Effects of L-Tetrahydropalmatine on the Expressions of bcl-2 and bax in Rat after Acute Global Cerebral Ischemia and Reperfusion

To investigate the effects of L-Tetrahydropalmatine (L-THP) on the expressions of bcl-2, bax and neuronal apoptosis after cerebral ischemia and reperfusion, 60 Wistars rats were randomly divided into 3 groups: sham-operation group (group S, n = 20), ischemic-reperfusion group treated with saline (group I, n=20) and ischemia-reperfusion group treated with L-THP (group T, n=20) .The rat model of global cerebral ischemia and reperfusion was induced by Pulsinelli's four-vessel occlusion method. The expression of bcl-2 and bax mRNA was detected by in situ hybridization and reverse transcriptional polymerase chain reaction (RT-PCR). The number of apoptotic neurons was examined by terminal deoxynucleotidyl-transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) method. Compared with group S, the expression of bcl-2 and bax mRNA in group I was increased significantly (P<0.01), and the number of apoptotic neurons increased either (P< 0.01). After L-THP treatment, the expression of bcl-2 mRNA was up-regulated (P<0.01) and that of bax mRNA was down-regulated (P<0.01); the number of apoptotic neurons was decreased (P<0.01). Our results indicated that bcl-2 may suppress apoptosis and bax promote apoptosis after cerebral ischemia and reperfusion. L-THP could ameliorate cerebral ischemia and reperfusion damage by reducing the apoptosis through regulating bcl-2 and bax.

Effect of basic fibroblast growth factor and danshen on bcl-2 and p53 mRNA expression in the brain of rats exposed to repeated, high, positive acceleration (+Gz)

BACKGROUND： Both animal experiments and clinical studies have shown that basic fibroblast growth factor （bFGF） and danshen （Salvia miltiorrhiza） can exhibit protective effects on ischemia-reperfusion cerebral injury. OBJECTIVE： To test whether bFGF and danshen can protect cerebral injury induced by exposure to repeated, high, positive acceleration （＋Gz） in an animal model and to analyze the possible mechanisms. DESIGN, TIME AND SETTING： Randomized controlled animal study. The experiment was performed at the Research Center for Molecular Biology, Air-force General Hospital of Chinese PLA from April to August 2000. MATERIALS： A total of 20 clean grade, healthy, Sprague Dawley rats of both genders, weighing （200 ± 15） g, were provided by our experimental animal center. Rats were randomly divided into 5 groups： the control group, ＋Gz exposure group, bFGF group, danshen group, and saline group, with 4 animals per group. bFGF （Beijing Bailuyuan Biotechnology Co. Ltd.） and danshen solution （Shanghai Zhongxi Pharmaceutical Co. Ltd.） were used. METHODS： All rats were fixed on a rotary arm of a centrifugal apparatus （2 m in radius） with their heads oriented towards the center of the apparatus. Except for rats in the control group, the value of ＋Gz exposure was ＋14 Gz with an acceleration rate of 1.5 G/s. The peak force lasted for 45 seconds. ＋Gz exposure was performed three times with intervals of 30 minutes. Rats in the control group received the same ＋Gz procedure, but the G value was ＋1 Gz. Rats in bFGF group and danshen group were intraperitoneally injected with 100 μg/kg bFGF or 15 g/kg danshen solution, respectively, at 30 minutes prior to centrifugation and immediately after centrifugation. Rats in saline group were injected with the same volume of saline. Six hours after exposure, rats were decapitated. One hemisphere was preserved in liquid nitrogen for RNA extraction and the other was processed for apoptosis detection. MAIN OUTCOME MEASURES： mRNA levels of bcl-2 and p53 were measured by semi-quantitative reverse-transcription polymerase chain reaction. Apoptotic cell death was detected by terminal deoxynuleotidyl transferase-mediated dUTP nick end labeling. RESULTS： Changes in mRNA expression of bcl-2 and p53 and apoptotic cells were observed in rat brain six hours after repeated ＋Gz exposures, bFGF and danshen were able block the changes of bcl-2 and p53 expression and inhibit apoptotic cell death. CONCLUSION： The data suggest that apoptosis and changes in bcl-2 and p53 expression in the rat brain can be induced by repeated ＋Gz exposures. Apoptosis is, therefore, one of the molecular mechanisms of brain damage induced by repeated ＋Gz exposures, bFGF and danshen were of the equal potency in preventing brain injury induced by repeated ＋Gz exposures.

