HIV 外膜糖蛋白 gp120 和 gp41 在昆虫细胞中表达及其免疫学特性的评价

将编码完整ｇｐ１２０和完整ｇｐ４１的基因分别克隆到杆状病毒转移质粒中。使用重组转移质粒与野生杆状病毒（ＡｃＮＰＶ）ＤＮＡ共转染Ｓｆ９昆虫细胞，经挑选获得分别带有编码ｇｐ１２０和ｇｐ４１基因的重组杆状病毒。重组杆状病毒感染Ｓｆ９细胞后在细胞中分别表达了ＨＩＶ外膜糖蛋白ｇｐ１２０和ｇｐ４１。其重组蛋白的分子量分别为１２０×１０３和４１×１０３。此重组糖蛋白在免疫荧光、免疫印染和酶联免疫实验中都能被ＨＩＶ阳性血清所识别。动物免疫实验表明此重组糖蛋白能诱导很强的特异性抗体产生。     

An Accurate Confirmation of Human Immunodeficiency Virus Type 1 (HIV-1) and 2 (HIV-2) Infections with a Dot blot assay Using Recombinant p24, gp41, gp120 and gp36 Antigens

An immunoblot assay using four recombinant proteins corresponding to human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2) gene products was developed to confirm the presence of antibodies to HIV-1 and 2 in sera reactive in screening ELISAs. Serum samples for testing were obtained from healthy seronegative blood donors and from different categories of HIV-infected individuals (asymptomatic HIV-infected, and AIDS). A positive reaction was defined as reactivity against gag (p24) and at least one other env (either gp41 or gp120) HIV gene products; negative result was defined as no reaction with any antigen; and indeterminate result was defined as reactivity with gag (p24) or with env (gp41 or gp120) alone. None of the 180 serum samples from healthy seronegative blood donors gave a positive result, and only 4 of these samples (2.2%) gave indeterminate results. The recombinant HIV Dot blotting assay identified seropositive individuals with a high degree of accuracy; none of the 125 HIV-seropositive subjects had a negative test result. Reactivity with these antigens, demonstrated 100% sensitivity and specificity in distinguishing seronegative from seropositive sera. All seronegative and seropositive samples were tested both with the commercially available ELISA and by Western blot. The recombinant in-house HIV Dot blot assay accurately identified more seropositive and seronegative samples and had fewer indeterminate results than did commercial Western blot (as interpreted by CDC criteria).     

Serologic characterization of human immunodeficiency virus infection by Western blot and radioimmunoprecipitation assays

The Western blot and radioimmunoprecipitation assay (RIPA) appear to be the most specific tests available for the detection of antibodies directed against human immunodeficiency virus (HIV). An investigation of 678 HIV-seropositive samples from 518 patients by the Western blot assay indicates that the majority of patients who have been exposed to HIV exhibit antibodies directed against glycoprotein (gp) 41. The HIV-seropositive samples were categorized into four groups according to their Western blot antibody reactive patterns. Group 1 had evidence of reactivities directed against protein (p) 24 and gp41; group 2 had reactivity to gp41 and no reactivity to p24; group 3 had reactivity to p24 and p55 and no reactivity to gp41; and group 4 had an isolated p24 reactivity. The RIPA revealed antibody reactivities directed against HIV envelope proteins (gp 160, gp 120, and gp41) in 91 of 95 samples that were tested. No HIV antibody reactivities were detected by RIPA in four samples from group 4. Specimens exhibiting an isolated antibody reactivity directed against p24 by Western blot analysis should have further evaluation before being labeled as indicative of HIV exposure. A western blot study on a subsequent sequential sample or another confirmatory assay, such as the RIPA, should be performed to identify antibodies directed against HIV envelope components.     

Evaluation of viral-lysate enzyme-linked immunosorbent assay kits for detecting human immunodeficiency virus (type 1) infections using human sera standardized by quantitative western blotting.

