干扰素-β转染对胶质瘤的治疗和细胞因子的调节作用

目的 探讨干扰素-β（IFN-β）基因转染对胶质瘤的生长抑制和诱导凋亡的作用,明确IFN—B在SK—MG-1细胞系中对其他细胞因子的调节作用。方法 用IFN—β基因转染和蛋白刺激胶质瘤细胞系SKMG-1,通过MTT方法检测细胞增殖情况,并运用流式细胞技术检测其对凋亡的影响,同时用RT—PCR的方法检测细胞因子的表达变化。结果 IFN—β基因转染可以明显抑制细胞增殖,转染后48h和72h对肿瘤细胞的生长抑制率达到37．3％和46．0％。IFN—β基因转染还可以诱发细胞凋亡,转染后48h和72h肿瘤凋亡率达到31．7％和48．2％。RT—PCR结果显示在胶质瘤细胞系中IFN—β上调白细胞介素-1β（IL-1β）和肿瘤坏死因子-α（TNF—α）的mRNA表达,同时一过性下调白细胞介素-6（IL-6）的mRNA表达,而后在24h后上调IL-6的表达。结论 IFN—β基因转染可以抑制胶质瘤细胞系SK-MG-1的增殖,诱发细胞的凋亡,IFN—β对胶质瘤的生长抑制作用可能与其对其它细胞因子的调节作用有关。     

转染外源性p16基因对大鼠恶性胶质瘤的生长抑制作用

探讨p16基因在体内对恶性胶质瘤的生长抑制作用。将外源性p16基因导入C6细胞内，应用立体定向技术将C6细胞种植于SD大鼠颅内尾状核头部，用核磁共振（MR）扫描技术，动态观察颅内肿瘤生长情况，并通过免疫组化，原位杂交和细胞凋亡检测肿瘤细胞的增殖活性，结果显示，转染组和治疗组大鼠生存期较对照组明显延长。治疗组肿瘤随时间的延长逐渐缩小，免疫组化显示转染组和治疗组p16蛋白表达明显增强，原位杂交和细胞凋亡检测表明，转染组和治疗组大鼠肿瘤细胞增殖活性降低。本实验表明，p16基因在体内有抑制恶性胶质瘤生长的作用；瘤体内注入p16cDNA质粒-脂质体复合物，可使肿瘤生长受到明显抑制。并使多数肿瘤消失。     

肺癌患者Th1/Th2状态及川芎嗪的调节作用

本研究采用RT PCR方法 ,以IFN γ和IL 2代表Th1型细胞因子 ,IL 4、IL 6、IL 10代表Th2型细胞因子 ,分别检测 3种肺癌细胞株 (鳞、腺、小细胞肺癌 )以及荷瘤机体外周血单个核细胞 (PBMC )Th1/Th2状态 ,并观察中药川芎嗪 (Tetram ethlpyrazine ,TTMP )的作用。结果显示 3种肺癌细胞株IFN γ和IL 2均无表达 ,而IL 4、IL 6、IL 10均表达 ;经川芎嗪培育后 ,3种肺癌细胞株均出现IFN γ的表达 ,而IL 4、IL 6的表达被抑制 ,小细胞肺癌株同时表达IL 2。肺癌患者PBMC中IL 4、IL 6和IL 10表达阳性率明显高于正常人 ,而IL 2无 1例表达 (0 / 2 3) ,IFN γ仅 1例表达 (1/ 2 3) ;与川芎嗪培养后 (两种浓度 ) ,肺癌患者IL 2 ,IFN γ的表达率明显提高 ;Th2型因子表达的优势状态较未加药组出现明显逆转。表明川芎嗪可促进肺癌细胞株和肺癌患者PBMC的Th2优势状态向Th1方向逆转     

