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Sample records for rapid hiv antibody

  1. Evaluation of a rapid test for HIV antibodies in saliva and blood ...

    African Journals Online (AJOL)

    Objective. To test whole blood and saliva for HIV antibodies (anti-HIV) using a rapid test strip capillary flow . immunoassay, and to correlate the test strip results with blood specimen results obtained from routine diagnostic antiHIV assays. Design. A prospective pilot study of selected HIV-positive and HIV-negative individuals ...

  2. evaluation of a rapid test for hiv antibodies in saliva and blood

    African Journals Online (AJOL)

    To test whole blood and saliva for HIV antibodies. (anti-HIV) using a rapid test strip capillary flow . immunoassay ... Design. A prospective pilot study of selected HIV-positive and ... defined by the underlying illness or condition is illustrated in.

  3. Rapid High-Level Production of Functional HIV Broadly Neutralizing Monoclonal Antibodies in Transient Plant Expression Systems

    Science.gov (United States)

    Rosenberg, Yvonne; Sack, Markus; Montefiori, David; Forthal, Donald; Mao, Lingjun; -Abanto, Segundo Hernandez; Urban, Lori; Landucci, Gary; Fischer, Rainer; Jiang, Xiaoming

    2013-01-01

    Passive immunotherapy using anti-HIV broadly neutralizing monoclonal antibodies (mAbs) has shown promise as an HIV treatment, reducing mother-to-child-transmission (MTCT) of simian/human immunodeficiency virus (SHIV) in non-human primates and decreasing viral rebound in patients who ceased receiving anti-viral drugs. In addition, a cocktail of potent mAbs may be useful as mucosal microbicides and provide an effective therapy for post-exposure prophylaxis. However, even highly neutralizing HIV mAbs used today may lose their effectiveness if resistance occurs, requiring the rapid production of new or engineered mAbs on an ongoing basis in order to counteract the viral resistance or the spread of a certain HIV-1 clade in a particular region or patient. Plant-based expression systems are fast, inexpensive and scalable and are becoming increasingly popular for the production of proteins and monoclonal antibodies. In the present study, Agrobacterium-mediated transient transfection of plants, utilizing two species of Nicotiana, have been tested to rapidly produce high levels of an HIV 89.6PΔ140env and several well-studied anti-HIV neutralizing monoclonal antibodies (b12, 2G12, 2F5, 4E10, m43, VRC01) or a single chain antibody construct (m9), for evaluation in cell-based viral inhibition assays. The protein-A purified plant-derived antibodies were intact, efficiently bound HIV envelope, and were equivalent to, or in one case better than, their counterparts produced in mammalian CHO or HEK-293 cells in both neutralization and antibody dependent viral inhibition assays. These data indicate that transient plant-based transient expression systems are very adaptable and could rapidly generate high levels of newly identified functional recombinant HIV neutralizing antibodies when required. In addition, they warrant detailed cost-benefit analysis of prolonged incubation in plants to further increase mAb production. PMID:23533588

  4. Rapid high-level production of functional HIV broadly neutralizing monoclonal antibodies in transient plant expression systems.

    Directory of Open Access Journals (Sweden)

    Yvonne Rosenberg

    Full Text Available Passive immunotherapy using anti-HIV broadly neutralizing monoclonal antibodies (mAbs has shown promise as an HIV treatment, reducing mother-to-child-transmission (MTCT of simian/human immunodeficiency virus (SHIV in non-human primates and decreasing viral rebound in patients who ceased receiving anti-viral drugs. In addition, a cocktail of potent mAbs may be useful as mucosal microbicides and provide an effective therapy for post-exposure prophylaxis. However, even highly neutralizing HIV mAbs used today may lose their effectiveness if resistance occurs, requiring the rapid production of new or engineered mAbs on an ongoing basis in order to counteract the viral resistance or the spread of a certain HIV-1 clade in a particular region or patient. Plant-based expression systems are fast, inexpensive and scalable and are becoming increasingly popular for the production of proteins and monoclonal antibodies. In the present study, Agrobacterium-mediated transient transfection of plants, utilizing two species of Nicotiana, have been tested to rapidly produce high levels of an HIV 89.6PΔ140env and several well-studied anti-HIV neutralizing monoclonal antibodies (b12, 2G12, 2F5, 4E10, m43, VRC01 or a single chain antibody construct (m9, for evaluation in cell-based viral inhibition assays. The protein-A purified plant-derived antibodies were intact, efficiently bound HIV envelope, and were equivalent to, or in one case better than, their counterparts produced in mammalian CHO or HEK-293 cells in both neutralization and antibody dependent viral inhibition assays. These data indicate that transient plant-based transient expression systems are very adaptable and could rapidly generate high levels of newly identified functional recombinant HIV neutralizing antibodies when required. In addition, they warrant detailed cost-benefit analysis of prolonged incubation in plants to further increase mAb production.

  5. Who accepts a rapid HIV antibody test? The role of race/ethnicity and HIV risk behavior among community adolescents.

    Science.gov (United States)

    Swenson, Rebecca R; Hadley, Wendy S; Houck, Christopher D; Dance, S Kwame; Brown, Larry K

    2011-05-01

    Centers for Disease Control and Prevention guidelines recommend routine human immunodeficiency virus (HIV) screening in health care settings for all individuals aged 13-64 years; however, overall testing rates among adolescents still continue to remain low. This study examined factors related to the acceptance of HIV testing among an at-risk sample of ethnically/racially diverse community adolescents. Adolescents aged 15-21 (N = 81) years were recruited from community-based youth organizations to complete HIV risk assessment surveys. After the completion of the survey, participants were offered a free OraQuick rapid HIV antibody test. More than half (53.1%) of the participants accepted the test, with the black population being more likely to accept testing as compared to Latinos (75% vs. 39%). After controlling for race/ethnicity, significant predictors of test acceptance included history of sexual intercourse (OR = 5.43), having only one sexual partner in the past 3 months (OR = 4.88), not always using a condom with a serious partner (OR = 3.94), and not using a condom during last sexual encounter (OR = 4.75). Given that many adolescents are willing to know their HIV status, policies that support free or low-cost routine testing may lead to higher rates of case identification among youth. However, approaches must be developed to increase test acceptance among Latino adolescents and teenagers with multiple sexual partners. Copyright © 2011 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  6. Human anti-HIV IgM detection by the OraQuick ADVANCE® Rapid HIV 1/2 Antibody Test.

    Science.gov (United States)

    Guillon, Geraldine; Yearwood, Graham; Snipes, Casey; Boschi, Daniel; Reed, Michael R

    2018-01-01

    The Centers for Disease Control and Prevention (CDC) and many public health jurisdictions continue to advocate for the most sensitive rapid HIV test that is available. Currently, the recommendation is to utilize tests that can detect HIV infection biomarkers within 30 days of infection, when initial immune responses are mounted. The infected patient's IgM response is often used to detect acute infection within a 20-25 days window after infection. This requirement applies to lab-based testing with automated analyzers and rapid, point of care (POC) testing used for screening in a non-clinical setting. A recent study has demonstrated that POC tests using a Protein A-based detection system can detect samples with predominantly HIV-1 IgM reactivity (Moshgabadi et al., 2015). The OraQuick ADVANCE ® Rapid HIV-1/2 Antibody Test (OraQuick ADVANCE ®) also uses Protein A as the detection protein in the antibody-binding colloidal gold conjugate, so it is expected that the OraQuick ADVANCE ® Test will also detect samples with predominantly IgM reactivity. This report definitively demonstrates that the OraQuick ADVANCE ® Test can detect IgM antibodies during an acute infection window period of approximately 20-25 days after infection, and is therefore suitable for use in testing environments requiring adherence to current CDC recommendations.

  7. Evaluation of Blood-Based Antibody Rapid Testing for HIV Early Therapy: A Meta-Analysis of the Evidence

    Directory of Open Access Journals (Sweden)

    Xiaojie Huang

    2018-06-01

    Full Text Available BackgroundWestern blot (WB assay is considered the gold standard test for HIV infection confirmation. However, it requires technical expertise and is quite time-consuming. WHO recommends blood-based rapid diagnosis to achieve same-day test and treatment. However, this rapid testing strategy has not been promoted worldwide due to inadequate research evaluating the effectiveness of rapid tests (RTs as an alternative confirmatory HIV test for WB. This study aims to compare the diagnostic performance of rapid HIV tests compared with WB.MethodsPubMed and Web of Science were searched for publications on rapid HIV tests using blood specimen. A meta-analysis was performed to quantitatively evaluate the diagnostic performance of rapid HIV tests compared with the WB assay in terms of pooled sensitivity, specificity, area under summary receiver operating characteristic (SROC curve, and diagnostic odds ratio (DOR.ResultsTwenty articles involving 27,343 fresh specimens for rapid HIV tests were included in the meta-analysis. Regarding Capillus HIV-1/HIV-2, the pooled sensitivity, specificity, area under SROC curve, and DOR derived from six studies were 0.999 (95% CI, 0.956–1.000, 0.999 (95% CI, 0.991–1.00, 1.00 (95% CI, 0.99–1.00, and 1.0 × 106 (95% CI, 2.6 × 104–3.9 × 107 compared with the WB assay, respectively. With respect to Determine HIV-1/2, the pooled sensitivity, specificity area under SROC, and DOR derived from eight studies were 1.00 (95% CI, 0.789–1.000, 0.992 (95% CI, 0.985–0.996, 1.00 (95% CI, 0.99–1.00, and 1.8 × 106 (95% CI 406.049–7.8 × 109 compared with the WB assay, respectively. Regarding two-step serial RTs, the pooled sensitivity, specificity area under SROC, and DOR derived from eight studies were 0.998 (95% CI, 0.991–1.000, 0.998 (95% CI, 0.994–0.999, and 1.00 (95% CI 0.99–1.00 compared with the WB assay, respectively.ConclusionOur meta-analysis results may provide evidenced-based support

  8. Rapid Immuno-Chromatographic Assay for the Detection of Antibodies to HIV Compare with Elisa among Voluntary and Replacement Blood Donor of Mymensingh Medical College Hospital.

    Science.gov (United States)

    Chakrabarty, P; Rudra, S; Hossain, M A; Begum, S A; Mirza, T T; Rudra, M

    2015-04-01

    Suitable algorithms based on a combination of two or more simple rapid HIV assays have been shown to have a diagnostic accuracy comparable to double enzyme-linked immunosorbent assay (ELISA) or double ELISA with Western Blot strategies. The aims of this study were to evaluate the performance of five simple rapid HIV assays using whole blood samples from voluntary and replacement blood donors & HIV-infected patients (positive samples from BSMMU, Dhaka). Five rapid HIV assays: Determine™ HIV-1/2 (Inverness Medical), SD Bioline HIV 1/2 3.0 (Standard Diagnostics Inc.), First Response HIV Card 1-2.0 (PMC Medical India Pvt Ltd.), HIV1/2 Stat-Pak Dipstick (Chembio Diagnostic System, Inc) and Uni-Gold™ HIV-1/2 (Biotech) were evaluated between 1st February to 30th June, 2013 using 400 whole blood samples from voluntary and replacement blood donors. All samples that were reactive on all or any of the five rapid assays and 10% of non-reactive samples were tested on a confirmatory Inno-Lia HIV I/II immunoblot assay (Immunogenetics). Only 01 sample including ten positive samples from BSMMU were confirmed HIV-1 antibody positive, while 399 were HIV negative. The sensitivity at initial testing of Determine, SD Bioline and Uni-Gold™ was 100% (95% CI; 99.1-100) while First Response and Stat-Pak had sensitivity of 99.5% (95% CI; 98.2-99.9) and 97.7% (95% CI; 95.7-98.9) respectively, which increased to 100% (95% CI; 99.1-100) on repeat testing. The initial specificity of the Uni-Gold™ assay was 100% (95% CI; 99.6-100) while specificities were 99.6% (95% CI; 99-99.9), 99.4% (95% CI; 98.8-99.7), 99.6% (95% CI; 99-99.9) and 99.8% (95% CI; 99.3-99.9) for Determine, SD Bioline, First Response and Stat-Pak assays, respectively. There was no any sample which was concordantly false positive in Uni-Gold™, Determine and SD Bioline assays. An alternative confirmatory HIV testing strategy based on initial testing on either SD Bioline or Determine assays followed by testing of reactive

  9. HIV antibodies for treatment of HIV infection.

    Science.gov (United States)

    Margolis, David M; Koup, Richard A; Ferrari, Guido

    2017-01-01

    The bar is high to improve on current combination antiretroviral therapy (ART), now highly effective, safe, and simple. However, antibodies that bind the HIV envelope are able to uniquely target the virus as it seeks to enter new target cells, or as it is expressed from previously infected cells. Furthermore, the use of antibodies against HIV as a therapeutic may offer advantages. Antibodies can have long half-lives, and are being considered as partners for long-acting antiretrovirals for use in therapy or prevention of HIV infection. Early studies in animal models and in clinical trials suggest that such antibodies can have antiviral activity but, as with small-molecule antiretrovirals, the issues of viral escape and resistance will have to be addressed. Most promising, however, are the unique properties of anti-HIV antibodies: the potential ability to opsonize viral particles, to direct antibody-dependent cellular cytotoxicity (ADCC) against actively infected cells, and ultimately the ability to direct the clearance of HIV-infected cells by effector cells of the immune system. These distinctive activities suggest that HIV antibodies and their derivatives may play an important role in the next frontier of HIV therapeutics, the effort to develop treatments that could lead to an HIV cure. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  10. Male Partner Risk Behaviors Are Associated With Reactive Rapid HIV Antibody Tests Among Pregnant Mexican Women: Implications for Prevention of Vertical and Sexual HIV Transmission in Concentrated HIV Epidemics.

    Science.gov (United States)

    Rivero, Estela; Kendall, Tamil

    2015-01-01

    Mexico's policies on antenatal HIV testing are contradictory, and little is known about social and behavioral characteristics that increase pregnant Mexican women's risks of acquiring HIV. We analyzed the association between risk behaviors reported by pregnant women for themselves and their male partners, and women's rapid HIV antibody test results from a large national sample. Three quarters of pregnant women with a reactive test did not report risk behaviors for themselves and one third did not report risk behaviors for themselves or their male partners. In the retrospective case-control analysis, other than reporting multiple sexual partners, reactive pregnant women reported risk behaviors did not differ from nonreactive women's behaviors. However, reactive pregnant women were significantly more likely to have reported risk behaviors for male partners. Our findings support universal offer of antenatal HIV testing and suggest that HIV prevention for women should focus on reducing risk of HIV acquisition within stable relationships. Copyright © 2015 Association of Nurses in AIDS Care. Published by Elsevier Inc. All rights reserved.

  11. Rapid transient production in plants by replicating and non-replicating vectors yields high quality functional anti-HIV antibody.

    Directory of Open Access Journals (Sweden)

    Frank Sainsbury

    2010-11-01

    Full Text Available The capacity of plants and plant cells to produce large amounts of recombinant protein has been well established. Due to advantages in terms of speed and yield, attention has recently turned towards the use of transient expression systems, including viral vectors, to produce proteins of pharmaceutical interest in plants. However, the effects of such high level expression from viral vectors and concomitant effects on host cells may affect the quality of the recombinant product.To assess the quality of antibodies transiently expressed to high levels in plants, we have expressed and characterised the human anti-HIV monoclonal antibody, 2G12, using both replicating and non-replicating systems based on deleted versions of Cowpea mosaic virus (CPMV RNA-2. The highest yield (approximately 100 mg/kg wet weight leaf tissue of affinity purified 2G12 was obtained when the non-replicating CPMV-HT system was used and the antibody was retained in the endoplasmic reticulum (ER. Glycan analysis by mass-spectrometry showed that the glycosylation pattern was determined exclusively by whether the antibody was retained in the ER and did not depend on whether a replicating or non-replicating system was used. Characterisation of the binding and neutralisation properties of all the purified 2G12 variants from plants showed that these were generally similar to those of the Chinese hamster ovary (CHO cell-produced 2G12.Overall, the results demonstrate that replicating and non-replicating CPMV-based vectors are able to direct the production of a recombinant IgG similar in activity to the CHO-produced control. Thus, a complex recombinant protein was produced with no apparent effect on its biochemical properties using either high-level expression or viral replication. The speed with which a recombinant pharmaceutical with excellent biochemical characteristics can be produced transiently in plants makes CPMV-based expression vectors an attractive option for

  12. HIV Antibody Test

    Science.gov (United States)

    ... 65 in the case of the USPSTF) and pregnant women be screened for HIV at least once. The CDC and American College ... to make sure she is not infected with HIV before getting pregnant may opt to get tested (see Pregnancy: HIV .) ...

  13. Evaluation of three commercial rapid tests for detecting antibodies to human immunodeficiency virus.

    Science.gov (United States)

    Ng, K P; Saw, T L; Baki, A; Kamarudin, R

    2003-08-01

    Determine HIV-1/2, Chembio HIV-1/2 STAT-PAK and PenTest are simple/rapid tests for the detection of antibodies to HIV-1 and HIV-2 in human whole blood, serum and plasma samples. The assay is one step and the result is read visually within 15 minutes. Using 92 known HIV-1 reactive sera and 108 known HIV-1 negative sera, the 3 HIV tests correctly identified all the known HIV-1 reactive and negative samples. The results indicated that Determine HIV-1/2, Chembio HIV-1/2 STAT-PAK and PenTest HIV are as sensitive and specific (100% concordance) as Microparticle Enzyme Immunoassay. The data indicated that these 3 HIV tests are effective testing systems for diagnosis of HIV infection in a situation when the conventional Enzyme Immunoassay is not suitable.

  14. Human immunodeficiency virus (HIV) specific antibodies among ...

    African Journals Online (AJOL)

    obtained from each sample was tested using parallel testing algorithm with DETERMINE® HIV-1/2 and HIV-1/2 STAT-PAK® test was used for statistical analysis of the data. The overall prevalence of HIV-1/2 antibodies was 29.1% (n = 199). Seroprevalence of 39.4 and 19.0% were observed for the CSWs and the PW, ...

  15. IDEPI: rapid prediction of HIV-1 antibody epitopes and other phenotypic features from sequence data using a flexible machine learning platform.

    Directory of Open Access Journals (Sweden)

    N Lance Hepler

    2014-09-01

    Full Text Available Since its identification in 1983, HIV-1 has been the focus of a research effort unprecedented in scope and difficulty, whose ultimate goals--a cure and a vaccine--remain elusive. One of the fundamental challenges in accomplishing these goals is the tremendous genetic variability of the virus, with some genes differing at as many as 40% of nucleotide positions among circulating strains. Because of this, the genetic bases of many viral phenotypes, most notably the susceptibility to neutralization by a particular antibody, are difficult to identify computationally. Drawing upon open-source general-purpose machine learning algorithms and libraries, we have developed a software package IDEPI (IDentify EPItopes for learning genotype-to-phenotype predictive models from sequences with known phenotypes. IDEPI can apply learned models to classify sequences of unknown phenotypes, and also identify specific sequence features which contribute to a particular phenotype. We demonstrate that IDEPI achieves performance similar to or better than that of previously published approaches on four well-studied problems: finding the epitopes of broadly neutralizing antibodies (bNab, determining coreceptor tropism of the virus, identifying compartment-specific genetic signatures of the virus, and deducing drug-resistance associated mutations. The cross-platform Python source code (released under the GPL 3.0 license, documentation, issue tracking, and a pre-configured virtual machine for IDEPI can be found at https://github.com/veg/idepi.

  16. Human immunodeficiency virus (HIV) specific antibodies among ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-03-20

    Mar 20, 2009 ... Key words: HIV-1/2 antibody prevalence, pregnant women, commercial sex workers, risk factors, Nigeria. INTRODUCTION. There are two .... Africa. However, among Japanese and Chilean female. SWs, Miyazaki et al. .... STIs (P = 0.0001, OR = 6.0), level of education (P = 0.0001, OR = 40.7) and age (P ...

  17. Screening Yield of HIV Antigen/Antibody Combination and Pooled HIV RNA Testing for Acute HIV Infection in a High-Prevalence Population.

    Science.gov (United States)

    Peters, Philip J; Westheimer, Emily; Cohen, Stephanie; Hightow-Weidman, Lisa B; Moss, Nicholas; Tsoi, Benjamin; Hall, Laura; Fann, Charles; Daskalakis, Demetre C; Beagle, Steve; Patel, Pragna; Radix, Asa; Foust, Evelyn; Kohn, Robert P; Marmorino, Jenni; Pandori, Mark; Fu, Jie; Samandari, Taraz; Gay, Cynthia L

    2016-02-16

    Although acute HIV infection contributes disproportionately to onward HIV transmission, HIV testing has not routinely included screening for acute HIV infection. To evaluate the performance of an HIV antigen/antibody (Ag/Ab) combination assay to detect acute HIV infection compared with pooled HIV RNA testing. Multisite, prospective, within-individual comparison study conducted between September 2011 and October 2013 in 7 sexually transmitted infection clinics and 5 community-based programs in New York, California, and North Carolina. Participants were 12 years or older and seeking HIV testing, without known HIV infection. All participants with a negative rapid HIV test result were screened for acute HIV infection with an HIV Ag/Ab combination assay (index test) and pooled human immunodeficiency virus 1 (HIV-1) RNA testing. HIV RNA testing was the reference standard, with positive reference standard result defined as detectable HIV-1 RNA on an individual RNA test. Number and proportion with acute HIV infections detected. Among 86,836 participants with complete test results (median age, 29 years; 75.0% men; 51.8% men who have sex with men), established HIV infection was diagnosed in 1158 participants (1.33%) and acute HIV infection was diagnosed in 168 participants (0.19%). Acute HIV infection was detected in 134 participants with HIV Ag/Ab combination testing (0.15% [95% CI, 0.13%-0.18%]; sensitivity, 79.8% [95% CI, 72.9%-85.6%]; specificity, 99.9% [95% CI, 99.9%-99.9%]; positive predictive value, 59.0% [95% CI, 52.3%-65.5%]) and in 164 participants with pooled HIV RNA testing (0.19% [95% CI, 0.16%-0.22%]; sensitivity, 97.6% [95% CI, 94.0%-99.4%]; specificity, 100% [95% CI, 100%-100%]; positive predictive value, 96.5% [95% CI, 92.5%-98.7%]; sensitivity comparison, P testing detected 82% of acute HIV infections detectable by pooled HIV RNA testing. Compared with rapid HIV testing alone, HIV Ag/Ab combination testing increased the relative HIV diagnostic yield (both

  18. Evaluation of simple rapid HIV assays and development of national rapid HIV test algorithms in Dar es Salaam, Tanzania.

    Science.gov (United States)

    Lyamuya, Eligius F; Aboud, Said; Urassa, Willy K; Sufi, Jaffer; Mbwana, Judica; Ndugulile, Faustin; Massambu, Charles

    2009-02-18

    Suitable algorithms based on a combination of two or more simple rapid HIV assays have been shown to have a diagnostic accuracy comparable to double enzyme-linked immunosorbent assay (ELISA) or double ELISA with Western Blot strategies. The aims of this study were to evaluate the performance of five simple rapid HIV assays using whole blood samples from HIV-infected patients, pregnant women, voluntary counseling and testing attendees and blood donors, and to formulate an alternative confirmatory strategy based on rapid HIV testing algorithms suitable for use in Tanzania. Five rapid HIV assays: Determine HIV-1/2 (Inverness Medical), SD Bioline HIV 1/2 3.0 (Standard Diagnostics Inc.), First Response HIV Card 1-2.0 (PMC Medical India Pvt Ltd), HIV1/2 Stat-Pak Dipstick (Chembio Diagnostic System, Inc) and Uni-Gold HIV-1/2 (Trinity Biotech) were evaluated between June and September 2006 using 1433 whole blood samples from hospital patients, pregnant women, voluntary counseling and testing attendees and blood donors. All samples that were reactive on all or any of the five rapid assays and 10% of non-reactive samples were tested on a confirmatory Inno-Lia HIV I/II immunoblot assay (Immunogenetics). Three hundred and ninety samples were confirmed HIV-1 antibody positive, while 1043 were HIV negative. The sensitivity at initial testing of Determine, SD Bioline and Uni-Gold was 100% (95% CI; 99.1-100) while First Response and Stat-Pak had sensitivity of 99.5% (95% CI; 98.2-99.9) and 97.7% (95% CI; 95.7-98.9), respectively, which increased to 100% (95% CI; 99.1-100) on repeat testing. The initial specificity of the Uni-Gold assay was 100% (95% CI; 99.6-100) while specificities were 99.6% (95% CI; 99-99.9), 99.4% (95% CI; 98.8-99.7), 99.6% (95% CI; 99-99.9) and 99.8% (95% CI; 99.3-99.9) for Determine, SD Bioline, First Response and Stat-Pak assays, respectively. There was no any sample which was concordantly false positive in Uni-Gold, Determine and SD Bioline assays. An

  19. High prevalence of HIV p24 antigen among HIV antibody negative prospective blood donors in Ile-Ife, Nigeria.

    Science.gov (United States)

    Japhet, Margaret Oluwatoyin; Adewumi, Moses Olubusuyi; Adesina, Olufisayo Adeyemi; Donbraye, Emmanuel

    2016-01-01

    Blood transfusion service centers in Nigeria screen donated blood for markers of HIV infection using antibody- (Ab) based rapid test and in some centers, positives are re-tested using Ab-based ELISA. Paucity of data exists on p24 antigen prevalence among HIV Ab-negative donors in Nigeria. This study aims at detecting HIV p24 antigen among prospective blood donors in Osun State, Nigeria. Prospective blood donors negative for HIV antibodies using Determine test kit were re-tested using BIORAD GENSCREEN Ultra Ag-Ab ELISA kit, a fourth-generation ELISA kit that detects HIV antibodies/p24 antigen. Of the 169 HIV Ab-negative prospective donors, 10 (5.9%) were positive for HIV p24 antigen and 70% (7/10) of them were in the age range 18-30 years. Results of this study show that blood transfusion is still one of the major routes of HIV transmission in Nigeria and a higher proportion is among youth. Inclusion of p24 antigen testing into the blood donor screening will help reduce transfusion associated HIV in Nigeria if Nucleic Acid Testing (NAT) of all blood donor samples is not affordable; also, HIV enlightenment programs tailored toward youth may help reduce this rate among donors since more young people donate blood in low/middle-income countries than in high-income countries.

  20. Acute HIV Discovered During Routine HIV Screening With HIV Antigen-Antibody Combination Tests in 9 US Emergency Departments.

    Science.gov (United States)

    White, Douglas A E; Giordano, Thomas P; Pasalar, Siavash; Jacobson, Kathleen R; Glick, Nancy R; Sha, Beverly E; Mammen, Priya E; Hunt, Bijou R; Todorovic, Tamara; Moreno-Walton, Lisa; Adomolga, Vincent; Feaster, Daniel J; Branson, Bernard M

    2018-01-05

    Newer combination HIV antigen-antibody tests allow detection of HIV sooner after infection than previous antibody-only immunoassays because, in addition to HIV-1 and -2 antibodies, they detect the HIV-1 p24 antigen, which appears before antibodies develop. We determine the yield of screening with HIV antigen-antibody tests and clinical presentations for new diagnoses of acute and established HIV infection across US emergency departments (EDs). This was a retrospective study of 9 EDs in 6 cities with HIV screening programs that integrated laboratory-based antigen-antibody tests between November 1, 2012, and December 31, 2015. Unique patients with newly diagnosed HIV infection were identified and classified as having either acute HIV infection or established HIV infection. Acute HIV infection was defined as a repeatedly reactive antigen-antibody test result, a negative HIV-1/HIV-2 antibody differentiation assay, or Western blot result, but detectable HIV ribonucleic acid (RNA); established HIV infection was defined as a repeatedly reactive antigen-antibody test result and a positive HIV-1/HIV-2 antibody differentiation assay or Western blot result. The primary outcomes were the number of new HIV diagnoses and proportion of patients with laboratory-defined acute HIV infection. Secondary outcomes compared reason for visit and the clinical presentation of acute HIV infection. In total, 214,524 patients were screened for HIV and 839 (0.4%) received a new diagnosis, of which 122 (14.5%) were acute HIV infection and 717 (85.5%) were established HIV infection. Compared with patients with established HIV infection, those with acute HIV infection were younger, had higher RNA and CD4 counts, and were more likely to have viral syndrome (41.8% versus 6.5%) or fever (14.3% versus 3.4%) as their reason for visit. Most patients with acute HIV infection displayed symptoms attributable to acute infection (median symptom count 5 [interquartile range 3 to 6]), with fever often

  1. Antiviral Therapy by HIV-1 Broadly Neutralizing and Inhibitory Antibodies

    Directory of Open Access Journals (Sweden)

    Zhiqing Zhang

    2016-11-01

    Full Text Available Human immunodeficiency virus type 1 (HIV-1 infection causes acquired immune deficiency syndrome (AIDS, a global epidemic for more than three decades. HIV-1 replication is primarily controlled through antiretroviral therapy (ART but this treatment does not cure HIV-1 infection. Furthermore, there is increasing viral resistance to ART, and side effects associated with long-term therapy. Consequently, there is a need of alternative candidates for HIV-1 prevention and therapy. Recent advances have discovered multiple broadly neutralizing antibodies against HIV-1. In this review, we describe the key epitopes on the HIV-1 Env protein and the reciprocal broadly neutralizing antibodies, and discuss the ongoing clinical trials of broadly neutralizing and inhibitory antibody therapy as well as antibody combinations, bispecific antibodies, and methods that improve therapeutic efficacy by combining broadly neutralizing antibodies (bNAbs with latency reversing agents. Compared with ART, HIV-1 therapeutics that incorporate these broadly neutralizing and inhibitory antibodies offer the advantage of decreasing virus load and clearing infected cells, which is a promising prospect in HIV-1 prevention and treatment.

  2. Non-reactive HIV-1 Rapid Tests after Sustained Viral Suppression Following Antiretroviral Therapy Initiation During Primary Infection.

    Science.gov (United States)

    Stefic, Karl; Novelli, Sophie; Mahjoub, Nadia; Seng, Remonie; Molina, Jean-Michel; Cheneau, Christine; Barin, Francis; Chaix, Marie-Laure; Meyer, Laurence; Delaugerre, Constance

    2018-03-02

    We assessed the impact of early antiretroviral treatment (ART) on HIV antibody detection by rapid tests in 44 individuals after several years of successful ART. HIV self-tests and point-of-care tests were negative in respectively 30% and 7-9% of cases. These data reinforce the message that patients should never be retested after entering HIV care.

  3. Antibody-Mediated Internalization of Infectious HIV-1 Virions Differs among Antibody Isotypes and Subclasses.

    Science.gov (United States)

    Tay, Matthew Zirui; Liu, Pinghuang; Williams, LaTonya D; McRaven, Michael D; Sawant, Sheetal; Gurley, Thaddeus C; Xu, Thomas T; Dennison, S Moses; Liao, Hua-Xin; Chenine, Agnès-Laurence; Alam, S Munir; Moody, M Anthony; Hope, Thomas J; Haynes, Barton F; Tomaras, Georgia D

    2016-08-01

    Emerging data support a role for antibody Fc-mediated antiviral activity in vaccine efficacy and in the control of HIV-1 replication by broadly neutralizing antibodies. Antibody-mediated virus internalization is an Fc-mediated function that may act at the portal of entry whereby effector cells may be triggered by pre-existing antibodies to prevent HIV-1 acquisition. Understanding the capacity of HIV-1 antibodies in mediating internalization of HIV-1 virions by primary monocytes is critical to understanding their full antiviral potency. Antibody isotypes/subclasses differ in functional profile, with consequences for their antiviral activity. For instance, in the RV144 vaccine trial that achieved partial efficacy, Env IgA correlated with increased risk of HIV-1 infection (i.e. decreased vaccine efficacy), whereas V1-V2 IgG3 correlated with decreased risk of HIV-1 infection (i.e. increased vaccine efficacy). Thus, understanding the different functional attributes of HIV-1 specific IgG1, IgG3 and IgA antibodies will help define the mechanisms of immune protection. Here, we utilized an in vitro flow cytometric method utilizing primary monocytes as phagocytes and infectious HIV-1 virions as targets to determine the capacity of Env IgA (IgA1, IgA2), IgG1 and IgG3 antibodies to mediate HIV-1 infectious virion internalization. Importantly, both broadly neutralizing antibodies (i.e. PG9, 2G12, CH31, VRC01 IgG) and non-broadly neutralizing antibodies (i.e. 7B2 mAb, mucosal HIV-1+ IgG) mediated internalization of HIV-1 virions. Furthermore, we found that Env IgG3 of multiple specificities (i.e. CD4bs, V1-V2 and gp41) mediated increased infectious virion internalization over Env IgG1 of the same specificity, while Env IgA mediated decreased infectious virion internalization compared to IgG1. These data demonstrate that antibody-mediated internalization of HIV-1 virions depends on antibody specificity and isotype. Evaluation of the phagocytic potency of vaccine

  4. Rapid screening of monoclonal antibodies: new 'microstick' radioimmunoassay

    International Nuclear Information System (INIS)

    Scheinberg, D.A.; Strand, M.; Wilsnack, R.

    1983-01-01

    A new system for assaying monoclonal antibodies consisting of an 8 x 12 array of sticks which fits into a 96-well microtiter plate is described. Tests using virus specific monoclonal antibodies and virus proteins demonstrated sensitivity equivalent to the conventional microtiter plate assay. Antibody production, antigen specific antibody, and immunoglobulin isotypes could be measured under sterile conditions directly in the original fusion mixture wells and much greater rapidity than with the microtiter plate assay. (Auth.)

  5. Polyfunctional HIV-Specific Antibody Responses Are Associated with Spontaneous HIV Control.

    Directory of Open Access Journals (Sweden)

    Margaret E Ackerman

    2016-01-01

    Full Text Available Elite controllers (ECs represent a unique model of a functional cure for HIV-1 infection as these individuals develop HIV-specific immunity able to persistently suppress viremia. Because accumulating evidence suggests that HIV controllers generate antibodies with enhanced capacity to drive antibody-dependent cellular cytotoxicity (ADCC that may contribute to viral containment, we profiled an array of extra-neutralizing antibody effector functions across HIV-infected populations with varying degrees of viral control to define the characteristics of antibodies associated with spontaneous control. While neither the overall magnitude of antibody titer nor individual effector functions were increased in ECs, a more functionally coordinated innate immune-recruiting response was observed. Specifically, ECs demonstrated polyfunctional humoral immune responses able to coordinately recruit ADCC, other NK functions, monocyte and neutrophil phagocytosis, and complement. This functionally coordinated response was associated with qualitatively superior IgG3/IgG1 responses, whereas HIV-specific IgG2/IgG4 responses, prevalent among viremic subjects, were associated with poorer overall antibody activity. Rather than linking viral control to any single activity, this study highlights the critical nature of functionally coordinated antibodies in HIV control and associates this polyfunctionality with preferential induction of potent antibody subclasses, supporting coordinated antibody activity as a goal in strategies directed at an HIV-1 functional cure.

  6. Evaluation of simple rapid HIV assays and development of national rapid HIV test algorithms in Dar es Salaam, Tanzania

    Directory of Open Access Journals (Sweden)

    Mbwana Judica

    2009-02-01

    Full Text Available Abstract Background Suitable algorithms based on a combination of two or more simple rapid HIV assays have been shown to have a diagnostic accuracy comparable to double enzyme-linked immunosorbent assay (ELISA or double ELISA with Western Blot strategies. The aims of this study were to evaluate the performance of five simple rapid HIV assays using whole blood samples from HIV-infected patients, pregnant women, voluntary counseling and testing attendees and blood donors, and to formulate an alternative confirmatory strategy based on rapid HIV testing algorithms suitable for use in Tanzania. Methods Five rapid HIV assays: Determine™ HIV-1/2 (Inverness Medical, SD Bioline HIV 1/2 3.0 (Standard Diagnostics Inc., First Response HIV Card 1–2.0 (PMC Medical India Pvt Ltd, HIV1/2 Stat-Pak Dipstick (Chembio Diagnostic System, Inc and Uni-Gold™ HIV-1/2 (Trinity Biotech were evaluated between June and September 2006 using 1433 whole blood samples from hospital patients, pregnant women, voluntary counseling and testing attendees and blood donors. All samples that were reactive on all or any of the five rapid assays and 10% of non-reactive samples were tested on a confirmatory Inno-Lia HIV I/II immunoblot assay (Immunogenetics. Results Three hundred and ninety samples were confirmed HIV-1 antibody positive, while 1043 were HIV negative. The sensitivity at initial testing of Determine, SD Bioline and Uni-Gold™ was 100% (95% CI; 99.1–100 while First Response and Stat-Pak had sensitivity of 99.5% (95% CI; 98.2–99.9 and 97.7% (95% CI; 95.7–98.9, respectively, which increased to 100% (95% CI; 99.1–100 on repeat testing. The initial specificity of the Uni-Gold™ assay was 100% (95% CI; 99.6–100 while specificities were 99.6% (95% CI; 99–99.9, 99.4% (95% CI; 98.8–99.7, 99.6% (95% CI; 99–99.9 and 99.8% (95% CI; 99.3–99.9 for Determine, SD Bioline, First Response and Stat-Pak assays, respectively. There was no any sample which was

  7. HIV antibodies among intravenous drug users in Bahrain.

    Science.gov (United States)

    al-Haddad, M K; Khashaba, A S; Baig, B Z; Khalfan, S

    1994-09-01

    A 12-month study was conducted to identify risk factors for human immunodeficiency virus (HIV) infections among intravenous drug users (IDU) attending drug rehabilitation clinic of the Psychiatric Hospital, Manama, Bahrain. Patients provided demographic and behavioural information based on a questionnaire. Two hundred and forty male IDUs participated in the study on voluntary basis. The seroprevalence of HIV was 21.1 per cent. The presence of HIV antibody was associated with educational status, frequency of injecting drugs and needle sharing.

