luciferase在小鼠体内的表达水平,幅度达35倍.HIV-1 Env DNA疫苗免疫结果 显示,8μg质粒剂量电穿孔途径诱导的体液和细胞免疫应答强于40μg质粒剂量单纯肌肉注射组;体内电穿孔途径免疫2次与单纯肌肉注射途径免疫3次诱导的体液和细胞免疫应答水平相当.结论 体内电穿孔技术可以大幅度提高报告基因在体内的表达水平和DNA疫苗的免疫应答.     

体内电穿孔在质粒介导的基因转移及DNA免疫中的应用

Objective To investigate the effects of in vivo electroporation on plasmid mediated reporter gene expression and immunogenicity of DNA vaccine. Methods Luciferase expression plasmid was administered intramuscularly to BALB/c mice at 8μg and 40μg dosage level through injection with or without eletroporation Luciferase expression level in murine muscle was detected by IVIS imaging system 24 h after injection. DNA vaccine plasmid p1.0-gp1455m carrying codon-optimized env gene of CN54 strain ( HIV-1 CRF07_BC) was administered to mice at dosages of 8μg and 40μg through the two approaches mentioned above. Mice were immunized at week 0,2 and 4. Env-specific immune responses were detected at two weeks post the second and the third vaccinations. Env-specific antibody immune responses were determined by ELISA. Euv-specific cellular immune responses were determined by IFN-γ ELISPOT. Results Luciferase expression level in murine muscle was significantly increased as much as 35 folds through in vivo eletroporation. Results of ELISA and ELISPOT revealed that in vivo eletroporation could significantly enhance both the humoral and cellular immune responses induced by DNA vaccination. The responses induced by electrodelivered p1.0-gp1455m at 8 μg dosage were better than those induced by simple intramuscular injection with 40 μg of plasmid DNA. On the other hand, 2 injections followed by electroporation elicited comparable level of humoral and cellular immune responses with those induced by 3 injections without electroporation. Conclusion In vivo electroporation was capable of enhancing both the plasmid-mediated gene expression and immunogenicity of DNA vaccine.     

乙型肝炎病毒pre S基因真核表达质粒诱导小鼠特异性？…

本文构建了含有ＨＢｓＡｇ ｐｒｅ Ｓ区基因的真核表达载体ｐＣＭＶ４－ｐｒｅ Ｓ，经大量提取质粒并纯化后，肌肉注射Ｂａｌｂ／ｃ小鼠，共免疫３次，间隔两周，结果有３／７的小鼠血清抗ｐｒｅ Ｓ２抗体呈阳性。     

体内电穿孔在质粒介导的基因转移及DNA免疫中的应用

Objective To investigate the effects of in vivo electroporation on plasmid mediated reporter gene expression and immunogenicity of DNA vaccine. Methods Luciferase expression plasmid was administered intramuscularly to BALB/c mice at 8μg and 40μg dosage level through injection with or without eletroporation Luciferase expression level in murine muscle was detected by IVIS imaging system 24 h after injection. DNA vaccine plasmid p1.0-gp1455m carrying codon-optimized env gene of CN54 strain ( HIV-1 CRF07_BC) was administered to mice at dosages of 8μg and 40μg through the two approaches mentioned above. Mice were immunized at week 0,2 and 4. Env-specific immune responses were detected at two weeks post the second and the third vaccinations. Env-specific antibody immune responses were determined by ELISA. Euv-specific cellular immune responses were determined by IFN-γ ELISPOT. Results Luciferase expression level in murine muscle was significantly increased as much as 35 folds through in vivo eletroporation. Results of ELISA and ELISPOT revealed that in vivo eletroporation could significantly enhance both the humoral and cellular immune responses induced by DNA vaccination. The responses induced by electrodelivered p1.0-gp1455m at 8 μg dosage were better than those induced by simple intramuscular injection with 40 μg of plasmid DNA. On the other hand, 2 injections followed by electroporation elicited comparable level of humoral and cellular immune responses with those induced by 3 injections without electroporation. Conclusion In vivo electroporation was capable of enhancing both the plasmid-mediated gene expression and immunogenicity of DNA vaccine.     

Inhibition of ovulation by low-dose mifepristone (RU 486).