Period2基因对大鼠神经胶质瘤放射敏感性的影响

目的:探讨Period2基因对肿瘤细胞放射敏感性的影响。方法:体外培养C6细胞(C6神经胶质瘤细胞,C6gliomacells),使用脂质体包裹法将Period2表达质粒(pcDNA3.1per2)转导入C6细胞内;以免疫组化及流式细胞术检测Period2表达;通过流式细胞术和克隆形成试验检测稳定转染Period2阳性表达的C6细胞在γ射线照射后的凋亡及增殖情况。结果:γ射线照射后Period2阳性表达的C6细胞射线照射后其较对照组细胞凋亡率减少、增殖率较高。结论:Period2基因过表达使C6神经胶质瘤细胞的放射敏感性降低。     

视黄酸对细胞因子诱导的人肺泡Ⅱ型上皮细胞分泌C3及B因子的影响

目的:探讨视黄酸(RA)对细胞因子诱导的人肺泡Ⅱ型上皮细胞A549分泌C3及B因子的影响。方法:用ELISA检测TNFα和IL1β诱导的A549细胞培养上清中C3及B因子的水平。用RTPCR分析C3及B因子mRNA的表达。结果:TNFα和IL1β诱导A549细胞分泌C3及B因子具有时间和剂量依赖性。IL6诱导A549细胞分泌C3和B因子的水平是未处理组的4.7、1.4倍,IFNγ诱导A549细胞分泌C3和B因子的水平是未处理组的2.1、1.7倍。RA本身对A549细胞分泌C3及B因子没有影响,但可显著增强TNFα和IL1β诱导的A549细胞分泌C3和B因子及其mRNA的表达,以及IL6和IFNγ诱导的B因子合成。结论:RA可上调TNFα、IL1β、IL6和IFNγ诱导的A549细胞分泌C3及B因子,调节肺局部组织的免疫防御反应,为临床上应用RA和细胞因子防治肺部疾病提供了理论依据。     

大鼠胰岛β细胞损伤中IL-18的作用研究

新生Wistar大鼠离体胰岛与细胞因子孵育后 ,观测胰岛素释放和一氧化氮 (NO )生成的变化 ,并用逆转录 聚合酶链反应 (RT PCR )观察IL 18受体信号链 (IL 18Rβ )mRNA的表达水平。结果表明 :(1) 0 6 2 5～ 10nmol/L基因重组小鼠 (rm )IL 18孵育胰岛 2 4h后 ,对累积的和葡萄糖刺激的胰岛素释放以及NO生成均无显著效应 ;(2 ) 2 0 0U/ml基因重组大鼠 (rr)γ干扰素 (IFN γ )或 2 5 0U/ml基因重组人 (rh )肿瘤坏死因子 α (TNF α)单独存在对胰岛素释放和NO生成均无明显效应 ,也不能促使 10nmol/LrmIL 18对胰岛素释放和NO生成产生影响 ;(3) 2 0 0U/mlrrIFN γ +2 5 0U/mlrhTNF α或 15pg/mlrhIL 1β均明显促进NO生成和抑制胰岛素释放 ,而 10nmol/LrmIL 18则不影响IFN γ +TNF α或IL 1β的上述效应 ;(4 )即使经IL 1β和 (或 )IFN γ +TNF α或IL 12孵育后 ,大鼠胰岛素瘤 (RIN )细胞或离体大鼠胰岛仍未见IL 18RβmRNA的表达。提示IL 18在细胞因子所致胰岛β细胞损伤中不发挥直接作用 ,原因是IL 18受体在胰岛 β细胞中不表达。     