  8. Persistent HIV antigenaemia and decline of HIV core antibodies associated with transition to AIDS

    NARCIS (Netherlands)

    Lange, J. M.; Paul, D. A.; Huisman, H. G.; de Wolf, F.; van den Berg, H.; Coutinho, R. A.; Danner, S. A.; van der Noordaa, J.; Goudsmit, J.

    1986-01-01

    Sequential serum samples from 13 homosexual men who seroconverted for antibodies to human immunodeficiency virus (HIV) were tested for HIV antigen. In one of these men, who developed the acquired immune deficiency syndrome (AIDS), HIV antigenaemia preceded the onset of AIDS by more than a year and

  9. Brief Report: Impact of Early Antiretroviral Therapy on the Performance of HIV Rapid Tests and HIV Incidence Assays.

    Science.gov (United States)

    Fogel, Jessica M; Piwowar-Manning, Estelle; Debevec, Barbara; Walsky, Tamara; Schlusser, Katherine; Laeyendecker, Oliver; Wilson, Ethan A; McCauley, Marybeth; Gamble, Theresa; Tegha, Gerald; Soko, Dean; Kumwenda, Johnstone; Hosseinipour, Mina C; Chen, Ying Q; Cohen, Myron S; Eshleman, Susan H

    2017-08-01

    Antiretroviral therapy (ART) can downregulate antibody responses to HIV infection. We evaluated the impact of early vs. delayed ART on the performance of HIV diagnostic and incidence assays. Samples were obtained from 207 participants in the HPTN 052 trial, who were stably suppressed on ART for ≥4 years [Malawi sites; pre-ART CD4 cell count 350-550 cells/mm (early ART arm, N = 180) or ART arm, N = 27)]. Samples were tested with 2 HIV rapid tests and 2 HIV incidence assays; selected samples were also tested with two fourth-generation immunoassays and a Western blot (WB) assay. A pre-ART sample was analyzed if the follow-up sample had a false-negative or weakly-reactive rapid test result, or had an incidence assay result indicative of recent infection (false-recent result). Ten (4.8%) samples had a nonreactive or weakly-reactive rapid test result (7/180 early ART arm, 3/27 delayed ART arm, P = 0.13); one sample had nonreactive fourth-generation assay results and 3 had indeterminate WBs. Forty (18.9%) samples had a false-recent incidence assay result; 16 (7.8%) had false-recent results with both incidence assays. Baseline samples had stronger rapid test and WB bands, higher fourth-generation assay signal-to-cutoff values, and fewer HIV incidence assay results indicative of recent infection. False-negative/weakly-reactive HIV rapid tests and false-recent HIV incidence assay results were observed in virally-suppressed individuals, regardless of pre-ART CD4 cell count. Downregulation of the antibody response to HIV infection in the setting of ART may impact population-level surveys of HIV prevalence and incidence.

  10. Maturation Pathways of Cross-Reactive HIV-1 Neutralizing Antibodies

    Directory of Open Access Journals (Sweden)

    Dimiter S. Dimitrov

    2009-11-01

    Full Text Available Several human monoclonal antibodies (hmAbs and antibody fragments, including the best characterized in terms of structure-function b12 and Fab X5, exhibit relatively potent and broad HIV-1 neutralizing activity. However, the elicitation of b12 or b12-like antibodies in vivo by vaccine immunogens based on the HIV-1 envelope glycoprotein (Env has not been successful. B12 is highly divergent from the closest corresponding germline antibody while X5 is less divergent. We have hypothesized that the relatively high degree of specific somatic hypermutations may preclude binding of the HIV-1 envelope glycoprotein (Env to closest germline antibodies, and that identifying antibodies that are intermediates in the pathways to maturation could help design novel vaccine immunogens to guide the immune system for their enhanced elicitation. In support of this hypothesis we have previously found that a germline-like b12 (monovalent and bivalent scFv as an Fc fusion protein or IgG lacks measurable binding to an Env as measured by ELISA with a sensitivity in the μM range [1]; here we present evidence confirming and expanding these findings for a panel of Envs. In contrast, a germline-like scFv X5 bound Env with high (nM affinity. To begin to explore the maturation pathways of these antibodies we identified several possible b12 intermediate antibodies and tested their neutralizing activity. These intermediate antibodies neutralized only some HIV-1 isolates and with relatively weak potency. In contrast, germline-like scFv X5 neutralized a subset of the tested HIV-1 isolates with comparable efficiencies to that of the mature X5. These results could help explain the relatively high immunogenicity of the coreceptor binding site on gp120 and the abundance of CD4-induced (CD4i antibodies in HIV-1-infected patients (X5 is a CD4i antibody as well as the maturation pathway of X5. They also can help identify antigens that can bind specifically to b12 germline and

  11. Monoclonal antibody technologies and rapid detection assays

    Science.gov (United States)

    Novel methodologies and screening strategies will be outlined on the use of hybridoma technology for the selection of antigen specific monoclonal antibodies. The development of immunoassays used for diagnostic detection of prions and bacterial toxins will be discussed and examples provided demonstr...

  12. HIV monoclonal antibodies: a new opportunity to further reduce mother-to-child HIV transmission.

    Directory of Open Access Journals (Sweden)

    Yegor Voronin

    2014-04-01

    Full Text Available Yegor Voronin and colleagues explore how monoclonal antibodies against HIV could provide a new opportunity to further reduce mother-to-child transmission of HIV and propose that new interventions should consider issues related to implementation, feasibility, and access. Please see later in the article for the Editors' Summary.

  13. Interplay of HIV-1 phenotype and neutralizing antibody response in pathogenesis of AIDS.

    Science.gov (United States)

    Scarlatti, G; Leitner, T; Hodara, V; Jansson, M; Karlsson, A; Wahlberg, J; Rossi, P; Uhlén, M; Fenyö, E M; Albert, J

    1996-06-01

    A majority of human immunodeficiency virus type 1 (HIV-1) infected individuals display a rapid loss of CD4+ lymphocytes with fast progression towards overt acquired immunodeficiency syndrome (AIDS). However, a small proportion of individuals infected by HIV-1 remain immunologically intact for many years. In order to identify factors that might influence the pathogenesis of HIV-1 infection, 21 Italian mothers and 11 Swedish homosexual men were studied for the presence of autologous neutralizing antibodies in serum, biological phenotype of virus isolates and envelope variable region 3 (V3) sequences. The results were compared to the risk of mother-to-child transmission and progression of the disease. The presence of a neutralizing antibody response to the autologous virus as well as a virus with slow replicative capacity were linked both to low risk of mother-to-child transmission and non-progression of the disease. Patients whose peripheral blood mononuclear cells contained a mutation in the tip of the V3 loop (Arg318 to serine, lysine or leucine) significantly more often had neutralizing antibodies to autologous virus isolates containing arginine at this position. Thus, it appears that the interplay and balance between neutralizing antibody response of the host and the biological phenotype of HIV-1 strongly influence pathogenesis.

  14. Anti-HIV Antibody Responses and the HIV Reservoir Size during Antiretroviral Therapy.

    Directory of Open Access Journals (Sweden)

    Sulggi A Lee

    Full Text Available A major challenge to HIV eradication strategies is the lack of an accurate measurement of the total burden of replication-competent HIV (the "reservoir". We assessed the association of anti-HIV antibody responses and the estimated size of the reservoir during antiretroviral therapy (ART.We evaluated anti-HIV antibody profiles using luciferase immunoprecipitation systems (LIPS assay in relation to several blood-based HIV reservoir measures: total and 2-LTR DNA (rtPCR or droplet digital PCR; integrated DNA (Alu PCR; unspliced RNA (rtPCR, multiply-spliced RNA (TILDA, residual plasma HIV RNA (single copy PCR, and replication-competent virus (outgrowth assay. We also assessed total HIV DNA and RNA in gut-associated lymphoid tissue (rtPCR. Spearman correlations and linear regressions were performed using log-transformed blood- or tissue-based reservoir measurements as predictors and log-transformed antibody levels as outcome variables.Among 51 chronically HIV-infected ART-suppressed participants (median age = 57, nadir CD4+ count = 196 cells/mm3, ART duration = 9 years, the most statistically significant associations were between antibody responses to integrase and HIV RNA in gut-associated lymphoid tissue (1.17 fold-increase per two-fold RNA increase, P = 0.004 and between antibody responses to matrix and integrated HIV DNA in resting CD4+ T cells (0.35 fold-decrease per two-fold DNA increase, P = 0.003. However, these associations were not statistically significant after a stringent Bonferroni-adjustment of P<0.00045. Multivariate models including age and duration of ART did not markedly alter results.Our findings suggest that anti-HIV antibody responses may reflect the size of the HIV reservoir during chronic treated HIV disease, possibly via antigen recognition in reservoir sites. Larger, prospective studies are needed to validate the utility of antibody levels as a measure of the total body burden of HIV during treatment.

  15. Rapid T4 radioimmunoassay with antibody of Czechoslovak production

    Energy Technology Data Exchange (ETDEWEB)

    Cechacek, Z [MUNZ, Brno (Czechoslovakia) Div. of Nuclear Nedicine

    1978-06-30

    Rapid T4-RIA based on the T4-antibody produced in Institute of Experimental Endocrinology in Bratislava is described. The used T4-antibody was found as suitable preparation for the routine T4-RIA and is comparable to the foreign materials. T4 antibody was obtained by rabbit immunization and supplied as antiserum in a frozen state. It was properly diluted with 0.08M barbital buffer, pH 8.6, containing 0.a5% sodium ethylmercurythiosalicylate and 0.5% BSA.

  16. Risk of iatrogenic human immunodeficiency virus infection through transfusion of blood tested by inappropriately stored or expired rapid antibody assays in a Zambian hospital

    NARCIS (Netherlands)

    Consten, E. C.; van der Meer, J. T.; de Wolf, F.; Heij, H. A.; Henny, P. C.; van Lanschot, J. J.

    1997-01-01

    BACKGROUND: The purpose of this study was to estimate the risk of human immunodeficiency virus (HIV) infection via the transfusion of blood tested by inappropriately stored or expired rapid antibody assays in Zambia. STUDY DESIGN AND METHODS: Surgical patients (n = 370) were tested with antibody

  17. HIV-1 binding and neutralizing antibodies of injecting drug users

    Directory of Open Access Journals (Sweden)

    E.P. Ouverney

    2005-09-01

    Full Text Available Previous studies have demonstrated a stronger seroreactivity against some synthetic peptides responsible for inducing neutralizing antibodies in injecting drug users (IDU compared to that of individuals sexually infected with HIV-1 (S, but the effectiveness in terms of the neutralizing ability of these antibodies has not been evaluated. Our objective was to study the humoral immune response of IDU by determining the specificity of their antibodies and the presence of neutralizing antibodies. The neutralization capacity against the HIV-1 isolate MN (genotype B, the primary HIV-1 isolate 95BRRJ021 (genotype F, and the seroreactivity with peptides known to induce neutralizing antibodies, from the V2 and V3 loops of different HIV-1 subtypes, were analyzed. Seroreactivity indicates that IDU plasma are more likely to recognize a broader range of peptides than S plasma, with significantly higher titers, especially of V3 peptides. Similar neutralization frequencies of the MN isolate were observed in plasma of the IDU (16/47 and S (20/60 groups in the 1:10 dilution. The neutralization of the 95BRRJ021 isolate was more frequently observed for plasma from the S group (15/23 than from the IDU group (15/47, P = 0.0108. No correlation between neutralization and seroreactivity with the peptides tested was observed. These results suggest that an important factor responsible for the extensive and broad humoral immune response observed in IDU is their infection route. There was very little difference in neutralizing antibody response between the IDU and S groups despite their differences in seroreactivity and health status.

  18. Towards HIV-1 remission: potential roles for broadly neutralizing antibodies.

    Science.gov (United States)

    Halper-Stromberg, Ariel; Nussenzweig, Michel C

    2016-02-01

    Current antiretroviral drug therapies do not cure HIV-1 because they do not eliminate a pool of long-lived cells harboring immunologically silent but replication-competent proviruses - termed the latent reservoir. Eliminating this reservoir and stimulating the immune response to control infection in the absence of therapy remain important but unsolved goals of HIV-1 cure research. Recently discovered broadly neutralizing antibodies (bNAbs) exhibit remarkable breadth and potency in their ability to neutralize HIV-1 in vitro, and recent studies have demonstrated new therapeutic applications for passively administered bNAbs in vivo. This Review discusses the roles bNAbs might play in HIV-1 treatment regimens, including prevention, therapy, and cure.

  19. Sero-prevalance of anti-R7V antibody in HIV infected patients in the ...

    African Journals Online (AJOL)

    The seroprevalence of Anti-R7V antibody was therefore investigated in HIV patients attending clinic within the Federal Capital Territory (FCT) and compared with HIV negative patients. Correlation between the presence of the antibody and the clinical status of patients was also investigated. The HIV positive patients were ...

  20. Development of Broadly Neutralizing Antibody Mimitopes for Characterization of CRF01_AE HIV-1 Antibody Responses

    Directory of Open Access Journals (Sweden)

    Jesse V. Schoen

    2017-10-01

    Full Text Available Mapping humoral immune responses to HIV-1 over the course of natural infection is important in understanding epitope exposure in relation to elicitation of broadly neutralizing antibodies (bNAbs, which is considered imperative for effective vaccine design. When analyzing HIV-specific immune responses, the antibody binding profiles may be a correlate for functional antibody activity. In this study, we utilized phage display technology to identify novel mimitopes that may represent Env epitope structures bound by bNAbs directed at V1V2 and V3 domains, CD4 binding site (CD4bs and the membrane proximal external region (MPER of Env. Mimitope sequence motifs were determined for each bNAb epitope. Given the ongoing vaccine development efforts in Thailand, these mimitopes that represent CD4bs and MPER epitopes were used to map immune responses of HIV-1 CRF01_AE-infected individuals with known neutralizing responses from two distinct time periods, 1996-98 and 2012-15. The more contemporary cohort showed an increase in binding breadth with binding observed for all MPER and CD4bs mimitopes, while the older cohort showed only 75% recognition of the CD4bs mimitopes and no MPER mimotope binding. Furthermore, mimitope binding profiles correlated significantly with magnitude (p=0.0036 and breadth (p=0.0358 of neutralization of a multi-subtype Tier 1 panel of pseudoviruses. These results highlight the utility of this mimitope mapping approach for detecting human plasma IgG-specificities that target known neutralizing antibody epitopes, and may also provide an indication of the plasticity of antibody binding within HIV-1 Env neutralization determinants.

  1. Predicting HIV-1 transmission and antibody neutralization efficacy in vivo from stoichiometric parameters.

    Directory of Open Access Journals (Sweden)

    Oliver F Brandenberg

    2017-05-01

    Full Text Available The potential of broadly neutralizing antibodies targeting the HIV-1 envelope trimer to prevent HIV-1 transmission has opened new avenues for therapies and vaccines. However, their implementation remains challenging and would profit from a deepened mechanistic understanding of HIV-antibody interactions and the mucosal transmission process. In this study we experimentally determined stoichiometric parameters of the HIV-1 trimer-antibody interaction, confirming that binding of one antibody is sufficient for trimer neutralization. This defines numerical requirements for HIV-1 virion neutralization and thereby enables mathematical modelling of in vitro and in vivo antibody neutralization efficacy. The model we developed accurately predicts antibody efficacy in animal passive immunization studies and provides estimates for protective mucosal antibody concentrations. Furthermore, we derive estimates of the probability for a single virion to start host infection and the risks of male-to-female HIV-1 transmission per sexual intercourse. Our work thereby delivers comprehensive quantitative insights into both the molecular principles governing HIV-antibody interactions and the initial steps of mucosal HIV-1 transmission. These insights, alongside the underlying, adaptable modelling framework presented here, will be valuable for supporting in silico pre-trial planning and post-hoc evaluation of HIV-1 vaccination or antibody treatment trials.

  2. Specificity and polyreactivity of the antibody response during natural HIV-1 infection

    OpenAIRE

    Wang, Xin

    2006-01-01

    The specificity and polyreactivity of the antibody response in natural HIV-1 infection were studied. First, to investigate the overall antibody response, overlapping linear peptides were used to screen sera taken from HIV-1-infected individuals. The polyclonal antibody response was relatively stable during long-term infection, compared with acute infection, and mostly directed against immunodominant regions. Low level, transient antibody responses were detected against membrane proximal exter...

  3. Toward Automating HIV Identification: Machine Learning for Rapid Identification of HIV-Related Social Media Data.

    Science.gov (United States)

    Young, Sean D; Yu, Wenchao; Wang, Wei

    2017-02-01

    "Social big data" from technologies such as social media, wearable devices, and online searches continue to grow and can be used as tools for HIV research. Although researchers can uncover patterns and insights associated with HIV trends and transmission, the review process is time consuming and resource intensive. Machine learning methods derived from computer science might be used to assist HIV domain experts by learning how to rapidly and accurately identify patterns associated with HIV from a large set of social data. Using an existing social media data set that was associated with HIV and coded by an HIV domain expert, we tested whether 4 commonly used machine learning methods could learn the patterns associated with HIV risk behavior. We used the 10-fold cross-validation method to examine the speed and accuracy of these models in applying that knowledge to detect HIV content in social media data. Logistic regression and random forest resulted in the highest accuracy in detecting HIV-related social data (85.3%), whereas the Ridge Regression Classifier resulted in the lowest accuracy. Logistic regression yielded the fastest processing time (16.98 seconds). Machine learning can enable social big data to become a new and important tool in HIV research, helping to create a new field of "digital HIV epidemiology." If a domain expert can identify patterns in social data associated with HIV risk or HIV transmission, machine learning models could quickly and accurately learn those associations and identify potential HIV patterns in large social data sets.

  4. Determination of HIV Status in African Adults With Discordant HIV Rapid Tests.

    Science.gov (United States)

    Fogel, Jessica M; Piwowar-Manning, Estelle; Donohue, Kelsey; Cummings, Vanessa; Marzinke, Mark A; Clarke, William; Breaud, Autumn; Fiamma, Agnès; Donnell, Deborah; Kulich, Michal; Mbwambo, Jessie K K; Richter, Linda; Gray, Glenda; Sweat, Michael; Coates, Thomas J; Eshleman, Susan H

    2015-08-01

    In resource-limited settings, HIV infection is often diagnosed using 2 rapid tests. If the results are discordant, a third tie-breaker test is often used to determine HIV status. This study characterized samples with discordant rapid tests and compared different testing strategies for determining HIV status in these cases. Samples were previously collected from 173 African adults in a population-based survey who had discordant rapid test results. Samples were classified as HIV positive or HIV negative using a rigorous testing algorithm that included two fourth-generation tests, a discriminatory test, and 2 HIV RNA tests. Tie-breaker tests were evaluated, including rapid tests (1 performed in-country), a third-generation enzyme immunoassay, and two fourth-generation tests. Selected samples were further characterized using additional assays. Twenty-nine samples (16.8%) were classified as HIV positive and 24 of those samples (82.8%) had undetectable HIV RNA. Antiretroviral drugs were detected in 1 sample. Sensitivity was 8.3%-43% for the rapid tests; 24.1% for the third-generation enzyme immunoassay; 95.8% and 96.6% for the fourth-generation tests. Specificity was lower for the fourth-generation tests than the other tests. Accuracy ranged from 79.5% to 91.3%. In this population-based survey, most HIV-infected adults with discordant rapid tests were virally suppressed without antiretroviral drugs. Use of individual assays as tie-breaker tests was not a reliable method for determining HIV status in these individuals. More extensive testing algorithms that use a fourth-generation screening test with a discriminatory test and HIV RNA test are preferable for determining HIV status in these cases.

  5. Antiviral Activity of HIV gp120 Targeting Bispecific T Cell Engager (BiTE®) Antibody Constructs.

    Science.gov (United States)

    Brozy, Johannes; Schlaepfer, Erika; Mueller, Christina K S; Rochat, Mary-Aude; Rampini, Silvana K; Myburgh, Renier; Raum, Tobias; Kufer, Peter; Baeuerle, Patrick A; Muenz, Markus; Speck, Roberto F

    2018-05-02

    Today's gold standard in HIV therapy is the combined antiretroviral therapy (cART). It requires strict adherence by patients and life-long medication, which can lower the viral load below detection limits and prevent HIV-associated immunodeficiency, but cannot cure patients. The bispecific T cell engaging (BiTE®) antibody technology has demonstrated long-term relapse-free outcomes in patients with relapsed and refractory acute lymphocytic leukemia. We here generated BiTE® antibody constructs that target the HIV-1 envelope protein gp120 (HIV gp120) using either the scFv B12 or VRC01, the first two extracellular domains (1+2) of human CD4 alone or joined to the single chain variable fragment (scFv) of the antibody 17b fused to an anti-human CD3ϵ scFv. These engineered human BiTE® antibody constructs showed engagement of T cells for redirected lysis of HIV gp120-transfected CHO cells. Furthermore, they substantially inhibited HIV-1 replication in PBMCs as well as in macrophages co-cultured with autologous CD8+ T-cells, the most potent being the human CD4(1+2) BiTE® antibody construct and the CD4(1+2)L17b BiTE® antibody construct. The CD4(1+2) h BiTE® antibody construct promoted HIV infection of human CD4-/CD8+ T cells. In contrast, the neutralizing B12 and the VRC01 BiTE® antibody constructs as well as the CD4(1+2)L17b BiTE® antibody construct did not. Thus, BiTE® antibody constructs targeting HIV gp120 are very promising for constraining HIV and warrant further development as novel antiviral therapy with curative potential. Importance HIV is a chronic infection well controlled with the current cART. However, we lack cure of HIV, and the HIV pandemic goes on. Here we showed in vitro and ex vivo t hat a bispecific T-cell engaging (BiTE®) antibody construct targeting HIV gp120 resulted in substantially reduced HIV replication. In addition, these BiTE® antibody constructs display efficient killing of gp120 expressing cells and inhibited replication in ex vivo

  6. Non-Neutralizing Antibodies Directed against HIV and Their Functions

    Directory of Open Access Journals (Sweden)

    Luzia M. Mayr

    2017-11-01

    Full Text Available B cells produce a plethora of anti-HIV antibodies (Abs but only few of them exhibit neutralizing activity. This was long considered a profound limitation for the enforcement of humoral immune responses against HIV-1 infection, especially since these neutralizing Abs (nAbs are extremely difficult to induce. However, increasing evidence shows that additional non-neutralizing Abs play a significant role in decreasing the viral load, leading to partial and sometimes even total protection. Mechanisms suspected to participate in protection are numerous. They involve the Fc domain of Abs as well as their Fab part, and consequently the induced Ab isotype will be determinant for their functions, as well as the quantity and quality of the Fc-receptors (FcRs expressed on immune cells. Fc-mediated inhibitory functions, such as Ab-dependent cellular cytotoxicity, antibody-dependent cellular phagocytosis, aggregation, and even immune activation have been proposed. However, as for nAbs, the non-neutralizing activities are limited to a subset of anti-HIV Abs. An improved in-depth characterization of the Abs displaying these functional responses is required for the development of new vaccination strategies, which aim to selectively trigger the B cells able to induce the right functional Ab combinations both at the right place and at the right time. This review summarizes our current knowledge on non-neutralizing functional inhibitory Abs and discusses the potential benefit of inducing them via vaccination. We also provide new insight into the roles of the FcγR-mediated Ab therapeutics in clinical trials for HIV diseases.

  7. Antibody maturation and viral diversification in HIV-infected women.

    Directory of Open Access Journals (Sweden)

    Maria M James

    Full Text Available The Post-exposure Prophylaxis in Infants (PEPI-Malawi trial evaluated infant antiretroviral regimens for prevention of post-natal HIV transmission. A multi-assay algorithm (MAA that includes the BED capture immunoassay, an avidity assay, CD4 cell count, and viral load was used to identify women who were vs. were not recently infected at the time of enrollment (MAA recent, N = 73; MAA non-recent, N = 2,488; a subset of the women in the MAA non-recent group known to have been HIV infected for at least 2 years before enrollment (known non-recent, N = 54. Antibody maturation and viral diversification were examined in these women.Samples collected at enrollment (N = 2,561 and 12-24 months later (N = 1,306 were available for serologic analysis using the BED and avidity assays. A subset of those samples was used for analysis of viral diversity, which was performed using a high resolution melting (HRM diversity assay. Viral diversity analysis was performed using all available samples from women in the MAA recent group (61 enrollment samples, 38 follow-up samples and the known non-recent group (43 enrollment samples, 22 follow-up samples. Diversity data from PEPI-Malawi were also compared to similar data from 169 adults in the United States (US with known recent infection (N = 102 and known non-recent infection (N = 67.In PEPI-Malawi, results from the BED and avidity assays increased over time in the MAA recent group, but did not change significantly in the MAA non-recent group. At enrollment, HIV diversity was lower in the MAA recent group than in the known non-recent group. HRM diversity assay results from women in PEPI-Malawi were similar to those from adults in the US with known duration of HIV infection.Antibody maturation and HIV diversification patterns in African women provide additional support for use of the MAA to identify populations with recent HIV infection.

  8. Evaluation Of Algorithms Of Anti- HIV Antibody Tests

    Directory of Open Access Journals (Sweden)

    Paranjape R.S

    1997-01-01

    Full Text Available Research question: Can alternate algorithms be used in place of conventional algorithm for epidemiological studies of HIV infection with less expenses? Objective: To compare the results of HIV sero- prevalence as determined by test algorithms combining three kits with conventional test algorithm. Study design: Cross â€" sectional. Participants: 282 truck drivers. Statistical analysis: Sensitivity and specificity analysis and predictive values. Results: Three different algorithms that do not include Western Blot (WB were compared with the conventional algorithm, in a truck driver population with 5.6% prevalence of HIV â€"I infection. Algorithms with one EIA (Genetic Systems or Biotest and a rapid test (immunocomb or with two EIAs showed 100% positive predictive value in relation to the conventional algorithm. Using an algorithm with EIA as screening test and a rapid test as a confirmatory test was 50 to 70% less expensive than the conventional algorithm per positive scrum sample. These algorithms obviate the interpretation of indeterminate results and also give differential diagnosis of HIV-2 infection. Alternate algorithms are ideally suited for community based control programme in developing countries. Application of these algorithms in population with low prevalence should also be studied in order to evaluate universal applicability.

  9. Escherichia coli surface display of single-chain antibody VRC01 against HIV-1 infection

    International Nuclear Information System (INIS)

    Wang, Lin-Xu; Mellon, Michael; Bowder, Dane; Quinn, Meghan; Shea, Danielle; Wood, Charles; Xiang, Shi-Hua

    2015-01-01

    Human immunodeficiency virus type 1 (HIV-1) transmission and infection occur mainly via the mucosal surfaces. The commensal bacteria residing in these surfaces can potentially be employed as a vehicle for delivering inhibitors to prevent HIV-1 infection. In this study, we have employed a bacteria-based strategy to display a broadly neutralizing antibody VRC01, which could potentially be used to prevent HIV-1 infection. The VRC01 antibody mimics CD4-binding to gp120 and has broadly neutralization activities against HIV-1. We have designed a construct that can express the fusion peptide of the scFv-VRC01 antibody together with the autotransporter β-barrel domain of IgAP gene from Neisseria gonorrhoeae, which enabled surface display of the antibody molecule. Our results indicate that the scFv-VRC01 antibody molecule was displayed on the surface of the bacteria as demonstrated by flow cytometry and immunofluorescence microscopy. The engineered bacteria can capture HIV-1 particles via surface-binding and inhibit HIV-1 infection in cell culture. - Highlights: • Designed single-chain VRC01 antibody was demonstrated to bind HIV-1 envelope gp120. • Single-chain VRC01 antibody was successfully displayed on the surface of E. coli. • Engineered bacteria can absorb HIV-1 particles and prevent HIV-1 infection in cell culture

  10. Aggregate complexes of HIV-1 induced by multimeric antibodies.

    Science.gov (United States)

    Stieh, Daniel J; King, Deborah F; Klein, Katja; Liu, Pinghuang; Shen, Xiaoying; Hwang, Kwan Ki; Ferrari, Guido; Montefiori, David C; Haynes, Barton; Pitisuttithum, Punnee; Kaewkungwal, Jaranit; Nitayaphan, Sorachai; Rerks-Ngarm, Supachai; Michael, Nelson L; Robb, Merlin L; Kim, Jerome H; Denny, Thomas N; Tomaras, Georgia D; Shattock, Robin J

    2014-10-02

    Antibody mediated viral aggregation may impede viral transfer across mucosal surfaces by hindering viral movement in mucus, preventing transcytosis, or reducing inter-cellular penetration of epithelia thereby limiting access to susceptible mucosal CD4 T cells and dendritic cells. These functions may work together to provide effective immune exclusion of virus from mucosal tissue; however little is known about the antibody characteristics required to induce HIV aggregation. Such knowledge may be critical to the design of successful immunization strategies to facilitate viral immune exclusion at the mucosal portals of entry. The potential of neutralizing and non-neutralizing IgG and IgA monoclonals (mAbs) to induce HIV-1 aggregation was assessed by Dynamic light scattering (DLS). Although neutralizing and non-neutralizing IgG mAbs and polyclonal HIV-Ig efficiently aggregated soluble Env trimers, they were not capable of forming viral aggregates. In contrast, dimeric (but not monomeric) IgA mAbs induced stable viral aggregate populations that could be separated from uncomplexed virions. Epitope specificity influenced both the degree of aggregation and formation of higher order complexes by dIgA. IgA purified from serum of uninfected RV144 vaccine trial responders were able to efficiently opsonize viral particles in the absence of significant aggregation, reflective of monomeric IgA. These results collectively demonstrate that dIgA is capable of forming stable viral aggregates providing a plausible basis for testing the effectiveness of aggregation as a potential protection mechanism at the mucosal portals of viral entry.

  11. Lack of HIV infection among truck drivers in Iran using rapid HIV test

    Directory of Open Access Journals (Sweden)

    Hossain Jabbari

    2010-01-01

    Full Text Available Background: The aim of this study was to evaluate the prevalence of HIV infection in Iranian long distance truck drivers using rapid HIV test. Methods: The study included 400 consecutive participants in Bazargan city, north-west of Iran in the late 2008 and the early 2009. Results: No HIV infection was observed among these long distance truck drivers. Conclusions: Although results of this study is plausible compared to other similar studies, repeated surveys are necessary to know the trend of HIV infection in truckers in Iran.

  12. Co-evolution of a broadly neutralizing HIV-1 antibody and founder virus

    Science.gov (United States)

    Liao, Hua-Xin; Lynch, Rebecca; Zhou, Tongqing; Gao, Feng; Alam, S. Munir; Boyd, Scott D.; Fire, Andrew Z.; Roskin, Krishna M.; Schramm, Chaim A.; Zhang, Zhenhai; Zhu, Jiang; Shapiro, Lawrence; Mullikin, James C.; Gnanakaran, S.; Hraber, Peter; Wiehe, Kevin; Kelsoe, Garnett; Yang, Guang; Xia, Shi-Mao; Montefiori, David C.; Parks, Robert; Lloyd, Krissey E.; Scearce, Richard M.; Soderberg, Kelly A.; Cohen, Myron; Kaminga, Gift; Louder, Mark K.; Tran, Lillan M.; Chen, Yue; Cai, Fangping; Chen, Sheri; Moquin, Stephanie; Du, Xiulian; Joyce, Gordon M.; Srivatsan, Sanjay; Zhang, Baoshan; Zheng, Anqi; Shaw, George M.; Hahn, Beatrice H.; Kepler, Thomas B.; Korber, Bette T.M.; Kwong, Peter D.; Mascola, John R.; Haynes, Barton F.

    2013-01-01

    Current HIV-1 vaccines elicit strain-specific neutralizing antibodies. However, cross-reactive neutralizing antibodies arise in ~20% of HIV-1-infected individuals, and details of their generation could provide a roadmap for effective vaccination. Here we report the isolation, evolution and structure of a broadly neutralizing antibody from an African donor followed from time of infection. The mature antibody, CH103, neutralized ~55% of HIV-1 isolates, and its co-crystal structure with gp120 revealed a novel loop-based mechanism of CD4-binding site recognition. Virus and antibody gene sequencing revealed concomitant virus evolution and antibody maturation. Notably, the CH103-lineage unmutated common ancestor avidly bound the transmitted/founder HIV-1 envelope glycoprotein, and evolution of antibody neutralization breadth was preceded by extensive viral diversification in and near the CH103 epitope. These data elucidate the viral and antibody evolution leading to induction of a lineage of HIV-1 broadly neutralizing antibodies and provide insights into strategies to elicit similar antibodies via vaccination. PMID:23552890

  13. Potential for false positive HIV test results with the serial rapid HIV testing algorithm

    Directory of Open Access Journals (Sweden)

    Baveewo Steven

    2012-03-01

    Full Text Available Abstract Background Rapid HIV tests provide same-day results and are widely used in HIV testing programs in areas with limited personnel and laboratory infrastructure. The Uganda Ministry of Health currently recommends the serial rapid testing algorithm with Determine, STAT-PAK, and Uni-Gold for diagnosis of HIV infection. Using this algorithm, individuals who test positive on Determine, negative to STAT-PAK and positive to Uni-Gold are reported as HIV positive. We conducted further testing on this subgroup of samples using qualitative DNA PCR to assess the potential for false positive tests in this situation. Results Of the 3388 individuals who were tested, 984 were HIV positive on two consecutive tests, and 29 were considered positive by a tiebreaker (positive on Determine, negative on STAT-PAK, and positive on Uni-Gold. However, when the 29 samples were further tested using qualitative DNA PCR, 14 (48.2% were HIV negative. Conclusion Although this study was not primarily designed to assess the validity of rapid HIV tests and thus only a subset of the samples were retested, the findings show a potential for false positive HIV results in the subset of individuals who test positive when a tiebreaker test is used in serial testing. These findings highlight a need for confirmatory testing for this category of individuals.

  14. Potential for false positive HIV test results with the serial rapid HIV testing algorithm.

    Science.gov (United States)

    Baveewo, Steven; Kamya, Moses R; Mayanja-Kizza, Harriet; Fatch, Robin; Bangsberg, David R; Coates, Thomas; Hahn, Judith A; Wanyenze, Rhoda K

    2012-03-19

    Rapid HIV tests provide same-day results and are widely used in HIV testing programs in areas with limited personnel and laboratory infrastructure. The Uganda Ministry of Health currently recommends the serial rapid testing algorithm with Determine, STAT-PAK, and Uni-Gold for diagnosis of HIV infection. Using this algorithm, individuals who test positive on Determine, negative to STAT-PAK and positive to Uni-Gold are reported as HIV positive. We conducted further testing on this subgroup of samples using qualitative DNA PCR to assess the potential for false positive tests in this situation. Of the 3388 individuals who were tested, 984 were HIV positive on two consecutive tests, and 29 were considered positive by a tiebreaker (positive on Determine, negative on STAT-PAK, and positive on Uni-Gold). However, when the 29 samples were further tested using qualitative DNA PCR, 14 (48.2%) were HIV negative. Although this study was not primarily designed to assess the validity of rapid HIV tests and thus only a subset of the samples were retested, the findings show a potential for false positive HIV results in the subset of individuals who test positive when a tiebreaker test is used in serial testing. These findings highlight a need for confirmatory testing for this category of individuals.

  15. Isotype Diversification of IgG Antibodies to HIV Gag Proteins as a Therapeutic Vaccination Strategy for HIV Infection.