Mifepristone (RU 486) is a potent antigestagen and antiglucocorticoid which when given at a dose of 25-600 mg disrupts folliculogenesis, inhibits ovulation and induces menses in healthy women. This study reports the effects of much lower doses of mifepristone than used previously, given for the duration of a complete menstrual cycle. Healthy female volunteers (n = 11) with regular menstrual cycles were given mifepristone at a daily dose of 5 mg (n = 6) or 2 mg (n = 5) for 30 days, beginning immediately after an ovulatory placebo cycle. Mifepristone prevented menstruation for the duration of the treatment period, with recurrence of menses 15-29 days after replacement of mifepristone with placebo. Daily mifepristone given in either 5 mg or 2 mg doses inhibited ovulation, as indicated by the lack of a rise in urinary pregnanediol excretion. The excretion of oestrone glucuronide in urine rose during treatment, suggesting ovarian follicular development. Inhibition of ovulation appeared to result from a failure of the positive feedback effect of oestradiol on the hypothalamo-pituitary axis, as no surges of luteinizing hormone were seen despite pre-ovulatory levels of oestrone glucuronide being measured during exposure to mifepristone. The cycle immediately following treatment was shorter than the pre-treatment cycle, with lower peak levels of pregnanediol glucuronide, suggesting an inadequate luteal phase. Recovery from the effects of mifepristone treatment was more rapid after 2 mg than after 5 mg and one subject conceived in the immediate post-treatment phase, indicating adequate ovulation and luteinization.(ABSTRACT TRUNCATED AT 250 WORDS)     

The steroid RU486 induces UCP1 expression in brown adipocytes

RU486 (mifepristone), a potent antagonist at progesterone and glucocorticoid receptors (PR and GR), is well known for its use in the termination of unwanted pregnancies, the potential development of oral contraceptives, treatment of certain cancers and other activities. Potentially, it could also play a role in obesity control, although the few studies that have addressed this aspect have focused mainly on its central and anti-glucocorticoid effects. We have shown previously that it could have a direct effect on brown adipocytes in culture when administered together with progesterone. The aim of the present work was to analyse the effects of RU486 on the expression of uncoupling proteins (UCPs) in brown adipocytes. In culture-grown, differentiated brown adipocytes, placed in a serum-free medium to exclude the presence of progesterone or glucocorticoids, RU486 stimulated UCP1 expression at both the mRNA and protein levels. These effects could be mediated by PR, GR or other unknown mechanisms but do not seem to be due to its anti-progestin or anti-glucocorticoid actions. The results suggest that the steroid RU486 has a direct action on adipocytes which could be useful for stimulating non-shivering BAT thermogenesis and therefore is of interest in obesity studies.     

Displacement of receptivity for nidation in the rat by progesterone antagonist RU 486: a scanning electron microscopy study

In the rat, the period of receptivity for nidation (implantationwindow) is characterized by specific change of the apical surfaceof the luminal uterine epithelium, such as the presence of largeectoplasmic projections (pinopodes). Under the conditions ofthis study, fully developed pinopodes appeared during normalpseudopregnancy on day 5 only. When RU 486 (5 mg/kg s.c.) wasgiven once on day 1, the chronological limits of the appearanceof these projections were changed. Fully formed pinopodes wereobserved on days 6-8 instead of day 5, indicating a displacementand enlargement of the receptive period. This property of theprogesterone antagonist could be of clinical interest if itcould be used to enlarge the ‘implantation window’in women after replacement of in-vitro fertilized eggs.     

Effects of RU486 in the expression of progesterone receptor isoforms in the hypothalamus and the preoptic area of the rat during postpartum estrus

In several mammalian species females undergo postpartum estrus, a brief period of ovulation and sexual receptivity that in rats usually occurs during the first 24 h following parturition. The maximal lordotic expression occurs at 12 h after the initiation of parturition and depends on intracellular progesterone receptor (PR). We studied the regulation of PR expression by its antagonist, RU486 in the hypothalamus and the preoptic area of the rat during postpartum estrus by Western blot. Adult female rats were treated with RU486 (1.25 and 5 mg) 3 h after parturition, and Western blot was performed to assess the expression of PR-A and PR-B at 12 h postpartum. RU486 (1.25 and 5 mg) reduced the expression of PR-A (63% and 95%) and that of PR-B (75% and 99%), respectively in the preoptic area whereas it had no effects in the hypothalamus. These results suggest a differential regulation of PR expression in the rat brain during postpartum estrus.     