The first generation of proprietary reagents for detecting antibodies to the Human Immunodeficiency Virus Type 1 (HIV-1) by enzyme-linked immunosorbent assay (ELISA) used as antigen partially purified virus from cell culture lysates. These tests, which are still in use, may vary in their antibody measurement capabilities if different proportions of the viral polypeptides are present in the viral lysate mixtures. We determined the quantities of antibodies in the serum of persons infected with HIV-1 by dilution analysis using 3 ELISA kits: Abbott [A], Du Pont [D], Genetic Systems [G]. The proportionate antibody titres of each serum to p24gag and gp160env/120env were established by quantitative Western blotting. Serum antibody titres were high, frequently over 1:10,000, a result observed both by ELISA and Western blot. For Kit D, sera with high proportions of antibody to p24gag produced antibody titration curves with steep slopes whereas shallower slopes were found in sera with high proportions of antibody to gp160env. In contrast, Kit A gave steeper slopes with sera enriched for gp160env antibodies. Kit G gave results with slopes intermediate between Kits A and D. Serum antibody titres differed between kits depending upon the proportion and concentration of antibodies in a given serum to gp160env and p24gag. The findings that both the concentration and proportion of antibodies to specific viral polypeptides in human sera markedly affect the signal intensity produced by proprietary ELISAs suggest the need for several control sera which reflect the diversity of human serum responses. Standardization of human reference sera by quantitative Western blotting will assist in evaluation and quality control of ELISA tests.     

Comparison of Western blot (immunoblot) based on recombinant-derived p41 with conventional tests for serodiagnosis of human immunodeficiency virus infections.

To evaluate the performance of a serological test for human immunodeficiency virus type 1 (HIV-1) infections based on the use of a recombinant envelope gene-derived protein as the antigen, we caused expression of a 1.4-kilobase fragment of HIV.DNA that codes for the complete gp41 transmembrane protein in an Escherichia coli expression vector and used Western blots (WB; immunoblots) prepared with recombinant material (pEX-41) to detect antibodies to HIV-1. This test detected all 339 sera which were positive by a combination of conventional serodiagnostic assays and produced no false-positive results with 311 negative samples. Also no false-positive results were obtained with 20 sera from systemic lupus erythematosus patients which had high titers of cross-reactive autoantibodies. In six cases, the pEX-41 WB proved to be more sensitive than individual assays applied on their own, and in five cases it was even more sensitive than a combination of conventional assays. We tested 221 sera in both our pEX-41 WB and a commercially available recombinant enzyme immunoassay (EIA [Abbott]). The results were identical in 188 cases. A total of 27 sera containing antibodies to gp41 as demonstrated in the pEX-41 WB, as well as the Abbott recombinant EIA, had no antibodies to the recombinant core antigen as measured in the Abbott EIA. However, 25 of these sera did stain the 24-kilodalton band on a WB with purified virus. Six sera that were positive in all of the conventional confirmatory assays and reacted strongly with the pEX-41 WB did not recognize the surface antigen used in the Abbott recombinant EIA. We conclude that the use of WB prepared with recombinant-derived p41 offers a very sensitive and specific method to detect antibodies to HIV.     

Utility of various commercially available human immunodeficiency virus (HIV) antibody diagnostic kits for use in conjunction with efficacy trials of HIV-1 vaccines.

There is a need for human immunodeficiency virus (HIV) screening assays which will distinguish uninfected HIV vaccine recipients from HIV-infected individuals. Commercial screening kits were used to test serum samples from low- and high-risk participants in clinical trials before and after immunization with various recombinant HIV type 1 (HIV-1) envelope glycoprotein 120 (gp120) candidate vaccines. All kits were 100% sensitive in detecting HIV infection. Both Murex Single Use Diagnostic System and United Biomedical, Inc., HIV type 1 or 2 (HIV-1/2) enzyme immunoassay (EIA) kits, which detect antibodies to HIV-1 gp41, were 98 to 100% specific when used to screen baseline or recombinant gp120-vaccinated populations as vaccine-induced antibodies to gp120 were nonreactive in these tests. The Abbott HIVAB HIV-1 EIA (lysate of whole infected cells, reactive with anti-gp120 antibodies) gave high levels of reactivity due to vaccine-induced antibodies and a high baseline rate of false positives (12 of 83) among nonvaccinated high-risk volunteers. Assays containing only gp41 and p24 solid-phase components are compatible with gp120-based vaccines but are unlikely to be useful in a similar role for vaccines containing gp160, gp41, or gp120 plus p24 antigens. Efficacy trials must be designed in concert with available diagnostic screening assays to avoid problems caused by vaccine-induced seroconversion in high-risk populations.     