    Science.gov (United States)

    French, Martyn A; Abudulai, Laila N; Fernandez, Sonia

    2013-08-09

    The development of vaccines to treat and prevent human immunodeficiency virus (HIV) infection has been hampered by an incomplete understanding of "protective" immune responses against HIV. Natural control of HIV-1 infection is associated with T-cell responses against HIV-1 Gag proteins, particularly CD8⁺ T-cell responses restricted by "protective" HLA-B alleles, but other immune responses also contribute to immune control. These immune responses appear to include IgG antibodies to HIV-1 Gag proteins, interferon-a-dependant natural killer (NK) cell responses and plasmacytoid dendritic cell (pDC) responses. Here, it is proposed that isotype diversification of IgG antibodies against HIV-1 Gag proteins, to include IgG2, as well as IgG3 and IgG1 antibodies, will broaden the function of the antibody response and facilitate accessory cell responses against HIV-1 by NK cells and pDCs. We suggest that this should be investigated as a vaccination strategy for HIV-1 infection.

  16. Isotype Diversification of IgG Antibodies to HIV Gag Proteins as a Therapeutic Vaccination Strategy for HIV Infection

    Directory of Open Access Journals (Sweden)

    Sonia Fernandez

    2013-08-01

    Full Text Available The development of vaccines to treat and prevent human immunodeficiency virus (HIV infection has been hampered by an incomplete understanding of “protective” immune responses against HIV. Natural control of HIV-1 infection is associated with T-cell responses against HIV-1 Gag proteins, particularly CD8+ T-cell responses restricted by “protective” HLA-B alleles, but other immune responses also contribute to immune control. These immune responses appear to include IgG antibodies to HIV-1 Gag proteins, interferon-a-dependant natural killer (NK cell responses and plasmacytoid dendritic cell (pDC responses. Here, it is proposed that isotype diversification of IgG antibodies against HIV-1 Gag proteins, to include IgG2, as well as IgG3 and IgG1 antibodies, will broaden the function of the antibody response and facilitate accessory cell responses against HIV-1 by NK cells and pDCs. We suggest that this should be investigated as a vaccination strategy for HIV-1 infection.

  17. [Analysis of HIV antibody positive cases in Peking University Hospital of Stomatology during 9 years].

    Science.gov (United States)

    Ding, Jian-fen; Qiu, Juan; Shen, Shu-ming

    2016-02-01

    To investigate the prevalence and characteristics of HIV patients found in Peking University Hospital of Stomatology during 9 years, and provide management strategy for early diagnosis and control of HIV in Stomatology Hospital. A retrospective study of the HIV positive patients diagnosed by HIV antibody screening was carried out. The related information about these patients found in Peking University School of Stomatology during 2005-2013 was obtained from China Disease Control Information System. 68,562 patients accepted HIV antibody screening in Peking University Hospital of Stomatology during 2005-2013. Thirty one patients were found HIV antibody positive. The ratio of HIV antibody positive was about 0.045%, which was composed of 25 males and 6 females. 61.29% patients aged between 20-40 years, and their career was mainly commercial service with a education level of junior high school. The proportion of sexual route of transmission was about 74.91%, and 34.78% of them were male homosexuality. Most of the patients with HIV antibody positive were found in the out-patient clinic, especially in the department of oral mucosal diseases, accounting for 70.97%. HIV antibody positive rate in Peking University School of Stomatology was slightly lower than that in general hospitals. Medical staff should increase their awareness of AIDS prevention and control, for higher HIV risk departments, such as oral mucosal diseases and periodontal disease, efforts should be made to increase HIV screening, expand the scope of screening, and promote provider-initiated HIV testing and counseling.

  18. HIV-1-Specific IgA Monoclonal Antibodies from an HIV-1 Vaccinee Mediate Galactosylceramide Blocking and Phagocytosis

    Science.gov (United States)

    2018-01-01

    ABSTRACT Vaccine-elicited humoral immune responses comprise an array of antibody forms and specificities, with only a fraction contributing to protective host immunity. Elucidation of antibody effector functions responsible for protective immunity against human immunodeficiency virus type 1 (HIV-1) acquisition is a major goal for the HIV-1 vaccine field. Immunoglobulin A (IgA) is an important part of the host defense against pathogens; however, little is known about the role of vaccine-elicited IgA and its capacity to mediate antiviral functions. To identify the antiviral functions of HIV-1-specific IgA elicited by vaccination, we cloned HIV-1 envelope-specific IgA monoclonal antibodies (MAbs) by memory B cell cultures from peripheral blood mononuclear cells from an RV144 vaccinee and produced two IgA clonal cell lines (HG129 and HG130) producing native, nonrecombinant IgA MAbs. The HG129 and HG130 MAbs mediated phagocytosis by monocytes, and HG129 blocked HIV-1 Env glycoprotein binding to galactosylceramide, an alternative HIV-1 receptor. These findings elucidate potential antiviral functions of vaccine-elicited HIV-1 envelope-specific IgA that may act to block HIV-1 acquisition at the portal of entry by preventing HIV-1 binding to galactosylceramide and mediating antibody Fc receptor-mediated virion phagocytosis. Furthermore, these findings highlight the complex and diverse interactions of vaccine-elicited IgA with pathogens that depend on IgA fine specificity and form (e.g., multimeric or monomeric) in the systemic circulation and mucosal compartments. IMPORTANCE Host-pathogen interactions in vivo involve numerous immune mechanisms that can lead to pathogen clearance. Understanding the nature of antiviral immune mechanisms can inform the design of efficacious HIV-1 vaccine strategies. Evidence suggests that both neutralizing and nonneutralizing antibodies can mediate some protection against HIV in animal models. Although numerous studies have characterized the

  19. Immunoglobulin G1 Allotype Influences Antibody Subclass Distribution in Response to HIV gp140 Vaccination

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    Sven Kratochvil

    2017-12-01

    Full Text Available Antibody subclasses exhibit extensive polymorphisms (allotypes that could potentially impact the quality of HIV-vaccine induced B cell responses. Allotypes of immunoglobulin (Ig G1, the most abundant serum antibody, have been shown to display altered functional properties in regard to serum half-life, Fc-receptor binding and FcRn-mediated mucosal transcytosis. To investigate the potential link between allotypic IgG1-variants and vaccine-generated humoral responses in a cohort of 14 HIV vaccine recipients, we developed a novel protocol for rapid IgG1-allotyping. We combined PCR and ELISA assays in a dual approach to determine the IgG1 allotype identity (G1m3 and/or G1m1 of trial participants, using human plasma and RNA isolated from PBMC. The IgG1-allotype distribution of our participants mirrored previously reported results for caucasoid populations. We observed elevated levels of HIV gp140-specific IgG1 and decreased IgG2 levels associated with the G1m1-allele, in contrast to G1m3 carriers. These data suggest that vaccinees homozygous for G1m1 are predisposed to develop elevated Ag-specific IgG1:IgG2 ratios compared to G1m3-carriers. This elevated IgG1:IgG2 ratio was further associated with higher FcγR-dimer engagement, a surrogate for potential antibody-dependent cellular cytotoxicity (ADCC and antibody-dependent cellular phagocytosis (ADCP function. Although preliminary, these results suggest that IgG1 allotype may have a significant impact on IgG subclass distribution in response to vaccination and associated Fc-mediated effector functions. These results have important implications for ongoing HIV vaccine efficacy studies predicated on engagement of FcγR-mediated cellular functions including ADCC and ADCP, and warrant further investigation. Our novel allotyping protocol provides new tools to determine the potential impact of IgG1 allotypes on vaccine efficacy.

  20. Overcoming the Constraints of Anti-HIV/CD89 Bispecific Antibodies That Limit Viral Inhibition

    Directory of Open Access Journals (Sweden)

    Xiaocong Yu

    2016-01-01

    Full Text Available Innovative strategies are necessary to maximize the clinical application of HIV neutralizing antibodies. To this end, bispecific constructs of human antibody F240, reactive with well-conserved gp41 epitope and antibody 14A8, reactive with the IgA receptor (CD89 on effector cells, were constructed. A F240 × 14A8 bispecific single chain variable region (scFv molecule was constructed by linking two scFvs using a conventional GGGGS linker. Despite immunoreactivity with HIV gp41 and neutrophils, this bispecific scFv failed to inhibit HIV infection. This is in sharp contrast to viral inhibition using a chemical conjugate of the Fab of these two antibodies. Therefore, we constructed two novel Fab-like bispecific antibody molecules centered on fusion of the IgG1 CH1 domain or CH1-hinge domain to the C-terminus of F240scFv and fusion of the kappa chain CL domain to the C-terminus of 14A8scFv. Both Bi-Fab antibodies showed significant ADCVI activity for multiple clade B and clade C isolates by arming the neutrophils to inhibit HIV infection. The approach presented in this study is unique for HIV immunotherapy in that the impetus of neutralization is to arm and mobilize PMN to destroy HIV and HIV infected cells.

  1. [HIV infection and associated factors in HIV-antibody positive clients of female sex workers recently reported in Shaanxi province].

    Science.gov (United States)

    Hu, T; Chang, W H; Zhang, M Y

    2017-03-10

    Objective: To investigate the current status of HIV infection and the related factors in HIV antibody positive clients of female sex workers (FSWs) recently reported in Shaanxi province. Methods: The HIV/AIDS cases newly diagnosed in males living in Shaanxi from January 1th of 2013 to June 30th of 2014 were selected and those infected through " commercial heterosexual behavior" were identified. The information about their demographic characteristics, previous unprotected heterosexual sex and the sample sources were collected, and serum or plasma samples were collected from them and tested with BED-CEIA. The proportion of recent HIV infections and associated factors were investigated. Results: The proportion of recent HIV infection and HIV-antibody detection rate in 212 HIV antibody positive male clients of FSWs were 25.5% and 6.6% respectively. The cases who had the educational level of junior middle school or high middle school were wore likely to have long term HIV infections than those with lower educational level (a OR =0.28, 95 % CI : 0.08-0.93). Compared with patients identified by hospitals or sexually transmitted diseases clinics, recent HIV infections were more likely to be found through preoperative test or blood transfusion test (a OR =3.14, 95 % CI : 1.06-9.30) and blood donation test (a OR =4.19, 95 % CI :1.01-17.42). Compared with the cases who had commercial sex only in Xi' an or other province or both in Xi' an and other province, the cases who had commercial sex in other cities in Shaanxi were more likely to be infected recently (a OR =0.19, 95 %CI : 0.07-0.57). Compared with the cases had temporary heterosexual sex partner, those who had no temporary sex partners were more likely to be infected recently (a OR =9.03, 95 % CI : 3.00-27.18) ( P HIV infections among HIV antibody positive clients of FSWs was high and the HIV-antibody detection rate among them was low. The educational level, sample source, geographic area and temporary heterosexual

  2. Association between HIV-1 coreceptor usage and resistance to broadly neutralizing antibodies.

    Science.gov (United States)

    Pfeifer, Nico; Walter, Hauke; Lengauer, Thomas

    2014-10-01

    Recently discovered broadly neutralizing antibodies have revitalized hopes of developing a universal vaccine against HIV-1. Mainly responsible for new infections are variants only using CCR5 for cell entry, whereas CXCR4-using variants can become dominant in later infection stages. We performed a statistical analysis on two different previously published data sets. The first data set was a panel of 199 diverse HIV-1 isolates for which IC50 neutralization titers were determined for the broadly neutralizing antibodies VRC01, VRC-PG04, PG9, and PG16. The second data set contained env sequences of viral variants extracted from HIV-1-infected humanized mice treated with the antibody PGT128 and from untreated control mice. For the panel of 199 diverse HIV-1 isolates, we found a statistically significant association between viral resistance to PG9 and PG16 and CXCR4 coreceptor usage (P = 0.0011 and P = 0.0010, respectively). Our analysis of viral variants from HIV-1-infected humanized mice under treatment with the broadly neutralizing antibody PGT128 indicated that certain antibodies might drive a viral population toward developing CXCR4 coreceptor usage capability (P = 0.0011 for the comparison between PGT128 and control measurement). These analyses highlight the importance of accounting for a possible coreceptor usage bias pertaining to the effectiveness of an HIV vaccine and to passive antibody transfer as therapeutic approach.

  3. Low sero-prevalence of hepatitis delta antibodies in HIV/ hepatitis B ...

    African Journals Online (AJOL)

    /198, 3.2% (95% CI 1.14-6.92%), associated with male gender and a duration of more than 5 years since HIV diagnosis. Conclusions: The sero-prevalence of HDV antibodies among the HIV/HBV co-infected patients is low in a Ugandan urban ...

  4. HIV-1 neutralizing antibodies induced by native-like envelope trimers

    NARCIS (Netherlands)

    Sanders, Rogier W.; van Gils, Marit J.; Derking, Ronald; Sok, Devin; Ketas, Thomas J.; Burger, Judith A.; Ozorowski, Gabriel; Cupo, Albert; Simonich, Cassandra; Goo, Leslie; Arendt, Heather; Kim, Helen J.; Lee, Jeong Hyun; Pugach, Pavel; Williams, Melissa; Debnath, Gargi; Moldt, Brian; van Breemen, Mariëlle J.; Isik, Gözde; Medina-Ramírez, Max; Back, Jaap Willem; Koff, Wayne C.; Julien, Jean-Philippe; Rakasz, Eva G.; Seaman, Michael S.; Guttman, Miklos; Lee, Kelly K.; Klasse, Per Johan; Labranche, Celia; Schief, William R.; Wilson, Ian A.; Overbaugh, Julie; Burton, Dennis R.; Ward, Andrew B.; Montefiori, David C.; Dean, Hansi; Moore, John P.

    2015-01-01

    A challenge for HIV-1 immunogen design is the difficulty of inducing neutralizing antibodies (NAbs) against neutralization-resistant (tier 2) viruses that dominate human transmissions. We show that a soluble recombinant HIV-1 envelope glycoprotein trimer that adopts a native conformation, BG505

  5. Pilot study of risk behaviour, voluntary HIV counselling and HIV antibody testing from saliva among inmates of prisons in Slovakia.

    Science.gov (United States)

    Staneková, D; Ondrejka, D; Habeková, M; Wimmerová, S; Kucerková, S

    2001-05-01

    To implement a pilot study of risk behaviour and HIV infection using HIV antibody testing from saliva to improve the situation as regards HIV/AIDS infection in prison institutions in the Slovak Republic. The study comprised adult and juvenile males of grade one correction categories and prisoners from the prison for juveniles in Martin, as well as females prisoners in Nitra. Preventive activities were implemented in May 1998 in the form of discussions concerning topics related to HIV/AIDS infection. Saliva was collected for the presence of HIV antibodies and a questionnaire regarding sexual practice was completed. 32 persons [8 adult males (25%), 6 juvenile males (18.7%) and 18 females (56%)] were voluntarily tested for the presence of HIV antibodies in saliva. Nobody was HIV-positive. 75 persons (20 adult males, 30 juvenile males and 25 females) were involved in the study of risk behaviour. 40.8% participants had primary education, 28.2% secondary education, 2.8% were students of universities and 28.2% were apprenticies. 60% inmates (mostly females) were religious. Juvenile males reported the highest number of partners while females the smallest (p prison while 19%, 5.6% and 8.3% in the prison, respectively. Paid sexual services were offered by 9.1% females, 15.8% adult males and 25% juvenile males. Outside prison adult and juvenile males used non-sterile used syringes as well as tattooing more often than females (p prisoners.

  6. Oral rapid test: an alternative to traditional HIV screening in Chile

    Directory of Open Access Journals (Sweden)

    Lisette Paola Irarrazábal

    2013-06-01

    Full Text Available OBJECTIVE: To compare the sensitivity and specificity of an Oral Rapid Test (ORT to that of the Enzyme-Linked Immunosorbent Assay (ELISA for HIV testing in Santiago, Chile; to track the number of study participants returning for ELISA testing results; and to analyze the participants' perceptions of the ORT compared to the ELISA. METHODS: A total of 497 people were recruited in Santiago, Chile: 153 had previously tested positive for HIV, and 344 were of unknown status. Participants were tested for HIV using both the ELISA and the ORT to examine and compare specificity and sensitivity. Qualitative data were collected from 22 participants to compare perceptions of the testing experience with ORT versus ELISA. RESULTS: The ELISA reported 184 (37% of the 497 participants as being "positive" for HIV antibodies; the ORT showed 181 (36.4% as being "reactive" for HIV. The ORT showed a sensitivity of 98.4% (95.7%-99.9%, 95% Confidence Interval and specificity of 100%. The Kappa test produced K = 0.983 (P < 0.0001. Of the 344 participants whose HIV status was unknown at the start of the study, 55 failed to return for their ELISA results. Participants positively perceived ORT as having reduced both waiting time and anxiety over obtaining their test results. ORT oral swabbing appeared more practical and less invasive than drawing blood for the ELISA. CONCLUSIONS: The ORT and ELISA were statistically equal in specificity and sensitivity. ORT provides quicker results, potentially ensuring that more people receive them, and does not require handling of or exposure to potentially hazardous blood products. Trial number: ClinicalTrials.gov identifier: NCT01733927.

  7. HIV-1-Specific Antibody Response and Function after DNA Prime and Recombinant Adenovirus 5 Boost HIV Vaccine in HIV-Infected Subjects.

    Directory of Open Access Journals (Sweden)

    Johannes S Gach

    Full Text Available Little is known about the humoral immune response against DNA prime-recombinant adenovirus 5 (rAd5 boost HIV vaccine among HIV-infected patients on long-term suppressive antiretroviral therapy (ART. Previous studies emphasized cellular immune responses; however, current research suggests both cellular and humoral responses are likely required for a successful therapeutic vaccine. Thus, we aimed to understand antibody response and function induced by vaccination of ART-treated HIV-1-infected patients with immune recovery. All subjects participated in EraMune 02, an open-label randomized clinical trial of ART intensification followed by a six plasmid DNA prime (envA, envB, envC, gagB, polB, nefB and rAd5 boost HIV vaccine with matching inserts. Antibody binding levels were determined with a recently developed microarray approach. We also analyzed neutralization efficiency and antibody-dependent cellular cytotoxicity (ADCC. We found that the DNA prime-rAd5 boost vaccine induced a significant cross-clade HIV-specific antibody response, which correlated with antibody neutralization efficiency. However, despite the increase in antibody binding levels, the vaccine did not significantly stimulate neutralization or ADCC responses. This finding was also reflected by a lack of change in total CD4+ cell associated HIV DNA in those who received the vaccine. Our results have important implications for further therapeutic vaccine design and administration, especially in HIV-1 infected patients, as boosting of preexisting antibody responses are unlikely to lead to clearance of latent proviruses in the HIV reservoir.

  8. rapid assessment of polio virus antibodies prevalence amongst

    African Journals Online (AJOL)

    ISSN 1597-6343. Polio Virus Antibodies Prevalence Amongst Children In Kano State ... poliovirus serotypes (types 1, 2 or 3) which cause poliomyelitis. They are spread by ..... all those that have contributed to the overall success of this work.

  9. TOXOPLASMA AND VIRAL ANTIBODIES AMONG HIV PATIENTS AND INMATES IN CENTRAL JAVA, INDONESIA.

    Science.gov (United States)

    Sari, Yulia; Haryati, Sri; Raharjo, Irvan; Prasetyo, Afiono Agung

    2015-11-01

    In Indonesia, Toxoplasma and its associations with blood-borne viruses have been poorly studied. In order to study the association between anti-Toxoplasma antibodies and blood-borne viral antibodies, blood samples from 497 participants (375 inmates from four prisons in Central Java, Indonesia and 122 HIV patients at a Voluntary Counseling and Testing Clinic in Surakarta, Indonesia) were tested for serological markers of Toxoplasma, human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV) and human T-lymphotropic virus types I and II (HTLV-1/2). Anti-Toxoplasma IgG and IgM positivity rates were 41.6% and 3.6%, respectively. One point two percent of participants was positive for both anti-Toxoplasma IgG and IgM antibodies. Sixteen point five percent, 11.3%, 2.6% and 2.8% of participants were positive for anti- Toxoplasma IgG combined with anti-HCV antibodies, anti-Toxoplasma IgG combined with anti-HIV antibodies, anti-Toxoplasma IgM combined with anti-HIV antibodes and anti-Toxoplasma IgG combined with both anti-HIV and anti-HCV antibodies, respectively. Anti-Toxoplasma IgM seropositivity was associated with anti-HIV (aOR = 4.3; 95% CI: 1.112-16.204, p = 0.034). Anti-Toxoplasma IgG antibodies were associated with anti-HCV (aOR = 2.8; 95% CI: 1.749-4.538, p < 0.001) and history of injection drug use (aOR = 3.1; 95% CI: 1.905-5.093, p < 0.001). In conclusion, we recommend patients with HIV, HCV infection and injection drug users should be screened for Toxoplasma infection in Indonesia.

  10. Defective proviruses rapidly accumulate during acute HIV-1 infection

    Science.gov (United States)

    Bruner, Katherine M.; Murray, Alexandra J.; Pollack, Ross A.; Soliman, Mary G.; Laskey, Sarah B.; Capoferri, Adam A.; Lai, Jun; Strain, Matthew C.; Lada, Steven M.; Hoh, Rebecca; Ho, Ya-Chi; Richman, Douglas D.; Deeks, Steven G.; Siliciano, Janet D.; Siliciano, Robert F.

    2016-01-01

    Although antiretroviral therapy (ART) suppresses viral replication to clinically undetectable levels, HIV-1 persists in CD4+ T cells in a latent form not targeted by the immune system or ART1–5. This latent reservoir is a major barrier to cure. Many individuals initiate ART during chronic infection, and in this setting, most proviruses are defective6. However, the dynamics of the accumulation and persistence of defective proviruses during acute HIV-1 infection are largely unknown. Here we show that defective proviruses accumulate rapidly within the first few weeks of infection to make up over 93% of all proviruses, regardless of how early ART is initiated. Using an unbiased method to amplify near full-length proviral genomes from HIV-1 infected adults treated at different stages of infection, we demonstrate that early ART initiation limits the size of the reservoir but does not profoundly impact the proviral landscape. This analysis allows us to revise our understanding of the composition of proviral populations and estimate the true reservoir size in individuals treated early vs. late in infection. Additionally, we demonstrate that common assays for measuring the reservoir do not correlate with reservoir size. These findings reveal hurdles that must be overcome to successfully analyze future HIV-1 cure strategies. PMID:27500724

  11. Anti-HIV activity in cervical-vaginal secretions from HIV-positive and -negative women correlate with innate antimicrobial levels and IgG antibodies.

    Directory of Open Access Journals (Sweden)

    Mimi Ghosh

    2010-06-01

    Full Text Available We investigated the impact of antimicrobials in cervicovaginal lavage (CVL from HIV(+ and HIV(- women on target cell infection with HIV. Since female reproductive tract (FRT secretions contain a spectrum of antimicrobials, we hypothesized that CVL from healthy HIV(+ and (- women inhibit HIV infection.CVL from 32 HIV(+ healthy women with high CD4 counts and 15 healthy HIV(- women were collected by gently washing the cervicovaginal area with 10 ml of sterile normal saline. Following centrifugation, anti-HIV activity in CVL was determined by incubating CVL with HIV prior to addition to TZM-bl cells. Antimicrobials and anti-gp160 HIV IgG antibodies were measured by ELISA. When CXCR4 and CCR5 tropic HIV-1 were incubated with CVL from HIV(+ women prior to addition to TZM-bl cells, anti-HIV activity in CVL ranged from none to 100% inhibition depending on the viral strains used. CVL from HIV(- controls showed comparable anti-HIV activity. Analysis of CH077.c (clone of an R5-tropic, mucosally-transmitted founder virus viral inhibition by CVL was comparable to laboratory strains. Measurement of CVL for antimicrobials HBD2, trappin-2/elafin, SLPI and MIP3alpha indicated that each was present in CVL from HIV(+ and HIV(- women. HBD2 and MIP3alpha correlated with anti-HIV activity as did anti-gp160 HIV IgG antibodies in CVL from HIV(+ women.These findings indicate that CVL from healthy HIV(+ and HIV(- women contain innate and adaptive defense mechanisms that inhibit HIV infection. Our data suggest that innate endogenous antimicrobials and HIV-specific IgG in the FRT can act in concert to contribute toward the anti-HIV activity of the CVL and may play a role in inhibition of HIV transmission to women.

  12. Development of an anti-HIV vaccine eliciting broadly neutralizing antibodies.

    Science.gov (United States)

    Ahmed, Yousuf; Tian, Meijuan; Gao, Yong

    2017-09-12

    The extreme HIV diversity posts a great challenge on development of an effective anti-HIV vaccine. To solve this problem, it is crucial to discover an appropriate immunogens and strategies that are able to prevent the transmission of the diverse viruses that are circulating in the world. Even though there have been a number of broadly neutralizing anti-HIV antibodies (bNAbs) been discovered in recent years, induction of such antibodies to date has only been observed in HIV-1 infection. Here, in this mini review, we review the progress in development of HIV vaccine in eliciting broad immune response, especially production of bNAbs, discuss possible strategies, such as polyvalent sequential vaccination, that facilitates B cell maturation leading to bNAb response.

  13. HIV-specific Fc effector function early in infection predicts the development of broadly neutralizing antibodies.

    Directory of Open Access Journals (Sweden)

    Simone I Richardson

    2018-04-01

    Full Text Available While the induction of broadly neutralizing antibodies (bNAbs is a major goal of HIV vaccination strategies, there is mounting evidence to suggest that antibodies with Fc effector function also contribute to protection against HIV infection. Here we investigated Fc effector functionality of HIV-specific IgG plasma antibodies over 3 years of infection in 23 individuals, 13 of whom developed bNAbs. Antibody-dependent cellular phagocytosis (ADCP, complement deposition (ADCD, cellular cytotoxicity (ADCC and cellular trogocytosis (ADCT were detected in almost all individuals with levels of activity increasing over time. At 6 months post-infection, individuals with bNAbs had significantly higher levels of ADCD and ADCT that correlated with antibody binding to C1q and FcγRIIa respectively. In addition, antibodies from individuals with bNAbs showed more IgG subclass diversity to multiple HIV antigens which also correlated with Fc polyfunctionality. Germinal center activity represented by CXCL13 levels and expression of activation-induced cytidine deaminase (AID was found to be associated with neutralization breadth, Fc polyfunctionality and IgG subclass diversity. Overall, multivariate analysis by random forest classification was able to group bNAb individuals with 85% sensitivity and 80% specificity based on the properties of their antibody Fc early in HIV infection. Thus, the Fc effector function profile predicted the development of neutralization breadth in this cohort, suggesting that intrinsic immune factors within the germinal center provide a mechanistic link between the Fc and Fab of HIV-specific antibodies.

  14. HIV-specific Fc effector function early in infection predicts the development of broadly neutralizing antibodies.

    Science.gov (United States)

    Richardson, Simone I; Chung, Amy W; Natarajan, Harini; Mabvakure, Batsirai; Mkhize, Nonhlanhla N; Garrett, Nigel; Abdool Karim, Salim; Moore, Penny L; Ackerman, Margaret E; Alter, Galit; Morris, Lynn

    2018-04-01

    While the induction of broadly neutralizing antibodies (bNAbs) is a major goal of HIV vaccination strategies, there is mounting evidence to suggest that antibodies with Fc effector function also contribute to protection against HIV infection. Here we investigated Fc effector functionality of HIV-specific IgG plasma antibodies over 3 years of infection in 23 individuals, 13 of whom developed bNAbs. Antibody-dependent cellular phagocytosis (ADCP), complement deposition (ADCD), cellular cytotoxicity (ADCC) and cellular trogocytosis (ADCT) were detected in almost all individuals with levels of activity increasing over time. At 6 months post-infection, individuals with bNAbs had significantly higher levels of ADCD and ADCT that correlated with antibody binding to C1q and FcγRIIa respectively. In addition, antibodies from individuals with bNAbs showed more IgG subclass diversity to multiple HIV antigens which also correlated with Fc polyfunctionality. Germinal center activity represented by CXCL13 levels and expression of activation-induced cytidine deaminase (AID) was found to be associated with neutralization breadth, Fc polyfunctionality and IgG subclass diversity. Overall, multivariate analysis by random forest classification was able to group bNAb individuals with 85% sensitivity and 80% specificity based on the properties of their antibody Fc early in HIV infection. Thus, the Fc effector function profile predicted the development of neutralization breadth in this cohort, suggesting that intrinsic immune factors within the germinal center provide a mechanistic link between the Fc and Fab of HIV-specific antibodies.

  15. Immunization with Clinical HIV-1 Env Proteins Induces Broad Antibody Dependent Cellular Cytotoxicity-Mediating Antibodies in a Rabbit Vaccination Model

    DEFF Research Database (Denmark)

    Karlsson, Ingrid; Borggren, Marie; Jensen, Sanne Skov

    2018-01-01

    The induction of both neutralizing antibodies and non-neutralizing antibodies with effector functions, for example, antibody-dependent cellular cytotoxicity (ADCC), is desired in the search for effective vaccines against HIV-1. In the pursuit of novel immunogens capable of inducing an efficient a...

  16. Evaluation of nine HIV rapid test kits to develop a national HIV testing algorithm in Nigeria

    Directory of Open Access Journals (Sweden)

    Orji Bassey

    2015-05-01

    Full Text Available Background: Non-cold chain-dependent HIV rapid testing has been adopted in many resource-constrained nations as a strategy for reaching out to populations. HIV rapid test kits (RTKs have the advantage of ease of use, low operational cost and short turnaround times. Before 2005, different RTKs had been used in Nigeria without formal evaluation. Between 2005 and 2007, a study was conducted to formally evaluate a number of RTKs and construct HIV testing algorithms. Objectives: The objectives of this study were to assess and select HIV RTKs and develop national testing algorithms. Method: Nine RTKs were evaluated using 528 well-characterised plasma samples. These comprised 198 HIV-positive specimens (37.5% and 330 HIV-negative specimens (62.5%, collected nationally. Sensitivity and specificity were calculated with 95% confidence intervals for all nine RTKs singly and for serial and parallel combinations of six RTKs; and relative costs were estimated. Results: Six of the nine RTKs met the selection criteria, including minimum sensitivity and specificity (both ≥ 99.0% requirements. There were no significant differences in sensitivities or specificities of RTKs in the serial and parallel algorithms, but the cost of RTKs in parallel algorithms was twice that in serial algorithms. Consequently, three serial algorithms, comprising four test kits (BundiTM, DetermineTM, Stat-Pak® and Uni-GoldTM with 100.0% sensitivity and 99.1% – 100.0% specificity, were recommended and adopted as national interim testing algorithms in 2007. Conclusion: This evaluation provides the first evidence for reliable combinations of RTKs for HIV testing in Nigeria. However, these RTKs need further evaluation in the field (Phase II to re-validate their performance.

  17. Antibody-dependent enhancement of HIV-1 infection in human term syncytiotrophoblast cells cultured in vitro.

    Science.gov (United States)

    Tóth, F D; Mosborg-Petersen, P; Kiss, J; Aboagye-Mathiesen, G; Zdravkovic, M; Hager, H; Aranyosi, J; Lampé, L; Ebbesen, P

    1994-06-01

    We examined if Fc receptor-mediated antibody-dependent enhancement (FcR-ADE) or complement-mediated antibody-dependent enhancement (C'-ADE) of virus infection can contribute to increasing replication of HIV-1 in human syncytiotrophoblast (ST) cells. Here we report that both FcR-ADE and C'-ADE may result in enhanced virus release from HIV-1-infected ST cells. We show that FcR-ADE of HIV-1 infection in ST cells is mediated by FcRIII and other FcR(s) belonging to undetermined Fc classes and does not require CD4 receptors, whereas C'-ADE uses both CD4 and CR2-like receptors. FcR-ADE seems to be more efficient in enhancing HIV-1 replication than C'-ADE. While FcR-ADE leads to increased internalization of HIV-1, C'-ADE does not result in enhanced endocytosis of the virus. In addition, antibodies mediating FcR-ADE are reactive with the gp120 viral envelope antigen, whereas antibodies involved in C'-ADE react with the viral transmembrane glycoprotein gp41. Data suggest that both FcR-ADE and C'-ADE may contribute to the spread of HIV-1 from mother to the fetus.

  18. Accuracy and user-acceptability of HIV self-testing using an oral fluid-based HIV rapid test.

    Directory of Open Access Journals (Sweden)

    Oon Tek Ng

    Full Text Available BACKGROUND: The United States FDA approved an over-the-counter HIV self-test, to facilitate increased HIV testing and earlier linkage to care. We assessed the accuracy of self-testing by untrained participants compared to healthcare worker (HCW testing, participants' ability to interpret sample results and user-acceptability of self-tests in Singapore. METHODOLOGY/PRINCIPAL FINDINGS: A cross-sectional study, involving 200 known HIV-positive patients and 794 unknown HIV status at-risk participants was conducted. Participants (all without prior self-test experience performed self-testing guided solely by visual instructions, followed by HCW testing, both using the OraQuick ADVANCE Rapid HIV 1/2 Antibody Test, with both results interpreted by the HCW. To assess ability to interpret results, participants were provided 3 sample results (positive, negative, and invalid to interpret. Of 192 participants who tested positive on HCW testing, self-testing was positive in 186 (96.9%, negative in 5 (2.6%, and invalid in 1 (0.5%. Of 794 participants who tested negative on HCW testing, self-testing was negative in 791 (99.6%, positive in 1 (0.1%, and invalid in 2 (0.3%. Excluding invalid tests, self-testing had sensitivity of 97.4% (95% CI 95.1% to 99.7% and specificity of 99.9% (95% CI: 99.6% to 100%. When interpreting results, 96%, 93.1% and 95.2% correctly read the positive, negative and invalid respectively. There were no significant demographic predictors for false negative self-testing or wrongly interpreting positive or invalid sample results as negative. Eighty-seven percent would purchase the kit over-the-counter; 89% preferred to take HIV tests in private. 72.5% and 74.9% felt the need for pre- and post-test counseling respectively. Only 28% would pay at least USD15 for the test. CONCLUSIONS/SIGNIFICANCE: Self-testing was associated with high specificity, and a small but significant number of false negatives. Incorrectly identifying model results as

  19. Broadly neutralizing antibodies for treatment and prevention of HIV-1 infection.

    Science.gov (United States)

    Cohen, Yehuda Z; Caskey, Marina

    2018-04-24

    Several anti-HIV-1 broadly neutralizing antibodies (bNAbs) with exceptional breadth and potency that target different HIV-1 envelope epitopes have been identified. bNAbs are an attractive new strategy for HIV-1 prevention and therapy, and potentially, for long-term remission or cure. Here, we discuss findings from early clinical studies that have evaluated these novel bNAbs. Phase 1 studies of bNAbs targeting two distinct HIV-1 envelope epitopes have demonstrated their favorable safety and pharmacokinetic profile. Single bNAb infusions led to significant, but transient, decline in viremia with selection of escape variants. A single bNAb also delayed viral rebound in ART-treated participants who discontinued ART. Importantly, in-vivo efficacy was related to antibody potency and to the level of preexisting resistance. Studies in animal models showed that bNAbs can clear HIV-infected cells and modulate host immune responses. These findings suggest that bNAbs may target the latent HIV reservoir in humans and could contribute to long-term remission of HIV-1 infection. bNAbs may offer advantages over traditional ART for both the prevention and treatment of HIV-1 infection. In addition, bNAbs may target the latent viral reservoir. bNAb combinations and bNAbs engineered for prolonged half-life and increased potency are currently undergoing clinical evaluation.

  20. Rapid isolation of antibody from a synthetic human antibody library by repeated fluorescence-activated cell sorting (FACS.

    Directory of Open Access Journals (Sweden)

    Sung Sun Yim

    Full Text Available Antibodies and their derivatives are the most important agents in therapeutics and diagnostics. Even after the significant progress in the technology for antibody screening from huge libraries, it takes a long time to isolate an antibody, which prevents a prompt action against the spread of a disease. Here, we report a new strategy for isolating desired antibodies from a combinatorial library in one day by repeated fluorescence-activated cell sorting (FACS. First, we constructed a library of synthetic human antibody in which single-chain variable fragment (scFv was expressed in the periplasm of Escherichia coli. After labeling the cells with fluorescent antigen probes, the highly fluorescent cells were sorted by using a high-speed cell sorter, and these cells were reused without regeneration in the next round of sorting. After repeating this sorting, the positive clones were completely enriched in several hours. Thus, we screened the library against three viral antigens, including the H1N1 influenza virus, Hepatitis B virus, and Foot-and-mouth disease virus. Finally, the potential antibody candidates, which show K(D values between 10 and 100 nM against the target antigens, could be successfully isolated even though the library was relatively small (∼ 10(6. These results show that repeated FACS screening without regeneration of the sorted cells can be a powerful method when a rapid response to a spreading disease is required.

  1. Evaluation of four rapid tests for diagnosis and differentiation of HIV-1 and HIV-2 infections in Guinea-Conakry, West Africa.