mB7-1转染大鼠卵巢癌细胞诱导细胞免疫应答及体内致瘤性研究

为探讨转染mB7 1基因大鼠卵巢癌细胞系后体外诱导细胞免疫应答及其致瘤性 ,我们以逆转录病毒为载体将mB7 1基因转染入大鼠低分化卵巢上皮癌细胞株NuTu 19中 ,流式细胞仪检测mB7 1的表达。用同源淋巴细胞肿瘤细胞混合培养实验 (MTLCs)测定淋巴细胞增殖指数 ,MTT法检测细胞毒淋巴细胞的增殖及其杀瘤活性。将NuTu 19/Neu、NuTu 19/mB7 1细胞分别接种于同源大鼠Fischer344皮下 ,观察mB7 1修饰的肿瘤细胞在动物体内的致瘤性。结果显示 ,mB7 1基因成功地转染入大鼠低分化卵巢上皮癌细胞株NuTu 19,流式细胞仪测定mB7 1基因呈阳性表达。NuTu 19/mB7 1体外刺激脾淋巴细胞增殖能力明显高于对照组细胞 (P <0 0 5 )。NuTu 19/mB7 1体外诱导的CTL较对照组对NuTu 19细胞的杀伤率显著增高 (P<0 0 1)。两种细胞体外增殖能力无明显改变 ,NuTu 19/mB7 1组在Fischer344大鼠体内成瘤时间明显晚于对照组 (P <0 0 5 )。由此可见 ,mB7 1基因修饰的鼠卵巢癌细胞可体外诱导细胞免疫应答 ,接种动物后 ,实验瘤苗的致瘤性下降     

稳定表达人乳头瘤病毒58型(HPV58)E6E7融合基因的人宫颈癌细胞株C33A的构建及验证

为构建稳定表达人乳头瘤病毒(HPV)58型E6E7融合基因的人宫颈癌C33A细胞系,将实验前期构建好并实现真核表达的重组慢病毒颗粒LV-HPV58E6E7转染入HPV(–)的人宫颈癌C33A细胞,经流式细胞仪分选出稳定转染的阳性克隆,利用四唑盐比色(MTT)法检测转染后细胞的生长情况以及流式细胞术检测细胞周期,并将稳定表达HPV58E6E7融合基因的C33A细胞LV-HPV58E6E7/C33A接种于裸鼠左腋下成瘤,用荧光定量PCR(q RT-PCR)、Western blot检测瘤组织中HPV58型E6E7融合基因的转录和表达。结果显示HPV58E6E7融合基因可促进C33A细胞的增殖;LV-HPV58E6E7/C33A细胞株能在裸鼠体内稳定转录及表达HPV58型E6E7融合基因。这表明我们成功建立了能稳定表达HPV58E6E7融合基因的人宫颈癌C33A细胞系LV-HPV58E6E7/C33A,为HPV58型治疗性疫苗的免疫效果检测提供了抗原细胞来源。     

慢性乙肝患者IFN-α治疗后Th1/Th2细胞因子表达与HLA-DRB1*07的相关性

为探讨广东地区汉族慢性乙型肝炎病毒患者IFN治疗 6个月Th1 /Th2因子的表达水平与HLA DRB1 0 7的相关性。收集 89例广东地区汉族接受IFN α正规治疗前和治疗 6个月慢性乙肝患者新鲜抗凝血各 5ml,通过序列特异性引物套式PCR(PCR SSP )方法进行HLA DRB1 0 7检测 ,并同时用双抗体夹心法检测患者外周血CD4+ T细胞分泌IFN γ和IL 4的水平。结果显示 ,所有患者经IFN α治疗 6个月后IFN γ水平增高 ,IL 4水平下降。HLA DRB1 0 7阳性患者治疗前后IFN γ浓度差异平均为 1 87 48pg/ml± 2 8 84pg/ml,IL 4浓度差异平均为 50 91pg/ml± 1 5 32pg/ml;HLA DRB1 0 7阴性患者治疗前后IFN γ浓度差异平均为 455 38pg/ml± 35 41pg/ml,IL 4浓度差异平均为 90 99pg/ml± 1 7 76pg/ml。慢性乙肝患者接受IFN治疗前后Th1 /Th2因子表达的变化水平与HLA DRB1 0 7位点相关     