THE EXPRESSION OF BCL-2 GENE AFTER TRANSIENT FOCAL ISCHAEMIA AND THE EFFECT OF MK-801

in order to clarify the pesible role of the bcl-2 gene imolved in the cell death Program,and the relatiouship of glutamate receptors with bcl-2 gene expressin, this study examied the expression of bcl-2 gene protein, the neuronal status of apoptosis and the effects of MK-801 using immunohistochemistry and in situ terminal.labelling methods after 30 min of.middle cerebral artery(MCA) occlusion and followed by 24 h of reperfusion. The presence of bcl-2 gene protein increased in the ipeilateral hemisphere of ischaemis espeially in the MCA territory MK-801 enhanced the expresion of the bcl-2 gene protein. No DNA fragmentation was detected in this experiment. In conclusion. bcl-2 gene activity increased during transient focal ischaemia, and was potentiated by MK MK801, which may be an endogenous protective mechanism .against ischaemic apoptosis. Apoptosis wasnot detected after tranient focal ischoemia. for 30 min rollowed by 24 h of reperfusiou.

赤眼鳟LGP2序列结构、组织表达及与MDA5互作特征

为探究赤眼鳟遗传学和生理学实验室蛋白2(laboratory of genetics and physiology 2,LGP2)的功能特征及抗草鱼呼肠孤病毒(grass carp reovirus,GCRV)育种参考潜力,实验克隆获得了2940 bp的赤眼鳟lgp2(Sclgp2)全长cDNA和721 bp的5′端上游序列。Sclgp2 cDNA编码680个氨基酸,包含DEXDc(DExD/H-box helicase domain)、HELICc(helicase superfamily C-terminal domain)和CTD(C-terminal regulatory domain)结构域;其5′端上游序列含有MafB(muscle aponeurosis fibromatosis B)和IRF3(interferon regulatory factor 3)等转录因子结合位点。不同物种LGP2的功能结构域、磷酸化修饰位点数具有相似性,同时也存在结构域排布位置及序列的差异。赤眼鳟和草鱼lgp2 cDNA序列比较初步发现2个位于RNA结合功能区的GCRV抗性关联位点。系统进化分析显示,赤眼鳟LGP2先与草鱼、鲫和青鱼聚在一起,再与鲤科鱼类等聚为一大支。荧光定量表达分析显示,赤眼鳟脾脏中sclgp2表达水平显著高于其他组织,肌肉、心脏中表达量次之,而肠中表达量最低。GCRV感染后,肝脏中ifn1表达水平在24~72 h显著下降,其他组织sclgp2和ifn1表达水平未有显著变化。相关性分析结果显示,赤眼鳟肌肉sclgp2与ifn1表达水平呈极显著正相关(0.999)。酵母双杂交互作检测发现,赤眼鳟LGP2与MDA5存在弱相互作用,而其DEXDc(1~201 aa)、HELICc(390~476 aa)以及CTD(553~668 aa)结构域与MDA5无互作。该研究成功获得了sclgp2全长cDNA及5′端上游序列,明确了其序列结构、免疫表达及与MDA5的互作特征,为赤眼鳟LGP2免疫功能属性研究奠定了基础,并为草鱼抗GCRV育种提供了参考。

TLR2 and TLR4 polymorphisms influence m RNA and protein expression in colorectal cancer