    OpenAIRE

    Chaillet, Pascale; Tayler-Smith, Katie; Zachariah, Rony; Duclos, Nanfack; Moctar, Diallo; Beelaert, Greet; Fransen, Katrien

    2010-01-01

    With both HIV-1 and HV-2 prevalent in Guinea-Conakry, accurate diagnosis and differentiation is crucial for treatment purposes. Thus, four rapid HIV tests were evaluated for their HIV-1 and HIV-2 diagnostic and discriminative capacity for use in Guinea-Conakry. These included SD Bioline HIV 1/2 3.0 (Standard Diagnostics Inc.), Genie II HIV1/HIV2 (Bio-Rad), First Response HIV Card Test 1-2.0 (PMC Medical) and Immunoflow HIV1-HIV2 (Core Diagnostics). Results were compared with gold standard tes...

  2. Thyroid Antibodies

    Science.gov (United States)

    ... PF4 Antibody Hepatitis A Testing Hepatitis B Testing Hepatitis C Testing HER2/neu Herpes Testing High-sensitivity C-reactive Protein (hs-CRP) Histamine Histone Antibody HIV Antibody and HIV Antigen (p24) HIV Antiretroviral Drug Resistance Testing, Genotypic HIV Viral Load HLA Testing HLA- ...

  3. Evaluation of HIV antigen /antibody combination ELISAs for ...

    African Journals Online (AJOL)

    Results: a total of 600 blood samples were included in the evaluation. ... as an alternative confirmatory testing strategy for screening of donated blood at the National and Zonal blood transfusion centres and in lab diagnosis of HIV infection.

  4. Modeling neutralization kinetics of HIV by broadly neutralizing monoclonal antibodies in genital secretions coating the cervicovaginal mucosa.

    Directory of Open Access Journals (Sweden)

    Scott A McKinley

    Full Text Available Eliciting broadly neutralizing antibodies (bnAb in cervicovaginal mucus (CVM represents a promising "first line of defense" strategy to reduce vaginal HIV transmission. However, it remains unclear what levels of bnAb must be present in CVM to effectively reduce infection. We approached this complex question by modeling the dynamic tally of bnAb coverage on HIV. This analysis introduces a critical, timescale-dependent competition: to protect, bnAb must accumulate at sufficient stoichiometry to neutralize HIV faster than virions penetrate CVM and reach target cells. We developed a model that incorporates concentrations and diffusivities of HIV and bnAb in semen and CVM, kinetic rates for binding (kon and unbinding (koff of select bnAb, and physiologically relevant thicknesses of CVM and semen layers. Comprehensive model simulations lead to robust conclusions about neutralization kinetics in CVM. First, due to the limited time virions in semen need to penetrate CVM, substantially greater bnAb concentrations than in vitro estimates must be present in CVM to neutralize HIV. Second, the model predicts that bnAb with more rapid kon, almost independent of koff, should offer greater neutralization potency in vivo. These findings suggest the fastest arriving virions at target cells present the greatest likelihood of infection. It also implies the marked improvements in in vitro neutralization potency of many recently discovered bnAb may not translate to comparable reduction in the bnAb dose needed to confer protection against initial vaginal infections. Our modeling framework offers a valuable tool to gaining quantitative insights into the dynamics of mucosal immunity against HIV and other infectious diseases.

  5. Modeling neutralization kinetics of HIV by broadly neutralizing monoclonal antibodies in genital secretions coating the cervicovaginal mucosa.

    Science.gov (United States)

    McKinley, Scott A; Chen, Alex; Shi, Feng; Wang, Simi; Mucha, Peter J; Forest, M Gregory; Lai, Samuel K

    2014-01-01

    Eliciting broadly neutralizing antibodies (bnAb) in cervicovaginal mucus (CVM) represents a promising "first line of defense" strategy to reduce vaginal HIV transmission. However, it remains unclear what levels of bnAb must be present in CVM to effectively reduce infection. We approached this complex question by modeling the dynamic tally of bnAb coverage on HIV. This analysis introduces a critical, timescale-dependent competition: to protect, bnAb must accumulate at sufficient stoichiometry to neutralize HIV faster than virions penetrate CVM and reach target cells. We developed a model that incorporates concentrations and diffusivities of HIV and bnAb in semen and CVM, kinetic rates for binding (kon) and unbinding (koff) of select bnAb, and physiologically relevant thicknesses of CVM and semen layers. Comprehensive model simulations lead to robust conclusions about neutralization kinetics in CVM. First, due to the limited time virions in semen need to penetrate CVM, substantially greater bnAb concentrations than in vitro estimates must be present in CVM to neutralize HIV. Second, the model predicts that bnAb with more rapid kon, almost independent of koff, should offer greater neutralization potency in vivo. These findings suggest the fastest arriving virions at target cells present the greatest likelihood of infection. It also implies the marked improvements in in vitro neutralization potency of many recently discovered bnAb may not translate to comparable reduction in the bnAb dose needed to confer protection against initial vaginal infections. Our modeling framework offers a valuable tool to gaining quantitative insights into the dynamics of mucosal immunity against HIV and other infectious diseases.

  6. Potent inhibition of drug-resistant HIV protease variants by monoclonal antibodies

    Czech Academy of Sciences Publication Activity Database

    Bartoňová, Vanda; Král, Vlastimil; Sieglová, Irena; Brynda, Jiří; Fábry, Milan; Hořejší, Magdalena; Kožíšek, Milan; Grantz Šašková, Klára; Konvalinka, Jan; Sedláček, Juraj; Řezáčová, Pavlína

    2008-01-01

    Roč. 78, č. 3 (2008), s. 275-277 ISSN 0166-3542 R&D Projects: GA MZd NR8571 Institutional research plan: CEZ:AV0Z50520514; CEZ:AV0Z40550506 Keywords : HIV protease * drug resistance * Inhibiting antibody Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.613, year: 2008

  7. Viral load, CD4+ T-lymphocyte counts and antibody titres in HIV-1 ...

    African Journals Online (AJOL)

    Viral load, CD4+ T-lymphocyte counts and antibody titres in HIV-1 infected untreated children in Kenya; implication for immunodeficiency and AIDS progression. Washingtone Ochieng, Dorington Ogoyi, Francis J Mulaa, Simon Ogola, Rachel Musoke, Moses G Otsyula ...

  8. Factors Associated with Participation in HIV Antibody Screening and Results Disclosure.

    Science.gov (United States)

    Silvestre, Anthony J.; And Others

    1993-01-01

    Identified differences among 110 gay and bisexual men who decided whether to be tested for antibodies to human immunodeficiency virus (HIV) and, if so, whether to return for results. Fifty percent refused testing. Of those tested, only 35% returned to obtain test results. Education was significantly and inversely related to being tested and to…

  9. Toxoplasma gondii IgG antibodies in HIV/AIDS patients attending ...

    African Journals Online (AJOL)

    Background: Toxoplasmosis is caused by Toxoplasma gondii, a parasite that gradually evolved to be the most opportunistic parasite that complicates the course of HIV/AIDS in developing countries. Aim: This study was undertaken to investigate the presence of Toxoplasma gondii IgG antibodies in HIVinfected patients ...

  10. Murine Antibody Responses to Cleaved Soluble HIV-1 Envelope Trimers Are Highly Restricted in Specificity

    NARCIS (Netherlands)

    Hu, Joyce K.; Crampton, Jordan C.; Cupo, Albert; Ketas, Thomas; van Gils, Marit J.; Sliepen, Kwinten; de Taeye, Steven W.; Sok, Devin; Ozorowski, Gabriel; Deresa, Isaiah; Stanfield, Robyn; Ward, Andrew B.; Burton, Dennis R.; Klasse, Per Johan; Sanders, Rogier W.; Moore, John P.; Crotty, Shane

    2015-01-01

    Generating neutralizing antibodies (nAbs) is a major goal of many current HIV-1 vaccine efforts. To be of practical value, these nAbs must be both potent and cross-reactive in order to be capable of preventing the transmission of the highly diverse and generally neutralization resistant (Tier-2)

  11. HIV Antibody Testing among Adults in the United States: Data from 1988 NHIS.

    Science.gov (United States)

    Hardy, Ann M.; Dawson, Deborah A.

    1990-01-01

    Analyzes statistical data from 1988 National Health Interview Survey to determine adult awareness of and experience with HIV antibody testing. Following findings reported: most knew of test; 17 percent had been tested; Blacks and Hispanics were more likely than Whites to have been voluntarily tested; and high-risk group members were more likely…

  12. Addressing unmet need for HIV testing in emergency care settings: a role for computer-facilitated rapid HIV testing?

    Science.gov (United States)

    Kurth, Ann E; Severynen, Anneleen; Spielberg, Freya

    2013-08-01

    HIV testing in emergency departments (EDs) remains underutilized. The authors evaluated a computer tool to facilitate rapid HIV testing in an urban ED. Randomly assigned nonacute adult ED patients were randomly assigned to a computer tool (CARE) and rapid HIV testing before a standard visit (n = 258) or to a standard visit (n = 259) with chart access. The authors assessed intervention acceptability and compared noted HIV risks. Participants were 56% nonWhite and 58% male; median age was 37 years. In the CARE arm, nearly all (251/258) of the patients completed the session and received HIV results; four declined to consent to the test. HIV risks were reported by 54% of users; one participant was confirmed HIV-positive, and two were confirmed false-positive (seroprevalence 0.4%, 95% CI [0.01, 2.2]). Half (55%) of the patients preferred computerized rather than face-to-face counseling for future HIV testing. In the standard arm, one HIV test and two referrals for testing occurred. Computer-facilitated HIV testing appears acceptable to ED patients. Future research should assess cost-effectiveness compared with staff-delivered approaches.

  13. Neutralisation of HIV-1 cell-cell spread by human and llama antibodies.

    Science.gov (United States)

    McCoy, Laura E; Groppelli, Elisabetta; Blanchetot, Christophe; de Haard, Hans; Verrips, Theo; Rutten, Lucy; Weiss, Robin A; Jolly, Clare

    2014-10-02

    Direct cell-cell spread of HIV-1 is a very efficient mode of viral dissemination, with increasing evidence suggesting that it may pose a considerable challenge to controlling viral replication in vivo. Much current vaccine research involves the study of broadly neutralising antibodies (bNabs) that arise during natural infection with the aims of eliciting such antibodies by vaccination or incorporating them into novel therapeutics. However, whether cell-cell spread of HIV-1 can be effectively targeted by bNabs remains unclear, and there is much interest in identifying antibodies capable of efficiently neutralising virus transmitted by cell-cell contact. In this study we have tested a panel of bNAbs for inhibition of cell-cell spread, including some not previously evaluated for inhibition of this mode of HIV-1 transmission. We found that three CD4 binding site antibodies, one from an immunised llama (J3) and two isolated from HIV-1-positive patients (VRC01 and HJ16) neutralised cell-cell spread between T cells, while antibodies specific for glycan moieties (2G12, PG9, PG16) and the MPER (2F5) displayed variable efficacy. Notably, while J3 displayed a high level of potency during cell-cell spread we found that the small size of the llama heavy chain-only variable region (VHH) J3 is not required for efficient neutralisation since recombinant J3 containing a full-length human heavy chain Fc domain was significantly more potent. J3 and J3-Fc also neutralised cell-cell spread of HIV-1 from primary macrophages to CD4+ T cells. In conclusion, while bNabs display variable efficacy at preventing cell-cell spread of HIV-1, we find that some CD4 binding site antibodies can inhibit this mode of HIV-1 dissemination and identify the recently described llama antibody J3 as a particularly potent inhibitor. Effective neutralisation of cell-cell spread between physiologically relevant cell types by J3 and J3-Fc supports the development of VHH J3 nanobodies for therapeutic or

  14. Fusion proteins of HIV-1 envelope glycoprotein gp120 with CD4-induced antibodies showed enhanced binding to CD4 and CD4 binding site antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Weizao, E-mail: chenw3@mail.nih.gov [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); Feng, Yang [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); Wang, Yanping [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); The Basic Research Program, Science Applications International Corporation-Frederick, Inc., National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); Zhu, Zhongyu; Dimitrov, Dimiter S. [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States)

    2012-09-07

    Highlights: Black-Right-Pointing-Pointer Some recombinant HIV-1 gp120s do not preserve their conformations on gp140s. Black-Right-Pointing-Pointer We hypothesize that CD4i antibodies could induce conformational changes in gp120. Black-Right-Pointing-Pointer CD4i antibodies enhance binding of CD4 and CD4bs antibodies to gp120. Black-Right-Pointing-Pointer CD4i antibody-gp120 fusion proteins could have potential as vaccine immunogens. -- Abstract: Development of successful AIDS vaccine immunogens continues to be a major challenge. One of the mechanisms by which HIV-1 evades antibody-mediated neutralizing responses is the remarkable conformational flexibility of its envelope glycoprotein (Env) gp120. Some recombinant gp120s do not preserve their conformations on gp140s and functional viral spikes, and exhibit decreased recognition by CD4 and neutralizing antibodies. CD4 binding induces conformational changes in gp120 leading to exposure of the coreceptor-binding site (CoRbs). In this study, we test our hypothesis that CD4-induced (CD4i) antibodies, which target the CoRbs, could also induce conformational changes in gp120 leading to better exposed conserved neutralizing antibody epitopes including the CD4-binding site (CD4bs). We found that a mixture of CD4i antibodies with gp120 only weakly enhanced CD4 binding. However, such interactions in single-chain fusion proteins resulted in gp120 conformations which bound to CD4 and CD4bs antibodies better than the original or mutagenically stabilized gp120s. Moreover, the two molecules in the fusion proteins synergized with each other in neutralizing HIV-1. Therefore, fusion proteins of gp120 with CD4i antibodies could have potential as components of HIV-1 vaccines and inhibitors of HIV-1 entry, and could be used as reagents to explore the conformational flexibility of gp120 and mechanisms of entry and immune evasion.

  15. [An evaluation of the China-made HIV antibody test reagents].

    Science.gov (United States)

    Zheng, X W; Zhu, D

    1990-06-01

    This paper reports the results of the evaluation of the China-made HIV antibody screening test reagents, including the IF and IE reagents prepared by the Institute of Virology, CAPM, the ELISA reagent prepared by the Shanghai Institute of Biological Products. Based on the results, the sensitivities of the IF and IE are from 91.2% to 96.9%; the specificities, from 94.6% to 97.3%. Due to the low HIV prevalence in China, the predictive values of negative of these reagents are up to 100%; but the predictive values of positive are very low. It is suggested that these reagents can be used for HIV antibody screen testing in China. The package of some reagents should be improved, the price of some reagents should be decreased.

  16. Resistance of Subtype C HIV-1 Strains to Anti-V3 Loop Antibodies

    Directory of Open Access Journals (Sweden)

    David Almond

    2012-01-01

    Full Text Available HIV-1’s subtype C V3 loop consensus sequence exhibits increased resistance to anti-V3 antibody-mediated neutralization as compared to the subtype B consensus sequence. The dynamic 3D structure of the consensus C V3 loop crown, visualized by ab initio folding, suggested that the resistance derives from structural rigidity and non-β-strand secondary protein structure in the N-terminal strand of the β-hairpin of the V3 loop crown, which is where most known anti-V3 loop antibodies bind. The observation of either rigidity or non-β-strand structure in this region correlated with observed resistance to antibody-mediated neutralization in a series of chimeric pseudovirus (psV mutants. The results suggest the presence of an epitope-independent, neutralization-relevant structural difference in the antibody-targeted region of the V3 loop crown between subtype C and subtype B, a difference that we hypothesize may contribute to the divergent pattern of global spread between these subtypes. As antibodies to a variable loop were recently identified as an inverse correlate of risk for HIV infection, the structure-function relationships discussed in this study may have relevance to HIV vaccine research.

  17. Early low-titer neutralizing antibodies impede HIV-1 replication and select for virus escape.

    Directory of Open Access Journals (Sweden)

    Katharine J Bar

    Full Text Available Single genome sequencing of early HIV-1 genomes provides a sensitive, dynamic assessment of virus evolution and insight into the earliest anti-viral immune responses in vivo. By using this approach, together with deep sequencing, site-directed mutagenesis, antibody adsorptions and virus-entry assays, we found evidence in three subjects of neutralizing antibody (Nab responses as early as 2 weeks post-seroconversion, with Nab titers as low as 1∶20 to 1∶50 (IC(50 selecting for virus escape. In each of the subjects, Nabs targeted different regions of the HIV-1 envelope (Env in a strain-specific, conformationally sensitive manner. In subject CH40, virus escape was first mediated by mutations in the V1 region of the Env, followed by V3. HIV-1 specific monoclonal antibodies from this subject mapped to an immunodominant region at the base of V3 and exhibited neutralizing patterns indistinguishable from polyclonal antibody responses, indicating V1-V3 interactions within the Env trimer. In subject CH77, escape mutations mapped to the V2 region of Env, several of which selected for alterations of glycosylation. And in subject CH58, escape mutations mapped to the Env outer domain. In all three subjects, initial Nab recognition was followed by sequential rounds of virus escape and Nab elicitation, with Nab escape variants exhibiting variable costs to replication fitness. Although delayed in comparison with autologous CD8 T-cell responses, our findings show that Nabs appear earlier in HIV-1 infection than previously recognized, target diverse sites on HIV-1 Env, and impede virus replication at surprisingly low titers. The unexpected in vivo sensitivity of early transmitted/founder virus to Nabs raises the possibility that similarly low concentrations of vaccine-induced Nabs could impair virus acquisition in natural HIV-1 transmission, where the risk of infection is low and the number of viruses responsible for transmission and productive clinical

  18. Prediction of HIV-1 sensitivity to broadly neutralizing antibodies shows a trend towards resistance over time.

    Science.gov (United States)

    Hake, Anna; Pfeifer, Nico

    2017-10-01

    Treatment with broadly neutralizing antibodies (bNAbs) has proven effective against HIV-1 infections in humanized mice, non-human primates, and humans. Due to the high mutation rate of HIV-1, resistance testing of the patient's viral strains to the bNAbs is still inevitable. So far, bNAb resistance can only be tested in expensive and time-consuming neutralization experiments. Here, we introduce well-performing computational models that predict the neutralization response of HIV-1 to bNAbs given only the envelope sequence of the virus. Using non-linear support vector machines based on a string kernel, the models learnt even the important binding sites of bNAbs with more complex epitopes, i.e., the CD4 binding site targeting bNAbs, proving thereby the biological relevance of the models. To increase the interpretability of the models, we additionally provide a new kind of motif logo for each query sequence, visualizing those residues of the test sequence that influenced the prediction outcome the most. Moreover, we predicted the neutralization sensitivity of around 34,000 HIV-1 samples from different time points to a broad range of bNAbs, enabling the first analysis of HIV resistance to bNAbs on a global scale. The analysis showed for many of the bNAbs a trend towards antibody resistance over time, which had previously only been discovered for a small non-representative subset of the global HIV-1 population.

  19. Alterations of HIV-1 envelope phenotype and antibody-mediated neutralization by signal peptide mutations.

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    Chitra Upadhyay

    2018-01-01

    Full Text Available HIV-1 envelope glycoprotein (Env mediates virus attachment and entry into the host cells. Like other membrane-bound and secreted proteins, HIV-1 Env contains at its N terminus a signal peptide (SP that directs the nascent Env to the endoplasmic reticulum (ER where Env synthesis and post-translational modifications take place. SP is cleaved during Env biosynthesis but potentially influences the phenotypic traits of the Env protein. The Env SP sequences of HIV-1 isolates display high sequence variability, and the significance of such variability is unclear. We postulate that changes in the Env SP influence Env transport through the ER-Golgi secretory pathway and Env folding and/or glycosylation that impact on Env incorporation into virions, receptor binding and antibody recognition. We first evaluated the consequences of mutating the charged residues in the Env SP in the context of infectious molecular clone HIV-1 REJO.c/2864. Results show that three different mutations affecting histidine at position 12 affected Env incorporation into virions that correlated with reduction of virus infectivity and DC-SIGN-mediated virus capture and transmission. Mutations at positions 8, 12, and 15 also rendered the virus more resistant to neutralization by monoclonal antibodies against the Env V1V2 region. These mutations affected the oligosaccharide composition of N-glycans as shown by changes in Env reactivity with specific lectins and by mass spectrometry. Increased neutralization resistance and N-glycan composition changes were also observed when analogous mutations were introduced to another HIV-1 strain, JRFL. To the best of our knowledge, this is the first study showing that certain residues in the HIV-1 Env SP can affect virus neutralization sensitivity by modulating oligosaccharide moieties on the Env N-glycans. The HIV-1 Env SP sequences thus may be under selective pressure to balance virus infectiousness with virus resistance to the host antibody

  20. HIV-1 subtype C superinfected individuals mount low autologous neutralizing antibody responses prior to intrasubtype superinfection

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    Basu Debby

    2012-09-01

    Full Text Available Abstract Background The potential role of antibodies in protection against intra-subtype HIV-1 superinfection remains to be understood. We compared the early neutralizing antibody (NAb responses in three individuals, who were superinfected within one year of primary infection, to ten matched non-superinfected controls from a Zambian cohort of subtype C transmission cases. Sequence analysis of single genome amplified full-length envs from a previous study showed limited diversification in the individuals who became superinfected with the same HIV-1 subtype within year one post-seroconversion. We hypothesized that this reflected a blunted NAb response, which may have made these individuals more susceptible to superinfection. Results Neutralization assays showed that autologous plasma NAb responses to the earliest, and in some cases transmitted/founder, virus were delayed and had low to undetectable titers in all three superinfected individuals prior to superinfection. In contrast, NAbs with a median IC50 titer of 1896 were detected as early as three months post-seroconversion in non-superinfected controls. Early plasma NAbs in all subjects showed limited but variable levels of heterologous neutralization breadth. Superinfected individuals also exhibited a trend toward lower levels of gp120- and V1V2-specific IgG binding antibodies but higher gp120-specific plasma IgA binding antibodies. Conclusions These data suggest that the lack of development of IgG antibodies, as reflected in autologous NAbs as well as gp120 and V1V2 binding antibodies to the primary infection virus, combined with potentially competing, non-protective IgA antibodies, may increase susceptibility to superinfection in the context of settings where a single HIV-1 subtype predominates.

  1. High Maternal HIV-1 Viral Load During Pregnancy Is Associated With Reduced Placental Transfer of Measles IgG Antibody

    Science.gov (United States)

    Farquhar, Carey; Nduati, Ruth; Haigwood, Nancy; Sutton, William; Mbori-Ngacha, Dorothy; Richardson, Barbra; John-Stewart, Grace

    2012-01-01

    Background Studies among HIV-1–infected women have demonstrated reduced placental transfer of IgG antibodies against measles and other pathogens. As a result, infants born to women with HIV-1 infection may not acquire adequate passive immunity in utero and this could contribute to high infant morbidity and mortality in this vulnerable population. Methods To determine factors associated with decreased placental transfer of measles IgG, 55 HIV-1–infected pregnant women who were enrolled in a Nairobi perinatal HIV-1 transmission study were followed. Maternal CD4 count, HIV-1 viral load, and HIV-1–specific gp41 antibody concentrations were measured antenatally and at delivery. Measles IgG concentrations were assayed in maternal blood and infant cord blood obtained during delivery to calculate placental antibody transfer. Results Among 40 women (73%) with positive measles titers, 30 (75%) were found to have abnormally low levels of maternofetal IgG transfer (<95%). High maternal HIV-1 viral load at 32 weeks’ gestation and at delivery was associated with reductions in placental transfer (P < 0.0001 and P = 0.0056, respectively) and infant measles IgG concentrations in cord blood (P < 0.0001 and P = 0.0073, respectively). High maternal HIV-1–specific gp41 antibody titer was also highly correlated with both decreased placental transfer (P = 0.0080) and decreased infant IgG (P < 0.0001). Conclusions This is the first study to evaluate the relationship between maternal HIV-1 viremia, maternal HIV-1 antibody concentrations, and passive immunity among HIV-1–exposed infants. These data support the hypothesis that high HIV-1 viral load during the last trimester may impair maternofetal transfer of IgG and increases risk of measles and other serious infections among HIV-1–exposed infants. PMID:16280707

  2. Assessment of sensitivity and specificity of first, second, and third generation EIA for the detection of antibodies to HIV-1 in oral fluid.

    Science.gov (United States)

    Louie, Brian; Lei, John; Liska, Sally; Dowling, Teri; Pandori, Mark W

    2009-07-01

    The performances of three blood-based immunoassays test kits were compared with regard to their ability to detect HIV-1 antibody in oral fluid. It was found that these three kits differ in their ability to detect HIV-1 antibody. Notably, a third generation EIA which has been shown to possess superior sensitivity for antibody detection in plasma appears to possess no sensitivity advantage for detecting HIV-1 antibody in oral fluid.

  3. Immunization with Clinical HIV-1 Env Proteins Induces Broad Antibody Dependent Cellular Cytotoxicity-Mediating Antibodies in a Rabbit Vaccination Model.

    Science.gov (United States)

    Karlsson, Ingrid; Borggren, Marie; Jensen, Sanne Skov; Heyndrickx, Leo; Stewart-Jones, Guillaume; Scarlatti, Gabriella; Fomsgaard, Anders

    2017-11-17

    The induction of both neutralizing antibodies and non-neutralizing antibodies with effector functions, for example, antibody-dependent cellular cytotoxicity (ADCC), is desired in the search for effective vaccines against HIV-1. In the pursuit of novel immunogens capable of inducing an efficient antibody response, rabbits were immunized with selected antigens using different prime-boost strategies. We immunized 35 different groups of rabbits with Env antigens from clinical HIV-1 subtypes A and B, including immunization with DNA alone, protein alone, and DNA prime with protein boost. The rabbit sera were screened for ADCC activity using a GranToxiLux-based assay with human peripheral blood mononuclear cells as effector cells and CEM.NKR CCR5 cells coated with HIV-1 envelope as target cells. The groups with the highest ADCC activity were further characterized for cross-reactivity between HIV-1 subtypes. The immunogen inducing the most potent and broadest ADCC response was a trimeric gp140. The ADCC activity was highest against the HIV-1 subtype corresponding to the immunogen. The ADCC activity did not necessarily reflect neutralizing activity in the pseudovirus-TZMbl assay, but there was an overall correlation between the two antiviral activities. We present a rabbit vaccination model and an assay suitable for screening HIV-1 vaccine candidates for the induction of ADCC-mediating antibodies in addition to neutralizing antibodies. The antigens and/or immunization strategies capable of inducing antibodies with ADCC activity did not necessarily induce neutralizing activity and vice versa. Nevertheless, we identified vaccine candidates that were able to concurrently induce both types of responses and that had ADCC activity that was cross-reactive between different subtypes. When searching for an effective vaccine candidate, it is important to evaluate the antibody response using a model and an assay measuring the desired function.

  4. Evaluation of four rapid tests for diagnosis and differentiation of HIV-1 and HIV-2 infections in Guinea-Conakry, West Africa.

    Science.gov (United States)

    Chaillet, Pascale; Tayler-Smith, Katie; Zachariah, Rony; Duclos, Nanfack; Moctar, Diallo; Beelaert, Greet; Fransen, Katrien

    2010-09-01

    With both HIV-1 and HV-2 prevalent in Guinea-Conakry, accurate diagnosis and differentiation is crucial for treatment purposes. Thus, four rapid HIV tests were evaluated for their HIV-1 and HIV-2 diagnostic and discriminative capacity for use in Guinea-Conakry. These included SD Bioline HIV 1/2 3.0 (Standard Diagnostics Inc.), Genie II HIV1/HIV2 (Bio-Rad), First Response HIV Card Test 1-2.0 (PMC Medical) and Immunoflow HIV1-HIV2 (Core Diagnostics). Results were compared with gold standard tests (INNO-LIA HIV-I/II Score) and NEW LAV BLOT II (Bio-Rad). Four hundred and forty three sequential stored HIV-positive serum samples, of known HIV-type, were evaluated. Genie II HIV1/HIV2, Immunoflow HIV1-HIV2 and SD Bioline HIV 1/2 3.0 had 100% sensitivity (95% CI, 98.9-100%) while for First Response HIV Card Test 1-2.0 this was 99.5% (95% CI, 98.2%-99.9%). In terms of discriminatory capacity, Genie II HIV1/HIV2 identified 382/ 384(99.5%) HIV-1 samples, 49/ 52(95%) HIV-2 and 7/7(100%) HIV-positive untypable samples. Immunoflow HIV1-HIV2 identified 99% HIV-1, 67% HIV-2 and all HIV-positive untypable samples. First Response HIV Card Test 1-2.0 identified 94% HIV-1, 64% HIV-2 and 57% HIV-positive untypable samples. SD-Bioline HIV 1/2 3.0 was the worst overall performer identifying 65% HIV-1, 69% HIV-2 and all HIV-positive untypable samples. The use of SD Bioline HIV 1/2 3.0 (the current standard in Guinea-Conakry) as a discriminatory HIV test is poor and may be best replaced by Immunoflow HIV1-HIV2. Copyright 2010 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

  5. Rapid enzyme-linked immunosorbent assay (ELISA) for Aspergillus fumigatus antibodies.

    OpenAIRE

    Richardson, M D; Stubbins, J M; Warnock, D W

    1982-01-01

    A rapid enzyme-linked immunosorbent assay (ELISA) where component incubation periods were shortened to one hour, was compared with agar gel double diffusion (AGDD) and a standard ELISA procedure for detecting antibodies to Aspergillus fumigatus in 28 asthmatic patients with suspected allergic aspergillosis. Using two A fumigatus antigens the rapid ELISA compared well with AGDD and the standard ELISA method. Eleven sera that reacted with both antigens in AGDD were all positive against antigen ...

  6. Prevalence of human cytomegalovirus (HCMV antibodies among patients HIV/AIDS in Kurdistan province, 2015

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    Arezo Omati

    2016-12-01

    Full Text Available Background : Cytomegalovirus (CMV infection is one of the most common causes of death in people with immune deficiency diseases such as: organ or tissue recipients, patients with HIV/AIDS and newborn infants. The aim of this study was to determine the prevalence of anti-CMV antibodies in patients with HIV/AIDS in the Kurdistan province. Materials and Methods: This cross-sectional study carried out on 151 patients with HIV/AIDS covered by behavioral health counseling centers in Kurdistan province, 2015. For all patients the values of CMV antibodies, include IgG and IgM, were determined by ELISA technique and Diagnostic Kits (EIA WELL, Rome, Italy. Data analyses were done by use of t-test and multiple linear regression tests in stata software, version 13. Results: 116 (76.8% and 35 (23.2% of the patients were male and female, respectively. Mean (SD age of the patients were 39.3 (9.1 years. All studied patients were found positive for CMV-IgG (prevalence=100%, whereas only one case (0.7% was found positive for CMV-IgM. The relationship between age and CMV-IgG levels was statistically significant. Conclusion: The results showed that high prevalence of CMV in patients with HIV/AIDS, so in addition to paying more attention to the issue of HIV and CMV co-infection, about value of early antiretroviral treatment conducting further studies seems necessary.

  7. No evidence for a protective effect of naturally induced HPV antibodies on subsequent anogenital HPV infection in HIV-negative and HIV-infected MSM

    NARCIS (Netherlands)

    Mooij, Sofie H.; Landén, Olivia; van der Klis, Fiona R. M.; van der Sande, Marianne A. B.; de Melker, Hester E.; Coutinho, Roel A.; van Eeden, Arne; van Rooijen, Martijn S.; Meijer, Chris J. L. M.; Schim van der Loeff, Maarten F.

    2014-01-01

    To assess whether HPV serum antibodies detected after natural infection protect against subsequent anal or penile infection with the same HPV type in HIV-negative and HIV-infected men who have sex with men (MSM). MSM aged ≥18 years were recruited in Amsterdam, the Netherlands (2010-2011), and

  8. The diagnosis of symptomatic acute antiretroviral syndrome during the window period with antigen/antibody testing and HIV viral load

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    Daniel O. Griffin

    Full Text Available Despite much focus on moving toward a cure to end the epidemic human immunodeficiency virus (HIV epidemic there are still thousands of new infections occurring every year in the United States. Although there is ongoing transmission of HIV in the United States and a growing population of people living with HIV, the acute presentation of HIV infection can be challenging to diagnose and is often not considered when patients present to healthcare providers. Although in certain states there are HIV testing laws that require that all persons between the ages of 13 and 64 be offered HIV testing in an opt-out approach, many patient presenting with an acute illness, that would warrant diagnostic testing for HIV, leave without having an HIV test performed for either diagnostic or screening purposes.We describe the case of a woman who presented to medical attention with symptoms later confirmed to be due to acute HIV infection. She was initially discharged from the hospital and only underwent HIV testing with confirmation of her diagnosis after readmission. We describe the algorithm where fourth generation testing combined with HIV viral load testing allowed for the diagnosis of acute HIV prior to the development of a specific immunoglobulin response. Consideration of this diagnosis, improved HIV screening, and understanding of the use of antigen/antibody screening tests, combined with Multispot and HIV viral RNA detection, when appropriate, can allow for early diagnosis of HIV before progression of disease and before undiagnosed patient spread the infection to new contacts.

  9. Molecular evolution of broadly neutralizing Llama antibodies to the CD4-binding site of HIV-1.

    Science.gov (United States)

    McCoy, Laura E; Rutten, Lucy; Frampton, Dan; Anderson, Ian; Granger, Luke; Bashford-Rogers, Rachael; Dekkers, Gillian; Strokappe, Nika M; Seaman, Michael S; Koh, Willie; Grippo, Vanina; Kliche, Alexander; Verrips, Theo; Kellam, Paul; Fassati, Ariberto; Weiss, Robin A

    2014-12-01

    To date, no immunization of humans or animals has elicited broadly neutralizing sera able to prevent HIV-1 transmission; however, elicitation of broad and potent heavy chain only antibodies (HCAb) has previously been reported in llamas. In this study, the anti-HIV immune responses in immunized llamas were studied via deep sequencing analysis using broadly neutralizing monoclonal HCAbs as a guides. Distinct neutralizing antibody lineages were identified in each animal, including two defined by novel antibodies (as variable regions called VHH) identified by robotic screening of over 6000 clones. The combined application of five VHH against viruses from clades A, B, C and CRF_AG resulted in neutralization as potent as any of the VHH individually and a predicted 100% coverage with a median IC50 of 0.17 µg/ml for the panel of 60 viruses tested. Molecular analysis of the VHH repertoires of two sets of immunized animals showed that each neutralizing lineage was only observed following immunization, demonstrating that they were elicited de novo. Our results show that immunization can induce potent and broadly neutralizing antibodies in llamas with features similar to human antibodies and provide a framework to analyze the effectiveness of immunization protocols.

  10. The cost of implementing rapid HIV testing in sexually transmitted disease clinics in the United States.

    Science.gov (United States)

    Eggman, Ashley A; Feaster, Daniel J; Leff, Jared A; Golden, Matthew R; Castellon, Pedro C; Gooden, Lauren; Matheson, Tim; Colfax, Grant N; Metsch, Lisa R; Schackman, Bruce R

    2014-09-01

    Rapid HIV testing in high-risk populations can increase the number of persons who learn their HIV status and avoid spending clinic resources to locate persons identified as HIV infected. We determined the cost to sexually transmitted disease (STD) clinics of point-of-care rapid HIV testing using data from 7 public clinics that participated in a randomized trial of rapid testing with and without brief patient-centered risk reduction counseling in 2010. Costs included counselor and trainer time, supplies, and clinic overhead. We applied national labor rates and test costs. We calculated median clinic start-up costs and mean cost per patient tested, and projected incremental annual costs of implementing universal rapid HIV testing compared with current testing practices. Criteria for offering rapid HIV testing and methods for delivering nonrapid test results varied among clinics before the trial. Rapid HIV testing cost an average of US $22/patient without brief risk reduction counseling and US $46/patient with counseling in these 7 clinics. Median start-up costs per clinic were US $1100 and US $16,100 without and with counseling, respectively. Estimated incremental annual costs per clinic of implementing universal rapid HIV testing varied by whether or not brief counseling is conducted and by current clinic testing practices, ranging from a savings of US $19,500 to a cost of US $40,700 without counseling and a cost of US $98,000 to US $153,900 with counseling. Universal rapid HIV testing in STD clinics with same-day results can be implemented at relatively low cost to STD clinics, if brief risk reduction counseling is not offered.