Investigation of atypical western blot (immunoblot) reactivity involving core proteins of human immunodeficiency virus type.

Serum specimens which originally exhibited a narrow (indeterminate) 24-kilodalton core protein (p24) or p24/p55 pattern of reactivity with human immunodeficiency virus (HIV) in the Western blot (immunoblot) test were studied to gather information on antibody specificity. A total of 12 specimens were initially reevaluated with an indirect immunofluorescence assay (IFA), three enzyme-linked immunosorbent assays (ELISAs), and Western blot analyses. Five of the specimens were IFA positive and contained anti-gp160/gp120 antibodies which were observed only when an HIV Western blot antigen rich in gp160 and gp120 was used. The remaining seven serum specimens were nonreactive by IFA and showed variable reactivity in HIV antibody ELISAs. The specimens did not cross-react with core antigens for human T-cell leukemia virus types 1 and 2 or contain detectable levels of HIV p24 antigen. The p24/p55 reactivity of six of the seven indeterminate specimens could be reduced or eliminated by preincubating the specimens with disrupted, HIV-infected H9 cells but not with uninfected H9 cells. The six specimens also exhibited discernible reactivity with recombinant HIV p24 antigen. When an additional 23 indeterminate specimens were assayed, all of the serum specimens were nonreactive by IFA while 65% (15 of 23) showed various degrees of reactivity with the recombinant p24 protein. There was no indication that any of the HIV core antibody reactivity was caused by HIV infection. Indeterminate results for five patients with specific p24 reactivity, who were retested after a period of weeks or months, remained indeterminate for HIV antibody with no significant change in ELISA or Western blot reactivity.     

HIV antibodies in whole saliva detected by ELISA and western blot assays

Paired serum and saliva samples were tested by enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) for the presence of human immunodeficiency virus (HIV) antibodies. The study group included 36 individuals known to be HIV seropositive and 14 healthy, seronegative controls. HIV antibodies were detected in all but one of the saliva samples of the seropositive subjects. In this particular patient, seroconversion was documented 1 week earlier by sequential testings. A further saliva sample obtained 2 months later was ELISA positive for salivary HIV antibodies. Antibodies against HIV proteins gp120 and gp160 were detected by Western blot assay in all saliva specimens taken from HIV seropositive subjects (including the ELISA-negative patient who seroconverted. Antibodies against other viral proteins (p65, p55, p51, gp41, p35, p24 p18) were found in saliva haphazardly without any clear-cut correlation with the clinical stage of the disease. Pretreatment of the saliva with protease inhibitor was essential for the diagnostic use of saliva for the detection of HIV antibodies by Western blot assay. Calculation of the ratio of titres in serum to those in saliva showed the highest ratios in symptomless subjects (mean +/- SD; 1844 +/- 1412) and the lowest in patients with acquired immune deficiency syndrome (AIDS) (mean +/- SD; 811 +/- 445). The ratio of serum to saliva by ELISA showed a positive correlation with salivary flow rate, indicating a dilution of salivary HIV antibodies with increasing salivary flow rate. The gingival bleeding index was negatively correlated with the ratio, supporting the concept that salivary HIV antibodies transudate from blood to saliva via gingival fluid.     

Passive hemagglutination test for detection of antibodies to human immunodeficiency virus type 1 and comparison of the test with enzyme-linked immunosorbent assay and Western blot (immunoblot) analysis.