The effect of RU486 on the gene expression profile in an endometrial explant model

Administration of RU486 in vivo during the receptive phase rapidly renders the endometrium non-receptive to the implanting embryo. In order to identify key pathways responsible for endometrial receptivity we have used cDNA arrays to monitor gene expression changes in short-term endometrial explants in response to RU486. Endometrial biopsies from five normal fertile women at mid-secretory phase were cultured in the presence of estradiol and progesterone with or without RU486 for 12 h. cDNA arrays were produced containing approximately 1000 sequence-verified clones which included genes known to be important in angiogenesis, apoptosis, cell signalling, extracellular matrix remodelling and cell cycle regulation. cDNA probes from the paired endometrial samples were hybridized to the arrays and hybridization signals were quantified. A total of 12 genes displayed significant changes in expression; six were up-regulated and six down-regulated following RU486 treatment. For five of these genes this is the first report suggesting that they are regulated by steroids in the endometrium. JAK1 and JNK1 were two of the genes shown by the arrays to be down-regulated in RU486-treated endometrial explants. This was confirmed by real time RT-PCR. JAK1 immunoreactivity was localized to both glandular epithelium and the stroma of normal endometrium and staining was much stronger in the luteal phase of the cycle. These results show that components of two important signalling pathways in endometrium-the JAK/STAT pathway, and the JNK pathway-are altered by RU486. Genes whose expression is controlled by these pathways are likely to be involved in the mechanism by which steroids render the endometrium receptive to the implanting embryo.     

携带人FL、GM-CSF基因的裸DNA的抑瘤作用

目的探讨可表达人FL和GM-CSF的裸DNA抑制小鼠移植肿瘤生长的作用。方法分别将带有信号肽序列的人FL和GM-CSF基因插入pcDNA3.1/zeo载体,构建分泌表达人FL和GM-CSF的治疗用表达载体,经SephacrylS1000柱层析法纯化了重组表达质粒。用Western印迹和ELISA法检测目的基因在293细胞中的表达,并用TF1细胞验证293细胞表达的GM-CSF的生物学活性。重组表达质粒与脂质体孵育形成复合物,隔天肌肉注射小鼠共6次,每只小鼠接种T细胞淋巴瘤细胞EL-4 2×105后,观察不同基因组合条件下肿瘤的生长情况。结果人FL和GM-CSF在293细胞中表达量分别为50μg/L和30μg/L,单用FL或GM-CSF和两者联用对肿瘤生长均有一定抑制作用,在第17天抑制率为30%~40%。联合应用组较单用FL或GM-CSF组更为有效抑制肿瘤生长,但小鼠生存时间并无延长。结论人FL和GM-CSF在293细胞中均获表达,且对肿瘤的早期生长具有一定的抑制作用,两者联合应用效果更为明显,但对小鼠最终生存时间并无影响。     

IL-12基因不同亚基真核表达载体的构建及表达

目的:克隆并构建含人白介素12(hIL-12)基因p35、p40不同亚基的真核表达载体,瞬时转染真核细胞并诱导IL-12的表达。方法:人单核细胞白血病细胞株(THP-1)和人白血病细胞株(HL-60),经DMSO、IFN-γ和LPS诱导后,用RT-PCR及SOEPCR扩增IL-12p40、p35及p40-p35融合基因;并构建pcDNA-p35、pcDNA-p40及pcDNA-IL-12真核表达载体。以3种重组质粒分别瞬时转染COS-7细胞后,通过RT-PCR及ELISA法检测目的基因的表达。结果:经诱导后,从HL-60细胞中扩增到IL-12p40和p35基因片段;但从THP-1细胞中只扩增到p35基因片段,未能扩增到p40基因片段;经酶切鉴定、PCR扩增及序列测定表明pcDNA-p35、pcDNA-p40及pcDNA-IL-12真核表达质粒构建成功;并在COS-7细胞中可检测到IL-12的表达。结论:含hIL-12基因不同亚基的真核表达质粒的成功构建,对进一步研究IL-12在免疫应答中的调节作用以及作为免疫佐剂改善BCG免疫保护效果的研究奠定了基础。