  11. A new rapid immunohistochemical staining technique using the EnVision antibody complex.

    Science.gov (United States)

    Kämmerer, U; Kapp, M; Gassel, A M; Richter, T; Tank, C; Dietl, J; Ruck, P

    2001-05-01

    Rapid immunohistochemical investigation, in addition to staining with hematoxylin and eosin, would be useful during intraoperative frozen section diagnosis in some cases. This study was undertaken to investigate whether the recently described EnVision system, a highly sensitive two-step immunohistochemical technique, could be modified for rapid immunostaining of frozen sections. Forty-five primary antibodies were tested on frozen sections from various different tissues. After fixation in acetone for 1 min and air-drying, the sections were incubated for 3 min each with the primary antibody, the EnVision complex (a large number of secondary antibodies and horseradish peroxidase coupled to a dextran backbone), and the chromogen (3,3'diaminobenzidine or 3-amino-9-ethylcarbazole). All reactions were carried out at 37C. Specific staining was seen with 38 antibodies (including HMB-45 and antibodies against keratin, vimentin, leukocyte common antigen, smooth muscle actin, synaptophysin, CD34, CD3, CD20, and prostate-specific antigen). A modification of the EnVision method allows the detection of a broad spectrum of antigens in frozen sections in less than 13 min. This method could be a useful new tool in frozen section diagnosis and research. (J Histochem Cytochem 49:623-630, 2001)

  12. Functional characterization of two scFv-Fc antibodies from an HIV controller selected on soluble HIV-1 Env complexes: a neutralizing V3- and a trimer-specific gp41 antibody.

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    Maria Trott

    Full Text Available HIV neutralizing antibodies (nAbs represent an important tool in view of prophylactic and therapeutic applications for HIV-1 infection. Patients chronically infected by HIV-1 represent a valuable source for nAbs. HIV controllers, including long-term non-progressors (LTNP and elite controllers (EC, represent an interesting subgroup in this regard, as here nAbs can develop over time in a rather healthy immune system and in the absence of any therapeutic selection pressure. In this study, we characterized two particular antibodies that were selected as scFv antibody fragments from a phage immune library generated from an LTNP with HIV neutralizing antibodies in his plasma. The phage library was screened on recombinant soluble gp140 envelope (Env proteins. Sequencing the selected peptide inserts revealed two major classes of antibody sequences. Binding analysis of the corresponding scFv-Fc derivatives to various trimeric and monomeric Env constructs as well as to peptide arrays showed that one class, represented by monoclonal antibody (mAb A2, specifically recognizes an epitope localized in the pocket binding domain of the C heptad repeat (CHR in the ectodomain of gp41, but only in the trimeric context. Thus, this antibody represents an interesting tool for trimer identification. MAb A7, representing the second class, binds to structural elements of the third variable loop V3 and neutralizes tier 1 and tier 2 HIV-1 isolates of different subtypes with matching critical amino acids in the linear epitope sequence. In conclusion, HIV controllers are a valuable source for the selection of functionally interesting antibodies that can be selected on soluble gp140 proteins with properties from the native envelope spike.

  13. Anxiety in voluntary HIV-antibody testing in pregnancy and its implications for preventive strategies.

    Science.gov (United States)

    Foldspang, A; Hedegaard, M

    1991-06-01

    During a three-month period in 1989, 820 pregnant women attending the antenatal clinic of the Aarhus University Hospital, Denmark, were offered a HIV-antibody test and asked to fill out an anonymous questionnaire about attitudes to HIV-antibody testing; 779 (95.0%) agreed to do so. One hundred and fifty-six women (20.0% of the participants) had been tested on a previous occasion, and 629 (80.7%) accepted the present offer to be tested. The most prevalent reasons to decline testing were indifference to the epidemic (45.3% of those declining), refusal of (further) blood testing (34.7%) and fear of being infected (16.7%). Women who consented to be tested most often expressed fear of being infected (21.8%). Fear of registration worried less than 5% of study group members; only 1% declined to be tested because of such worry. The pattern of worries expressed by the pregnant women is interpreted as one of anxiety and, in part at least, perplexity as concerns how to take rational consequences of public messages about the HIV epidemic. It is suggested that future surveillance be based primarily on voluntary testing and, whenever needed and possible, supplied with anonymous unlinked testing of existing blood samples from groups and persons declining to be tested. Such surveillance strategies should be supported in individual patient contacts and public health educational campaigns underscoring the risk of heterosexual transmission of HIV and the need for repeated HIV-antibody testing of selected groups and individuals.

  14. Rapid preparative separation of monoclonal antibody charge variants using laterally-fed membrane chromatography.

    Science.gov (United States)

    Sadavarte, Rahul; Madadkar, Pedram; Filipe, Carlos Dm; Ghosh, Raja

    2018-01-15

    Monoclonal antibodies undergo various forms of chemical transformation which have been shown to cause loss in efficacy and alteration in pharmacokinetic properties of these molecules. Such modified antibody molecules are known as variants. They also display physical properties such as charge that are different from intact antibody molecules. However, the difference in charge is very subtle and separation based on it is quite challenging. Charge variants are usually separated using ion-exchange column chromatography or isoelectric focusing. In this paper, we report a rapid and scalable method for fractionating monoclonal antibody charge variants, based on the use of cation exchange laterally-fed membrane chromatography (LFMC). Starting with a sample of monoclonal antibody hIgG1-CD4, three well-resolved fractions were obtained using either pH or salt gradient. These fractions were identified as acidic, neutral and basic variants. Each of these fractions contained intact heavy and light chains and so antibody fragmentation had no role in variant generation. The separation was comparable to that using column chromatography but was an order of magnitude faster. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Rapid production of antigen-specific monoclonal antibodies from a variety of animals

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    Kurosawa Nobuyuki

    2012-09-01

    Full Text Available Abstract Background Although a variety of animals have been used to produce polyclonal antibodies against antigens, the production of antigen-specific monoclonal antibodies from animals remains challenging. Results We propose a simple and rapid strategy to produce monoclonal antibodies from a variety of animals. By staining lymph node cells with an antibody against immunoglobulin and a fluorescent dye specific for the endoplasmic reticulum, plasma/plasmablast cells were identified without using a series of antibodies against lineage markers. By using a fluorescently labeled antigen as a tag for a complementary cell surface immunoglobulin, antigen-specific plasma/plasmablast cells were sorted from the rest of the cell population by fluorescence-activated cell sorting. Amplification of cognate pairs of immunoglobulin heavy and light chain genes followed by DNA transfection into 293FT cells resulted in the highly efficient production of antigen-specific monoclonal antibodies from a variety of immunized animals. Conclusions Our technology eliminates the need for both cell propagation and screening processes, offering a significant advantage over hybridoma and display strategies.

  16. An efficiently cleaved HIV-1 clade C Env selectively binds to neutralizing antibodies.

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    Saikat Boliar

    Full Text Available An ideal HIV-1 Env immunogen is expected to mimic the native trimeric conformation for inducing broadly neutralizing antibody responses. The native conformation is dependent on efficient cleavage of HIV-1 Env. The clade B isolate, JRFL Env is efficiently cleaved when expressed on the cell surface. Here, for the first time, we report the identification of a native clade C Env, 4-2.J41 that is naturally and efficiently cleaved on the cell surface as confirmed by its biochemical and antigenic characteristics. In addition to binding to several conformation-dependent neutralizing antibodies, 4-2.J41 Env binds efficiently to the cleavage-dependent antibody PGT151; thus validating its native cleaved conformation. In contrast, 4-2.J41 Env occludes non-neutralizing epitopes. The cytoplasmic-tail of 4-2.J41 Env plays an important role in maintaining its conformation. Furthermore, codon optimization of 4-2.J41 Env sequence significantly increases its expression while retaining its native conformation. Since clade C of HIV-1 is the prevalent subtype, identification and characterization of this efficiently cleaved Env would provide a platform for rational immunogen design.

  17. Tandem bispecific broadly neutralizing antibody - a novel approach to HIV-1 treatment.

    Science.gov (United States)

    Ferrari, Guido

    2018-04-23

    The last decade has led to a significant advance in our knowledge of HIV-1 latency and immunity. However, we are still not close to finding a cure for HIV-1. Although combination antiretroviral therapy (cART) has led to increased survival, almost close to that of the general population, it is still not curative. In the current issue of the JCI, Wu et al. studied the prophylactic and therapeutic potential of an engineered tandem bispecific broadly neutralizing antibody (bs-bnAb), BiIA-SG. This bnAb's breadth and potency were highly effective in protection and treatment settings, as measured by complete viremia control following direct infusion, as well as elimination of infected cells and delay in viral rebound when delivered with a recombinant vector. These observations underscore the need for the clinical development of BiIA-SG for the prevention of HIV-1.

  18. Using an improved phagocytosis assay to evaluate the effect of HIV on specific antibodies to pregnancy-associated malaria.

    Science.gov (United States)

    Ataíde, Ricardo; Hasang, Wina; Wilson, Danny W; Beeson, James G; Mwapasa, Victor; Molyneux, Malcolm E; Meshnick, Steven R; Rogerson, Stephen J

    2010-05-25

    Pregnant women residing in malaria endemic areas are highly susceptible to Plasmodium falciparum malaria, particularly during their first pregnancy, resulting in low birth weight babies and maternal anaemia. This susceptibility is associated with placental sequestration of parasitised red blood cells expressing pregnancy-specific variant surface antigens. Acquisition of antibodies against these variant surface antigens may protect women and their offspring. Functions of such antibodies may include prevention of placental sequestration or opsonisation of parasitised cells for phagocytic clearance. Here we report the development and optimisation of a new high-throughput flow cytometry-based phagocytosis assay using undifferentiated Thp-1 cells to quantitate the amount of opsonizing antibody in patient sera, and apply this assay to measure the impact of HIV on the levels of antibodies to a pregnancy malaria-associated parasite line in a cohort of Malawian primigravid women. The assay showed high reproducibility, with inter-experimental correlation of r(2) = 0.99. In primigravid women, concurrent malaria infection was associated with significantly increased antibodies, whereas HIV decreased the ability to acquire opsonising antibodies (Mann-Whitney ranksum: p = 0.013). This decrease was correlated with HIV-induced immunosuppression, with women with less than 350 x 10(6) CD4+ T- cells/L having less opsonising antibodies (coef: -11.95,P = 0.002). Levels of antibodies were not associated with protection from low birth weight or anaemia. This flow cytometry-based phagocytosis assay proved to be efficient and accurate for the measurement of Fc-receptor mediated phagocytosis-inducing antibodies in large cohorts. HIV was found to affect mainly the acquisition of antibodies to pregnancy-specific malaria in primigravidae. Further studies of the relationship between opsonising antibodies to malaria in pregnancy and HIV are indicated.

  19. The Role of Natural Antibodies to CC Chemokine Receptor 5 in HIV Infection

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    Assunta Venuti

    2017-10-01

    Full Text Available The CC chemokine receptor 5 (CCR5 is responsible for immune and inflammatory responses by mediation of chemotactic activity in leukocytes, although it is expressed on different cell types. It has been shown to act as co-receptor for the human and simian immunodeficiency viruses (HIV-1, HIV-2, and SIV. Natural reactive antibodies (Abs recognizing first loop (ECL1 of CCR5 have been detected in several pools of immunoglobulins from healthy donors and from several cohorts of either HIV-exposed but uninfected subjects (ESN or HIV-infected individuals who control disease progression (LTNP as well. The reason of development of anti-CCR5 Abs in the absence of autoimmune disease is still unknown; however, the presence of these Abs specific for CCR5 or for other immune receptors and mediators probably is related to homeostasis maintenance. The majority of anti-CCR5 Abs is directed to HIV binding site (N-terminus and ECL2 of the receptor. Conversely, it is well known that ECL1 of CCR5 does not bind HIV; thus, the anti-CCR5 Abs directed to ECL1 elicit a long-lasting internalization of CCR5 but not interfere with HIV binding directly; these Abs block HIV infection in either epithelial cells or CD4+ T lymphocytes and the mechanism differs from those ones described for all other CCR5-specific ligands. The Ab-mediated CCR5 internalization allows the formation of a stable signalosome by interaction of CCR5, β-arrestin2 and ERK1 proteins. The signalosome degradation and the subsequent de novo proteins synthesis determine the CCR5 reappearance on the cell membrane with a very long-lasting kinetics (8 days. The use of monoclonal Abs to CCR5 with particular characteristics and mode of action may represent a novel mode to fight viral infection in either vaccinal or therapeutic strategies.

  20. A retrospective evaluation of proficiency testing, and rapid HIV test ...

    African Journals Online (AJOL)

    Background: Proficiency testing (PT) has been implemented as a form of External Quality Assurance (EQA) by the National HIV Reference Laboratory in Kenya since 2007 in order to monitor and improve on the quality of HIV testing and counselling HTC services. Objective: To compare concordance between National HIV ...

  1. Viral hepatitis and rapid diagnostic test based screening for HBsAg in HIV-infected patients in rural Tanzania.

    Directory of Open Access Journals (Sweden)

    Fabian C Franzeck

    Full Text Available BACKGROUND: Co-infection with hepatitis B virus (HBV is highly prevalent in people living with HIV in Sub-Saharan Africa. Screening for HBV surface antigen (HBsAg before initiation of combination antiretroviral therapy (cART is recommended. However, it is not part of diagnostic routines in HIV programs in many resource-limited countries although patients could benefit from optimized antiretroviral therapy covering both infections. Screening could be facilitated by rapid diagnostic tests for HBsAg. Operating experience with these point of care devices in HIV-positive patients in Sub-Saharan Africa is largely lacking. We determined the prevalence of HBV and Hepatitis C virus (HCV infection as well as the diagnostic accuracy of the rapid test device Determine HBsAg in an HIV cohort in rural Tanzania. METHODS: Prospectively collected blood samples from adult, HIV-1 positive and antiretroviral treatment-naïve patients in the Kilombero and Ulanga antiretroviral cohort (KIULARCO in rural Tanzania were analyzed at the point of care with Determine HBsAg, a reference HBsAg EIA and an anti-HCV EIA. RESULTS: Samples of 272 patients were included. Median age was 38 years (interquartile range [IQR] 32-47, 169/272 (63% subjects were females and median CD4+ count was 250 cells/µL (IQR 97-439. HBsAg was detected in 25/272 (9.2%, 95% confidence interval [CI] 6.2-13.0% subjects. Of these, 7/25 (28% were positive for HBeAg. Sensitivity of Determine HBsAg was rated at 96% (95% CI 82.8-99.6% and specificity at 100% (95% CI, 98.9-100%. Antibodies to HCV (anti-HCV were found in 10/272 (3.7%, 95% CI 2.0-6.4% of patients. CONCLUSION: This study reports a high prevalence of HBV in HIV-positive patients in a rural Tanzanian setting. The rapid diagnostic test Determine HBsAg is an accurate assay for screening for HBsAg in HIV-1 infected patients at the point of care and may further help to guide cART in Sub-Saharan Africa.

  2. Antibodies to the HIV-1 Tat protein correlated with nonprogression to AIDS: a rationale for the use of Tat toxoid as an HIV-1 vaccine.

    Science.gov (United States)

    Zagury, J F; Sill, A; Blattner, W; Lachgar, A; Le Buanec, H; Richardson, M; Rappaport, J; Hendel, H; Bizzini, B; Gringeri, A; Carcagno, M; Criscuolo, M; Burny, A; Gallo, R C; Zagury, D

    1998-01-01

    To investigate which immune parameters, such as antibodies against HIV-1 specificities, or viral parameters, such as p24 antigenemia, are predictive of disease progression. We performed studies on serum collected from individuals exhibiting two extremes of disease evolution--67 fast progressors (FP) and 182 nonprogressors (NP)--at their enrollment. After a 1- to 2-year clinical follow-up of 104 nonprogressors after their enrollment, we could determine the best serologic predictors for disease progression. We investigated levels of antibodies to tetanus toxoid and to HIV antigens including Env, Gag, Nef, and Tat proteins, as well as p24 antigenemia, viremia, CD4 cell count, and interferon-alpha (IFN-alpha) titers in FPs and NPs, and we correlated these data with clinical and biologic signs of progression. p24 Antigenemia, a marker of viral replication, and anti-Tat antibodies were highly and inversely correlated in both groups (P < .001). Furthermore, anti-p24 antibodies and low serum IFN-alpha levels were correlated to the NP versus the FP cohort. Finally, among NPs, only antibodies to Tat and not to the other HIV specificities (Env, Nef, Gag) were significantly predictive of clinical stability during their follow-up. Antibodies toward HIV-1 Tat, which are inversely correlated to p24 antigenemia, appear as a critical marker for a lack of disease progression. This study strongly suggests that rising anti-Tat antibodies through active immunization may be beneficial in AIDS vaccine development to control viral replication.

  3. Mimotopes selected by biopanning with high-titer HIV-neutralizing antibodies in plasma from Chinese slow progressors

    Directory of Open Access Journals (Sweden)

    Xiaoli Zhang

    Full Text Available OBJECTIVE: One approach to identifying HIV-1 vaccine candidates is to dissect the natural antiviral immune response in treatment-naïve individuals infected for over ten years, considered slow progressor patients (SPs. It is suspected that SP plasma has strongly neutralizing antibodies (NAb targeting specific HIV viral epitopes. METHODS: NAbs levels of 11 HIV-1-infected SPs were detected by PBMC-based neutralization assays. To investigate SP NAb epitope, this study used a biopanning approach to obtain mimotopes of HIV-1 that were recognized by SP plasma NAbs. IgG was purified from hightiter NAb SP plasma, and used as the ligand for three rounds of biopanning to select HIV-specific mimotopes from a phage-displayed random peptide library. Double-antibody sandwich ELISA, competitive inhibition assays, and peptide sequence analysis were used to evaluate the characteristics of phage-borne mimotopes. RESULTS: SPs had significantly more plasma neutralizing activity than typical progressors (TPs (p = 0.04. P2 and P9 plasma, which have highest-titer HIV-NAb, were selected as ligands for biopanning. After three rounds of biopanning, 48 phage clones were obtained, of which 22 clones were consistent with requirement, binding with HIV-1 positive plasma and unbinding with HIV-1 negative plasma. Compared with linear HIV-1 protein sequence and HIV-1 protein structure files, only 12 clones were possible linear mimotopes of NAbs. In addition, the C40 clone located in gp41 CHR was found to be a neutralizing epitope, which could inhibit pooled HIV-1 positive plasma reaction. CONCLUSION: Biopanning of serum IgG can yield mimotopes of HIV-1-related antigen epitopes. This methodology provides a basis for exploration into HIV-1-related antigen-antibody interactions and furthers NAb immunotherapy and vaccine design.

  4. Acceptability of rapid HIV diagnosis technology among primary healthcare practitioners in Spain.

    Science.gov (United States)

    Agustí, C; Fernàndez-López, L; Mascort, J; Carrillo, R; Aguado, C; Montoliu, A; Puigdengolas, X; De La Poza, M; Rifà, B; Casabona, J

    2013-01-01

    This study investigated the acceptability of rapid HIV testing among general practitioners (GP) and aimed to identify perceived barriers and needs in order to implement rapid testing in primary care settings. An anonymous questionnaire was distributed online to all members of the two largest Spanish scientific medical societies for family and community medicine. The study took place between 15 June 2012 and 31 October 2010. Completed questionnaires were returned by 1308 participants. The majority (90.8%) of respondents were GP. Among all respondents, 70.4% were aware of the existence of rapid tests for the diagnosis of HIV but they did not know how to use them. Nearly 80% of participants would be willing to offer rapid HIV testing in their practices and 74.7% would be confident of the result obtained by these tests. The barriers most commonly identified by respondents were a lack of time and a need for training, both in the use of rapid tests (44.3% and 56.4%, respectively) and required pre- and post-test counselling (59.2% and 34.5%, respectively). This study reveals a high level of acceptance and willingness on the part of GPs to offer rapid HIV testing in their practices. Nevertheless, the implementation of rapid HIV testing in primary care will not be possible without moving from comprehensive pre-test counselling towards brief pre-test information and improving training in the use of rapid tests.

  5. An automated robotic platform for rapid profiling oligosaccharide analysis of monoclonal antibodies directly from cell culture.

    Science.gov (United States)

    Doherty, Margaret; Bones, Jonathan; McLoughlin, Niaobh; Telford, Jayne E; Harmon, Bryan; DeFelippis, Michael R; Rudd, Pauline M

    2013-11-01

    Oligosaccharides attached to Asn297 in each of the CH2 domains of monoclonal antibodies play an important role in antibody effector functions by modulating the affinity of interaction with Fc receptors displayed on cells of the innate immune system. Rapid, detailed, and quantitative N-glycan analysis is required at all stages of bioprocess development to ensure the safety and efficacy of the therapeutic. The high sample numbers generated during quality by design (QbD) and process analytical technology (PAT) create a demand for high-performance, high-throughput analytical technologies for comprehensive oligosaccharide analysis. We have developed an automated 96-well plate-based sample preparation platform for high-throughput N-glycan analysis using a liquid handling robotic system. Complete process automation includes monoclonal antibody (mAb) purification directly from bioreactor media, glycan release, fluorescent labeling, purification, and subsequent ultra-performance liquid chromatography (UPLC) analysis. The entire sample preparation and commencement of analysis is achieved within a 5-h timeframe. The automated sample preparation platform can easily be interfaced with other downstream analytical technologies, including mass spectrometry (MS) and capillary electrophoresis (CE), for rapid characterization of oligosaccharides present on therapeutic antibodies. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Soluble HIV-1 envelope immunogens derived from an elite neutralizer elicit cross-reactive V1V2 antibodies and low potency neutralizing antibodies.

    Directory of Open Access Journals (Sweden)

    Sara Carbonetti

    Full Text Available We evaluated four gp140 Envelope protein vaccine immunogens that were derived from an elite neutralizer, subject VC10042, whose plasma was able to potently neutralize a wide array of genetically distinct HIV-1 isolates. We sought to determine whether soluble Envelope proteins derived from the viruses circulating in VC10042 could be used as immunogens to elicit similar neutralizing antibody responses by vaccination. Each gp140 was tested in its trimeric and monomeric forms, and we evaluated two gp140 trimer vaccine regimens in which adjuvant was supplied at all four immunizations or at only the first two immunizations. Interestingly, all four Envelope immunogens elicited high titers of cross-reactive antibodies that recognize the variable regions V1V2 and are potentially similar to antibodies linked with a reduced risk of HIV-1 acquisition in the RV144 vaccine trial. Two of the four immunogens elicited neutralizing antibody responses that neutralized a wide array of HIV-1 isolates from across genetic clades, but those responses were of very low potency. There were no significant differences in the responses elicited by trimers or monomers, nor was there a significant difference between the two adjuvant regimens. Our study identified two promising Envelope immunogens that elicited anti-V1V2 antibodies and broad, but low potency, neutralizing antibody responses.

  7. Tandem bispecific neutralizing antibody eliminates HIV-1 infection in humanized mice.

    Science.gov (United States)

    Wu, Xilin; Guo, Jia; Niu, Mengyue; An, Minghui; Liu, Li; Wang, Hui; Jin, Xia; Zhang, Qi; Lam, Ka Shing; Wu, Tongjin; Wang, Hua; Wang, Qian; Du, Yanhua; Li, Jingjing; Cheng, Lin; Tang, Hang Ying; Shang, Hong; Zhang, Linqi; Zhou, Paul; Chen, Zhiwei

    2018-04-23

    The discovery of an HIV-1 cure remains a medical challenge because the virus rebounds quickly after the cessation of combination antiretroviral therapy (cART). Here, we investigate the potential of an engineered tandem bispecific broadly neutralizing antibody (bs-bnAb) as an innovative product for HIV-1 prophylactic and therapeutic interventions. We discovered that by preserving 2 single-chain variable fragment (scFv) binding domains of each parental bnAb, a single gene-encoded tandem bs-bnAb, BiIA-SG, displayed substantially improved breadth and potency. BiIA-SG neutralized all 124 HIV-1-pseudotyped viruses tested, including global subtypes/recombinant forms, transmitted/founder viruses, variants not susceptible to parental bnAbs and to many other bnAbs with an average IC50 value of 0.073 μg/ml (range HIV-1 stains. Moreover, whereas BiIA-SG delayed viral rebound in a short-term therapeutic setting when combined with cART, a single injection of adeno-associated virus-transferred (AAV-transferred) BiIA-SG gene resulted dose-dependently in prolonged in vivo expression of BiIA-SG, which was associated with complete viremia control and subsequent elimination of infected cells in humanized mice. These results warrant the clinical development of BiIA-SG as a promising bs-bnAb-based biomedical intervention for the prevention and treatment of HIV-1 infection.

  8. Computer-facilitated rapid HIV testing in emergency care settings: provider and patient usability and acceptability.

    Science.gov (United States)

    Spielberg, Freya; Kurth, Ann E; Severynen, Anneleen; Hsieh, Yu-Hsiang; Moring-Parris, Daniel; Mackenzie, Sara; Rothman, Richard

    2011-06-01

    Providers in emergency care settings (ECSs) often face barriers to expanded HIV testing. We undertook formative research to understand the potential utility of a computer tool, "CARE," to facilitate rapid HIV testing in ECSs. Computer tool usability and acceptability were assessed among 35 adult patients, and provider focus groups were held, in two ECSs in Washington State and Maryland. The computer tool was usable by patients of varying computer literacy. Patients appreciated the tool's privacy and lack of judgment and their ability to reflect on HIV risks and create risk reduction plans. Staff voiced concerns regarding ECS-based HIV testing generally, including resources for follow-up of newly diagnosed people. Computer-delivered HIV testing support was acceptable and usable among low-literacy populations in two ECSs. Such tools may help circumvent some practical barriers associated with routine HIV testing in busy settings though linkages to care will still be needed.

  9. Temporal relation of antigenaemia and loss of antibodies to core antigens to development of clinical disease in HIV infection

    DEFF Research Database (Denmark)

    Pedersen, C; Nielsen, C M; Vestergaard, B F

    1987-01-01

    and 16 months after the estimated time of seroconversion. These results show that the late stages of HIV infection are characterised by increased production of antigen and a decrease in antibodies directed against the core protein. Antigenaemia indicates a poor prognosis; and as the antigen test......A total of 276 sequential serum samples from 34 men with antibodies to the human immunodeficiency virus (HIV) followed up for two to seven years were analysed for HIV antigen and antibodies to the viral core and envelope proteins. Results were correlated with clinical outcome and CD4 T lymphocyte...... count. Both antigenaemia and the disappearance of antibodies to the core protein were associated with development of the acquired immune deficiency syndrome (AIDS) or AIDS related complex and depletion of CD4 cells. Thus AIDS or AIDS related complex developed in eight out of 16 patients...

  10. Low prevalence of antibodies and other plasma factors binding to CC chemokines and IL-2 in HIV-positive patients

    DEFF Research Database (Denmark)

    Meyer, C N; Svenson, M; Schade Larsen, C

    2000-01-01

    of HIV-infected patients were therefore assessed by radioimmunoassay and radioreceptor assay. IgG from 4/505 HIV patients and 9/2000 healthy controls (p>0.05) bound rMIP-1alpha and rMIP-1beta, but not rRANTES. No other plasma factors bound the chemokines. The antibodies inhibited receptor binding of both...... chemokines. There was no association between presence of antibodies and disease stage or HIV progression rate. Three of 11 patients treated with rIL-2 developed IgG antibodies suppressing cellular binding and growth promotion of rIL-2. Hence, circulating factors, including antibodies MIP-1alpha/MIP-1beta...

  11. Antibody Responses with Fc-Mediated Functions after Vaccination of HIV-Infected Subjects with Trivalent Influenza Vaccine

    DEFF Research Database (Denmark)

    Kristensen, Anne B; Lay, William N; Ana-Sosa-Batiz, Fernanda

    2016-01-01

    to immunize this at-risk group. IMPORTANCE: Infection with HIV is associated with increasing disease severity following influenza infections, and annual influenza vaccinations are recommended for this target group. However, HIV-infected individuals respond relatively poorly to vaccination compared to healthy......This study seeks to assess the ability of seasonal trivalent inactivated influenza vaccine (TIV) to induce nonneutralizing antibodies (Abs) with Fc-mediated functions in HIV-uninfected and HIV-infected subjects. Functional influenza-specific Ab responses were studied in 30 HIV-negative and 27 HIV......-positive subjects immunized against seasonal influenza. All 57 subjects received the 2015 TIV. Fc-mediated antihemagglutinin (anti-HA) Ab activity was measured in plasma before and 4 weeks after vaccination using Fc-receptor-binding assays, NK cell activation assays, and phagocytosis assays. At baseline, the HIV...

  12. HIV-specific antibodies but not t-cell responses are associated with protection in seronegative partners of HIV-1-infected individuals in Cambodia.

    Science.gov (United States)

    Nguyen, Marie; Pean, Polidy; Lopalco, Lucia; Nouhin, Janin; Phoung, Viseth; Ly, Nary; Vermisse, Pierre; Henin, Yvette; Barré-Sinoussi, Françoise; Burastero, Samuele E; Reynes, Jean-Marc; Carcelain, Guislaine; Pancino, Gianfranco

    2006-08-01

    To study biological factors related to protection against HIV-1 infection in Cambodia, we recruited 48 partners of HIV-1-infected patients who remained uninfected (exposed uninfected individuals, EUs) despite unprotected sexual intercourse for more than 1 year and 49 unexposed controls (UCs). HIV-1-specific antibodies (IgA anti-gp41 and IgG anti-CD4-gp120 complex), T-cell responses, and cellular factors that may be involved in protection (peripheral blood mononuclear cell [PBMC] resistance to HIV-1 infection and beta-chemokine production) were evaluated. Anti-HIV-1 antibodies were higher in EUs than those in UCs (P = 0.01 and P = 0.04 for anti-gp41 and anti-CD4-gp120, respectively). We observed a decreased susceptibility to a primary Cambodian isolate, HIV-1KH019, in EU PBMCs as compared with UC PBMCs (P = 0.03). A weak T-cell response to one pool of HIV-1 Gag peptides was found by ELISpot in 1 of 19 EUs. Whereas T-cell specific immunity was not associated to protection, our results suggest that HIV-specific humoral immunity and reduced cell susceptibility to infection may contribute to protection against HIV-1 infection in Cambodian EUs.

  13. Epitope mapping and characterization of a novel CD4-induced human monoclonal antibody capable of neutralizing primary HIV-1 strains

    International Nuclear Information System (INIS)

    Xiang Shihua; Wang Liping; Abreu, Mariam; Huang, C.-C.; Kwong, Peter D.; Rosenberg, Eric; Robinson, James E.; Sodroski, Joseph

    2003-01-01

    Human immunodeficiency virus (HIV-1) enters target cells by binding its gp120 exterior envelope glycoprotein to CD4 and one of the chemokine receptors, CCR5 or CXCR4. CD4-induced (CD4i) antibodies bind gp120 more efficiently after CD4 binding and block the interaction with the chemokine receptor. Examples of CD4i antibodies are limited, and the prototypes of the CD4i antibodies exhibit only weak neutralizing activity against primary, clinical HIV-1 isolates. Here we report the identification of a novel antibody, E51, that exhibits CD4-induced binding to gp120 and neutralizes primary HIV-1 more efficiently than the prototypic CD4i antibodies. The E51 antibody blocks the interaction of gp120-CD4 complexes with CCR5 and binds to a highly conserved, basic gp120 element composed of the β19-strand and surrounding structures. Thus, on primary HIV-1 isolates, this gp120 region, which has been previously implicated in chemokine receptor binding, is accessible to a subset of CD4i antibodies

  14. A Cross Section Study to Determine the Prevalence of Antibodies against HIV Infection among Hepatitis B and C Infected Individuals

    Directory of Open Access Journals (Sweden)

    Geane L. Flores

    2016-03-01

    Full Text Available (1 Background: There are limited data regarding human immunodeficiency virus (HIV prevalence among hepatitis B virus (HBV or hepatitis C virus (HCV infected individuals. The aim of this cross-sectional study is to determine the prevalence of HBV and HCV infection among HIV individuals; (2 Methods: A total of 409 patients (126 HBV+ and 283 HCV+ referred to the Brazilian Reference Laboratory for Viral Hepatitis from 2010 to 2013 donated serum samples. Anti-HIV, HBsAg, anti-HBc, anti-HBs, anti-HBcIgM, anti-HBe, HBeAg, and anti-HCV antibodies were measured, and anti-HCV positive samples were tested for viral RNA and genotype; (3 Results: The anti-HIV antibody prevalence was 10.31% and 4.59% among HBV+ and HCV+ patients, respectively. The HCV mean (SD viral load was log 5.14 ± 1.64 IU/mL, and genotype I was most prevalent (163/283. Anti-HBs and anti-HBc were detected in 40% and 26% of HCV+ individuals, respectively. Among the HBV+ population, the presence of anti-HIV antibodies was associated with male gender, marital status (married, tattoo, sexual orientation, sexual practices (oral sex and anal sex, history of sexually transmitted diseases (STDs, history of viral hepatitis treatment, and a sexual partner with hepatitis or HIV. For the HCV+ group, the presence of anti-HIV antibodies was associated with female gender, marital status (married, anal intercourse, previous history of STDs, and number of sexual partners; (4 Conclusion: A high prevalence of anti-HIV antibodies was found among individuals with HBV and HCV, showing the importance of education programmes towards HIV infection among HBV- and HCV-infected individuals.

  15. Identification of a CD4-Binding-Site Antibody to HIV that Evolved Near-Pan Neutralization Breadth

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Jinghe; Kang, Byong H.; Ishida, Elise; Zhou, Tongqing; Griesman, Trevor; Sheng, Zizhang; Wu, Fan; Doria-Rose, Nicole A.; Zhang, Baoshan; McKee, Krisha; O’Dell, Sijy; Chuang, Gwo-Yu; Druz, Aliaksandr; Georgiev, Ivelin S.; Schramm, Chaim A.; Zheng, Anqi; Joyce, M.  Gordon; Asokan, Mangaiarkarasi; Ransier, Amy; Darko, Sam; Migueles, Stephen A.; Bailer, Robert T.; Louder, Mark K.; Alam, S.  Munir; Parks, Robert; Kelsoe, Garnett; Von Holle, Tarra; Haynes, Barton F.; Douek, Daniel C.; Hirsch, Vanessa; Seaman, Michael S.; Shapiro, Lawrence; Mascola, John R.; Kwong, Peter D.; Connors, Mark

    2016-11-01

    Detailed studies of the broadly neutralizing antibodies (bNAbs) that underlie the best available examples of the humoral immune response to HIV are providing important information for the development of therapies and prophylaxis for HIV-1 infection. Here, we report a CD4-binding site (CD4bs) antibody, named N6, that potently neutralized 98% of HIV-1 isolates, including 16 of 20 that were resistant to other members of its class. N6 evolved a mode of recognition such that its binding was not impacted by the loss of individual contacts across the immunoglobulin heavy chain. In addition, structural analysis revealed that the orientation of N6 permitted it to avoid steric clashes with glycans, which is a common mechanism of resistance. Thus, an HIV-1-specific bNAb can achieve potent, near-pan neutralization of HIV-1, making it an attractive candidate for use in therapy and prophylaxis.

  16. Structure-based, targeted deglycosylation of HIV-1 gp120 and effects on neutralization sensitivity and antibody recognition

    International Nuclear Information System (INIS)

    Koch, Markus; Pancera, Marie; Kwong, Peter D.; Kolchinsky, Peter; Grundner, Christoph; Wang Liping; Hendrickson, Wayne A.; Sodroski, Joseph; Wyatt, Richard

    2003-01-01

    The human immunodeficiency virus (HIV-1) exterior envelope glycoprotein, gp120, mediates receptor binding and is the major target for neutralizing antibodies. Primary HIV-1 isolates are characteristically more resistant to broadly neutralizing antibodies, although the structural basis for this resistance remains obscure. Most broadly neutralizing antibodies are directed against functionally conserved gp120 regions involved in binding to either the primary virus receptor, CD4, or the viral coreceptor molecules that normally function as chemokine receptors. These antibodies are known as CD4 binding site (CD4BS) and CD4-induced (CD4i) antibodies, respectively. Inspection of the gp120 crystal structure reveals that although the receptor-binding regions lack glycosylation, sugar moieties lie proximal to both receptor-binding sites on gp120 and thus in proximity to both the CD4BS and the CD4i epitopes. In this study, guided by the X-ray crystal structure of gp120, we deleted four N-linked glycosylation sites that flank the receptor-binding regions. We examined the effects of selected changes on the sensitivity of two prototypic HIV-1 primary isolates to neutralization by antibodies. Surprisingly, removal of a single N-linked glycosylation site at the base of the gp120 third variable region (V3 loop) increased the sensitivity of the primary viruses to neutralization by CD4BS antibodies. Envelope glycoprotein oligomers on the cell surface derived from the V3 glycan-deficient virus were better recognized by a CD4BS antibody and a V3 loop antibody than were the wild-type glycoproteins. Absence of all four glycosylation sites rendered a primary isolate sensitive to CD4i antibody-mediated neutralization. Thus, carbohydrates that flank receptor-binding regions on gp120 protect primary HIV-1 isolates from antibody-mediated neutralization

  17. Antibody to gp41 MPER alters functional properties of HIV-1 Env without complete neutralization.

    Directory of Open Access Journals (Sweden)

    Arthur S Kim

    2014-07-01

    Full Text Available Human antibody 10E8 targets the conserved membrane proximal external region (MPER of envelope glycoprotein (Env subunit gp41 and neutralizes HIV-1 with exceptional potency. Remarkably, HIV-1 containing mutations that reportedly knockout 10E8 binding to linear MPER peptides are partially neutralized by 10E8, producing a local plateau in the dose response curve. Here, we found that virus partially neutralized by 10E8 becomes significantly less neutralization sensitive to various MPER antibodies and to soluble CD4 while becoming significantly more sensitive to antibodies and fusion inhibitors against the heptad repeats of gp41. Thus, 10E8 modulates sensitivity of Env to ligands both pre- and post-receptor engagement without complete neutralization. Partial neutralization by 10E8 was influenced at least in part by perturbing Env glycosylation. With unliganded Env, 10E8 bound with lower apparent affinity and lower subunit occupancy to MPER mutant compared to wild type trimers. However, 10E8 decreased functional stability of wild type Env while it had an opposite, stabilizing effect on MPER mutant Envs. Clade C isolates with natural MPER polymorphisms also showed partial neutralization by 10E8 with altered sensitivity to various gp41-targeted ligands. Our findings suggest a novel mechanism of virus neutralization by demonstrating how antibody binding to the base of a trimeric spike cross talks with adjacent subunits to modulate Env structure and function. The ability of an antibody to stabilize, destabilize, partially neutralize as well as alter neutralization sensitivity of a virion spike pre- and post-receptor engagement may have implications for immunotherapy and vaccine design.