AIM: To evaluate the effect of promoter region polymorphisms of toll-like receptor(TLR)2-196 to-174 del and TLR4-1607T/C(rs10759932) on m RNA and protein expression in tumor tissue and of TLR4+896A/G(rs4986790) on colorectal cancer(CRC) risk.METHODS: The TLR2-196 to-174 del polymorphism was investigated using allele-specific polymerase chain reaction(PCR) and the TLR4-1607T/C and TLR4+896A/G by PCR-restriction fragment length p o l y m o r p h i s m( R F L P). W e g e n o t y p e d 4 3 4 D N A samples from 194 CRC patients and 240 healthy individuals. The m RNA relative quantification(RQ) was performed in 40 tumor tissue samples by quantitative PCR Taq Man assay, using specific probes for TLR2 and TLR4 genes, and ACTB and GAPDH reference geneswere used as endogenous controls. Protein expression was analyzed by immunohistochemistry with specific primary antibodies.RESULTS: No association was found for TLR4-1607T/C and TLR4+896A/G by three statistical models(logadditive, dominant and recessive). However, based on dominant and log-additive models, the polymorphic variant TLR2-196 to-174 del was associated with increased CRC risk [dominant: odds ratio(OR) = 1.72, 95%CI: 1.03-2.89; P = 0.038 and log-additive: OR =1.59, 95%CI: 1.02-2.48; P = 0.039]. TLR2 m RNA expression was increased in tumor tissue(RQ = 2.36) when compared to adjacent normal tissue(RQ = 1; P < 0.0001), whereas the TLR4 m RNA showed a basal expression(RQ = 0.74 vs RQ = 1, P = 0.452). Immunohistochemistry analysis of TLR2 and TLR4 protein expression was concordant with the findings of m RNA expression. In addition, the TLR2-196 to-174 del variant carriers showed m RNA relative expression 2.19 times higher than wild-genotype carriers. The TLR2 protein expression was also higher for the TLR2-196 to-174 del variant carriers [117 ± 10 arbitrary unit(a.u.) vs 95 ± 4 a.u., P = 0.03]. However, for the TLR4-1607T/C polymorphism no significant difference was found for both m RNA(P = 0.56) and protein expression(P = 0.26).CONCLUSION: Our findings suggest that TLR2-196 to-174 del polymorphism increases TLR2 m RNA expression and is associated with higher CRC risk, indicating an important role in CRC genetic susceptibility.

应用RNAi沉默STAT3基因促裸鼠移植瘤细胞凋亡及对Bax/Bcl-2基因表达的影响

目的应用RNAi技术沉默信号转导子与转录活化子3(STAT3)基因,探讨其对人乳腺癌裸鼠移植瘤的细胞凋亡及其对Bax/Bcl2基因表达的影响。方法于雌裸鼠皮下种植MCF7细胞,肿瘤长至一定大小时,随机分为盐水对照(A)组、空质粒对照(B)组及实验(C)组。于肿瘤局部分别注射盐水、psilencer1.0U6空质粒和psilencer1.0U6STAT3siRNA重组质粒。当A组肿瘤长至足够大时处死全部动物,取肿瘤,测其大小及重量,行HE及免疫组化染色,同时用Westernblot检测STAT3,Bax,Bcl2基因的表达水平。结果C组肿瘤瘤块的体积和重量明显小于A,B组(P<0.01)。免疫组化及HE显示C组肿瘤中心区出现大面积细胞坏死及细胞凋亡征象,STAT3免疫组化呈阴性,而A,B组无此现象。Westernblot显示C组STAT3的表达明显低于A,B组(P<0.01),而Bax的表达明显高于A,B组(P<0.05),各组Bcl2的表达水平差异无显著性(P<0.05)。结论应用RNAi技术沉默STAT3基因可以降低人乳腺癌裸鼠移植瘤中STAT3的表达,同时引起Bax基因的表达上调,导致细胞凋亡进而抑制肿瘤的生长。

