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     

Ⅰ型人类免疫缺陷病毒包膜gp120与乙型肝炎病毒表面抗原免疫原性比较

目的 比较Ⅰ型人类免疫缺陷病毒(HIV-1)及乙型肝炎病毒(HBV)包膜蛋白初次免疫及加强免疫后诱导产生抗体的规律,为提高HIV-1包膜蛋白诱导保护性抗体产生能力提供创新思路.方法 以10周龄雌性C57BL/6小鼠为动物模型,分别用HIV-1 06044毒株gp120三聚体(gp120T)、HBV表面抗原(HBsAg)蛋白与AddaVax佐剂免疫小鼠,背部皮下注射,共免疫3次,每次免疫间隔3周,第一、第二次免疫后7d和第三次免疫后3d、7d取血;第一次免疫后7d、第三次免疫后3d、7d取脾组织.用酶联免疫吸附实验(ELISA)及酶联免疫斑点实验(ELISpot)方法检测免疫小鼠血浆特异性结合抗体滴度及抗体分泌细胞(ASC)数量.结果 gp120T和HBsAg两种蛋白初次免疫后,动物均未产生明显的特异性抗体.两种蛋白加强免疫后特异性抗体水平明显升高,gp120T一次加强免疫及两次加强特异性抗体滴度逐渐升高,而HBsAg一次加强抗体滴度已经接近两次加强的水平.二次加强免疫后,gp120T和HBsAg免疫鼠脾脏特异性ASC数量差异不显著.结论 HIV-1包膜gp120T加强免疫诱导抗体水平达到高峰慢于HBsAg加强免疫,即加强免疫后gp120T诱导的回忆反应慢于HBsAg.     

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     

Ⅰ型人免疫缺陷病毒gag-gp120嵌合基因核酸疫苗的构建与鉴定

目的：构建含Ⅰ型人免疫缺陷病毒(HIV-1)gag—gp120嵌合基因核酸疫苗的表达质粒。方法：将gag和gp120连接后的嵌合基因插入到真核表达载体pVAX1中，构建真核表达质粒pVAXGE。用脂质体法将构建的重组质粒转染Hela细胞72h后，取转染的Hela细胞进行RT—PCR检测和和Dot—ELISA分析。结果：重组质粒转染细胞的总RNA中，可扩增出目的基因的转录产物。Dot-ELISA的结果显示，目的基因在Hela细胞内得到表达。结论：成功地构建了表达gag—gp120嵌合基因的核酸疫苗质粒，为HIV—1核酸疫苗的制备奠定基础。     

人Ⅱ型免疫缺陷病毒gag基因在大肠杆菌中的表达

目的：表达ＨＩＶ－２基因工程ｇａｇ抗原。方法：将编码ＨＩＶ－２型ｇａｇ的部分和全部ｐ５５ｇａｇ１／２基因,克隆到载体ｐＥＴ－１７ｂ后,分别在Ｅ．Ｃｏｌｉ ＢＩ２１中表达。结果;表达产物为５１和６１ｋＤ融合蛋白,并可与ＨＩＶ－２病人血清发生特异性反应。     

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。     

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.     

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;     

原代HIV-1包膜糖蛋白修饰体诱导小鼠产生高滴度gp120抗体

目的 探索1型人类免疫缺陷病毒(HIV-1)包膜糖蛋白修饰对包膜免疫原性的的影响.方法 通过PCR扩增获得原代HIV-1 06044株包膜gp120基因及其突变体gp120/W427S基因,并构建gp120三聚体蛋白真核表达载体pcT-gp120和pcT-gp120/W427S,重组表达载体体外瞬时转染人胚肾HEK2...     