  18. Strategies for induction of catalytic antibodies toward HIV-1 glycoprotein gp120 in autoimmune prone mice.

    Science.gov (United States)

    Durova, Oxana M; Vorobiev, Ivan I; Smirnov, Ivan V; Reshetnyak, Andrew V; Telegin, Georgy B; Shamborant, Olga G; Orlova, Nadezda A; Genkin, Dmitry D; Bacon, Andrew; Ponomarenko, Natalia A; Friboulet, Alain; Gabibov, Alexander G

    2009-11-01

    Tremendous efforts to produce an efficient vaccine for HIV infection have been unsuccessful. The ability of HIV to utilize sophisticated mechanisms to escape killing by host immune system rises dramatic problems in the development of antiviral therapeutics. The HIV infection proceeds by interaction of coat viral glycoprotein gp120 trimer with CD4(+) receptor of the lymphocyte. Thus this surface antigen may be regarded as a favorable target for immunotherapy. In the present study, we have developed three different strategies to produce gp120-specific response in autoimmune prone mice (SJL strain) as potential tools for production "catalytic vaccine". Therefore (i) reactive immunization by peptidylphosphonate, structural part of the coat glycoprotein, (ii) immunization by engineered fused epitopes of gp120 and encephalogenic peptide, a part of myelin basic protein, and (iii) combined vaccination by DNA and corresponding gp120 fragments incorporated into liposomes were investigated. In the first two cases monoclonal antibodies and their recombinant fragments with amidolytic and gp120-specific proteolytic activities were characterized. In the last case, catalytic antibodies with virus neutralizing activity proved in cell line models were harvested.

  19. Induction of HIV neutralizing antibodies against the MPER of the HIV envelope protein by HA/gp41 chimeric protein-based DNA and VLP vaccines.

    Directory of Open Access Journals (Sweden)

    Ling Ye

    Full Text Available Several conserved neutralizing epitopes have been identified in the HIV Env protein and among these, the MPER of gp41 has received great attention and is widely recognized as a promising target. However, little success has been achieved in eliciting MPER-specific HIV neutralizing antibodies by a number of different vaccine strategies. We investigated the ability of HA/gp41 chimeric protein-based vaccines, which were designed to enhance the exposure of the MPER in its native conformation, to induce MPER-specific HIV neutralizing antibodies. In characterization of the HA/gp41 chimeric protein, we found that by mutating an unpaired Cys residue (Cys-14 in its HA1 subunit to a Ser residue, the modified chimeric protein HA-C14S/gp41 showed increased reactivity to a conformation-sensitive monoclonal antibody against HA and formed more stable trimers in VLPs. On the other hand, HA-C14S/gp41 and HA/gp41 chimeric proteins expressed on the cell surfaces exhibited similar reactivity to monoclonal antibodies 2F5 and 4E10. Immunization of guinea pigs using the HA-C14S/gp41 DNA or VLP vaccines induced antibodies against the HIV gp41 as well as to a peptide corresponding to a segment of MPER at higher levels than immunization by standard HIV VLPs. Further, sera from vaccinated guinea pigs were found to exhibit HIV neutralizing activities. Moreover, sera from guinea pigs vaccinated by HA-C14S/gp41 DNA and VLP vaccines but not the standard HIV VLPs, were found to neutralize HIV pseudovirions containing a SIV-4E10 chimeric Env protein. The virus neutralization could be blocked by a MPER-specific peptide, thus demonstrating induction of MPER-specific HIV neutralizing antibodies by this novel vaccine strategy. These results show that induction of MPER-specific HIV neutralizing antibodies can be achieved through a rationally designed vaccine strategy.

  20. Antibody Response is More Likely to Pneumococcal Proteins Than to Polysaccharide After HIV-associated Invasive Pneumococcal Disease

    DEFF Research Database (Denmark)

    Kantsø, Bjørn; Green, Nicola; Goldblatt, David

    2015-01-01

    to at least 1 protein compared to 51% of non-IPD controls. HIV IPD cases responded to more proteins than non-IPD controls (8.6 ± 8.4 vs 4.2 ± 7.6 proteins; P = .01), and had a significantly higher probability of yielding an antibody response to the proteins PiaA, PsaA, and PcpA. Twenty-two percent of HIV......-infected individuals with IPD had a serotype-specific antibody response. Younger age at the time of IPD was the only predictor of a serotype-specific pneumococcal antibody response, whereas we did not identify predictors of a protein-specific antibody response. CONCLUSIONS: Antibody responses occurred more frequently...

  1. Development of a definition for Rapid Progression (RP) of renal function in HIV-positive persons

    DEFF Research Database (Denmark)

    Kamara, David A; Nielsen, Lene Ryom; Ross, Michael

    2014-01-01

    No consensus exists on how to define abnormally rapid deterioration in renal function (Rapid Progression, RP). We developed an operational definition of RP in HIV-positive persons with baseline estimated glomerular filtration rate (eGFR) >90ml/min/1.73m2 (using Cockcroft Gault) in the Data...

  2. Hepatitis B virus surface antigen and anti-hepatitis C virus rapid tests underestimate hepatitis prevalence among HIV-infected patients.

    Science.gov (United States)

    Hønge, Bl; Jespersen, S; Medina, C; Té, Ds; da Silva, Zj; Ostergaard, L; Laursen, Al; Wejse, C; Krarup, H; Erikstrup, C

    2014-10-01

    In the case of coinfection with HIV and hepatitis B virus (HBV) and/or hepatitis C virus (HCV), hepatic disease progression is often accelerated, with higher rates of liver cirrhosis and liver-related mortality. We aimed to evaluate the performance of the rapid tests used routinely to detect HBV surface antigen (HBsAg) and anti-HCV among HIV-infected patients in Guinea-Bissau. Blood samples from HIV-infected patients in Guinea-Bissau were stored after testing for HBsAg and anti-HCV with rapid tests. Samples were subsequently re-tested for HBsAg and anti-HCV in Denmark. Two rapid tests were used in Guinea-Bissau: HBsAg Strip Ref 2034 (VEDA.LAB, Alençon, France; sensitivity 62.3%; specificity 99.2%) and HEPA-SCAN (Bhat Bio-Tech, Bangalore, India; sensitivity 57.1%; specificity 99.7%). In the two tests the ability to obtain the correct outcome depended on the antigen and antibody concentrations, respectively. Sex, age, CD4 cell count and antiretroviral therapy status did not differ between false negative and true positive samples in either of the tests. The study is limited by a low number of anti-HCV positive samples. New diagnostic rapid tests should always be evaluated in the setting in which they will be used before implementation. © 2014 British HIV Association.

  3. Comprehensive Cross-Clade Characterization of Antibody-Mediated Recognition, Complement-Mediated Lysis, and Cell-Mediated Cytotoxicity of HIV-1 Envelope-Specific Antibodies toward Eradication of the HIV-1 Reservoir.

    Science.gov (United States)

    Mujib, Shariq; Liu, Jun; Rahman, A K M Nur-Ur; Schwartz, Jordan A; Bonner, Phil; Yue, Feng Yun; Ostrowski, Mario A

    2017-08-15

    Immunotherapy with passive administration of broadly neutralizing HIV-1 envelope-specific antibodies (bnAbs) in the setting of established infection in vivo has yielded mixed results. The contribution of different antibodies toward the direct elimination of infected cells is poorly understood. In this study, we determined the ability of 12 well-characterized anti-HIV-1 neutralizing antibodies to recognize and eliminate primary CD4 T cells infected with HIV-1 belonging to clades A, B, C, and D, via antibody-dependent complement-mediated lysis (ADCML) and antibody-dependent cell-mediated cytotoxicity (ADCC), in vitro We further tested unique combinations of these antibodies to determine the optimal antibody cocktails to be tested in future clinical trials. We report that antibody binding to infected CD4 T cells is highly variable and correlates with ADCML and ADCC processes. Particularly, antibodies targeting the envelope glycan shield (2G12) and V1/V2 site (PG9, PG16, and PGT145) are best at recognizing HIV-1-infected CD4 T cells. However, only PG9 and PG16 and their combinations with other bnAbs sufficiently induced the elimination of HIV-1-infected CD4 T cells by ADCML, ADCC, or both. Notably, CD4 binding site antibodies VRC01, 3BNC117, and NIH45-46 G54W did not exhibit recognition of infected cells and were unable to induce their killing. Future trials geared toward the development of a cure for HIV/AIDS should incorporate V1/V2 antibodies for maximal clearance of infected cells. With the use of only primary immune cells, we conducted a comprehensive cross-clade physiological analysis to aid the direction of antibodies as therapeutics toward the development of a cure for HIV/AIDS. IMPORTANCE Several antibodies capable of neutralizing the majority of circulating HIV-1 strains have been identified to date and have been shown to prevent infection in animal models. However, the use of combinations of such broadly neutralizing antibodies (bnAbs) for the treatment and

  4. Knowledge of HIV and willingness to conduct oral rapid HIV testing among dentists in Xi'an China.

    Directory of Open Access Journals (Sweden)

    Lirong Wang

    Full Text Available China is considered a country of low HIV prevalence (780,000 people living with HIV, however, HIV infections among high-risk populations continue to grow at alarming rates. Voluntary Counseling and Testing services were first implemented in 2003, and oral rapid HIV testing (ORHT began in 2012. Dentists, as oral health experts, would be well placed to conduct ORHT. We assessed willingness of dentists to undertake ORHT in their clinical practice.A cross-sectional, paper-based survey of dentists from the Xi'an region of China was conducted from April to June 2013. Dentists were recruited from Shaanxi Stomatological Association using a stratified sampling methodology. A 40-item survey was used to measure knowledge of HIV, attitudes toward people living with HIV and willingness to conduct ORHT.477 dentists completed the survey with a mean HIV knowledge test score of 13.2/18 (SD 1.9. If made available in the dental setting, 276 (57.9% preferred to use blood to diagnose HIV, only 190 (39.8% preferred saliva or both. Four hundred and thirty-five (91.2% thought that ORHT was needed in dental clinics. Female dentists felt more accepting of ORHT than males (93.8% vs. 87.8%; χ2=5.145; p<0.05. 42.6% of the participants who responded thought that lack of education on ORHT for dentists was the most urgent problem to solve for ORHT, 144 (31.3% thought that lack of support for ORHT from patients was the most urgent problem. There was statistically significant difference among dental hospital, dentistry and department of dentistry (χ2=24.176; p<0.05.The majority of Chinese dentists thought that ORHT was needed in the dental setting. Providing opportunities for dentists and dental students to learn about HIV testing guidelines and practices is needed as well as feasibility and implementation science research.

  5. Performance evaluation of the Bio-Rad Laboratories GS HIV Combo Ag/Ab EIA, a 4th generation HIV assay for the simultaneous detection of HIV p24 antigen and antibodies to HIV-1 (groups M and O) and HIV-2 in human serum or plasma.

    Science.gov (United States)

    Bentsen, Christopher; McLaughlin, Lisa; Mitchell, Elizabeth; Ferrera, Carol; Liska, Sally; Myers, Robert; Peel, Sheila; Swenson, Paul; Gadelle, Stephane; Shriver, M Kathleen

    2011-12-01

    A multi-center study was conducted to evaluate the Bio-Rad GS HIV Combo Ag/Ab EIA, a 4th generation HIV-1/HIV-2 assay for the simultaneous detection of HIV p24 antigen and antibodies to HIV-1 (groups M and O) and HIV-2 in human serum or plasma in adult and pediatric populations. The objectives of the study were to assess assay performance for the detection of acute HIV infections; sensitivity in known HIV positive samples; percent agreement with HIV status; specificity in low and high risk individuals of unknown HIV status; and to compare assay performance to a 3rd generation HIV assay. The evaluation included testing 9150 samples at four U.S. clinical trial sites, using three kit lots. Unlinked samples were from routine testing, repositories or purchased from vendors. GS HIV Combo Ag/Ab EIA detection in samples from individuals in two separate populations with acute HIV infection was 95.2% (20/21) and 86.4% (38/44). Sensitivity was 100% (1603/1603) in known antibody positive [HIV-1 Groups M and O, and HIV-2] samples. HIV p24 antigen detection was 100% (53/53) in HIV-1 culture supernatants. HIV-1 seroconversion panel detection improved by a range of 0-20 days compared to a 3rd generation HIV test. Specificity was 99.9% (5989/5996) in low risk, 99.9% (959/960) in high risk and 100% (100/100) in pediatric populations. The GS HIV Combo Ag/Ab EIA significantly reduced the diagnostic window when compared to the 3rd generation screening assay, enabling earlier diagnosis of HIV infection. The performance parameters of the Bio-Rad GS HIV Combo Ag/Ab EIA are well suited for use in HIV diagnostic settings. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. A rapid and quantitative assay for measuring antibody-mediated neutralization of West Nile virus infection

    International Nuclear Information System (INIS)

    Pierson, Theodore C.; Sanchez, Melissa D.; Puffer, Bridget A.; Ahmed, Asim A.; Geiss, Brian J.; Valentine, Laura E.; Altamura, Louis A.; Diamond, Michael S.; Doms, Robert W.

    2006-01-01

    West Nile virus (WNV) is a neurotropic flavivirus within the Japanese encephalitis antigenic complex that is responsible for causing West Nile encephalitis in humans. The surface of WNV virions is covered by a highly ordered icosahedral array of envelope proteins that is responsible for mediating attachment and fusion with target cells. These envelope proteins are also primary targets for the generation of neutralizing antibodies in vivo. In this study, we describe a novel approach for measuring antibody-mediated neutralization of WNV infection using virus-like particles that measure infection as a function of reporter gene expression. These reporter virus particles (RVPs) are produced by complementation of a sub-genomic replicon with WNV structural proteins provided in trans using conventional DNA expression vectors. The precision and accuracy of this approach stem from an ability to measure the outcome of the interaction between antibody and viral antigens under conditions that satisfy the assumptions of the law of mass action as applied to virus neutralization. In addition to its quantitative strengths, this approach allows the production of WNV RVPs bearing the prM-E proteins of different WNV strains and mutants, offering considerable flexibility for the study of the humoral immune response to WNV in vitro. WNV RVPs are capable of only a single round of infection, can be used under BSL-2 conditions, and offer a rapid and quantitative approach for detecting virus entry and its inhibition by neutralizing antibody

  7. Structural basis for diverse N-glycan recognition by HIV-1-neutralizing V1-V2-directed antibody PG16

    Energy Technology Data Exchange (ETDEWEB)

    Pancera, Marie; Shahzad-ul-Hussan, Syed; Doria-Rose, Nicole A.; McLellan, Jason S.; Bailer, Robert T.; Dai, Kaifan; Loesgen, Sandra; Louder, Mark K.; Staupe, Ryan P.; Yang, Yongping; Zhang, Baoshan; Parks, Robert; Eudailey, Joshua; Lloyd, Krissey E.; Blinn, Julie; Alam, S. Munir; Haynes, Barton F.; Amin, Mohammed N.; Wang, Lai-Xi; Burton, Dennis R.; Koff, Wayne C.; Nabel, Gary J.; Mascola, John R.; Bewley, Carole A; Kwong, Peter D. [NIH; (Scripps); (Duke); (Maryland-MED); (IAVI)

    2013-08-05

    HIV-1 uses a diverse N-linked-glycan shield to evade recognition by antibody. Select human antibodies, such as the clonally related PG9 and PG16, recognize glycopeptide epitopes in the HIV-1 V1–V2 region and penetrate this shield, but their ability to accommodate diverse glycans is unclear. Here we report the structure of antibody PG16 bound to a scaffolded V1–V2, showing an epitope comprising both high mannose–type and complex-type N-linked glycans. We combined structure, NMR and mutagenesis analyses to characterize glycan recognition by PG9 and PG16. Three PG16-specific residues, arginine, serine and histidine (RSH), were critical for binding sialic acid on complex-type glycans, and introduction of these residues into PG9 produced a chimeric antibody with enhanced HIV-1 neutralization. Although HIV-1–glycan diversity facilitates evasion, antibody somatic diversity can overcome this and can provide clues to guide the design of modified antibodies with enhanced neutralization.

  8. A novel lentiviral scFv display library for rapid optimization and selection of high affinity antibodies.

    Science.gov (United States)

    Qudsia, Sehar; Merugu, Siva B; Mangukiya, Hitesh B; Hema, Negi; Wu, Zhenghua; Li, Dawei

    2018-04-30

    Antibody display libraries have become a popular technique to screen monoclonal antibodies for therapeutic purposes. An important aspect of display technology is to generate an optimization library by changing antibody affinity to antigen through mutagenesis and screening the high affinity antibody. In this study, we report a novel lentivirus display based optimization library antibody in which Agtuzumab scFv is displayed on cell membrane of HEK-293T cells. To generate an optimization library, hotspot mutagenesis was performed to achieve diverse antibody library. Based on sequence analysis of randomly selected clones, library size was estimated approximately to be 1.6 × 10 6 . Lentivirus display vector was used to display scFv antibody on cell surface and flow cytometery was performed to check the antibody affinity to antigen. Membrane bound scFv antibodies were then converted to secreted antibody through cre/loxP recombination. One of the mutant clones, M8 showed higher affinity to antigen in flow cytometery analysis. Further characterization of cellular and secreted scFv through western blot showed that antibody affinity was increased by three fold after mutagenesis. This study shows successful construction of a novel antibody library and suggests that hotspot mutagenesis could prove a useful and rapid optimization tool to generate similar libraries with various degree of antigen affinity. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Evaluation of rapid HIV test kits on whole blood and development of rapid testing algorithm for voluntary testing and counseling centers in Ethiopia.

    Science.gov (United States)

    Tegbaru, Belete; Messele, Tsehaynesh; Wolday, Dawit; Meles, PhD Hailu; Tesema, Desalegn; Birhanu, Hiwot; Tesfaye, Girma; Bond, Kyle B; Martin, Robert; Rayfield, Mark A; Wuhib, Tadesse; Fekadu, Makonnen

    2004-10-01

    Five simple and rapid HIV antibody detection assays viz. Determine, Capillus, Oraquick, Unigold and Hemastrip were evaluated to examine their performance and to develop an alternative rapid test based testing algorithm for voluntary counseling and testing (VCT) in Ethiopia. All the kits were tested on whole blood, plasma and serum. The evaluation had three phases: Primary lab review, piloting at point of service and implementation. This report includes the results of the first two phases. A total of 2,693 specimens (both whole blood and plasma) were included in the evaluation. Results were compared to double Enzyme Linked Immuno-Sorbent Assay (ELISA) system. Discordant EIA results were resolved using Western Blot. The assays had very good sensitivities and specificities, 99-100%, at the two different phases of the evaluation. A 98-100% result agreement was obtained from those tested at VCT centers and National Referral Laboratory for AIDS (NRLA), in the quality control phase of the evaluation. A testing strategy yielding 100% [95% CI; 98.9-100.0] sensitivity was achieved by the sequential use of the three rapid test kits. Direct cost comparison showed serial testing algorithm reduces the cost of testing by over 30% compared to parallel testing in the current situation. Determine, Capillus/Oraquick (presence/absence of frefrigeration) and Unigold were recommended as screening, confirmation and tiebreaker tests, respectively.

  10. Genetic signatures in the envelope glycoproteins of HIV-1 that associate with broadly neutralizing antibodies.

    Directory of Open Access Journals (Sweden)

    S Gnanakaran

    Full Text Available A steady increase in knowledge of the molecular and antigenic structure of the gp120 and gp41 HIV-1 envelope glycoproteins (Env is yielding important new insights for vaccine design, but it has been difficult to translate this information to an immunogen that elicits broadly neutralizing antibodies. To help bridge this gap, we used phylogenetically corrected statistical methods to identify amino acid signature patterns in Envs derived from people who have made potently neutralizing antibodies, with the hypothesis that these Envs may share common features that would be useful for incorporation in a vaccine immunogen. Before attempting this, essentially as a control, we explored the utility of our computational methods for defining signatures of complex neutralization phenotypes by analyzing Env sequences from 251 clonal viruses that were differentially sensitive to neutralization by the well-characterized gp120-specific monoclonal antibody, b12. We identified ten b12-neutralization signatures, including seven either in the b12-binding surface of gp120 or in the V2 region of gp120 that have been previously shown to impact b12 sensitivity. A simple algorithm based on the b12 signature pattern was predictive of b12 sensitivity/resistance in an additional blinded panel of 57 viruses. Upon obtaining these reassuring outcomes, we went on to apply these same computational methods to define signature patterns in Env from HIV-1 infected individuals who had potent, broadly neutralizing responses. We analyzed a checkerboard-style neutralization dataset with sera from 69 HIV-1-infected individuals tested against a panel of 25 different Envs. Distinct clusters of sera with high and low neutralization potencies were identified. Six signature positions in Env sequences obtained from the 69 samples were found to be strongly associated with either the high or low potency responses. Five sites were in the CD4-induced coreceptor binding site of gp120, suggesting an

  11. Differential Antibody Responses to Conserved HIV-1 Neutralizing Epitopes in the Context of Multivalent Scaffolds and Native-Like gp140 Trimers.

    Science.gov (United States)

    Morris, Charles D; Azadnia, Parisa; de Val, Natalia; Vora, Nemil; Honda, Andrew; Giang, Erick; Saye-Francisco, Karen; Cheng, Yushao; Lin, Xiaohe; Mann, Colin J; Tang, Jeffrey; Sok, Devin; Burton, Dennis R; Law, Mansun; Ward, Andrew B; He, Linling; Zhu, Jiang

    2017-02-28

    Broadly neutralizing antibodies (bNAbs) have provided valuable insights into the humoral immune response to HIV-1. While rationally designed epitope scaffolds and well-folded gp140 trimers have been proposed as vaccine antigens, a comparative understanding of their antibody responses has not yet been established. In this study, we probed antibody responses to the N332 supersite and the membrane-proximal external region (MPER) in the context of heterologous protein scaffolds and native-like gp140 trimers. Ferritin nanoparticles and fragment crystallizable (Fc) regions were utilized as multivalent carriers to display scaffold antigens with grafted N332 and MPER epitopes, respectively. Trimeric scaffolds were also identified to stabilize the MPER-containing BG505 gp140.681 trimer in a native-like conformation. Following structural and antigenic evaluation, a subset of scaffold and trimer antigens was selected for immunization in BALB/c mice. Serum binding revealed distinct patterns of antibody responses to these two bNAb targets presented in different structural contexts. For example, the N332 nanoparticles elicited glycan epitope-specific antibody responses that could also recognize the native trimer, while a scaffolded BG505 gp140.681 trimer generated a stronger and more rapid antibody response to the trimer apex than its parent gp140.664 trimer. Furthermore, next-generation sequencing (NGS) of mouse splenic B cells revealed expansion of antibody lineages with long heavy-chain complementarity-determining region 3 (HCDR3) loops upon activation by MPER scaffolds, in contrast to the steady repertoires primed by N332 nanoparticles and a soluble gp140.664 trimer. These findings will facilitate the future development of a coherent vaccination strategy that combines both epitope-focused and trimer-based approaches. IMPORTANCE Both epitope-focused and trimer-based strategies are currently being explored in HIV-1 vaccine development, which aims to elicit broadly neutralizing

  12. Acute HIV infection with rapid progression to AIDS

    Directory of Open Access Journals (Sweden)

    Marcio de Oliveira Silva

    Full Text Available Acute HIV infection is rarely recognized as the signs and symptoms are normally unspecific and can persist for days or weeks. The normal HIV course is characterized by a progressive loss of CD4+ cells, which normally leads to severe immunodeficiency after a variable time interval. The mean time from initial infection to development of clinical AIDS is approximately 8-10 years, but it is variable among individuals and depends on a complex interaction between virus and host. Here we describe an extraordinary case of a man who developed Pneumocisits jiroveci pneumonia within one month after sexual exposure to HIV-1, and then presented with 3 consecutive CD4 counts bellow 200 cells/mm³ within 3 months, with no other opportunistic disease. Although antiretroviral therapy (AZT+3TC+ATZ/r was started, with full adherence of the patient, and genotyping indicating no primary antiretroviral resistance mutations, he required more than six months to have a CD4 restoration to levels above 200 cells/mm³ and 10 months to HIV-RNA to become undetectable.

  13. Usefulness of enzyme immunoassay (EIA) for screening of anti HIV antibodies in urinary specimens: A comparative analysis.

    Science.gov (United States)

    Sahni, A K; Nagendra, A; Roy, Partha; Patrikar, S

    2014-07-01

    Standard HIV testing is done using serum or plasma. FDA approved ELISA to screen urine for IgG antibodies to HIV-1 in 1996. It is a simple, noninvasive test and is appropriate for developing countries where health care personnel may not be professionally trained or where clean needles for drawing blood may not always be available. 436 individuals with high-risk behavior and strong clinical suspicion of HIV infection were screened for IgG antibodies to HIV-1 in urine by ELISA. Urine HIV testing was performed by enzyme immunoassay, at the ongoing Voluntary Confidential Counseling and Testing Center (VCCTC) at a large tertiary care microbiology lab. The individuals enrolled for the study had high-risk exposure to the virus and majorities were from a state with a high incidence of HIV infection. In all individuals, both serum and urine were tested for IgG antibodies to HIV-1. Overall, 135 individuals (30.96%) were HIV-positive, of whom 96 (71%) had never previously tested positive; 87% of those who tested positive received their results, and most were referred for medical care. Sensitivity, specificity and predictive values of HIV-1 urine ELISA test kit were determined. Sensitivity was found to be 89.6%; 95% CI [82.9-94.0], specificity 97.3%; 95% CI [94.6-98.8], positive predictive value 93.8%; 95% CI [87.8-97.1] and negative predictive value 95.4%; 95% CI [92.3-97.4]. Efficiency, sensitivity, and specificity of the urine-based screening for HIV-1 test kits were excellent as compared to the reference test.

  14. Quantification of the Impact of the HIV-1-Glycan Shield on Antibody Elicitation

    Directory of Open Access Journals (Sweden)

    Tongqing Zhou

    2017-04-01

    Full Text Available While the HIV-1-glycan shield is known to shelter Env from the humoral immune response, its quantitative impact on antibody elicitation has been unclear. Here, we use targeted deglycosylation to measure the impact of the glycan shield on elicitation of antibodies against the CD4 supersite. We engineered diverse Env trimers with select glycans removed proximal to the CD4 supersite, characterized their structures and glycosylation, and immunized guinea pigs and rhesus macaques. Immunizations yielded little neutralization against wild-type viruses but potent CD4-supersite neutralization (titers 1: >1,000,000 against four-glycan-deleted autologous viruses with over 90% breadth against four-glycan-deleted heterologous strains exhibiting tier 2 neutralization character. To a first approximation, the immunogenicity of the glycan-shielded protein surface was negligible, with Env-elicited neutralization (ID50 proportional to the exponential of the protein-surface area accessible to antibody. Based on these high titers and exponential relationship, we propose site-selective deglycosylated trimers as priming immunogens to increase the frequency of site-targeting antibodies.

  15. Quantification of the Impact of the HIV-1-Glycan Shield on Antibody Elicitation

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Tongqing; Doria-Rose, Nicole A.; Cheng, Cheng; Stewart-Jones, Guillaume B. E.; Chuang, Gwo-Yu; Chambers, Michael; Druz, Aliaksandr; Geng, Hui; McKee, Krisha; Kwon, Young Do; O’Dell, Sijy; Sastry, Mallika; Schmidt, Stephen D.; Xu, Kai; Chen, Lei; Chen, Rita E.; Louder, Mark K.; Pancera, Marie; Wanninger, Timothy G.; Zhang, Baoshan; Zheng, Anqi; Farney, S. Katie; Foulds, Kathryn E.; Georgiev, Ivelin S.; Joyce, M. Gordon; Lemmin, Thomas; Narpala, Sandeep; Rawi, Reda; Soto, Cinque; Todd, John-Paul; Shen, Chen-Hsiang; Tsybovsky, Yaroslav; Yang, Yongping; Zhao, Peng; Haynes, Barton F.; Stamatatos, Leonidas; Tiemeyer, Michael; Wells, Lance; Scorpio, Diana G.; Shapiro, Lawrence; McDermott, Adrian B.; Mascola, John R.; Kwong, Peter D.

    2017-04-01

    While the HIV-1-glycan shield is known to shelter Env from the humoral immune response, its quantitative impact on antibody elicitation has been unclear. Here, we use targeted deglycosylation to measure the impact of the glycan shield on elicitation of antibodies against the CD4 supersite. We engineered diverse Env trimers with select glycans removed proximal to the CD4 supersite, characterized their structures and glycosylation, and immunized guinea pigs and rhesus macaques. Immunizations yielded little neutralization against wild-type viruses but potent CD4-supersite neutralization (titers 1: >1,000,000 against four-glycan-deleted autologous viruses with over 90% breadth against four-glycan-deleted heterologous strains exhibiting tier 2 neutralization character). To a first approximation, the immunogenicity of the glycan-shielded protein surface was negligible, with Env-elicited neutralization (ID50) proportional to the exponential of the protein-surface area accessible to antibody. Based on these high titers and exponential relationship, we propose site-selective deglycosylated trimers as priming immunogens to increase the frequency of site-targeting antibodies.

  16. Cleavage-Independent HIV-1 Trimers From CHO Cell Lines Elicit Robust Autologous Tier 2 Neutralizing Antibodies

    Directory of Open Access Journals (Sweden)

    Shridhar Bale

    2018-05-01

    Full Text Available Native flexibly linked (NFL HIV-1 envelope glycoprotein (Env trimers are cleavage-independent and display a native-like, well-folded conformation that preferentially displays broadly neutralizing determinants. The NFL platform simplifies large-scale production of Env by eliminating the need to co-transfect the precursor-cleaving protease, furin that is required by the cleavage-dependent SOSIP trimers. Here, we report the development of a CHO-M cell line that expressed BG505 NFL trimers at a high level of homogeneity and yields of ~1.8 g/l. BG505 NFL trimers purified by single-step lectin-affinity chromatography displayed a native-like closed structure, efficient recognition by trimer-preferring bNAbs, no recognition by non-neutralizing CD4 binding site-directed and V3-directed antibodies, long-term stability, and proper N-glycan processing. Following negative-selection, formulation in ISCOMATRIX adjuvant and inoculation into rabbits, the trimers rapidly elicited potent autologous tier 2 neutralizing antibodies. These antibodies targeted the N-glycan “hole” naturally present on the BG505 Env proximal to residues at positions 230, 241, and 289. The BG505 NFL trimers that did not expose V3 in vitro, elicited low-to-no tier 1 virus neutralization in vivo, indicating that they remained intact during the immunization process, not exposing V3. In addition, BG505 NFL and BG505 SOSIP trimers expressed from 293F cells, when formulated in Adjuplex adjuvant, elicited equivalent BG505 tier 2 autologous neutralizing titers. These titers were lower in potency when compared to the titers elicited by CHO-M cell derived trimers. In addition, increased neutralization of tier 1 viruses was detected. Taken together, these data indicate that both adjuvant and cell-type expression can affect the elicitation of tier 2 and tier 1 neutralizing responses in vivo.

  17. Post-marketing surveillance of OraQuick whole blood and oral fluid rapid HIV testing.

    Science.gov (United States)

    Wesolowski, Laura G; MacKellar, Duncan A; Facente, Shelley N; Dowling, Teri; Ethridge, Steven F; Zhu, Julia H; Sullivan, Patrick S

    2006-08-01

    Post-marketing surveillance was conducted to monitor the performance of the OraQuick Advance rapid HIV-1/2 antibody test (OraQuick) on whole blood and oral fluid. Surveillance of routinely collected data on clients tested with OraQuick in 368 testing sites affiliated with 17 state and city health departments between 11 August 2004 and 30 June 2005. For whole blood and oral fluid, we report the median (range) health department OraQuick specificity and positive predictive value (PPV), and the number of clients with discordant results (e.g. who had a reactive rapid test not confirmed positive by Western blot or indirect immunofluorescence). At one site with lower than expected oral-fluid specificity, we evaluated whether device expiration, manufacturing lot, operator practices, or device-storage or testing-area temperatures were associated with false-positive tests. During the surveillance period, 135 724 whole blood and 26 066 oral fluid rapid tests were conducted. The median health department whole blood OraQuick specificity was 99.98% (range: 99.73-100%) and PPV was 99.24% (range: 66.67-100%); the median oral fluid specificity was 99.89% (range: 99.44-100%) and PPV was 90.00% (range: 50.00-100%). A total of 124 discordant results were reported from 68 (0.05%) whole blood and 56 (0.22%) oral fluid rapid tests. The oral fluid specificity at the site with excess oral fluid false-positive tests was 98.7% (95% confidence interval: 98.18-99.11%). The increase in false-positive tests at that site was not associated with any specific device characteristic, operator procedure or temperature condition. The specificity of OraQuick performed on whole blood and oral fluid during post-marketing surveillance was compatible with the manufacturer's claim within the package insert. However, one site experienced lower than expected oral fluid specificity. Sites that observe that the specificity of OraQuick is lower than the range indicated in the package insert should notify the

  18. Amperometric biosensor based on a single antibody of dual function for rapid detection of Streptococcus agalactiae.

    Science.gov (United States)

    Vásquez, Gersson; Rey, Alba; Rivera, Camilo; Iregui, Carlos; Orozco, Jahir

    2017-01-15

    Pathogenic bacteria are responsible for several diseases in humans and in a variety of hosts. Detection of pathogenic bacteria is imperative to avoid and/or fight their potential harmful effects. This work reports on the first amperometric biosensor for the rapid detection of Streptococcus agalactiae (S. agalactiae). The biosensor relies on a single biotinylated antibody that immobilizes the bacteria on a screen-printed carbon electrode while is further linked to a streptavidin-conjugated HRP reporter. The biotinylated antibody provides selectivity to the biosensor whereas serves as an anchoring point to the reporter for further amplification of the electrochemical signal. The resultant immunosensor is simple, responds rapidly, and allows for the selective and highly sensitive quantification of S. agalactiae cells in a concentration range of 10 1 -10 7 CFUml -1 , with a detection limit of 10CFUml -1 . The approach not only enables a rapid detection and quantification of S. agalactiae in environmental samples but also opens up new opportunities for the simple fabrication of electrochemical immunosensors for different target pathogens. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. HIV-1 specific antibody titers and neutralization among chronically infected patients on long-term suppressive antiretroviral therapy (ART: a cross-sectional study.

    Directory of Open Access Journals (Sweden)

    Johannes S Gach

    Full Text Available The majority of potent and broadly neutralizing antibodies against HIV-1 have been isolated from untreated patients with acute or chronic infection. To assess the extent of HIV-1 specific antibody response and neutralization after many years of virologic suppression from potent combination ART, we examined antibody binding titers and neutralization of 51 patients with chronic HIV-1 infection on suppressive ART for at least three years. In this cross-sectional analysis, we found high antibody titers against gp120, gp41, and the membrane proximal external region (MPER in 59%, 43%, and 27% of patients, respectively. We observed significantly higher endpoint binding titers for gp120 and gp41 for patients with >10 compared to ≤ 10 years of detectable HIV RNA. Additionally, we observed higher median gp120 and gp41 antibody titers in patients with HIV RNA 10 years of detectable HIV RNA (8/20 [40.0%] versus 3/31 [9.7%] for ≤ 10 years, p = 0.02 and a trend toward greater neutralization in patients with ≤ 5 years of HIV RNA 5 years, p = 0.08. All patients with neutralizing activity mediated successful phagocytosis of VLPs by THP-1 cells after antibody opsonization. Our findings of highly specific antibodies to several structural epitopes of HIV-1 with antibody effector functions and neutralizing activity after long-term suppressive ART, suggest continuous antigenic stimulation and evolution of HIV-specific antibody response occurs before and after suppression with ART. These patients, particularly those with slower HIV progression and more time with detectable viremia prior to initiation of suppressive ART, are a promising population to identify and further study functional antibodies against HIV-1.