抗癌药物对乳腺癌细胞Bcl-2、p53、Ki-67表达的影响及相互关系

目的 研究抗癌药物对乳腺癌细胞Bcl 2、p5 3、Ki 67表达的影响及相互关系。方法 取病理诊断为乳腺癌的手术切除标本 ,体外分离细胞作培养 ,应用四甲基偶氮唑盐 (MTT)法分析多柔比星 (ADM )、丝裂霉素 (MMC)、5 氟脲嘧啶 (5 FU)、顺铂 (DDP)、长春新碱 (VCR) 5种化疗药物对乳腺癌细胞的相对抑制率 ,通过免疫细胞化学染色法和图像定量法分析乳腺癌细胞Bcl 2、p5 3、Ki 67的表达改变。结果 乳腺癌细胞在 0 .1XPPC药物浓度体外处理 2 4h后出现形态改变 ,化疗药物对乳腺癌细胞的相对抑制率依次为VCR >5 FU >ADM >MMC >DDP ,各用药组乳腺癌细胞Bcl 2、p5 3、Ki 67表达均有不同程度改变 ,与未用药组比较P <0 .0 0 1,等级相关分析P <0 .0 1和P <0 .0 5。结论 化疗药物主要通过诱导乳腺癌细胞凋亡、抑制细胞增殖等作用 。

Expression,deleton and mnutation of ρ16 gene in human gastric cancer

AIM To investigate the relationship between the expression of p16 gene and the gastric carcinogenesis,depth of invasion and lymph node metastases, and to evaluate the deletion and mutation of exon 2 in p16 gene in gastric carcinoma.METHODS The expression of P16 protein was examined by streptavidin-peroxidase conjugated method (S-P); the deletion and mutation of p16 gene were respectively examined by polymerase chain reaction (PCR) and polymerase chain reaction single-strand conformation polymorphism analysis (PCR-SSCP) in gastric carcinoma.RESULTS Expression of P16 protein was detected in 96.25% (77/80) of the normal gastric mucosa, in 92.00% (45/50) of the dysplastic gastric mucosa and in 47.54% (58/122) of the gastric carcinoma. The positive rate of P16 protein expression in gastric carcinoma was significantly lower than that in normal gastric mucosa and dysplastic gastric mucosa (P＜0.05). The positive rate of P16 protein expression in mucoid carcinoma 10.00% (1/ 10) was significantly lower than that in poorly differentiated carcinoma 51.22% ( 21/ 41 ),undifferentiated carcinoma 57.69% (15/26) and signet ring cell carcinoma 62.50% (10/ 16) (P＜0.05). The positive rate of p16 protein in 30 cases paired primary and lymph node metastatic gastric carcinoma: There was 46.67% (14/30) in primary gastric carcinoma, 16.67% (5/30) in lymph node metastatic gastric carcinoma. The positive rate of lymph node metastatic carcinoma was significantly lower than that of primary carcinoma (P＜0.05). There was of p16 gene mutation in exon 2, but 5 cases displayed deletion of p16 gene in exon 2 in the 25 primary gastric carcinomas.CONCLUSIONS The expression loss of P16 protein related to the gastric carcinogenesis, gastric carcinoma histopathological subtypes and lymph metastasis. The mutation of p16 gene in exon 2 may not be involved in gastric carcinogenesis. But the deletion of p16 gene in exon 2 may be involved in gastric carcinogenesis.

Genetic dissection of glutathione S-transferase omega-1:identification of novel downstream targets and Alzheimer's disease pathways

