抗HIV-1 gp120单克隆抗体的制备及其初步应用

目的：制备抗HIV-1 gp120单克隆抗体（mAb），并建立一种可用于检测gp120的ELISA法。方法：采用基因工程抗原HIV-1gp120免疫BALB／c小鼠，通过B细胞杂交瘤技术制备抗HIV-1gp120的mAb。用ELISA法答定mAb的Ig亚类、效价及特异性。用饱和硫酸铵（SAS）纯化mAb，并用HRP标记后建立双mAb夹心ELISA法。结果：筛选出10株稳定分泌抗HIV-1gp120 mAb的杂交瘤细胞株，9株为IgG，其中4株的腹水效价为32X10～256X10所得mAb与HIV-1gp41、HIV-1p24及HIV一2gp36Ag均无交义反应，仅与HIV-1gp120产生特异性反应。用mAb 6H9和9H12，建立了双夹心ELISA法，检测gp120抗原的灵敏度是10μg／L。结论：获得10株特异性强、效价高的机HIV-1gp120的mAb，并建立了灵敏度良好的双mAb夹心ELISA法.     

人免疫缺陷病毒Ⅰ型包膜糖蛋白gp120基因在大肠杆？…

目的 提高人免疫缺陷病毒Ⅰ型（ＨＩＶ－１）包膜糖蛋白ｇｐ１２０基因在原核中的表达量。方法 采用聚合酶链反应（ＰＣＲ）技术扩增出５６０ｂｐ的ＨＩＶ－１ＬＡＶ株ｇｐ１２０Ｎ端基因片段，经ＥｃｏＲⅠ及ＳａｌⅠ酶切后插入高效表达载体ＰＥＴ２８ａ得到重组质粒ｐＥＴ／１２０，并转化表达宿主菌ＢＬ２１（ＤＥ３），经诱导高效表达出ＨＩＶ－１ｇｐ１２０基因片段。结果 间接酶联免疫吸附试验（ＥＬＩＳＡ）及Ｗｅｓｔｅｒ     

人类免疫缺陷病毒Ⅰ型包膜糖蛋白gp41的基因重组表达

目的基因重组表达（ＨＩＶ１ｇｐ４１）抗原，并研制一种快速、简便、灵敏性高、特异性强的国产ＨＩＶ１免疫检测试剂。方法选用ＨＩＶ１型ＢＨ１０毒株的包膜糖蛋白ｇｐ４１的部分基因（６９７７７４９７），重组在ＰＢＶ２２１表达载体上。表达产物通过１５％ＳＤＳ聚丙烯酰胺凝胶电泳初步分离纯化，根据ＲＦ值，切下含特异蛋白的胶带，以Ｗｅｓｔｅｒｎｂｌｏｔ法转移在硝酸纤维素膜上；免疫血清法检测合格者制备的抗原检测条带，经国家标准参比血清检测。结果获得１株含ＨＩＶ１ｇｐ４１基因的重组质粒，其蛋白的特异性表达为８％，经ＨＩＶ１阳性血清检测和国家标准参比血清检定，该表达蛋白灵敏性、特异性均为１００％。结论（１）可以选用单一的ｇｐ４１作为ＨＩＶ１感染初筛试剂的抗原。（２）表达载体ＰＢＶ２２１其表达的目的蛋白为非融合蛋白，作为试剂中的抗原，可降低检测中的非特异性。（３）该试剂是一种简便、特异、灵敏性高的试剂。     