A passive hemagglutination test (PHA) was developed for detecting antibodies to human immunodeficiency virus type 1 (HIV-1) utilizing sheep erythrocytes cross-linked with purified envelope glycoprotein (gp160) of HIV-1. In an analysis of 216 human serum samples, 100% correlation was observed in 86 reactive and 124 nonreactive serum samples between PHA and commercial enzyme-linked immunosorbent assays and Western blot (immunoblot) analysis. Serum samples from gp160-immunized chimpanzees also reacted equally well in PHA. The test is simple, rapid, and inexpensive, thus providing an alternate, quick method of detecting HIV antibodies. These advantages and the thermal stability of the reagents that are used make this an attractive alternative for detecting prior exposure of individuals to HIV-1.     

Biosynthesis and chemical and immunological characterization of avian reticuloendotheliosis virus env gene-encoded proteins

Two glycosylated proteins designated gp90 and gp20 were purified from replication-competent avian reticuloendotheliosis associated virus (REV-A). The N-terminal sequences of gp90 and gp20 were determined and found to match the REV-A-env-gene sequence. The alignments of the determined amino acid sequences with the predicted sequence indicate that gp20 and gp90 are the REV-A-encoded viral transmembrane and surface glycoprotein, respectively, and predict a signal peptide of 36 residues on the 5' end of the env-gene. Furthermore, gp90 of REV-A was detected by Western blot analysis with antibodies to a tridecapeptide corresponding to an env-gene nucleotide segment immediately preceding gp20 and thus representing the C-terminal portion of gp90. The env-gene precursor polyprotein gPr75-79env and Pr22(E), the precursor to gp20 and p2(E) were identified in the infected cells by monospecific antibodies raised against purified gp20. Thus the organization of gPR75-79env is likely to be N-gp90-gp20-p2(E), resembling that of M-MuLV gp85env. Sequence comparisons showed that the env gene of REV-A is highly related to both baboon endogenous virus and Type D retroviruses. In Western blot analyses, antibodies to REV-A gp20 cross-reacted with a panel of mammalian Type C and Type D viruses. Evolutionary aspects of these findings are discussed.     

Detection of early antibodies in human immunodeficiency virus infection by enzyme-linked immunosorbent assay, Western blot, and radioimmunoprecipitation.

A current concept of the serological response to human immunodeficiency virus (HIV) infection in humans is that antibodies to core antigens (p55, p24, and p15) are detectable earlier during initial stages of antibody production than antibodies against envelope antigens (gp160, gp120, and gp41). Comparative studies of Western blot (immunoblot), radioimmunoprecipitation assay (RIPA), and enzyme-linked immunosorbent assay (ELISA) during initial antibody production are limited to case reports and have not resolved the issue. Thirty of the 37 participants who are part of a prospective study had at least one specimen that was negative for anti-gp41 but had one or more other bands on Western blot. Twenty-seven of these 30 specimens were reactive for anti-gp120/160 in the RIPA. Of the same 30 specimens, kits from Bionetics identified 2 (7%), ElectroNucleonics 4 (13%), Abbott 13 (43%), Du Pont 25 (83%), and Genetic Systems 25 (83%). All participants had evidence of serological progression by Western blot, including a gp41 band, on subsequent visits; the ELISA kits of all manufacturers identified these later specimens with greater accuracy. These data show that the RIPA detects anti-envelope antibodies that may be not detectable by Western blot and that the production of anti-envelope antibodies approximately parallels the production of anti-core antibodies. The false-negative results by ELISA would permit transmission of HIV by blood transfusion from donors in early stages of infection. The sensitivity of licensed ELISA kits should be improved to identify antibody as soon as possible after infection.     

Multicenter evaluation of the novel ABN Western blot (immunoblot) system in comparison with an enzyme-linked immunosorbent assay and a different Western blot.