Alzheimer's disease(AD)is affected by genetic factors.Polymorphisms in the glutathione S-transfe rase omega-1(Gsto1)gene have been shown by genetic correlation analyses performed in different ethnic populations to be genetic risk factors for AD.Gene expression profile data from BXD recombinant inbred mice were used in combination with genetic and bioinformatic analyses to chara cterize the mechanisms underlying regulation of Gstol variation regulation and to identify network membe rs that may contribute to AD risk or progression.Allele-specific assays confirmed that variation in Gstol expression is controlled by cis-expression quantitative trait loci.We found that Gstol mRNA levels were related to several central nervous system traits,such as glial acidic fibrillary protein levels in the caudate putamen,co rtical gray matter volume,and hippocampus mossy fiber pathway volume.We identified 2168 genes whose expression was highly correlated with that of Gsto1.Some genes were enriched for the most common neurodegenerative diseases.Some Gsto1-related genes identified in this study had previously been identified as susceptibility genes for AD,such as APP,Grin2 b,Ide,and Psenen.To evaluate the relationships between Gstol and candidate network members,we transfected astrocytes with Gstol siRNA and assessed the effect on putative downstream effecto rs.We confirmed that knockdown of Gstol had a significant influence on Pa2g4 expression,suggesting that Pa2g4 may be a downstream effector of Gstol,and that both genes intera ct with other genes in a network during AD pathogenesis.

The production of Strains Highly Expressing Human Interleukin-2 cDNA

The plasmid pTLIL-2,which only directed a low-level expression of human interleukin 2(IL-2) cDNA in E.coli,was reconstructed:a series of deletions were made in 3'non-coding region of human IL-2 cDNA,and 7 recombinant plasmids with different deletions were selected,on the other hand, a Tac promoter sequence from pDR540 was inserted to upstream of IL-2 cDNA in pTLIL-2 so that pTLIL-2DT,which contains double Tac promoters,was constructed.And then,E.coli JM103 was transformed with the above 8 recombinant plasmids respectively.The expression efficiency of IL-2 cDNA in E.cbli transformed with different plasmids was evaluated by means of SDS-PAGE and measuring 3H-TdR incorporation of IL-2-dependent activated T lymphocytes in the presence of bacterial extracts.Three engineering strains with high efficiency of IL-2 expression were selected,and all of these strains could produce recombinant IL-2(rIL-2)4 times more than E.coil JM103/pTLIL-2.

The relationship between bcl-2 gene abnormality and nasopharyeal carcinoma

objective To explore the relationship between bcl--2 gene abnormality and nasopharyngeal carcinoma (NPC) Methods: bcl--2/JH fusion gene and bcl-2 protein expression were examined with semi--nested insitu PCR (SNISPCR) and immunohistochemistry technique in 41 NPC. Results: (l) Bcl-2/JH fusion genewere found in 6 cases of 41 NPC (positivity rate, 14. 6% ). (2)Bol-2 protein was expressed in 34 cases of 41NPC, the positivity rate being 82. 9 %. No bcl-2 expression was seen in benign nasopharyngeal lesions. Conclusion: (l) Translocation was not a specific change in lymphoma, but mbr and mcr regions are the two important breakpoint regions in NPC. Bcl-2/JH fusion gene formation may not play an important role in pathogenesis of NPC for its low positive rate. (2) There was no corresponding relationship between formation ofhcf-2/JH fusion gene and aberrant hcf-2 protein expression in NPC.

利用pcDNA3．1／TOPO~TA克隆构建ANNEXIN A2基因的真核表达载体

目的克隆人类ANNEXIN A2基因,构建其正义真核表达质粒。方法采用逆转录聚合酶链式反应技术,从人类正常肺组织中扩增出人类ANNEXIN A2基因的完整编码区全长序列,通过DNA重组技术将该基因重组于pcDNA3．1／TOPO(?)TA真核表达载体上,构建出人类ANNEXIN A2基因正义表达质粒。通过DNA 测序方法对重组表达质粒进行鉴定。结果通过测序分析证实,构建的重组表达质粒目的基因片段为人类 ANNEXIN A2基因的完整编码区1 032 bp。结论构建真核表达载体的方法快速简便,适于进一步研究基因的细胞生物学作用。