HIV-1糖蛋白gp120激发人小胶质细胞钙内流效应和ERK磷酸化

目的： 探讨HIV-1糖蛋白gp120对人小胶质细胞钙离子内流和ERK磷酸化的作用及其机制。方法: 用钙离子探针Fluo-4标记粘附在盖玻片上的人小胶质细胞，运用共聚焦显微镜以荧光强度为指标实时观察各种条件下的细胞内钙离子水平的变化；用gp120处理并用anti-gp120-FITC进行染色，运用共聚焦显微镜术和流式细胞术分析人小胶质细胞与gp120结合情况；用抗磷酸化ERK 抗体免疫荧光方法进行染色，运用共聚焦显微镜术和流式细胞术进行ERK磷酸化水平分析。结果: 共聚焦显微镜检测结果显示HIV-1 糖蛋白gp120能够激发人小胶质细胞钙离子内流效应；共聚焦显微镜和流式细胞仪分析结果显示gp120可以与人小胶质细胞结合；共聚焦显微镜和流式细胞仪分析结果显示gp120刺激可增加人小胶质细胞ERK磷酸化。结论: HIV-1 糖蛋白gp120能在人小胶质细胞激发钙离子内流并且增加胞内ERK的磷酸化，从而导致了小胶质细胞的活化，这一效应提示，在HIV-1相关性脑炎中，gp120可能参与了某些发病机制。     

以Rev依赖性凋亡增强HIV-1gp160的抗原性

目的　检测Rev(HIV的调控基因 )依赖性肿瘤坏死因子受体 (TNFR 1)和gp16 0双重表达质粒pDM12 8 TNFR 1(pT12 8)的凋亡诱导功能。方法　采用基因枪转导及流式细胞仪检测新质粒的表达功能。结果　新结构具有特异的选择性表达作用。当Rev存在时 ,能间接表达TNFR 1,明显诱导HeLa细胞凋亡 ,使绿荧光细胞百分率非常显著地低于阴性对照 (P <0 .0 1)。等质量转染时 ,TNFR 1表达量少于Hup6 0TNFR 1的pDC30 2 (pT6 0 ) ,故间接表达不及单纯pT6 0的直接表达 ,绿荧光细胞百分率显著高于pT6 0转染组 (P <0 .0 1)。培养 40h ,才有明显杀伤功能并接近单纯pT6 0 ,差异无显著性 (P>0 .0 1)。单纯pT12 8不能直接表达TNFR 1,绿荧光细胞百分率非常显著地高于单纯pT6 0转染组 (P<0 .0 1) ,接近阴性对照 ,培养 40h时差异无显著性 (P >0 .0 1)。当AD8或pMD +pRnv存在并表达Rev时 ,pT12 8均能表达TNFR 1,杀伤HeLa细胞 ,绿荧光细胞百分率非常显著地低于阴性对照 (P <0 .0 1)。pT12 8与pRev或AD8转染人正常的角质生成细胞时 ,能表达TNFR 1,诱导细胞凋亡。培养 72h后 ,阴性对照和单纯pT12 8组的绿荧光角质生成细胞数皆显著地超过pT12 8+pRev和pT12 8+pAD8组 (P <0 .0 1)。结论　pT12 8可调控的凋亡诱导保证了HIVDNA疫苗足量的抗原表     

HIV-1包膜蛋白gp120在神经元损伤诱发认知障碍中的作用

目的探索HIV-1包膜蛋白gp120在神经元损伤引起认知障碍中的作用。方法免疫印迹和免疫荧光检测gp120处理后的小胶质细胞活化、炎症因子表达和神经元损伤情况;免疫组化分析gp120转基因小鼠的神经元损伤情况;行为学分析转基因小鼠的神经认知状况。结果体内和体外试验结果表明HIV-1 gp120可显著诱导caspase-1与IL-1β表达,并间接引起神经元突触变短和神经元损伤(P<0.05);与野生型小鼠相比,gp120转基因小鼠出现明显的皮层和海马回小胶质细胞激活、神经元丢失与树突损伤以及神经认知紊乱现象。结论HIV-1 gp120可能通过激活小胶质细胞炎症因子释放导致神经元损伤并可能与神经认知障碍发生相关。     