重组人免疫缺陷病毒Ⅰ型逆转录酶的纯化及其动力学性质

目的纯化重组人免疫缺陷病毒Ⅰ型逆转录酶（ＨＩＶ－１ＲＴ），筛选新的ＨＩＶ－１ＲＴ抑制剂。方法在适宜的培养条件下诱导工程菌Ｅ．ｃｏｌｉＪＭ１０９（ＰＫＲＴ２）可高效表达重组人免疫缺陷病毒Ⅰ型（ＨＩＶ－１）逆转录酶（ＲＴ）。应用ＤＥＡＥ－纤维素和磷酸纤维素离子交换柱层析法从细菌裂解液中分离、纯化重组ＲＴ。结果１升细菌培养液可得到１．１ｍｇ产物。ＳＤＳ－聚丙烯酰胺凝胶电泳分析显示所纯化的重组ＲＴ为由两个分子量分别为６６ｋＤ和５１ｋＤ的亚基组成的杂二聚体。酶活性测定结果表明，经纯化的重组ＲＴ具有很高的逆转录酶活性（比活力为１．４×１０４ｕｍｇ）。结论本文通过对ＲＴ反应条件的研究，优化了ＲＴ反应系统，并测定了磷甲酸钠（ＰＦＡ）对重组ＲＴ的抑制效应，结果表明ＰＦＡ对重组ＲＴ的抑制反应动力学机制与天然ＲＴ相同，从而进一步说明用此法纯化的重组ＲＴ可直接用于抗ＨＩＶ药物的筛选与评价。     

Different proliferative response of human and chimpanzee lymphocytes after contact with human immunodeficiency virus type 1 gp120

T cell functional defects are a common aspect of human immunodeficiency virus (HIV) infection. Moreover, it has been suggested that indirect mechanisms are involved in CD4⁺ cell depletion. Unresponsiveness to proliferative stimuli of lymphocytes incubated with HIV particles or with viral proteins is well documented. Nevertheless, drawing a clear picture of the anergy phenomenon is difficult because of several unresolved and controversial questions. Here we report that recombinant gp120 induces anergy in T helper lymphocytes cultured with different stimuli. The proliferative responses to interleukin (IL)-2, IL-4, IL-6, anti-CD2, anti-CD3 and phorbol 12-myristate 13-acetate are inhibited. Moreover, anergic cells show a different distribution in cell cycle phases as compared to control cells, leading us to suggest that the progresion in the cell cycle is hampered and that a pre-mitotic block takes place. Furthermore, since chimpanzees are susceptible to HIV-1 infection without showing immunodeficiency signs, we analyzed the proliferation of chimpanzee lymphocytes without observing anergy in cells preincubated with gp120. Taken together, these results support the hypothesis that anergy plays an important role in HIV infection in vivo.     

人类免疫缺陷病毒1型云南株外膜蛋白原核表达克隆的构建

目的为研究我国云南１型人类免疫缺陷病毒（Ｈｕｍａｎｉｍｍｕｎｏｄｅｆｉｃｉｅｎｃｙｖｉｒｕｓｔｙｐｅ１，ＨＩＶ－１）流行株外膜蛋白（ｇｐ１２０）的有关抗原表位。方法采用套式聚合酶链式反应，以来自云南流行区ＨＩＶ－１感染者的外周血单核巨噬细胞基因组为模板，进行云南流行株外膜蛋白基因（ｅｎｖ）片段的扩增，并将ｅｎｖ基因片段与原核表达载体ｐＢＶ２２０进行重组，构建成质粒ｐＹＮｅｎｖ并在大肠杆菌（Ｅ．ｃｏｌｉＤＨ１０ｂ）中获得表达。采用限制性内切酶分析进行重组质粒的鉴定。结果含重组质粒的宿主菌经３０℃２０小时培养后，转入４２℃培养５小时，经ＳＤＳ－ＰＡＧＥ蛋白电泳分析有重组蛋白的表达。经Ｗｅｓｔｅｒｎｂｌｏｔ反应证实，该重组蛋白可与来自该流行区的ＨＩＶ－１感染者血清（含多克隆抗体）发生特异反应。结论该重组膜蛋白可作为抗原用于ＨＩＶ－１膜蛋白抗体的检测，并为进一步研究ＨＩＶ－１ｇｐ１２０的病理机制奠定了基础。     

Role of the gp120 inner domain beta-sandwich in the interaction between the human immunodeficiency virus envelope glycoprotein subunits

The inner domain of the human immunodeficiency virus (HIV-1) gp120 glycoprotein has been proposed to mediate the noncovalent interaction with the gp41 transmembrane envelope glycoprotein. We used mutagenesis to investigate the functional importance of a conserved beta-sandwich located within the gp120 inner domain. Changes in aliphatic residues lining a hydrophobic groove on the surface of the beta-sandwich decreased the association of the gp120 and gp41 glycoproteins. Other changes in the base of the hydrophobic groove resulted in envelope glycoproteins that were structurally intact and able to bind receptors, but were inefficient in mediating either syncytium formation or virus entry. These results support a model in which the beta-sandwich in the gp120 inner domain contributes to gp120-gp41 contacts, thereby maintaining the integrity of the envelope glycoprotein complex and allowing adjustments in the gp120-gp41 interaction required for membrane fusion.     