A new, modular Western blot (immunoblot) system for human immunodeficiency virus (HIV) antibodies (ABN WesPage; Wellcome) was compared with enzyme immunoassays (Wellcome, Behringwerke, and Abbott) and with a U.S. Food and Drug Administration (FDA)-licensed Western blot (DuPont) in a multicenter study. A total of 649 serum samples from HIV patients at different stages of the disease, as well as from high-risk patients, from patients with conditions unrelated to AIDS, and from healthy blood donors, were used in the evaluation along with nine seroconversion panels. For evaluation of Western blot reactivity, both Centers for Disease Control (CDC) and FDA criteria were used. With the DuPont Western blot as the reference assay, the overall sensitivity and specificity of the ABN WesPage were 100 and 99.1%, respectively, when indeterminate results were not taken into account and when both tests were interpreted in accordance with CDC criteria. The DuPont Western blot detected significantly more antibodies to pol and gag gene products than the ABN WesPage. The ABN WesPage showed a higher positive rate of detection of viral envelope band gp160. When both Western blots were interpreted in accordance with CDC criteria, the ABN WesPage and the DuPont Western blot yielded 9.3 and 10.4% indeterminate results, respectively. When the DuPont Western blot was interpreted in accordance with the manufacturer's instructions (FDA criteria), 25.7% of the samples tested were regarded as indeterminate. The choice of interpretation criteria is of paramount importance for the evaluation of HIV Western blot patterns.     

HIV-1 C亚型Gp120蛋白表达、纯化及其抗体制备的研究

目的 制备HIV-1 C亚型Gp120蛋白及其抗体.方法 用PCR技术从表达C亚型HIV-1全长gp16O基因的质粒上扩增gP120基因羧基末端部分片段,其长度为612个核苷酸,编码204个氨基酸.将测序鉴定正确的gp120基因片段克隆到原核表达载体pET-30a上,以包涵体的形式在大肠埃希菌BL21(DE3)中高效表达,Gp120蛋白C端融合6×His标签便于纯化.将纯化的蛋白免疫新西兰大白兔制备C亚型Gp120特异性兔多克隆抗体,用间接ELISA法测定抗体滴度,并用Western Blot方法验证该抗体是否可识别在哺乳动物细胞内表达的C亚型Gp160蛋白.结果 成功地获得高纯度的C亚型Gp120融合蛋白,用其制备的多克隆抗体滴度可达1:204 800,该抗体可特异性识别在COS-1细胞中瞬时表达的C亚型Gp160蛋白.结论 获得了高纯度的C亚型Gp120融合蛋白及其高效价的抗体.     

Characterization and large production of human monoclonal antibodies against the HIV-1 envelope.

Peripheral blood lymphocytes from a volunteer immunized with a recombinant vaccinia virus VSC-25 expressing the gp160 env protein of HTLV-IIIB strain and from an asymptomatic HIV-infected individual were immortalized by Epstein-Barr (EBV). Clones which secrete human monoclonal antibodies from the two individuals (DZ, IgG1, lambda and C31, IgG1, kappa) were obtained and were stable for more than 2 years. The two monoclonals were directed against the gp160 env protein of HIV, DZ directed against the gp41 and C31 directed against the gp120. C31 was group-specific, whereas DZ was directed against the HTLV-IIIB and HTLV-RF strains. The epitope recognized by DZ was mapped to the carboxy terminus of the gp41, by expression of HIV DNA fragments in a yeast system and peptide analysis. The C31 epitope was not expressed by the yeast library and not present among the peptides which were tested. Monoclonal antibodies had no inhibitory effect in an HIV-induced cell fusion assay, but DZ showed a weak neutralizing activity against the HTLV-IIIB strain. Cloned EBV-transformed cell lines were fused to a murine myeloma, which allowed the heteromyeloma to be cultivated in serum-free medium. The monoclonal antibodies were produced in large quantity in a hollow-fibre reactor at defined culture conditions and purification procedures.     