人免疫缺陷病毒Ⅰ型包膜糖蛋白gp120基因在大肠杆菌中的高效表达

目的提高人免疫缺陷病毒Ⅰ型（ＨＩＶ－１）包膜糖蛋白ｇｐ１２０基因在原核系统中的表达量。方法采用聚合酶链反应（ＰＣＲ）技术扩增出５６０ｂｐ的ＨＩＶ－１ＬＡＶ株ｇｐ１２０Ｎ端基因片段，经ＥｃｏＲⅠ及ＳａｌⅠ酶切后插入高效表达载体ｐＥＴ２８ａ，得到重组质粒ｐＥＴ１２０，并转化表达宿主菌ＢＬ２１（ＤＥ３），经诱导高效表达出ＨＩＶ－１ｇｐ１２０基因片段。结果间接酶联免疫吸附试验（ＥＬＩＳＡ）及Ｗｅｓｔｅｒｎｂｌｏｔ实验表明，表达产物具有良好的抗原性及特异性。ＳＤＳ－ＰＡＧＥ电泳分析结果表明，ｇｐ１２０表达量占总菌体蛋白的５０％。结论在原核系统中高效表达了ＨＩＶ－１ｇｐ１２０基因     

抗人免疫缺陷病毒1型gp120人源单链抗体的表达

目的研究人源抗人免疫缺陷病毒１型（ＨＩＶ－１）ｇｐ１２０单链抗体（ＳｃＦｖ）。方法以人工合成的ＨＩＶ－ｌｇｐ１２０Ｖ３环多肽为抗原，利用噬菌体抗体库技术，筛选含有抗－ｇｐ１２０ＳｃＦｖ基因的噬菌体，提取质粒，转化大肠杆菌ＨＢ２１５１，表达可溶性ＳｃＦｖ。结果经ＳＤＳ－ＰＡＧＥ和Ｗｅｓｔｅｒｎｂｌｏｔ分析，表达产物分子量为２８ｋＤ左右，且具有ｃ－ｍｙｃ活性；ＥＬＩＳＡ和Ｄｏｔｂｌｏｔ结果表明，可溶性ＳｃＦｖ具有较好的抗原结合活性和较强的特异性；竞争性ＥＬＩＳＡ实验结果进一步证明表达产物的特异抗－ｇｐ１２０活性。结论该技术便捷有效，可大量获得人源抗ＨＩＶ抗体片段，为进一步研究抗ＨＩＶ抗体的生物活性和ＨＩＶ感染诊治打下基础     

共表达HIV-1 gp120与IFN-α重组鸡痘病毒诱导特异性CTL的初步研究

目的:探讨共表达HIV -1gp12 0与IFN- α重组鸡痘病毒诱导小鼠产生特异性的CTL杀伤活性。方法:将重组鸡痘病毒经肌肉注射免疫BALB c小鼠后,制备小鼠脾淋巴细胞悬液。以免疫小鼠的脾淋巴细胞为效应细胞,以表达HIV- 1结构蛋白的P815细胞为靶细胞,用乳酸脱氢酶释放法测定免疫小鼠脾特异性CTL杀伤活性。结果:重组病毒可有效地诱导特异性CTL的产生,且重组病毒免疫组小鼠脾特异性CTL对靶细胞的杀伤活性显著高于FPV对照组(P <0 .0 1)和PBS对照组(P <0. 0 1)。结论:共表达HIV- 1gp12 0和IFN -α的重组鸡痘病毒可激发强烈的细胞免疫,可作为我国HIV- 1疫苗候选株。     

人类免疫缺陷病毒I型包膜糖蛋白gp41的基因重组表达

目的 基因重组表达（ＨＩＶ－１ ｇｐ４１）抗原,并研制一种快速,简便,灵敏性高,特异性强的国产ＨＩＶ－１免疫检测试剂。方法 选用ＨＩＶ－１型ＢＨ１０毒株的包膜糖蛋白ｇｐ４１的部分基因（６９７７－７４９７）,重组在ＰＢＶ２２１表达载体上。表达产物通过１５％ＳＤＳ－聚丙烯酰胺凝胶电泳初步分离纯化,根据ＲＦ值,切下含特异蛋白的胶带,以Ｗｅｓｔｅｒｎ ｂｌｏｔ法转移在硝酸纤维素膜上;     