丹参酮ⅡA对C6胶质瘤细胞的增殖抑制和诱导凋亡作用

目的：探讨丹参酮ⅡA对大鼠胶质瘤细胞株C6的增殖抑制作用及其作用机理。 方法： 应用MTT比色法检测不同浓度丹参酮ⅡA对C6细胞的增殖抑制，应用流式细胞仪观察丹参酮ⅡA对C6细胞周期的影响，应用琼脂糖凝胶电泳观察C6细胞DNA的变化，应用RT-PCR观察相关基因c-myc表达的变化。 结果： 丹参酮ⅡA对C6细胞增殖抑制作用呈剂量依赖性。细胞周期分析显示：用1.0 mg/L丹参酮ⅡA作用C6细胞，在作用72 h出现凋亡峰，凋亡细胞占细胞总数7.7%；用2.0 mg/L丹参酮ⅡA作用C6细胞，在作用72 h出现凋亡峰，凋亡细胞占细胞总数21.6%。琼脂糖凝胶电泳结果显示：一定剂量丹参酮ⅡA作用后，C6细胞具有明显的凋亡特征，细胞核DNA呈梯状降解。RT-PCR结果显示：随着丹参酮ⅡA作用剂量的增加，c-myc基因的表达被明显抑制。 结论： 丹参酮ⅡA对大鼠胶质瘤细胞系C6的增殖具有明显的抑制作用及诱导凋亡的作用，并对原癌基因c-myc的表达具有抑制作用。     

低免疫原性肿瘤可诱导调节性T细胞增生

目的以小鼠低免疫原性瘤细胞和高免疫原性瘤细胞与同系脾细胞混合培养为肿瘤免疫体外模型,研究培养后的脾细胞中CIM（＋）CD25（＋）调节性T细胞（TR）的分布,揭示肿瘤免疫逃逸的机制。方法3种不同高低免疫原性瘤细胞与同系脾细胞混合培养,建立模拟肿瘤免疫的体外模型,以放射性核素掺入法检测混合培养后的脾细胞的增殖,流式细胞术分析TR、CIM（＋）干扰素（IFN）γ（＋）以及CIM（＋）白细胞介素（IL）-10（＋）T细胞分布状况,ELISA法检测混合脾细胞和肿瘤细胞培养卜清液中IFN-1和IL-10水平。结果高免疫原性瘤细胞FBL3或H22刺激的同系脾细胞增殖指数较低免疫原性瘤细胞D5刺激的旧系脾细胞要高,分别高3倍（D5：FBL3=4．94：12．20）和10倍（D5：H22=4．94：44．60）,而3种瘤细胞刺激的同种脾细胞其增殖指数均较相应的肿瘤免疫组要高（D5 1．9倍,FBL3 2．1倍,H22 1．1倍）。在与低免疫原性瘤细胞D,混合培养的同系脾细胞中,与高免疫原性瘤细胞FBL3或H22相比,含更多的TR（D5：H22P〈0．05）和CD4^＋IL-10^＋细胞（D5：FBL3P〈0．01,D5：H22P〈0．01）,上清液中含更高水平的IL-10（P〈0．01,P〈0．01）,而IFN-γ水平很低（P〈0．01,P〈0．01）。结论低免疫原性肿瘤可诱导TR细胞的增生,TR细胞在肿瘤免疫逃逸中有重要作用。     