Inhibition of human immunodeficiency virus infection by the lectin jacalin and by a derived peptide showing a sequence similarity with gp120

Jacalin is a plant lectin known to specifically induce the proliferation of CD4⁺ T lymphocytes in human. We demonstrate here that jacalin completely blocks human immunodeficiency virus type 1 (HIV-1) in vitro infection of lymphoid cells. Jacalin does not bind the viral envelope glycoprotein gp120. Besides other T cell surface molecules, it interacts with CD4, the high-affinity receptor to HIV. Binding of jacalin to CD4 does not prevent gp120-CD4 interaction and does not inhibit virus binding and syncytia formation. The anti-HIV effect of the native lectin can be reproduced by its separated a-subunits. More importantly, we have defined in the a-chain of jacalin a 14-amino acid sequence which shows high similarities with a peptide of the second conserved domain of gpl20. A synthetic peptide corresponding to this similar stretch also exerts a potent anti-HIV effect. This peptide is not mitogenic for peripheral blood mononuclear cells and does not inhibit anti-CD3-induced lymphocyte proliferation. These results make jacalin a chain-derived peptide a potentially valuable therapeutic agent for acquired immunodeficiency syndrome.     

Alloactivated cytotoxic T cells recognize the carboxy-terminal domain of human immunodeficiency virus-1 gp120 envelope glycoprotein

Infection with the human immunodeficiency virus (HIV) virus leads to clinical disease in humans but not in chimpanzees. Progression to disease is associated with activation of the immune system followed by loss of T helper cell function and a slow decline in CD4-positive lymphocytes. The presence of autoreactive and cytotoxic cells in humans but not chimpanzees suggests that mechanisms other than, or in addition to, direct virus-induced cell killing, are required for disease to develop. The observed changes are similar to those seen in chronic allogeneic disease. Here we show that a peptide from the carboxy terminus of gp120, predicted to have a structure similar to the major α-helices of major histocompatibility complex (MHC) class I and class II, acts as a cytolytic target when presented on syngeneic cells for alloactivated cytotoxic T effector cells. These data add further evidence to the hypothesis that HIV can act as an allostimulant due to its dual properties of CD4 binding and MHC mimicry. The ability to signal nonspecifically through the T cell receptor could explain the initially paradoxical responses of proliferation, anergy and apoptosis.     

The envelope glycoprotein of HIV-1 gp120 and human complement protein C1q bind to the same peptides derived from three different regions of gp41, the transmembrane glycoprotein of HIV-1, and share antigenic homology

Gp41, the transmembrane glycoprotein of HIV-1, has been shown to be non-covalently associated with gp120. We have shown that it also binds human C1q. To analyze the interaction site(s) of gp41 with these two molecules, we established an enzyme-linked immunosorbent assay (ELISA) system using recombinant soluble gp41 [amino acids (aa) 539–684] and peptides thereof. In the cell-external part of gp41 three sites (aa 526–538, aa 590–613 and aa 625–655) were found to bind both gp120 and C1q. That gp120 and C1q use the same sites was evidenced by the fact that these proteins competed with each other for the same sites in recombinant soluble gp41 and gp41 peptides. It could be demonstrated by ELISA, that rabbit antibodies against human C1q recognized gp120, and rabbit antibodies against gp120 cross-reacted with C1q. Rabbit anti-gp120, HIV-1-positive human sera and anti-gp120 obtained from such sera agglutinated sensitized sheep erythrocytes with human C1q (EAC1q). These data suggest that in addition to functional homology between C1q and gp120 structural homology between these two molecules exists. This molecular mimicry might become the basis for immunologically relevant autoimmune phenomena.