gp120mAb对gp120抑制大鼠海马脑片CA1区LTP作用的研究

目的探讨人类免疫缺陷病毒Ⅰ型(HIV-1)的包膜糖蛋白gp120特异抗体gp120mAb对gp120引起大鼠海马脑片CA1区的突触传递及可塑性变化的影响.方法应用离体脑片记录技术,记录大鼠海马CA1区的兴奋性突触后电位(EPSP),研究gp120mAb对gp120抑制高频电刺激Schaffer侧支引起的鼠海马长时程增强效应(LTP)作用的影响.结果gp120对高频电刺激(HFS,100 Hz,1 000 ms×2,串间隔20秒,共2次)Schaffer侧支引起的大鼠海马CA1区LTP产生抑制作用,而对其基础EPSP没有影响.用浓度为200 pmol/L的gp120灌流脑片,可引起LTP的维持发生抑制.这种抑制作用可被gp120特异抗体gp120mAb(50 ng/ml)所拮抗.结论gp120mAb可能是通过拮抗gp120抑制海马CA1区的LTP诱发和维持而参与艾滋病痴呆(HIV-1 associated dementia,HAD)的形成.     

Potency of HIV-1 envelope glycoprotein gp120 antibodies to inhibit the interaction of DC-SIGN with HIV-1 gp120

The interaction of DC-SIGN with gp120 provides an attractive target for intervention of HIV-1 transmission. Here, we have investigated the potency of gp120 antibodies to inhibit the DC-SIGN-gp120 interaction. We demonstrate that although the V3 loop is not essential for DC-SIGN binding, antibodies against the V3 loop partially inhibit DC-SIGN binding, suggesting that these antibodies sterically hinder DC-SIGN binding to gp120. Polyclonal antibodies raised against non-glycosylated gp120 inhibited both low and high avidity DC-SIGN-gp120 interactions in contrast to polyclonal antibodies raised against glycosylated gp120. Thus, glycans present on gp120 may prevent the generation of antibodies that block the DC-SIGN-gp120 interactions. Moreover, the polyclonal antibodies against non-glycosylated gp120 efficiently inhibited HIV-1 capture by both DC-SIGN transfectants and immature dendritic cells. Therefore, non-glycosylated gp120 may be an attractive immunogen to elicit gp120 antibodies that block the binding to DC-SIGN. Furthermore, we demonstrate that DC-SIGN binding to gp120 enhanced CD4 binding, suggesting that DC-SIGN induces conformational changes in gp120, which may provide new targets for neutralizing antibodies.     

HIV-1 gp120 AND IMMUNE NETWORK

It has been demonstrated that the immunodominant V3 loop of HIV-1 gp120 and its flanking regions bear sequence and structural homology to the framework and complementarity-determining regions of human immunoglobulins. It has been proposed that the Ig-like domain of gp120 might encode idiotypes and in this way permit HIV-1 entry into the immune regulatory network. This notion is strongly supported by results demonstrating that the anti-V3 loop and anti-Ig antibodies of healthy individuals share complementary structure and that V3 reactive antibodies are present in HIV-negative sera. This might be the mechanism by which HIV induces immunological abnormalities, and it should be taken into consideration in AIDS vaccine development.     

Role of flanking variable sequences in antigenicity of consensus regions of HIV gp120 for recognition by specific human T helper clones

Human T helper cells can discriminate among strain variants of HIV gp120 because of T cell clones recognizing non-conserved regions, as demonstrated with T cells from HIV-infected individuals and vaccinated volunteers and with primary T cell lines and clones obtained by in vitro immunization. To obtain a better definition of cross-reactions among T cell determinants within HIVgp120 variants, we used a panel of analog peptides within residues 236-251 from the BRU, MN, SF2 and RF strain sequences to induce primary human T cell lines and clones. Different patterns of response were obtaind using each of the analog peptides, although they all share the consensus sequence 246-251. Clones recognizing this sequence were generated by priming with the BRU and RF analog peptides, but not with the SF2 analog peptide. SF2 did not induce any 242-245-specific clones, but only T cells recognizing the 236-240 sequence. A preferential response to residues 236-240 was obtained by priming with the BRU and SF2 peptides, but not with the MN and RF peptides. These results suggest that although the analog peptides exhibit a high degee of homology and share a consensus of the C-terminal sequence (246-251), the T cell response to the conserved sequence 246-251 is controlled by flanking sequences. Therefore the presence of a shared sequence per se does not imply in vitro expansion of clones with that fine specificity, even though such clones are available within the naive repertoire and can be triggered by an analog peptide.     