逆转录病毒介导的小鼠IL-23基因在小鼠结肠癌细胞中的表达及其抗肿瘤活性

目的：获得表达小鼠IL-23(mIL-23)基因的小鼠结肠癌细胞株。方法：应用逆转录病毒载体，将mIL-23基因导入小鼠结肠癌细胞株Colon26，经G418筛选后获得表达mIL-23的阳性细胞克隆(Colon26／IL-23)。用PCR和RT—PCR检测目的基因的表达，用ELISA法检测mIL-23的产生及mIL-23诱导的小鼠脾细胞IFN-γ的产生，用MTT比色法检测Colon26／IL-23细胞和Colon26细胞的体外增殖，将Colon26／IL-23细胞接种于BALB／c小鼠的右侧背部皮下，观察其致瘤性结果：建立了可表达mIL-23基因的小鼠结肠癌细胞株。分泌至培养上清中的IL-23，可诱导小鼠脾细胞产生IFN-γ在体外Colon26／IL-23细胞的生长与Colon26细胞无明显不同，但其在体内的致瘤性下降，具有抗瘤作用。结论：Colon6／IL-23细胞可分泌IL-23并证明其具有抗瘤活性。     

Foxp3转染对哮喘小鼠脾淋巴细胞功能的影响

目的: 转染Foxp3至哮喘小鼠脾淋巴细胞,探讨Foxp3表达对脾淋巴细胞功能的影响。方法: 卵白蛋白(OVA)致敏激发制作哮喘小鼠模型,收集培养脾脏淋巴细胞;使用电穿孔法转染真核表达载体pcDNA3.1(-)-Foxp3至脾脏淋巴细胞,并设转染空质粒组和对照组;RT-PCR和Western blotting检测Foxp3的表达;流式细胞术检测转染后CD4⁺CD25⁺ Treg细胞/CD4⁺细胞比例;MTT法检测转染后的脾脏淋巴细胞增殖反应,ELISA检测脾淋巴细胞上清中白细胞介素4(IL-4)和干扰素γ(IFN-γ)的含量。结果: 转染组Foxp3 mRNA 和蛋白的表达水平显著高于空质粒组和对照组;转染Foxp3后CD4⁺CD25⁺ Treg细胞/CD4⁺细胞比例显著高于空质粒组和对照组;与空质粒组和对照组相比,转染pcDNA3.1(-)-Foxp3质粒明显抑制了脾淋巴细胞增殖;转染组细胞上清中IL-4和IFN-γ含量低于空质粒组和对照组。结论: 转染pcDNA3.1(-)-Foxp3至哮喘小鼠脾淋巴细胞,Foxp3得到有效表达。Foxp3的高表达能增加CD4⁺CD25⁺ T细胞的数量,抑制哮喘小鼠脾淋巴细胞的增殖以及Th1和Th2细胞因子的产生。     

Constitutive expression of IL-18 and IL-18R in differentiated IEC-6 cells: effect of TNF-alpha and IFN-gamma treatment.

The multifunctional cytokine interleukin-18 (IL-18) is an important mediator in intestinal inflammatory processes. The aim of this study was to evaluate the constitutive expression of IL-18 and its receptors (IL-18Ralpha and IL-18Rbeta) in intestinal epithelial cells (IEC) stimulated by tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma). In addition, cellular proliferation and evaluation of brush border enzymes as differentiation markers were studied. Nontransformed rat intestinal epithelial IEC-6 cells were grown on an extracellular matrix (ECM) in medium with or without TNF-alpha, IFN-gamma, or a combination of both. Gene expression of IL-18, its receptors and apoptotic markers was evaluated using real-time PCR. Expression of IL-18Ralpha protein was demonstrated by flow cytometry and Western blot. Enzymatic activities of brush border enzymes and caspase-1 were determined. The constitutive expression of IL-18, IL-18Ralpha and IL-18Rbeta mRNAs and proteins were detected in IEC-6 cells. The biologically active form of IL-18 was released in response to TNF-alpha and IFN-gamma treatment. Exogenous IL-18 had no effect on cellular proliferation, brush border enzyme activities, and gene expression of apoptotic markers. However, the addition of IL-18 stimulated production and release of the chemokine IL-8. These data suggest that IEC-6 cells may be not only a source of IL-18 but also a target for its action.     