马泰勒虫RON2基因的原核表达及生物信息学分析

【目的】对马泰勒虫棒状体颈部蛋白2(RON2)进行原核表达和生物信息学分析,为后续蛋白互作试验提供材料基础。【方法】以马泰勒虫新疆分离株为研究对象,克隆其RON2基因,并与GenBank中已知的马泰勒虫美国WA株基因组数据和顶复门原虫RON2基因序列本地数据库进行BLAST比对,确定其进化关系。构建重组表达载体pET-32a-RON2,融合表达重组蛋白,对RON2基因编码蛋白进行生物信息学分析。【结果】马泰勒虫新疆株RON2基因(NCBI登录号MT939257)长3920 bp,高度保守,与顶复门原虫RON2基因核苷酸和氨基酸序列的相似性分别为31.2%~82.7%和23.8%~79.5%。成功构建原核表达重组质粒,获得的RON2融合重组蛋白分子质量为26 ku,为包涵体蛋白。生物信息学分析表明,RON2蛋白是一种碱性、不稳定亲水性跨膜蛋白,二级结构以α螺旋为主,亲水性较差,抗原性较弱,与其他顶复门原虫RON2蛋白具有相似的三级空间特殊结构和氨基酸序列,且可能与其他入侵蛋白存在相互作用关系。【结论】获得马泰勒虫新疆株RON2基因,诱导表达获得部分RON2融合重组蛋白,该蛋白存在与其他入侵相关蛋白相互作用的位点,可能参与了虫体入侵宿主细胞的过程。

内部核糖体进入位点控制人癌胚抗原与IL-2的共表达

目的 构建能在真核细胞内高效表达的癌胚抗原 (CEA ) /IL 2共表达核酸疫苗 ,为进一步研究CEA核苷酸疫苗、佐剂及它们的特异性抗肿瘤作用奠定基础。方法 通过RT PCR及基因重组技术获得CEA的真核表达质粒 pcDNA 3 CEA ,并利用酶切、连接等手段与IL 2基因重组通过内部核糖体进入位点连接的含有两个表达单元的真核共表达质粒 pIRES CEA /IL 2。 结果 全自动电化学法定量测定CEA表达量为 (2 3 .73± 0 .2 6)ng/ml ,ELISA试剂盒测定IL 2表达量为 (2 0 .17± 0 .13 )ng/ml。 结论 CEA /IL 2共表达载体在真核细胞中能高效表达CEA和IL 2 ,并在表达量上无明显差异。

双Tac启动子的构建及其对人白细胞介素2在大肠杆菌中表达的影响

采用基因工程技术,在表达质粒 PTLIL-2中于人白细胞介素 2(interleukin 2,IL-2)cD-NA 片段前插入了来自质粒PDR540的含Tac 启动子的片段,并适当调整SD 序列与ATG 密码之间的距离,构建成含双Tac 启动子和双SD 序列的质粒 PTLIL-2DT。结果该重组质粒的IL-2 基因在大肠杆菌中表达效率提高了4倍。本文对重组 IL-2抽提和生物活性恢复的处理方法也作了探讨。

中国人组织因子途径抑制物-2基因的真核表达载体的构建

目的 构建组织因子途径抑制物-2（TFPI-2）-pcDNA3．1的表达载体，为进一步研究其表达和蛋白功能奠定基础。方法 设计带有BamHⅠ和XhoⅠ的上、下游引物，从TFPI-2-pcDNA2．1克隆载体中扩增TFPI-2基因片段，PCR产物电泳、胶回收。将回收产物与BamHⅠ和XhoⅠ双酶切的pcDNA3．1表达载体连接，用酶切鉴定其长度和方向并正、反测序鉴定。结果 TFPL2成功插入pcDNA3．1表达载体，酶切鉴定其长度和方向均正确，测序结果也证实其正确的载人。结论 通过上述方法能成功构建TFPI-2-pcDNA3．1表达载体，为进-步研究其功能奠定基础。