  20. Detection of anti-HIV-1 IgG antibodies in whole saliva by GACELISA and Western blot assays.

    Science.gov (United States)

    Matee, M I; Lyamuya, E F; Simon, E; Mbena, E C; Kagoma, C; Samaranayake, L P; Scheutz, F

    1996-05-01

    The present study, based on 158 HIV seropositives and 167 HIV seronegatives, demonstrates that saliva collected with the Omni-SAL device and tested with GACELISA (an IgG antibody capture ELISA) is an effective non-invasive alternative to serum for anti-HIV IgG antibody screening. The study also shows that a conventional serum Western blot kit can be used, with slight modifications, for confirmatory testing of saliva specimens. Collecting saliva with the Omni-SAL device had a very good acceptance rate among Tanzanian subjects, and although this diagnostic method is not yet known by the general public, 65% of the study participants preferred to give saliva instead of blood for HIV testing.

  1. Rapid Antiretroviral Therapy Initiation for Women in an HIV-1 Prevention Clinical Trial Experiencing Primary HIV-1 Infection during Pregnancy or Breastfeeding.

    Science.gov (United States)

    Morrison, Susan; John-Stewart, Grace; Egessa, John J; Mubezi, Sezi; Kusemererwa, Sylvia; Bii, Dennis K; Bulya, Nulu; Mugume, Francis; Campbell, James D; Wangisi, Jonathan; Bukusi, Elizabeth A; Celum, Connie; Baeten, Jared M

    2015-01-01

    During an HIV-1 prevention clinical trial in East Africa, we observed 16 cases of primary HIV-1 infection in women coincident with pregnancy or breastfeeding. Nine of eleven pregnant women initiated rapid combination antiretroviral therapy (ART), despite having CD4 counts exceeding national criteria for ART initiation; breastfeeding women initiated ART or replacement feeding. Rapid ART initiation during primary HIV-1 infection during pregnancy and breastfeeding is feasible in this setting.

  2. Rapid Antiretroviral Therapy Initiation for Women in an HIV-1 Prevention Clinical Trial Experiencing Primary HIV-1 Infection during Pregnancy or Breastfeeding.

    Directory of Open Access Journals (Sweden)

    Susan Morrison

    Full Text Available During an HIV-1 prevention clinical trial in East Africa, we observed 16 cases of primary HIV-1 infection in women coincident with pregnancy or breastfeeding. Nine of eleven pregnant women initiated rapid combination antiretroviral therapy (ART, despite having CD4 counts exceeding national criteria for ART initiation; breastfeeding women initiated ART or replacement feeding. Rapid ART initiation during primary HIV-1 infection during pregnancy and breastfeeding is feasible in this setting.

  3. Diagnostic accuracy of the rapid urine lipoarabinomannan test for pulmonary tuberculosis among HIV-infected adults in Ghana-findings from the DETECT HIV-TB study

    DEFF Research Database (Denmark)

    Bjerrum, Stephanie; Kenu, Ernest; Lartey, Margaret

    2015-01-01

    BACKGROUND: Rapid diagnostic tests are urgently needed to mitigate HIV-associated tuberculosis (TB) mortality. We evaluated diagnostic accuracy of the rapid urine lipoarabinomannan (LAM) test for pulmonary TB and assessed the effect of a two-sample strategy. METHODS: HIV-infected adults eligible...

  4. Somatic populations of PGT135-137 HIV-1-neutralizing antibodies identified by 454 pyrosequencing and bioinformatics

    Directory of Open Access Journals (Sweden)

    Jiang eZhu

    2012-09-01

    Full Text Available Select HIV-1-infected individuals develop sera capable of neutralizing diverse viral strains. The molecular basis of this neutralization is currently being deciphered by the isolation of HIV-1-neutralizing antibodies. In one infected donor, three neutralizing antibodies, PGT135-137, were identified by assessment of neutralization from individually sorted B cells and found to recognize an epitope containing an N-linked glycan at residue 332 on HIV-1 gp120. Here we use deep sequencing and bioinformatics methods to interrogate the B cell record of this donor to gain a more complete understanding of the humoral immune response. PGT135-137-gene family-specific primers were used to amplify heavy and light chain-variable domain sequences. 454 pyrosequencing produced 141,298 heavy-chain sequences of IGHV4-39 origin and 87,229 light-chain sequences of IGKV3-15 origin. A number of heavy and light chain sequences of ~90% identity to PGT137, several to PGT136, and none of high identity to PGT135 were identified. After expansion of these sequences to include close phylogenetic relatives, a total of 202 heavy-chain sequences and 72 light-chain sequences were identified. These sequences were clustered into populations of 95% identity comprising 15 for heavy chain and 10 for light chain, and a select sequence from each population was synthesized and reconstituted with a PGT137-partner chain. Reconstituted antibodies showed varied neutralization phenotypes for HIV-1 clade A and D isolates. Sequence diversity of the antibody population represented by these tested sequences was notably higher than observed with a 454 pyrosequencing-control analysis on 10 antibodies of defined sequence, suggesting that this diversity results primarily from somatic maturation. Our results thus provide an example of how pathogens like HIV-1 are opposed by a varied humoral immune response, derived from intrinsic mechanisms of antibody development, and embodied by somatic populations

  5. Optimization and validation of a neutralizing antibody assay for HIV-1 in A3R5 cells.

    Science.gov (United States)

    Sarzotti-Kelsoe, Marcella; Daniell, Xiaoju; Todd, Christopher A; Bilska, Miroslawa; Martelli, Amanda; LaBranche, Celia; Perez, Lautaro G; Ochsenbauer, Christina; Kappes, John C; Rountree, Wes; Denny, Thomas N; Montefiori, David C

    2014-07-01

    A3R5 is a human CD4(+) lymphoblastoid cell line that was engineered to express CCR5 and is useful for the detection of weak neutralizing antibody responses against tier 2 strains of HIV-1. Here we describe the optimization and validation of the HIV-1 neutralizing antibody assay that utilizes A3R5 cells, performed in compliance with Good Clinical Laboratory Practice (GCLP) guidelines. The assay utilizes Renilla luciferase-expressing replication competent infectious molecular clones (IMC) encoding heterologous env genes from different HIV-1 clades. Key assay validation parameters tested included specificity, accuracy, precision, limit of detection and quantitation, specificity, linearity and range, and robustness. Plasma samples demonstrated higher non-specific activity than serum samples in the A3R5 assay. This assay can tolerate a wide range of virus input but is more sensitive to cell concentration. The higher sensitivity of the A3R5 assay in neutralization responses to tier 2 strains of HIV-1 makes it complementary to, but not a substitute for the TZM-bl assay. The validated A3R5 assay is employed as an endpoint immunogenicity test for vaccine-elicited neutralizing antibodies against tier 2 strains of HIV-1, and to identify correlates of protection in HIV-1 vaccine trials conducted globally. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Field evaluation of a dual rapid diagnostic test for HIV infection and syphilis in Lima, Peru.

    Science.gov (United States)

    Bristow, Claire C; Leon, Segundo R; Huang, Emily; Brown, Brandon J; Ramos, Lourdes B; Vargas, Silver K; Flores, Juan A; Caceres, Carlos F; Klausner, Jeffrey D

    2016-05-01

    Screening for HIV and syphilis in key populations is recommended by the WHO to reduce the morbidity, mortality and transmission associated with undiagnosed and untreated infections. Rapid point-of-care tests that can detect multiple infections with a single fingerprick whole blood specimen using a single device are gaining popularity. We evaluated the field performance of a rapid dual HIV and syphilis test in people at high risk of HIV and syphilis infections. Participants included men who have sex with men and transgender women recruited in Lima, Peru. Reference standard testing for detection of HIV and syphilis infections, conducted using blood samples from venipuncture, included Treponema pallidum particle agglutination and fourth-generation HIV enzyme immunoassay for which positive results had a confirmation HIV Western blot test. For the evaluation test, SD BIOLINE HIV/Syphilis Duo test (Standard Diagnostics, Korea), a fingerprick blood specimen was used. Sensitivity and specificity were calculated and the exact binomial method was used to determine 95% CIs. A total of 415 participants were recruited for the study. The dual test sensitivity for detection of T. pallidum infection was 89.2% (95% CI 83.5% to 93.5%) and specificity 98.8% (95% CI 96.5% to 99.8%). For detection of HIV infection, the sensitivity of the dual test was 99.1% (95% CI 94.8% to 100%) and specificity 99.4% (95% CI 97.7% to 99.9%). This high performing dual test should be considered for the use in clinical settings to increase uptake of simultaneous testing of HIV and syphilis and accelerate time to treatment for those who need it. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  7. Antibodies from the sera of HIV-infected patients efficiently hydrolyze all human histones.

    Science.gov (United States)

    Baranova, Svetlana V; Buneva, Valentina N; Nevinsky, Georgy A

    2016-08-01

    Histones and their post-translational modifications have key roles in chromatin remodeling and gene transcription. Besides intranuclear functions, histones act as damage-associated molecular pattern molecules when they are released into the extracellular space. Administration of exogenous histones to animals leads to systemic inflammatory and toxic responses through activating Toll-like receptors and inflammasome pathways. Here, using ELISA it was shown that sera of HIV-infected patients and healthy donors contain autoantibodies against histones. Autoantibodies with enzymic activities (abzymes) are a distinctive feature of autoimmune diseases. It was interesting whether antibodies from sera of HIV-infected patients can hydrolyze human histones. Electrophoretically and immunologically homogeneous IgGs were isolated from sera of HIV-infected patients by chromatography on several affinity sorbents. We present first evidence showing that 100% of IgGs purified from the sera of 32 HIV-infected patients efficiently hydrolyze from one to five human histones. Several rigid criteria have been applied to show that the histone-hydrolyzing activity is an intrinsic property of IgGs of HIV-infected patients. The relative efficiency of hydrolysis of histones (H1, H2a, H2b, H3, and H4) significantly varied for IgGs of different patients. IgGs from the sera of 40% of healthy donors also hydrolyze histones but with an average efficiency approximately 16-fold lower than that of HIV-infected patients. Similar to proteolytic abzymes from the sera of patients with several autoimmune diseases, histone-hydrolyzing IgGs from HIV-infected patients were inhibited by specific inhibitors of serine and of metal-dependent proteases, but an unexpected significant inhibition of the activity by specific inhibitor of thiol-like proteases was also observed. Because IgGs can efficiently hydrolyze histones, a negative role of abzymes in development of acquired immune deficiency syndrome cannot be

  8. A cross-sectional survey of attitudes to HIV risk and rapid HIV testing among clients of sex workers in Switzerland.

    Science.gov (United States)

    Darling, Katharine E A; Diserens, Esther-Amélie; N'garambe, Chantal; Ansermet-Pagot, Anne; Masserey, Eric; Cavassini, Matthias; Bodenmann, Patrick

    2012-10-01

    To assess attitudes to HIV risk and acceptability of rapid HIV testing among clients of street-based female sex workers (FSW) in Lausanne, Switzerland, where HIV prevalence in the general population is 0.4%. The authors conducted a cross-sectional study in the red light district of Lausanne for five nights in September of 2008, 2009 and 2010. Clients of FSW were invited to complete a questionnaire in the street assessing demographic characteristics, attitudes to HIV risk and HIV testing history. All clients interviewed were then offered anonymous finger stick rapid HIV testing in a van parked on-site. The authors interviewed 112, 127 and 79 clients in 2008, 2009 and 2010, respectively. All were men, average age 32-37 years old; 40-60% were in a stable relationship. History of unprotected sex was higher with non-commercial partners (33-50%) than with FSW (6-11%); 29-46% of clients had never undergone an HIV test. Anonymous rapid HIV testing was accepted by 45-50% of clients. Out of 109 HIV tests conducted during the three study periods, none was reactive. On-site HIV counselling and testing is acceptable among clients of FSW in this urban setting. These individuals represent an unquantified population, a proportion of which has an incomplete understanding of HIV risk in the face of high-risk behaviour, with implications for potential onward transmission to non-commercial sexual partners.

  9. The Isolation of Novel Phage Display-Derived Human Recombinant Antibodies Against CCR5, the Major Co-Receptor of HIV

    OpenAIRE

    Shimoni, Moria; Herschhorn, Alon; Britan-Rosich, Yelena; Kotler, Moshe; Benhar, Itai; Hizi, Amnon

    2013-01-01

    Selecting for antibodies against specific cell-surface proteins is a difficult task due to many unrelated proteins that are expressed on the cell surface. Here, we describe a method to screen antibody-presenting phage libraries against native cell-surface proteins. We applied this method to isolate antibodies that selectively recognize CCR5, which is the major co-receptor for HIV entry (consequently, playing a pivotal role in HIV transmission and pathogenesis). We employed a phage screening s...

  10. [The social marketing models and policy advices for HIV rapid testing initiated by non-govermental organization].

    Science.gov (United States)

    Liu, H; Cai, L P; Xue, H; Zhao, Y; Wu, D; Zhang, D P; Yin, W Y; Sun, J P

    2016-10-06

    Currently, a growing number of community-based organizations are providing rapid HIV testing service in various forms, some people with specific needs also purchase HIV rapid test papers through online sales channels, those imply that the demand of HIV self-test is in increasing year by year.In this paper, aims to understand the current situation of HIV rapid test led by CBOs and the approach, strategies and results of social marketing by means of expert interviews and site visits. Hope to illustrate the current situation, and make recommendations for future work.

  11. Differential Antibody Responses to Conserved HIV-1 Neutralizing Epitopes in the Context of Multivalent Scaffolds and Native-Like gp140 Trimers

    Directory of Open Access Journals (Sweden)

    Charles D. Morris

    2017-02-01

    Full Text Available Broadly neutralizing antibodies (bNAbs have provided valuable insights into the humoral immune response to HIV-1. While rationally designed epitope scaffolds and well-folded gp140 trimers have been proposed as vaccine antigens, a comparative understanding of their antibody responses has not yet been established. In this study, we probed antibody responses to the N332 supersite and the membrane-proximal external region (MPER in the context of heterologous protein scaffolds and native-like gp140 trimers. Ferritin nanoparticles and fragment crystallizable (Fc regions were utilized as multivalent carriers to display scaffold antigens with grafted N332 and MPER epitopes, respectively. Trimeric scaffolds were also identified to stabilize the MPER-containing BG505 gp140.681 trimer in a native-like conformation. Following structural and antigenic evaluation, a subset of scaffold and trimer antigens was selected for immunization in BALB/c mice. Serum binding revealed distinct patterns of antibody responses to these two bNAb targets presented in different structural contexts. For example, the N332 nanoparticles elicited glycan epitope-specific antibody responses that could also recognize the native trimer, while a scaffolded BG505 gp140.681 trimer generated a stronger and more rapid antibody response to the trimer apex than its parent gp140.664 trimer. Furthermore, next-generation sequencing (NGS of mouse splenic B cells revealed expansion of antibody lineages with long heavy-chain complementarity-determining region 3 (HCDR3 loops upon activation by MPER scaffolds, in contrast to the steady repertoires primed by N332 nanoparticles and a soluble gp140.664 trimer. These findings will facilitate the future development of a coherent vaccination strategy that combines both epitope-focused and trimer-based approaches.

  12. HIV rapid testing in a Veterans Affairs hospital ED setting: a 5-year sustainability evaluation.

    Science.gov (United States)

    Knapp, Herschel; Hagedorn, Hildi; Anaya, Henry D

    2014-08-01

    Routine HIV testing in primary care settings is now recommended in the United States. The US Department of Veterans Affairs (VA) has increased the number of patients tested for HIV, but overall HIV testing rates in VA remain low. A proven strategy for increasing such testing involves nurse-initiated HIV rapid testing (HIV RT). The purpose of this work was to use a mixed methodology approach to evaluate the 5-year sustainability of an intervention that implemented HIV RT in a VA emergency department setting in a large, urban VA medical center to reduce missed diagnostic and treatment opportunities in this vulnerable patient population. In-person semistructured interviews were conducted with providers and stakeholders. Interview notes were qualitatively coded for emerging themes. Quarterly testing rates were evaluated for a 5-year time span starting from the launch in July 2008. Findings indicate that HIV RT was sustained by the enthusiasm of 2 clinical champions who oversaw the registered nurses responsible for conducting the testing. The departure of the clinical champions was correlated with a substantial drop-off in testing. Findings also indicate potential strategies for improving sustainability including engaging senior leadership in the project, engaging line staff in the implementation planning from the start to increase ownership over the innovation, incorporating information into initial training explaining the importance of the innovation to quality patient care, providing ongoing training to maintain skills, and providing routine progress reports to staff to demonstrate the ongoing impact of their efforts. Published by Elsevier Inc.

  13. Electronic vending machines for dispensing rapid HIV self-testing kits: a case study.

    Science.gov (United States)

    Young, Sean D; Klausner, Jeffrey; Fynn, Risa; Bolan, Robert

    2014-02-01

    This short report evaluates the feasibility of using electronic vending machines for dispensing oral, fluid, rapid HIV self-testing kits in Los Angeles County. Feasibility criteria that needed to be addressed were defined as: (1) ability to find a manufacturer who would allow dispensing of HIV testing kits and could fit them to the dimensions of a vending machine, (2) ability to identify and address potential initial obstacles, trade-offs in choosing a machine location, and (3) ability to gain community approval for implementing this approach in a community setting. To address these issues, we contracted a vending machine company who could supply a customized, Internet-enabled machine that could dispense HIV kits and partnered with a local health center available to host the machine onsite and provide counseling to participants, if needed. Vending machines appear to be feasible technologies that can be used to distribute HIV testing kits.

  14. Rapid turnover of 2-LTR HIV-1 DNA during early stage of highly active antiretroviral therapy.

    Directory of Open Access Journals (Sweden)

    Weijun Zhu

    Full Text Available BACKGROUND: Despite prolonged treatment with highly active antiretroviral therapy (HAART, the infectious HIV-1 continues to replicate and resides latently in the resting memory CD4+ T lymphocytes, which blocks the eradication of HIV-1. The viral persistence of HIV-1 is mainly caused by its proviral DNA being either linear nonintegrated, circular nonintegrated, or integrated. Previous reports have largely focused on the dynamics of HIV-1 DNA from the samples collected with relatively long time intervals during the process of disease and HAART treatment, which may have missed the intricate changes during the intervals in early treatment. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we investigated the dynamics of HIV-1 DNA in patients during the early phase of HARRT treatment. Using optimized real time PCR, we observed significant changes in 2-LTR during the first 12-week of treatment, while total and integrated HIV-1 DNA remained stable. The doubling time and half-life of 2-LTR were not correlated with the baseline and the rate of changes in plasma viral load and various CD4+ T-cell populations. Longitudinal analyses on 2-LTR sequences and plasma lipopolysaccharide (LPS levels did not reveal any significant changes in the same treatment period. CONCLUSIONS/SIGNIFICANCE: Our study revealed the rapid changes in 2-LTR concentration in a relatively large number of patients during the early HAART treatment. The rapid changes indicate the rapid infusion and clearance of cells bearing 2-LTR in the peripheral blood. Those changes are not expected to be caused by the blocking of viral integration, as our study did not include the integrase inhibitor raltegravir. Our study helps better understand the dynamics of HIV-DNA and its potential role as a biomarker for the diseases and for the treatment efficacy of HAART.

  15. HIV rapid diagnostic testing by lay providers in a key population-led health service programme in Thailand.

    Science.gov (United States)

    Wongkanya, Rapeeporn; Pankam, Tippawan; Wolf, Shauna; Pattanachaiwit, Supanit; Jantarapakde, Jureeporn; Pengnongyang, Supabhorn; Thapwong, Prasopsuk; Udomjirasirichot, Apichat; Churattanakraisri, Yutthana; Prawepray, Nanthika; Paksornsit, Apiluk; Sitthipau, Thidadaow; Petchaithong, Sarayut; Jitsakulchaidejt, Raruay; Nookhai, Somboon; Lertpiriyasuwat, Cheewanan; Ongwandee, Sumet; Phanuphak, Praphan; Phanuphak, Nittaya

    2018-01-01

    Introduction:  Rapid diagnostic testing (RDT) for HIV has a quick turn-around time, which increases the proportion of people testing who receive their result. HIV RDT in Thailand has traditionally been performed only by medical technologists (MTs), which is a barrier to its being scaled up. We evaluated the performance of HIV RDT conducted by trained lay providers who were members of, or worked closely with, a group of men who have sex with men (MSM) and with transgender women (TG) communities, and compared it to tests conducted by MTs. Methods:  Lay providers received a 3-day intensive training course on how to perform a finger-prick blood collection and an HIV RDT as part of the Key Population-led Health Services (KPLHS) programme among MSM and TG. All the samples were tested by lay providers using Alere Determine HIV 1/2. HIV-reactive samples were confirmed by DoubleCheckGold Ultra HIV 1&2 and SD Bioline HIV 1/2. All HIV-positive and 10% of HIV-negative samples were re-tested by MTs using Serodia HIV 1/2. Results:  Of 1680 finger-prick blood samples collected and tested using HIV RDT by lay providers in six drop-in centres in Bangkok, Chiang Mai, Chonburi and Songkhla, 252 (15%) were HIV-positive. MTs re-tested these HIV-positive samples and 143 randomly selected HIV-negative samples with 100% concordant test results. Conclusion:  Lay providers in Thailand can be trained and empowered to perform HIV RDT as they were found to achieve comparable results in sample testing with MTs. Based on the task-shifting concept, this rapid HIV testing performed by lay providers as part of the KPLHS programme has great potential to enhance HIV prevention and treatment programmes among key at-risk populations.

  16. Broadly Neutralizing Antibody Responses in a Large Longitudinal Sub-Saharan HIV Primary Infection Cohort.

    Directory of Open Access Journals (Sweden)

    Elise Landais

    2016-01-01

    Full Text Available Broadly neutralizing antibodies (bnAbs are thought to be a critical component of a protective HIV vaccine. However, designing vaccines immunogens able to elicit bnAbs has proven unsuccessful to date. Understanding the correlates and immunological mechanisms leading to the development of bnAb responses during natural HIV infection is thus critical to the design of a protective vaccine. The IAVI Protocol C program investigates a large longitudinal cohort of primary HIV-1 infection in Eastern and South Africa. Development of neutralization was evaluated in 439 donors using a 6 cross-clade pseudo-virus panel predictive of neutralization breadth on larger panels. About 15% of individuals developed bnAb responses, essentially between year 2 and year 4 of infection. Statistical analyses revealed no influence of gender, age or geographical origin on the development of neutralization breadth. However, cross-clade neutralization strongly correlated with high viral load as well as with low CD4 T cell counts, subtype-C infection and HLA-A*03(- genotype. A correlation with high overall plasma IgG levels and anti-Env IgG binding titers was also found. The latter appeared not associated with higher affinity, suggesting a greater diversity of the anti-Env responses in broad neutralizers. Broadly neutralizing activity targeting glycan-dependent epitopes, largely the N332-glycan epitope region, was detected in nearly half of the broad neutralizers while CD4bs and gp41-MPER bnAb responses were only detected in very few individuals. Together the findings suggest that both viral and host factors are critical for the development of bnAbs and that the HIV Env N332-glycan supersite may be a favorable target for vaccine design.

  17. Antibody-dependent cellular cytotoxicity and neutralizing activity in sera of HIV-1-infected mothers and their children.

    Science.gov (United States)

    Broliden, K; Sievers, E; Tovo, P A; Moschese, V; Scarlatti, G; Broliden, P A; Fundaro, C; Rossi, P

    1993-01-01

    The prognostic and protective role of antibodies mediating cellular cytotoxicity (ADCC) and neutralization was evaluated in sera of HIV-1-infected mothers and their consecutively followed children. The presence and titres of ADCC mediating and/or neutralizing antibodies in maternal sera did not predict HIV-1 infection in their respective children. No significant difference in the sera from the children was seen when comparing the presence of neutralizing antibodies between the uninfected and infected children. Stratification of the infected group according to clinical status revealed differences. Only one of 24 AIDS patients had a high neutralizing titre against IIIB. Four patients had a very low titre and the remaining had no detectable neutralizing antibodies at all. In contrast, 10/17 infected non-AIDS children had neutralizing antibodies. Similarly, no significant difference was seen when comparing the presence of ADCC-mediating antibodies between the uninfected and the infected group of children. However, a significantly higher frequency of ADCC was seen in the seropositive non-AIDS children compared with the AIDS children. This study clearly shows that the presence of antibodies mediating ADCC and neutralization in infected children, 0-2 years old, is associated with a better clinical status and delayed disease progression. PMID:8324904

  18. Low prevalence of antibodies and other plasma factors binding to CC chemokines and IL-2 in HIV-positive patients

    DEFF Research Database (Denmark)

    Meyer, C N; Svenson, M; Larsen, Carsten Schade

    2000-01-01

    Neutralizing cytokine antibodies are found in healthy and diseased individuals, including patients treated with recombinant cytokines. Identification of CCR-5 as co-receptor for HIV has focused interest on CC chemokines and their potential therapeutic use. Chemokine-binding components in plasma...

  19. Involvement of lymphocyte function-associated antigen-1 (LFA-1) in HIV infection: inhibition by monoclonal antibody

    DEFF Research Database (Denmark)

    Hansen, J E; Nielsen, C; Mathiesen, Lars Reinhardt

    1991-01-01

    Monoclonal antibodies (MAbs) against the alpha- and beta-chain of lymphocyte-associated antigen-1 (LFA-1) were examined for inhibition of HIV-1 infection in vitro. Infection of the T cell line MT4 and the monocytic cell line U937 by isolates HTLVIIIB and SSI-002, respectively was inhibited...

  20. Human antibody response to a strain-specific HIV-1 gp120 epitope associated with cell fusion inhibition

    NARCIS (Netherlands)

    Goudsmit, J.; Boucher, C. A.; Meloen, R. H.; Epstein, L. G.; Smit, L.; van der Hoek, L.; Bakker, M.

    1988-01-01

    PEPSCAN analysis, performed using 536 overlapping nonapeptides derived from the HTLV-III B nucleotide sequence of the region encoding the external envelope protein of 120 kDa (gp120), identified in the V3 region of gp120 a major binding site for antibodies of HIV-1-infected humans. The minimal amino

  1. Global panel of HIV-1 Env reference strains for standardized assessments of vaccine-elicited neutralizing antibodies.

    Science.gov (United States)

    deCamp, Allan; Hraber, Peter; Bailer, Robert T; Seaman, Michael S; Ochsenbauer, Christina; Kappes, John; Gottardo, Raphael; Edlefsen, Paul; Self, Steve; Tang, Haili; Greene, Kelli; Gao, Hongmei; Daniell, Xiaoju; Sarzotti-Kelsoe, Marcella; Gorny, Miroslaw K; Zolla-Pazner, Susan; LaBranche, Celia C; Mascola, John R; Korber, Bette T; Montefiori, David C

    2014-03-01

    Standardized assessments of HIV-1 vaccine-elicited neutralizing antibody responses are complicated by the genetic and antigenic variability of the viral envelope glycoproteins (Envs). To address these issues, suitable reference strains are needed that are representative of the global epidemic. Several panels have been recommended previously, but no clear answers have been available on how many and which strains are best suited for this purpose. We used a statistical model selection method to identify a global panel of reference Env clones from among 219 Env-pseudotyped viruses assayed in TZM-bl cells with sera from 205 HIV-1-infected individuals. The Envs and sera were sampled globally from diverse geographic locations and represented all major genetic subtypes and circulating recombinant forms of the virus. Assays with a panel size of only nine viruses adequately represented the spectrum of HIV-1 serum neutralizing activity seen with the larger panel of 219 viruses. An optimal panel of nine viruses was selected and augmented with three additional viruses for greater genetic and antigenic coverage. The spectrum of HIV-1 serum neutralizing activity seen with the final 12-virus panel closely approximated the activity seen with subtype-matched viruses. Moreover, the final panel was highly sensitive for detection of many of the known broadly neutralizing antibodies. For broader assay applications, all 12 Env clones were converted to infectious molecular clones using a proviral backbone carrying a Renilla luciferase reporter gene (Env.IMC.LucR viruses). This global panel should facilitate highly standardized assessments of vaccine-elicited neutralizing antibodies across multiple HIV-1 vaccine platforms in different parts of the world. An effective HIV-1 vaccine will need to overcome the extraordinary genetic variability of the virus, where most variation occurs in the viral envelope glycoproteins that are the sole targets for neutralizing antibodies. Efforts to elicit

  2. Seroprevalence of Toxoplasma gondii IgG antibody in HIV-infected patients at the Lagos University Teaching Hospital

    Directory of Open Access Journals (Sweden)

    Osunkalu VO

    2011-09-01

    Full Text Available Vincent O Osunkalu1, Sulaimon A Akanmu1, Nkolika J Ofomah1, Igwebuike V Onyiaorah2, Adewumi A Adediran1, Ralph O Akinde3, Ifeanyi A Onwuezobe41Department of Haematology and Blood Transfusion, College of Medicine Idi-Araba, Lagos, Nigeria; 2Department of Histopathology, Nnamdi Azikiwe University, Nnewi Campus, Lagos, Nigeria; 3Department of Morbid Anatomy, College of Medicine Idi-Araba, Lagos, Nigeria; 4Department of Microbiology, University of Calabar, NigeriaBackground: Toxoplasmosis is caused by infection with a ubiquitous intracellular protozoan parasite, Toxoplasma gondii. With the advent of the HIV pandemic in Nigeria, toxoplasmic encephalitis has become one of the more frequent opportunistic infections and the most commonly implicated cause of focal brain lesions complicating the course of AIDS.Objectives: This study was conducted to compare the pattern of seroprevalence of T. gondii (Toxo-IgG antibodies among HIV-infected persons presenting with neurological complications and those without.Materials and methods: Plasma specimens collected from 380 subjects were tested for Toxo-IgG antibodies by enzyme immunoassay technique and CD4 estimation by flow cytometry. Close-ended questionnaires were applied to all respondents to collect relevant data, with ethical approval from the hospital ethical committee. Plasma was obtained from two study groups comprising 300 HIV-positive respondents without neurological presentations, and 80 HIV-positive respondents with neurological complications.Results: Seroprevalence of Toxo-IgG antibodies was 58% in the HIV-positive study group without neurological complications (of these, 79.2% were males and 38.5% were females and 40% in the study group with neurological complications (46.2% of these were males and 28.6% were females. The overall seroprevalence of Toxo-IgG antibodies among the HIV-positive respondents (with and without neurological complications was 54.2% (206 of 380. Seroprevalence of Toxo

  3. Will gay and bisexually active men at high risk of infection use over-the-counter rapid HIV tests to screen sexual partners?

    Science.gov (United States)

    Carballo-Diéguez, Alex; Frasca, Timothy; Dolezal, Curtis; Balan, Ivan

    2012-01-01

    The Food and Drug Administration may license OraQuick™, a rapid HIV test, for over-the-counter (OTC) sale. This study investigated whether HIV-uninfected, non-monogamous, gay and bisexual men who never or rarely use condoms would use the test with partners as a harm-reduction approach. Sixty participants responded to two computer-assisted self-interviews, underwent an in-depth interview, and chose whether to test themselves with OraQuick. Over 80% of the men said they would use the kit to test sexual partners or themselves if it became available OTC. Most participants understood that antibody tests have a window period in which the virus is undetectable, yet saw advantages to using the test to screen partners; 74% tested themselves in our offices. Participants offered several possible strategies to introduce the home-test idea to partners, frequently endorsed mutual testing, and highlighted that home testing could stimulate greater honesty in serostatus disclosure. Participants drew distinctions between testing regular versus occasional partners. Non-monogamous men who have sex with men, who never or rarely use condoms, may nevertheless seek to avoid HIV. Technologies that do not interfere with sexual pleasure are likely to be used when available. Studies are needed to evaluate the advantages and disadvantages of using OTC rapid HIV tests as one additional harm-reduction tool.

  4. Pregnancy does not affect HIV incidence test results obtained using the BED capture enzyme immunoassay or an antibody avidity assay.

    Directory of Open Access Journals (Sweden)

    Oliver Laeyendecker

    2010-10-01

    Full Text Available Accurate incidence estimates are needed for surveillance of the HIV epidemic. HIV surveillance occurs at maternal-child health clinics, but it is not known if pregnancy affects HIV incidence testing.We used the BED capture immunoassay (BED and an antibody avidity assay to test longitudinal samples from 51 HIV-infected Ugandan women infected with subtype A, C, D and intersubtype recombinant HIV who were enrolled in the HIVNET 012 trial (37 baseline samples collected near the time of delivery and 135 follow-up samples collected 3, 4 or 5 years later. Nineteen of 51 women were also pregnant at the time of one or more of the follow-up visits. The BED assay was performed according to the manufacturer's instructions. The avidity assay was performed using a Genetic Systems HIV-1/HIV-2 + O EIA using 0.1M diethylamine as the chaotropic agent.During the HIVNET 012 follow-up study, there was no difference in normalized optical density values (OD-n obtained with the BED assay or in the avidity test results (% when women were pregnant (n = 20 results compared to those obtained when women were not pregnant (n = 115; for BED: p = 0.9, generalized estimating equations model; for avidity: p = 0.7, Wilcoxon rank sum. In addition, BED and avidity results were almost exactly the same in longitudinal samples from the 18 women who were pregnant at only one study visit during the follow-up study (p = 0.6, paired t-test.These results from 51 Ugandan women suggest that any changes in the antibody response to HIV infection that occur during pregnancy are not sufficient to alter results obtained with the BED and avidity assays. Confirmation with larger studies and with other HIV subtypes is needed.

  5. Analysis of memory B cell responses and isolation of novel monoclonal antibodies with neutralizing breadth from HIV-1-infected individuals.

    Directory of Open Access Journals (Sweden)

    Davide Corti

    2010-01-01

    Full Text Available The isolation of human monoclonal antibodies (mAbs that neutralize a broad spectrum of primary HIV-1 isolates and the characterization of the human neutralizing antibody B cell response to HIV-1 infection are important goals that are central to the design of an effective antibody-based vaccine.We immortalized IgG(+ memory B cells from individuals infected with diverse clades of HIV-1 and selected on the basis of plasma neutralization profiles that were cross-clade and relatively potent. Culture supernatants were screened using various recombinant forms of the envelope glycoproteins (Env in multiple parallel assays. We isolated 58 mAbs that were mapped to different Env surfaces, most of which showed neutralizing activity. One mAb in particular (HJ16 specific for a novel epitope proximal to the CD4 binding site on gp120 selectively neutralized a multi-clade panel of Tier-2 HIV-1 pseudoviruses, and demonstrated reactivity that was comparable in breadth, but distinct in neutralization specificity, to that of the other CD4 binding site-specific neutralizing mAb b12. A second mAb (HGN194 bound a conserved epitope in the V3 crown and neutralized all Tier-1 and a proportion of Tier-2 pseudoviruses tested, irrespective of clade. A third mAb (HK20 with broad neutralizing activity, particularly as a Fab fragment, recognized a highly conserved epitope in the HR-1 region of gp41, but showed striking assay-dependent selectivity in its activity.This study reveals that by using appropriate screening methods, a large proportion of memory B cells can be isolated that produce mAbs with HIV-1 neutralizing activity. Three of these mAbs show unusual breadth of neutralization and therefore add to the current panel of HIV-1 neutralizing antibodies with potential for passive protection and template-based vaccine design.

  6. Performance of rapid tests and algorithms for HIV screening in Abidjan, Ivory Coast.

    Science.gov (United States)

    Loukou, Y G; Cabran, M A; Yessé, Zinzendorf Nanga; Adouko, B M O; Lathro, S J; Agbessi-Kouassi, K B T

    2014-01-01

    Seven rapid diagnosis tests (RDTs) of HIV were evaluated by a panel group who collected serum samples from patients in Abidjan (HIV-1 = 203, HIV-2 = 25, HIV-dual = 25, HIV = 305). Kit performances were recorded after the reference techniques (enzyme-linked immunosorbent assay). The following RDTs showed a sensitivity of 100% and a specificity higher than 99%: Determine, Oraquick, SD Bioline, BCP, and Stat-Pak. These kits were used to establish infection screening strategies. The combination with 2 or 3 of these tests in series or parallel algorithms showed that series combinations with 2 tests (Oraquick and Bioline) and 3 tests (Determine, BCP, and Stat-Pak) gave the best performances (sensitivity, specificity, positive predictive value, and negative predictive value of 100%). However, the combination with 2 tests appeared to be more onerous than the combination with 3 tests. The combination with Determine, BCP, and Stat-Pak tests serving as a tiebreaker could be an alternative to the HIV/AIDS serological screening in Abidjan.