日本血吸虫重组28GST T细胞表位谱的预测及鉴定

目的 :用软件预测日本血吸虫重组 2 8GST抗原分子T细胞表位谱 ,并鉴定其Th1型细胞表位。方法 :用软件预测重组2 8GSTT细胞表位谱 ,并筛选几种较好的T细胞表位 ,人工合成表位肽或用基因工程制备重组表位肽融合蛋白。体外刺激经照射的尾蚴感染并用 2 8GST加强免疫的C5 7BL/ 6小鼠 (H 2 b)脾细胞 ,通过淋巴细胞增殖试验、ELISA及流式细胞术等 ,分析各种表位的免疫刺激作用 ,鉴定Th1型细胞表位。结果 :在 9个候选的表位中 ,P6 (73～ 86aa)是刺激作用最强的Th1型细胞表位。结论 :重组 2 8GST含有功能性Th1型细胞表位     

重组质粒pcDNA3.1-IL-15转染对小鼠骨髓DC上表面分子的表达及功能的影响

目的: 探讨重组质粒pcDNA3. 1 IL- 15对小鼠骨髓树突状细胞(DC)表面共刺激分子的表达及免疫功能的影响。方法: 构建真核表达质粒pcDNA3. 1 IL- 15, 以其转染小鼠骨髓DC。用流式细胞仪检测转染的DC表面CD40、CD80及CD86的表达, 并分析转染的DC刺激脾淋巴细胞中CD4 、CD8 T细胞亚群的变化。用MTT比色法检测转染的DC刺激T细胞增殖的作用。用ELISA法检测T细胞产生IFN- γ的水平。结果: pcDNA3. 1- IL- 15转染的DC表面CD40、CD80及CD86的表达均有不同程度的升高。重组质粒转染的DC可诱导小鼠脾淋巴细胞中CD4 、CD8 T细胞增殖, 但CD4 /CD8 T细胞的比值降低。结论: 重组质粒pcDNA3. 1 -IL- 15转染可提高DC表面共刺激分子的表达并增强其免疫功能。     

Effect of IL-10 gene transmission on the PTg-stimulated splenocytes proliferation and Th1 cytokines production from experimental autoimminue thyroiditis rats

Objective: To investigate the effects of gene therapy with IL-10 on PTg-induced proliferation of splenocytes and Th1 cytokine production from PTg-stimulated splenocytes. Methods: EAT rats were divided into four groups:group A (PBS+PLL) , group B (pORF+PLL), group C (pORFmIL10+PLL), and group D (pORFmIL10+ MEM). The substances mixed with lipofectamine were injected into the thyroid tissues of rats on the 18th dday after immunization. The rats were sacrificed at the 8th week. In vitro proliferative responses to ConA and different concentration of PTg were measured by culturing 4×105 splenocytes pulsed with 18.SKBq of [3H] thymidine for the final 12h and then harvested for liquid scintillation counting. In vitro splenocytes were cultured with PTg (25 mg/L). Th1 cytokine IFN-γ,TNF-αand IL-2 were detected by ELISA. Results: The proliferative response to PTg was suppressed in group C, compared with that of group A and B (P＜0.05). The levels of IFN-γ,TNF-oand IL-2 in the supernatant of PTg-stimulated splenocytes were 3548.25 ± 779.47 pg/ml, 27.66±10.50 pg/ml and 3617.73± 609.15 pg/ml, respectively,which were much lower in group C than those in group A and B(P＜0.01, P＜0.05, P＜0.001, respectively). Conclusion: IL-10 gene transmission in thyroid tissues could inhibit PTg specific proliferation of splenocytes from EAT rats and the secretion of Thl cytokines from PTg-stimulated splenocytes.     

Interferon-gamma stimulates the secretion of IL-1, but not of IL-6, by glomerular mesangial cells.