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     

HIV抗体不确定结果的特征与鉴别方法研究

目的 分析HIV抗体不确定的血清学特征及预示HIV感染的意义,评价3种实验方法鉴别HIV抗体不确定的效果.方法 收集394例HIV抗体不确定标本,分析免疫印迹确认的条带类型.2对97例HIV抗体不确定病例进行随访,观察HIV抗体的发展和变化.3对67例随访病例的首次标本进行病毒载量、条带免疫印迹和HIV-1 p24抗原检测,以随访的结果为金标准,判断3种方法鉴别不确定的效果.结果 394例不确定标本共有38种带型,env类不确定的构成比例是37.54%;pol不确定占4.04%;gag类不确定占的比例最大,为58.37%.97例接受随访的HIV抗体不确定病例中,5例发生HIV抗体阳转,均为env类不确定.阳转病例的HIV抗体发展很快,约2周就可以看出变化.病毒载量检测鉴别HIV抗体不确定的敏感性最好.结论 针对gag蛋白的不确定反应最为常见,但基本上都是非特异反应.env类不确定预示HIV感染的意义较大,特别是gp160p24和gp160.HIV抗体不确定如为早期HIV感染,血清抗体发展的速度很快,大约2周抗体就有发展.病毒载量检测可有效鉴别不确定结果.     

多种单抗联合检测HIV抗原

目的 建立多种单抗联合早期检测HIV抗原的夹心ELISA方法.方法 以SAS盐析沉淀法和亲和层析法纯化抗HIV-1 p24、gp41、gp120及抗HIV-2 gp36的腹水型单克隆抗体(McAb),用高碘酸钠法将纯化的McAb以HRP进行标记.建立针对单个抗原的双抗体夹心ELISA法,对其灵敏度及特异性进行检测.将筛选得到的4株捕获McAb按比例混合作为捕获抗体,4株酶标McAb按比例混合作为检测抗体,建立多种单抗联合检测HIV抗原的夹心ELISA方法,检测混合HIV抗原.结果 按确定的最优反应条件建立的多种McAb联合夹心ELISA方法,检测到的最高稀释度的HIV混合抗原中各抗原的终浓度分别为:重组HIV-1 p24:0.625 pg/ml,gp41:6.25 ng/ml,gp120:6.25 ng/ml;HIV-2 gp36:9.25 ng/ml.结论 建立了具有高度敏感性的鸡尾酒式多种单抗联合检测HIV抗原的夹心ELISA法,为早期榆测HIV抗原提供了新的思路,为后续的研究奠定了一定基础.     

多种单抗联合检测HIV抗原

目的 建立多种单抗联合早期检测HIV抗原的夹心ELISA方法.方法 以SAS盐析沉淀法和亲和层析法纯化抗HIV-1 p24、gp41、gp120及抗HIV-2 gp36的腹水型单克隆抗体(McAb),用高碘酸钠法将纯化的McAb以HRP进行标记.建立针对单个抗原的双抗体夹心ELISA法,对其灵敏度及特异性进行检测.将筛选得到的4株捕获McAb按比例混合作为捕获抗体,4株酶标McAb按比例混合作为检测抗体,建立多种单抗联合检测HIV抗原的夹心ELISA方法,检测混合HIV抗原.结果 按确定的最优反应条件建立的多种McAb联合夹心ELISA方法,检测到的最高稀释度的HIV混合抗原中各抗原的终浓度分别为:重组HIV-1 p24:0.625 pg/ml,gp41:6.25 ng/ml,gp120:6.25 ng/ml;HIV-2 gp36:9.25 ng/ml.结论 建立了具有高度敏感性的鸡尾酒式多种单抗联合检测HIV抗原的夹心ELISA法,为早期榆测HIV抗原提供了新的思路,为后续的研究奠定了一定基础.     

Detection of antibodies to human immunodeficiency virus by latex agglutination with recombinant antigen.

Recombinant human immunodeficiency virus (HIV) env antigen was attached to polystyrene particles, and these complexes were used to develop the first latex agglutination assay for antibodies to HIV. A total of 95 positive and 116 negative human serum samples were assayed for antibodies to HIV by latex agglutination, and results were compared with those of a commercial enzyme immunoassay. Latex agglutination was also compared with, and found to be completely concordant with, Western blot (immunoblot) analysis with virion antigens.