RECOMBINATION PROPERTY OF THE HIV-1 gp120 GENE

Using a chimeric primer consisting of the nucleotide sequence derived from the HIV-1 envelope gene coding for the second conserved region of gp120, and the highly conserved sequence derived from the human immunoglobulin gene coding for the V_HIII domain, it has been identified in sera of AIDS patients HIV-1 field isolates carrying the complete and active Chi recombination hot spot (GCTGGTGG). The recombination between the HIV-1 gene coding for the central portion of gp120 and the bacterial gene coding for the clp protease was also demonstrated in vivo. These results point out serious concern that vectored AIDS vaccine candidates carrying the HIV-1 env gene on viral and bacterial vectors could become the source of potentially new infectious diseases rather than an effective instrument for AIDS prevention.     

不同治疗效果的艾滋病患者抗病毒治疗前HIV-1gp120准种特征差异

目的 探讨HIV-1 gp120准种在不同治疗效果的艾滋病患者抗病毒治疗前的特征差异.方法 回顾性收集治疗方案为AZT+NVP+3TC的艾滋病患者在抗病毒治疗前的血浆样本,包括病毒抑制(VS)组12例,治疗失败(TF)组12例.采用单基因组扩增技术获得gp120准种序列,分析比较遗传多样性、氨基酸长度、潜在糖基化位点及特征性氨基酸的特点.结果 本研究共获得gpl20序列365条序列,其中VS组168条(6-20条),TF组197条(7-28条).TF组的gp120准种复杂度高于VS组,差异有统计学意义(P=0.003);TF组的gp120准种dS及dN中位数均高于VS组(P=0.017;P=0.002).TF组HIV-1准种gpl20氨基酸长度长于VS组(P=0.00l).TF与VS组的gpl20准种相比共有9个氨基酸位点存在明显差异,多数分布在V1/V2区(6/9,66.6％).结论 不同治疗效果的艾滋病患者治疗前的HIV-1 gp120准种基因特征存在差异,TF组患者来源的HIV-1准种遗传多样性更高.     

中国株HIV-1 gp120核酸疫苗的实验免疫研究

目的　探讨表达中国株HIV 1gp12 0基因的核酸疫苗在小鼠体内的免疫反应。方法　将表达HIV 1gp12 0的核酸疫苗质粒pVAXP经肌肉注射免疫Balb c小鼠 ,检测免疫小鼠脾CD4 +、CD8+T细胞亚群的数量 ,脾特异性CTL杀伤活性和血清抗体滴度。结果　重组质粒pVAXP免疫组小鼠脾CD4 +、CD8+T细胞亚群的数值均比对照组高 (P <0 .0 5 ) ;免疫组脾特异性CTL杀伤活性与对照组相比差异极显著 (P <0 .0 1) ;血清抗体滴度显著高于对照组 (P <0 .0 5 )。结论　表达HIV 1gp12 0基因的核酸疫苗质粒pVAXP能诱导小鼠产生特异性细胞和体液免疫。     

Assembly, structure, and antigenic properties of virus-like particles rich in HIV-1 envelope gp120

In order to improve the immunogenicity of HIV-1 envelope glycoproteins, we have fused gp120 to a carrier protein, hepatitis B surface antigen (HBsAg), which is capable of spontaneous assembly into virus-like particles. The HBsAg-gp120 hybrid proteins assembled efficiently into 20-30 nm particles. The particles resemble native HBsAg particles in size and density, consistent with a lipid composition of about 25% and a gp120 content of about 100 per particle. Particulate gp120 folds in its native conformation and is biologically active, as shown by high affinity binding of CD4. The particles express conformational determinants targeted by a panel of broadly cross-reactive neutralizing antibodies, and they show tight packing of gp120. Because the particles are lipoprotein micelles, an array of gp120 on their surface closely mimics gp120 on the surface of HIV-1 virions. These gp120-rich particles can enhance the quality, as well as quantity, of antibodies elicited by a gp120 vaccine.