白细胞介素-10对人外周血白细胞β-防御素2基因诱导性表达的影响

目的:探讨炎症抑制因子白细胞介素-10(白介素-10)在β-防御素2(hBD-2)基因诱导性表达中的作用。方法:22例健康人被纳入本研究中,以终浓度0 ng/m l的LPS、100 ng/m l的LPS、10ng/m l的IL-10、100 ng/m l的LPS+10 ng/m l的IL-10加入900μl人外周血中,于37℃刺激培养6 h后,提取外周血白细胞总RNA,用实时定量RT-PCR的方法测定外周血白细胞hBD-2mRNA的表达水平。结果:0 ng/m l的LPS或10 ng/m l的IL-10刺激6 h的白细胞中未检测到hBD-2 mRNA,100 ng/m l的LPS刺激6 h后hBD-2mRNA的表达水平为166.9±35.14,而IL-10与LPS共同刺激6 h后hBD-2 mRNA的表达水平为30.40±9.18。IL-10使hBD-2mRNA的诱导性表达水平明显降低(P<0.05)。结论:人外周血白细胞中hBD-2基因呈现诱导性表达,IL-10能下调hBD-2的诱导性表达。

辽宁地区PPARγ2基因Pro12Ala多态性与2型糖尿病的相关性研究

目的:探讨PPARγ2外显子B的Pro12Ala多态性与辽宁地区2型糖尿病的的关系。方法:应用聚合酶链反应-限制性片段长度多态性技术(PCR-RFLP),对358例2型糖尿病患者和326例的非糖尿病对照人群PPARγ2基因外显子的Pro12Ala多态性基因型进行对照分析。结果:PPARγ2基因12Ala等位基因在对照组和2型糖尿病组的频率分别为5.21%,3.35%,两者间无有显著性差异。结论:PPARγ2基因外显子的pro12Ala多态性与2型糖尿病有无明显相关性。

鲤鱼LGP2的基因克隆与表达

利用反转录-聚合酶链式反应和互补脱氧核糖核酸(cDNA)末端快速扩增技术克隆得到鲤鱼的遗传和生理学实验室蛋白2(LGP2)基因的cDNA全长,并对其在鲤鱼抵抗病毒和细菌感染过程中的免疫作用进行研究。结果表明:鲤鱼的LGP2的cDNA全长共2 978 bp,开放阅读框为2 037 bp,编码679个氨基酸;实时荧光定量聚合酶链式反应(Real-time PCR)检测鲤鱼的LGP2的信使核糖核酸(mRNA)表达于所有被测组织中,且在鳃和脑中的表达量较大,而在性腺和血液中的表达量较小;采用poly I:C和嗜水气单胞菌腹腔注射刺激鲤鱼后,各组织中LGP2的mRNA表达量均有所增大;LGP2是鲤鱼以依赖维甲酸诱导基因I样受体(RIG-like receptors,RLR)信号通路的方式进行抗病毒和抗细菌天然免疫过程中的重要调节因子。

白细胞介素-2-乙肝病毒前S抗原融合蛋白在真核细胞中的分泌表达

为了协同人白细胞介素-2（IL－2）与乙型肝炎（乙肝）病毒（HBV）前S抗原（preSAg）的生物学功能，探索能打破持续性感染者对HBV表面抗原（HBsAg）的免疫耐受，诱导机体对HB－sAg和preSAg产生体液和细胞免疫应答的基因免疫与治疗药物，用基因重组方法构建了IL－2和HBV完整preSAg的真核表达嵌合基因及表达质粒pCWIIP。pCWIIP转染的Cos－7细胞能分泌表达IL－2－preS融合蛋白，其表达效率与pCIIL－2转染的细胞表达IL－2一致，细胞上清中IL－2活性单位大于3×103u／ml，并用酶免疫实验法（EIA）检测了preSAg，而其细胞裂解液中IL－2活性很低，preSAg未检测到。本文结果说明preSAg2～19位氨基酸序列的滞留效应是可以克服的。该发现不仅为构建带完整preSAg的新型乙肝疫苗和特异性免疫治疗剂提供了理论与实验依据，而且对蛋白质分泌表达调控的研究也有一定意义。