IL-1 activity in culture supernatant and cell lysate from rat mesangial cells stimulated with interferon-gamma (IFN-gamma) was measured by a thymocyte proliferation assay. While IFN-gamma alone had no effect on the secretion or the intracellular pool of IL-1, the enhancement by IFN-gamma of IL-1 secretion in response to lipopolysaccharide (LPS) was observed. The stimulatory effect of culture supernatant on thymocyte proliferation was abrogated by preincubation with the anti-IL-1 antibody. At least 4-h incubation with IFN-gamma and LPS was required to detect enhancing effect of IFN-gamma. The addition of as little as 1 U/ml IFN-gamma significantly increased IL-1 secretion in the presence of 10 micrograms/ml LPS. The IL-6 activity in culture supernatants was determined by measurement of thymidine uptake in mouse IL-6-dependent cell line (MH60.BSF2). Mesangial cells secreted IL-6 in culture supernatant without additional stimuli and LPS distinctly increased it as described previously. However, in contrast to IL-1 production, no effect of IFN-gamma on IL-6 secretion was observed in the presence or absence of LPS. Moreover, we determined whether enhanced IL-1 release is associated with Ia expression on mesangial cells. IFN-gamma alone and the combination with LPS induced marked expression of Ia antigen, whereas LPS alone did not. We conclude that IFN-gamma stimulates the production of IL-1, but not IL-6, by mesangial cells and suggest an important role of IFN-gamma in the pathogenesis of glomerulonephritis by regulating the mesangial production of IL-1 and the accessory cell function of mesangial cells.     

大鼠CD4+ CD25+ T调节细胞的分离培养及其功能分析

目的:研究大鼠CD4 CD25 T调节细胞(Tr)的分离培养,并对其功能进行初步分析。方法:无菌条件下切取大鼠脾脏分离脾淋巴细胞。用免疫磁珠细胞分离系统(MACS)分选CD4 CD25 T细胞,并以流式细胞术检测其纯度后,对其进行扩增。采用混合淋巴细胞反应研究CD4 CD25 Tr细胞对CD4 CD25-T细胞的免疫抑制作用。用ELISA法检测培养上清中IL-2、IFN-γ及IL-10水平的差异。结果:MACS分离的CD4 CD25 T细胞的纯度达86%~93%。该细胞与CD4 CD25-T细胞相比能特异性地表达Foxp3基因。体外培养中能明显抑制效应T细胞增殖及其分泌IFN-γ、IL-2,但其自身能分泌Th2型细胞因子IL-10。结论:采用MACS系统阴性加阳性分选,可高效快速的获得理想纯度和免疫抑制功能的大鼠CD4 CD25 T调节细胞,该细胞对CD4 CD25-T细胞具有明显的免疫抑制作用,并能特异性的表达Foxp3基因。     

Structure and characterization of hamster IL-12 p35 and p40

Complementary DNAs coding for two subunits of hamster interleukin-12 (IL-12), p35 and p40, were cloned from a hamster dendritic cell (DC) cDNA library. The cloning demonstrated that hamster IL-12 consisted of a p35 subunit with 216 amino acid (aa) residues and a p40 subunit with 327 aa. Structural comparison of hamster p35 and p40 at the protein level showed the highest homologies with each counterpart of sigmodon (hispid cotton rat). The gene expressions of hamster IL-12 p35 and p40 in bone marrow (BM) cells cultured in the presence of mouse granulocyte macrophage-colony-stimulating factor (mGM-CSF) and IL-4 were up-regulated during culture. Immunoblot analysis of 293 cells transfected with hamster p35 and p40 expression vectors suggested the presence of a covalently linked p35/p40 heterodimer. Furthermore, supernatant from the 293 cells transfected with both expression vectors induced the up-regulation of interferon-gamma (IFN-gamma) mRNA in hamster splenocytes, indicating that the p35/p40 heterodimer IL-12 protein present in the supernatant was functional. These results suggest that the vectors containing hamster IL-12 cDNA might be suitable tools for developing an immunotherapeutic approach against experimental cancer in a hamster model.