  7. A Rapid Zika Diagnostic Assay to Measure Neutralizing Antibodies in Patients

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    Chao Shan

    2017-03-01

    Full Text Available The potential association of microcephaly and other congenital abnormalities with Zika virus (ZIKV infection during pregnancy underlines the critical need for a rapid and accurate diagnosis. Due to the short duration of ZIKV viremia in infected patients, a serologic assay that detects antibody responses to viral infection plays an essential role in diagnosing patient specimens. The current serologic diagnosis of ZIKV infection relies heavily on the labor-intensive Plaque Reduction Neutralization Test (PRNT that requires more than one-week turnaround time and represents a major bottleneck for patient diagnosis. To overcome this limitation, we have developed a high-throughput assay for ZIKV and dengue virus (DENV diagnosis that can attain the “gold standard” of the current PRNT assay. The new assay is homogeneous and utilizes luciferase viruses to quantify the neutralizing antibody titers in a 96-well format. Using 91 human specimens, we showed that the reporter diagnostic assay has a higher dynamic range and maintains the relative specificity of the traditional PRNT assay. Besides the improvement of assay throughput, the reporter virus technology has also shortened the turnaround time to less than two days. Collectively, our results suggest that, along with the viral RT-PCR assay, the reporter virus-based serologic assay could be potentially used as the first-line test for clinical diagnosis of ZIKV infection as well as for vaccine clinical trials.

  8. Merkel cell polyomavirus IgG antibody levels are associated with progression to AIDS among HIV-infected individuals.

    Science.gov (United States)

    Vahabpour, Rouhollah; Nasimi, Maryam; Naderi, Niloofar; Salehi-Vaziri, Mostafa; Mohajel, Nasir; Sadeghi, Farzin; Keyvani, Hossein; Monavari, Seyed Hamidreza

    2017-04-01

    The association of Merkel cell polyomavirus (MCP y V) with Merkel cell carcinoma (MCC) in immunocompromised individuals has been revealed in a number of surveys. The study of MCP y V specific antibody titers and viral loads in such patients has a great attraction for research groups interested in viral reactivation. In this cross-sectional study to evaluate MCP y V antibody titer, DNA prevalence and viral load in peripheral blood mononuclear cells (PBMCs), we examined 205 HIV-1 infected patients and 100 un-infected controls. The HIV-1 infected patients divided into two groups (HIV/AIDS and non-AIDS) according to their CD4 status. Total IgG antibody titer against MCP y V was analyzed by virus like particle (VLP)-based enzyme linked immunosorbent assay (ELISA). Presence of MCP y V-DNA in subject's PBMCs was examined by quantitative real-time PCR assay. Levels of anti-MCP y V IgG in HIV/AIDS patients were significantly higher than those in non-AIDS HIV-infected and control subjects (p value = <0.001). The prevalence rate of MCP y V-DNA in PBMCs of HIV/AIDS, non-AIDS HIV-infected and un-infected controls were 17%, 16%, and 14% respectively. The MCP y V viral load among the groups ranged between 0.15 to 2.9 copies/10 3 cells (median, 1.9 copies/10 3 cells), with no significant difference between the studied populations (p value = 0.3).

  9. Persistence of hepatitis A virus antibodies after primary immunization and response to revaccination in children and adolescents with perinatal HIV exposure

    Science.gov (United States)

    Gouvêa, Aída de Fátima Thomé Barbosa; Pinto, Maria Isabel de Moraes; Miyamoto, Maristela; Machado, Daisy Maria; Pessoa, Silvana Duarte; do Carmo, Fabiana Bononi; Beltrão, Suênia Cordeiro de Vasconcelos; Succi, Regina Célia de Menezes

    2015-01-01

    OBJECTIVE: To assess possible factors associated with the loss of antibodies to hepatitis A 7 years after the primary immunization in children of HIV-infected mothers and the response to revaccination in patients seronegative for hepatitis A. METHODS: Quantification of HAV antibodies by electrochemiluminescence was performed in 39 adolescents followed up at the Pediatric Aids Clinic of Federal University of São Paulo (Unifesp): 29 HIV-infected (HIV group) (median age: 12.8 years) and 10 HIV-exposed but non-infected (ENI group) (median age: 13.4 years). All of them received two doses of HAV vaccine (Havrix(r)) in 2002. RESULTS: The median age at primary immunization (PI) was 5.4 years for HIV group and 6.5 years for ENI group. All children, from both groups, had antibodies to HAV >20 mIU/mL after PI. Seven years later, the ENI group showed a median concentration of antibodies = 253.5 mIU/mL, while the HIV group = 113.0 mIU/mL (Mann-Whitney test, p=0.085). All ENI group and 23/29 (79.3%) from HIV group mantained HAV antibodies 7 years after PI. The levels of hepatitis A antibodies in the primary vaccination were the only factor independently associated with maintaining these antibodies for 7 years. The group that lost HAV seropositivity was revaccinated and 83.3% (5/6) responded with antibodies >20 mUI/mL. CONCLUSIONS: The antibodies levels acquired in the primary vaccination in the HIV group were the main factor associated with antibodies loss after HAV immunization. PMID:25918013

  10. Direct, Specific and Rapid Detection of Staphylococcal Proteins and Exotoxins Using a Multiplex Antibody Microarray.

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    Bettina Stieber

    Full Text Available S. aureus is a pathogen in humans and animals that harbors a wide variety of virulence factors and resistance genes. This bacterium can cause a wide range of mild to life-threatening diseases. In the latter case, fast diagnostic procedures are important. In routine diagnostic laboratories, several genotypic and phenotypic methods are available to identify S. aureus strains and determine their resistances. However, there is a demand for multiplex routine diagnostic tests to directly detect staphylococcal toxins and proteins.In this study, an antibody microarray based assay was established and validated for the rapid detection of staphylococcal markers and exotoxins. The following targets were included: staphylococcal protein A, penicillin binding protein 2a, alpha- and beta-hemolysins, Panton Valentine leukocidin, toxic shock syndrome toxin, enterotoxins A and B as well as staphylokinase. All were detected simultaneously within a single experiment, starting from a clonal culture on standard media. The detection of bound proteins was performed using a new fluorescence reading device for microarrays.110 reference strains and clinical isolates were analyzed using this assay, with a DNA microarray for genotypic characterization performed in parallel. The results showed a general high concordance of genotypic and phenotypic data. However, genotypic analysis found the hla gene present in all S. aureus isolates but its expression under given conditions depended on the clonal complex affiliation of the actual isolate.The multiplex antibody assay described herein allowed a rapid and reliable detection of clinically relevant staphylococcal toxins as well as resistance- and species-specific markers.

  11. HIV Rapid Testing in a VA Emergency Department Setting: Cost Analysis at 5 Years.

    Science.gov (United States)

    Knapp, Herschel; Chan, Kee

    2015-07-01

    To conduct a comprehensive cost-minimization analysis to comprehend the financial attributes of the first 5 years of an implementation wherein emergency department (ED) registered nurses administered HIV oral rapid tests to patients. A health science research implementation team coordinated with ED stakeholders and staff to provide training, implementation guidelines, and support to launch ED registered nurse-administered HIV oral rapid testing. Deidentified quantitative data were gathered from the electronic medical records detailing quarterly HIV rapid test rates in the ED setting spanning the first 5 years. Comprehensive cost analyses were conducted to evaluate the financial impact of this implementation. At 5 years, a total of 2,620 tests were conducted with a quarterly mean of 131 ± 81. Despite quarterly variability in testing rates, regression analysis revealed an average increase of 3.58 tests per quarter. Over the course of this implementation, Veterans Health Administration policy transitioned from written to verbal consent for HIV testing, serving to reduce the time and cost(s) associated with the testing process. Our data indicated salient health outcome benefits for patients with respect to the potential for earlier detection, and associated long-run cost savings. Copyright © 2015. Published by Elsevier Inc.

  12. Rapid polyclonal desensitization with antibodies to IgE and FcεRIα.

    Science.gov (United States)

    Khodoun, Marat V; Kucuk, Zeynep Yesim; Strait, Richard T; Krishnamurthy, Durga; Janek, Kevin; Lewkowich, Ian; Morris, Suzanne C; Finkelman, Fred D

    2013-06-01

    Rapid desensitization, a procedure in which persons allergic to an antigen are treated at short intervals with increasing doses of that antigen until they tolerate a large dose, is an effective, but risky, way to induce temporary tolerance. We wanted to determine whether this approach can be adapted to suppress all IgE-mediated allergies in mice by injecting serially increasing doses of monoclonal antibodies (mAbs) to IgE or FcεRIα. Active and passive models of antigen- and anti-IgE mAb-induced IgE-mediated anaphylaxis were used. Mice were desensitized with serially increasing doses of anti-IgE mAb, anti-FcεRIα mAb, or antigen. Development of shock (hypothermia), histamine and mast cell protease release, cytokine secretion, calcium flux, and changes in cell number and FcεRI and IgE expression were evaluated. Rapid desensitization with anti-IgE mAb suppressed IgE-mediated immediate hypersensitivity; however, some mice developed mild anaphylaxis during desensitization. Rapid desensitization with anti-FcεRIα mAb that only binds FcεRI that is not occupied by IgE suppressed both active and passive IgE-mediated anaphylaxis without inducing disease. It quickly, but temporarily, suppressed IgE-mediated anaphylaxis by decreasing mast cell signaling through FcεRI, then slowly induced longer lasting mast cell unresponsiveness by removing membrane FcεRI. Rapid desensitization with anti-FcεRIα mAb was safer and longer lasting than rapid desensitization with antigen. A rapid desensitization approach with anti-FcεRIα mAb safely desensitizes mice to IgE-mediated anaphylaxis by inducing mast cell anergy and later removing all mast cell IgE. Rapid desensitization with an anti-human FcεRIα mAb may be able to prevent human IgE-mediated anaphylaxis. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  13. HIV-1 tat promotes integrin-mediated HIV transmission to dendritic cells by binding Env spikes and competes neutralization by anti-HIV antibodies.

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    Paolo Monini

    Full Text Available Use of Env in HIV vaccine development has been disappointing. Here we show that, in the presence of a biologically active Tat subunit vaccine, a trimeric Env protein prevents in monkeys virus spread from the portal of entry to regional lymph nodes. This appears to be due to specific interactions between Tat and Env spikes that form a novel virus entry complex favoring R5 or X4 virus entry and productive infection of dendritic cells (DCs via an integrin-mediated pathway. These Tat effects do not require Tat-transactivation activity and are blocked by anti-integrin antibodies (Abs. Productive DC infection promoted by Tat is associated with a highly efficient virus transmission to T cells. In the Tat/Env complex the cysteine-rich region of Tat engages the Env V3 loop, whereas the Tat RGD sequence remains free and directs the virus to integrins present on DCs. V2 loop deletion, which unshields the CCR5 binding region of Env, increases Tat/Env complex stability. Of note, binding of Tat to Env abolishes neutralization of Env entry or infection of DCs by anti-HIV sera lacking anti-Tat Abs, which are seldom present in natural infection. This is reversed, and neutralization further enhanced, by HIV sera containing anti-Tat Abs such as those from asymptomatic or Tat-vaccinated patients, or by sera from the Tat/Env vaccinated monkeys. Thus, both anti-Tat and anti-Env Abs are required for efficient HIV neutralization. These data suggest that the Tat/Env interaction increases HIV acquisition and spreading, as a mechanism evolved by the virus to escape anti-Env neutralizing Abs. This may explain the low effectiveness of Env-based vaccines, which are also unlikely to elicit Abs against new Env epitopes exposed by the Tat/Env interaction. As Tat also binds Envs from different clades, new vaccine strategies should exploit the Tat/Env interaction for both preventative and therapeutic interventions.

  14. Broad and potent HIV-1 neutralization by a human antibody that binds the gp41-gp120 interface

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    Huang, Jinghe; Kang, Byong H.; Pancera, Marie; Lee, Jeong Hyun; Tong, Tommy; Feng, Yu; Imamichi, Hiromi; Georgiev, Ivelin S.; Chuang, Gwo-Yu; Druz, Aliaksandr; Doria-Rose, Nicole A.; Laub, Leo; Sliepen, Kwinten; van Gils, Marit J.; de la Peña, Alba Torrents; Derking, Ronald; Klasse, Per-Johan; Migueles, Stephen A.; Bailer, Robert T.; Alam, Munir; Pugach, Pavel; Haynes, Barton F.; Wyatt, Richard T.; Sanders, Rogier W.; Binley, James M.; Ward, Andrew B.; Mascola, John R.; Kwong, Peter D.; Connors, Mark [NIH

    2015-10-15

    The isolation of human monoclonal antibodies is providing important insights into the specificities that underlie broad neutralization of HIV-1 (reviewed in ref. 1). Here we report a broad and extremely potent HIV-specific monoclonal antibody, termed 35O22, which binds a novel HIV-1 envelope glycoprotein (Env) epitope. 35O22 neutralized 62% of 181 pseudoviruses with a half-maximum inhibitory concentration (IC50) <50 μg ml-1. The median IC50 of neutralized viruses was 0.033 μg ml-1, among the most potent thus far described. 35O22 did not bind monomeric forms of Env tested, but did bind the trimeric BG505 SOSIP.664. Mutagenesis and a reconstruction by negative-stain electron microscopy of the Fab in complex with trimer revealed that it bound to a conserved epitope, which stretched across gp120 and gp41. The specificity of 35O22 represents a novel site of vulnerability on HIV Env, which serum analysis indicates to be commonly elicited by natural infection. Binding to this new site of vulnerability may thus be an important complement to current monoclonal-antibody-based approaches to immunotherapies, prophylaxis and vaccine design.

  15. High prevalence of antibodies against hepatitis E virus in HIV-infected patients with unexplained liver disease.

    Science.gov (United States)

    Merchante, Nicolás; Parra-Sánchez, Manuel; Rivero-Juárez, Antonio; Cifuentes, Celia; Camacho, Ángela; Macías, Juan; Martínez-Dueñas, Loreto; Pérez-Navarro, Elisabet; Rivero, Antonio; Pineda, Juan A

    2015-10-01

    To look for evidence of hepatitis E virus (HEV) exposure in HIV-infected patients with unexplained elevations of liver stiffness (LS). Case-control study conducted in 31 HIV-infected patients with unexplained elevations of LS and in 31 HIV-controls with normal LS, matched by age, sex and CD4 cell-counts. Serum HEV antibodies were tested by two ELISA procedures and by Immunoblot. We defined exposure to HEV as the detection of serum HEV antibodies by at least one of the two ELISA assays, provided that it was confirmed by Immunoblot. A real-time PCR RNA assay was conducted in all plasma samples to identify subjects with active HEV infection. Exposure to HEV was demonstrated, according to the criteria used in this study, in 9 (29%) of the cases, whereas it was shown in 5 (16%) of the controls (p=.3). Serum HEV RNA was detected in none of the controls and in only in one case. This patient had a documented chronic hepatitis E with progression to cirrhosis. HEV antibodies are frequently found in HIV-infected patients with unexplained liver disease. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  16. Factors associated with willingness to accept oral fluid HIV rapid testing among most-at-risk populations in China.

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    Huanmiao Xun

    Full Text Available The availability of oral fluid HIV rapid testing provides an approach that may have the potential to expand HIV testing in China, especially among most-a-risk populations. There are few investigations about the acceptability of oral fluid HIV testing among most-at-risk populations in China.A cross-sectional study with men who have sex with men (MSM, female sex workers (FSW and voluntary counseling and testing (VCT clients was conducted in three cities of Shandong province, China from 2011 to 2012. Data were collected by face-to-face questionnaire.About 71% of participants were willing to accept the oral fluid HIV rapid testing, and home HIV testing was independently associated with acceptability of the new testing method among MSM, FSW and VCT clients (AOR of 4.46, 3.19 and 5.74, respectively. Independent predictors of oral fluid HIV rapid testing acceptability among MSM were having ever taken an oral fluid HIV rapid test (AOR= 15.25, having ever taken an HIV test (AOR= 2.07, and education level (AOR= 1.74. Engagement in HIV-related risk behaviors (AOR= 1.68 was an independent predictor of acceptability for FSW. Having taken an HIV test (AOR= 2.85 was an independent predictor of acceptability for VCT clients. The primary concern about the oral fluid HIV testing was accuracy. The median price they would pay for the testing ranged from 4.8 to 8.1 U.S. dollars.High acceptability of oral fluid HIV rapid testing was shown among most-at-risk populations. Findings provide support for oral rapid HIV testing as another HIV prevention tool, and provide a backdrop for the implementation of HIV home testing in the near future. Appropriate pricing and increased public education through awareness campaigns that address concerns about the accuracy and safety of the oral fluid HIV rapid testing may help increase acceptability and use among most-at-risk populations in China.

  17. Basis and Statistical Design of the Passive HIV-1 Antibody Mediated Prevention (AMP) Test-of-Concept Efficacy Trials.

    Science.gov (United States)

    Gilbert, Peter B; Juraska, Michal; deCamp, Allan C; Karuna, Shelly; Edupuganti, Srilatha; Mgodi, Nyaradzo; Donnell, Deborah J; Bentley, Carter; Sista, Nirupama; Andrew, Philip; Isaacs, Abby; Huang, Yunda; Zhang, Lily; Capparelli, Edmund; Kochar, Nidhi; Wang, Jing; Eshleman, Susan H; Mayer, Kenneth H; Magaret, Craig A; Hural, John; Kublin, James G; Gray, Glenda; Montefiori, David C; Gomez, Margarita M; Burns, David N; McElrath, Julie; Ledgerwood, Julie; Graham, Barney S; Mascola, John R; Cohen, Myron; Corey, Lawrence

    2017-01-01

    Anti-HIV-1 broadly neutralizing antibodies (bnAbs) have been developed as potential agents for prevention of HIV-1 infection. The HIV Vaccine Trials Network and the HIV Prevention Trials Network are conducting the Antibody Mediated Prevention (AMP) trials to assess whether, and how, intravenous infusion of the anti-CD4 binding site bnAb, VRC01, prevents HIV-1 infection. These are the first test-of-concept studies to assess HIV-1 bnAb prevention efficacy in humans. The AMP trials are two parallel phase 2b HIV-1 prevention efficacy trials conducted in two cohorts: 2700 HIV-uninfected men and transgender persons who have sex with men in the United States, Peru, Brazil, and Switzerland; and 1500 HIV-uninfected sexually active women in seven countries in sub-Saharan Africa. Participants are randomized 1:1:1 to receive an intravenous infusion of 10 mg/kg VRC01, 30 mg/kg VRC01, or a control preparation every 8 weeks for a total of 10 infusions. Each trial is designed (1) to assess overall prevention efficacy (PE) pooled over the two VRC01 dose groups vs. control and (2) to assess VRC01 dose and laboratory markers as correlates of protection (CoPs) against overall and genotype- and phenotype-specific infection. Each AMP trial is designed to have 90% power to detect PE > 0% if PE is ≥ 60%. The AMP trials are also designed to identify VRC01 properties (i.e., concentration and effector functions) that correlate with protection and to provide insight into mechanistic CoPs. CoPs are assessed using data from breakthrough HIV-1 infections, including genetic sequences and sensitivities to VRC01-mediated neutralization and Fc effector functions. The AMP trials test whether VRC01 can prevent HIV-1 infection in two study populations. If affirmative, they will provide information for estimating the optimal dosage of VRC01 (or subsequent derivatives) and identify threshold levels of neutralization and Fc effector functions associated with high-level protection, setting a benchmark

  18. [Introduction of rapid syphilis and HIV testing in prenatal care in Colombia: qualitative analysis].

    Science.gov (United States)

    Ochoa-Manjarrés, María Teresa; Gaitán-Duarte, Hernando Guillermo; Caicedo, Sidia; Gómez, Berta; Pérez, Freddy

    2016-12-01

    Interpret perceptions of Colombian health professionals concerning factors that obstruct and facilitate the introduction of rapid syphilis and HIV testing in prenatal care services. A qualitative study based on semi-structured interviews was carried out. A convenience sample was selected with 37 participants, who included health professionals involved in prenatal care services, programs for pregnant women, clinical laboratories, and directors of health care units or centers, as well as representatives from regional departments and the Ministry of Health. Colombia does not do widespread screening with rapid syphilis and HIV tests in prenatal care. The professionals interviewed stated they did not have prior experience in the use of rapid tests-except for laboratory staff-or in the course of action in response to a positive result. The insurance system hinders access to timely diagnosis and treatment. Health authorities perceive a need to review existing standards, strengthen the first level of care, and promote comprehensive prenatal care starting with contracts between insurers and health service institutional providers. Participants recommended staff training and integration between health-policymaking and academic entities for updating training programs. The market approach and the characteristics of the Colombian health system constitute the main barriers to implementation of rapid testing as a strategy for elimination of mother-to-child transmission of syphilis and HIV. Measures identified include making changes in contracts between insurers and health service institutional providers, adapting the timing and duration of prenatal care procedures, and training physicians and nurses involved in prenatal care.

  19. Characterization of a Large Panel of Rabbit Monoclonal Antibodies against HIV-1 gp120 and Isolation of Novel Neutralizing Antibodies against the V3 Loop.

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    Yali Qin

    Full Text Available We recently reported the induction of potent, cross-clade neutralizing antibodies (nAbs against Human Immunodeficiency Virus type-1 (HIV-1 in rabbits using gp120 based on an M-group consensus sequence. To better characterize these antibodies, 93 hybridomas were generated, which represent the largest panel of monoclonal antibodies (mAbs ever generated from a vaccinated rabbit. The single most frequently recognized epitope of the isolated mAbs was at the very C-terminal end of the protein (APTKAKRRVVEREKR, followed by the V3 loop. A total of seven anti-V3 loop mAbs were isolated, two of which (10A3 and 10A37 exhibited neutralizing activity. In contrast to 10A3 and most other anti-V3 loop nAbs, 10A37 was atypical with its epitope positioned more towards the C-terminal half of the loop. To our knowledge, 10A37 is the most potent and broadly neutralizing anti-V3 loop mAb induced by vaccination. Interestingly, all seven anti-V3 loop mAbs competed with PGT121, suggesting a possibility that early induction of potent anti-V3 loop antibodies could prevent induction of more broadly neutralizing PGT121-like antibodies that target the conserved base of the V3 loop stem.

  20. [Persistence of hepatitis A virus antibodies after primary immunization and response to revaccination in children and adolescents with perinatal HIV exposure].

    Science.gov (United States)

    Gouvêa, Aída de Fátima Thomé Barbosa; Pinto, Maria Isabel de Moraes; Miyamoto, Maristela; Machado, Daisy Maria; Pessoa, Silvana Duarte; Carmo, Fabiana Bononi do; Beltrão, Suênia Cordeiro de Vasconcelos; Succi, Regina Célia de Menezes

    2015-01-01

    To assess possible factors associated with the loss of antibodies to hepatitis A 7 years after the primary immunization in children of HIV-infected mothers and the response to revaccination in patients seronegative for hepatitis A. Quantification of HAV antibodies by electrochemiluminescence was performed in 39 adolescents followed up at the Pediatric Aids Clinic of Federal University of São Paulo (Unifesp): 29 HIV-infected (HIVgroup) (median age: 12.8 years) and 10 HIV-exposed but non-infected (ENI group) (median age: 13.4 years). All of them received two doses of HAV vaccine (Havrix(®)) in 2002. The median age at primary immunization (PI) was 5.4 years for HIV group and 6.5 years for ENI group. All children, from both groups, had antibodies to HAV >20 mIU/mL after PI. Seven years later, the ENI group showed a median concentration of antibodies = 253.5 mIU/mL, while the HIV group = 113.0 mIU/mL (Mann-Whitney test, p=0.085). All ENI group and 23/29 (79.3%) from HIV group mantained HAV antibodies 7 years after PI. The levels of hepatitis A antibodies in the primary vaccination were the only factor independently associated with maintaining these antibodies for 7 years. The group that lost HAV seropositivity was revaccinated and 83.3% (5/6) responded with antibodies >20 mUI/mL. The antibodies levels acquired in the primary vaccination in the HIV group were the main factor associated with antibodies loss after HAV immunization. Copyright © 2015 Associação de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

  1. The evaluation of a rapid in situ HIV confirmation test in a programme with a high failure rate of the WHO HIV two-test diagnostic algorithm.

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    Derryck B Klarkowski

    Full Text Available BACKGROUND: Concerns about false-positive HIV results led to a review of testing procedures used in a Médecins Sans Frontières (MSF HIV programme in Bukavu, eastern Democratic Republic of Congo. In addition to the WHO HIV rapid diagnostic test algorithm (RDT (two positive RDTs alone for HIV diagnosis used in voluntary counselling and testing (VCT sites we evaluated in situ a practical field-based confirmation test against western blot WB. In addition, we aimed to determine the false-positive rate of the WHO two-test algorithm compared with our adapted protocol including confirmation testing, and whether weakly reactive compared with strongly reactive rapid test results were more likely to be false positives. METHODOLOGY/PRINCIPAL FINDINGS: 2864 clients presenting to MSF VCT centres in Bukavu during January to May 2006 were tested using Determine HIV-1/2 and UniGold HIV rapid tests in parallel by nurse counsellors. Plasma samples on 229 clients confirmed as double RDT positive by laboratory retesting were further tested using both WB and the Orgenics Immunocomb Combfirm HIV confirmation test (OIC-HIV. Of these, 24 samples were negative or indeterminate by WB representing a false-positive rate of the WHO two-test algorithm of 10.5% (95%CI 6.6-15.2. 17 of the 229 samples were weakly positive on rapid testing and all were negative or indeterminate by WB. The false-positive rate fell to 3.3% (95%CI 1.3-6.7 when only strong-positive rapid test results were considered. Agreement between OIC-HIV and WB was 99.1% (95%CI 96.9-99.9% with no false OIC-HIV positives if stringent criteria for positive OIC-HIV diagnoses were used. CONCLUSIONS: The WHO HIV two-test diagnostic algorithm produced an unacceptably high level of false-positive diagnoses in our setting, especially if results were weakly positive. The most probable causes of the false-positive results were serological cross-reactivity or non-specific immune reactivity. Our findings show that the OIC-HIV

  2. [Benefits of using rapid HIV testing at the PMU-FLON walk-in clinic in Lausanne].

    Science.gov (United States)

    Gilgien, W; Aubert, J; Bischoff, T; Herzig, L; Perdrix, J

    2012-05-16

    Lab tests are frequently used in primary care to guide patient care. This is particularly the case when a severe disorder, or one that will affect patients' initial care, needs to be excluded rapidly. At the PMU-FLON walk-in clinic the use of HIV testing as recommended by the Swiss Office of Public Health was hampered by the delay in obtaining test results. This led us to introduce rapid HIV testing which provides results within 30 minutes. Following the first 250 tests the authors discuss the results as well as the benefits of rapid HIV testing in an urban walk-in clinic.

  3. HIV-infected children living in Central Africa have low persistence of antibodies to vaccines used in the Expanded Program on Immunization.

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    Mathurin C Tejiokem

    Full Text Available BACKGROUND: The Expanded Program on Immunization (EPI is the most cost-effective measures to control vaccine-preventable diseases. Currently, the EPI schedule is similar for HIV-infected children; the introduction of antiretroviral therapy (ART should considerably prolong their life expectancy. METHODS AND PRINCIPAL FINDINGS: To evaluate the persistence of antibodies to the EPI vaccines in HIV-infected and HIV-exposed uninfected children who previously received these vaccines in routine clinical practice, we conducted a cross-sectional study of children, aged 18 to 36 months, born to HIV-infected mothers and living in Central Africa. We tested blood samples for antibodies to the combined diphtheria, tetanus, and whole-cell pertussis (DTwP, the measles and the oral polio (OPV vaccines. We enrolled 51 HIV-infected children of whom 33 were receiving ART, and 78 HIV-uninfected children born to HIV-infected women. A lower proportion of HIV-infected children than uninfected children had antibodies to the tested antigens with the exception of the OPV types 1 and 2. This difference was substantial for the measles vaccine (20% of the HIV-infected children and 56% of the HIV-exposed uninfected children, p<0.0001. We observed a high risk of low antibody levels for all EPI vaccines, except OPV types 1 and 2, in HIV-infected children with severe immunodeficiency (CD4(+ T cells <25%. CONCLUSIONS AND SIGNIFICANCE: Children were examined at a time when their antibody concentrations to EPI vaccines would have still not undergone significant decay. However, we showed that the antibody concentrations were lowered in HIV-infected children. Moreover, antibody concentration after a single dose of the measles vaccine was substantially lower than expected, particularly low in HIV-infected children with low CD4(+ T cell counts. This study supports the need for a second dose of the measles vaccine and for a booster dose of the DTwP and OPV vaccines to maintain the

  4. Rapid quantification of the latent reservoir for HIV-1 using a viral outgrowth assay.

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    Gregory M Laird

    Full Text Available HIV-1 persists in infected individuals in a stable pool of resting CD4(+ T cells as a latent but replication-competent provirus. This latent reservoir is the major barrier to the eradication of HIV-1. Clinical trials are currently underway investigating the effects of latency-disrupting compounds on the persistence of the latent reservoir in infected individuals. To accurately assess the effects of such compounds, accurate assays to measure the frequency of latently infected cells are essential. The development of a simpler assay for the latent reservoir has been identified as a major AIDS research priority. We report here the development and validation of a rapid viral outgrowth assay that quantifies the frequency of cells that can release replication-competent virus following cellular activation. This new assay utilizes bead and column-based purification of resting CD4(+ T cells from the peripheral blood of HIV-1 infected patients rather than cell sorting to obtain comparable resting CD4(+ T cell purity. This new assay also utilizes the MOLT-4/CCR5 cell line for viral expansion, producing statistically comparable measurements of the frequency of latent HIV-1 infection. Finally, this new assay employs a novel quantitative RT-PCR specific for polyadenylated HIV-1 RNA for virus detection, which we demonstrate is a more sensitive and cost-effective method to detect HIV-1 replication than expensive commercial ELISA detection methods. The reductions in both labor and cost make this assay suitable for quantifying the frequency of latently infected cells in clinical trials of HIV-1 eradication strategies.

  5. Comparison of the Cerebrospinal Fluid (CSF) Toluidine Red Unheated Serum Test and the CSF Rapid Plasma Reagin Test with the CSF Venereal Disease Research Laboratory Test for Diagnosis of Neurosyphilis among HIV-Negative Syphilis Patients in China

    OpenAIRE

    Zhu, Lin; Gu, Xin; Peng, Rui-Rui; Wang, Cuini; Gao, Zixiao; Zhou, Pingyu; Gao, Ying; Shi, Mei; Guan, Zhifang; Seña, Arlene C.

    2014-01-01

    In this study, we aimed to investigate the performance of nontreponemal antibody tests in cerebrospinal fluid (CSF) specimens from syphilis patients. From September 2009 to September 2012, CSF specimens were collected at the Shanghai Skin Disease Hospital in Shanghai, China, from 1,132 syphilis patients without HIV infection, including 154 with symptomatic and 56 with asymptomatic neurosyphilis. All of the CSF specimens underwent testing with a rapid plasma reagin (RPR) test, an RPR-V (commer...

  6. Induction of antibodies against epitopes inaccessible on the HIV type 1 envelope oligomer by immunization with recombinant monomeric glycoprotein 120

    DEFF Research Database (Denmark)

    Schønning, Kristian; Bolmstedt, A; Novotny, J

    1998-01-01

    An N-glycan (N306) at the base of the V3 loop of HIV-BRU gp120 is shielding a linear neutralization epitope at the tip of the V3 loop on oligomeric Env. In contrast, this epitope is readily antigenic on monomeric gp120. Immunization with recombinant monomeric HIV-BRU gp120 may thus be expected...... immunogenic structures inaccessible on the envelope oligomer. The limited ability of recombinant gp120 vaccines to induce neutralizing antibodies against primary isolates may thus not exclusively reflect genetic variation....

  7. Involvement of lymphocyte function-associated antigen-1 (LFA-1) in HIV infection: inhibition by monoclonal antibody

    DEFF Research Database (Denmark)

    Hansen, J E; Nielsen, C; Mathiesen, Lars Reinhardt

    1991-01-01

    Monoclonal antibodies (MAbs) against the alpha- and beta-chain of lymphocyte-associated antigen-1 (LFA-1) were examined for inhibition of HIV-1 infection in vitro. Infection of the T cell line MT4 and the monocytic cell line U937 by isolates HTLVIIIB and SSI-002, respectively was inhibited...... in a concentration dependent manner by MAb against the beta-chain but not against the alpha-chain. No cross-reactivity was found between MAb against LFA-1 and against the CD4 receptor (MAb Leu3a). MAbs against the beta-chain and the CD4 receptor were found to act synergistically in inhibiting HIV infection...

  8. Integrase inhibitors in late pregnancy and rapid HIV viral load reduction.

    Science.gov (United States)

    Rahangdale, Lisa; Cates, Jordan; Potter, JoNell; Badell, Martina L; Seidman, Dominika; Miller, Emilly S; Coleman, Jenell S; Lazenby, Gweneth B; Levison, Judy; Short, William R; Yawetz, Sigal; Ciaranello, Andrea; Livingston, Elizabeth; Duthely, Lunthita; Rimawi, Bassam H; Anderson, Jean R; Stringer, Elizabeth M

    2016-03-01

    Minimizing time to HIV viral suppression is critical in pregnancy. Integrase strand transfer inhibitors (INSTIs), like raltegravir, are known to rapidly suppress plasma HIV RNA in nonpregnant adults. There are limited data in pregnant women. We describe time to clinically relevant reduction in HIV RNA in pregnant women using INSTI-containing and non-INSTI-containing antiretroviral therapy (ART) options. We conducted a retrospective cohort study of pregnant HIV-infected women in the United States from 2009 through 2015. We included women who initiated ART, intensified their regimen, or switched to a new regimen due to detectable viremia (HIV RNA >40 copies/mL) at ≥20 weeks gestation. Among women with a baseline HIV RNA permitting 1-log reduction, we estimated time to 1-log RNA reduction using the Kaplan-Meier estimator comparing women starting/adding an INSTI in their regimen vs other ART. To compare groups with similar follow-up time, we also conducted a subgroup analysis limited to women with ≤14 days between baseline and follow-up RNA data. This study describes 101 HIV-infected pregnant women from 11 US clinics. In all, 75% (76/101) of women were not taking ART at baseline; 24 were taking non-INSTI containing ART, and 1 received zidovudine monotherapy. In all, 39% (39/101) of women started an INSTI-containing regimen or added an INSTI to their ART regimen. Among 90 women with a baseline HIV RNA permitting 1-log reduction, the median time to 1-log RNA reduction was 8 days (interquartile range [IQR], 7-14) in the INSTI group vs 35 days (IQR, 20-53) in the non-INSTI ART group (P pregnancy. Inclusion of an INSTI may play a role in optimal reduction of HIV RNA for HIV-infected pregnant women presenting late to care or failing initial therapy. Larger studies are urgently needed to assess the safety and effectiveness of this approach. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Neutralizing antibodies against two HIV-1 strains in consecutively collected serum samples: cross neutralization and association to HIV-1 related disease

    DEFF Research Database (Denmark)

    Arendrup, M; Nielsen, C M; Hansen, J E

    1992-01-01

    97 sera collected during a 10-year period from 10 HIV-1 infected individuals were tested for neutralizing capacity against a virus isolate FICPH-22 obtained from a Danish AIDS patient, and the laboratory strain HTLV-IIIB. Three patterns of serum neutralizing activity were demonstrated: (a) patients...... developing high neutralizing activity against both HIV strains; (b) patients developing high neutralizing activity against the Danish virus isolate; and (c) patients developing only low titers of neutralizing antibodies (NA) against both HIV strains. The HTLV-IIIB strain was less sensitive to serum...... neutralization than the FICPH-22 isolate and the appearance of NA against HTLV-IIIB was typically lacking several years behind that against FICPH-22 indicating a broadening of the NA response over time. No difference in clinical outcome was observed comparing patients reaching high titers of NA and patients...

  10. Production and characterization of human anti-V3 monoclonal antibodies from the cells of HIV-1 infected Indian donors

    Directory of Open Access Journals (Sweden)

    Andrabi Raiees

    2012-09-01

    Full Text Available Abstract Background Analysis of human monoclonal antibodies (mAbs developed from HIV-1 infected donors have enormously contributed to the identification of neutralization sensitive epitopes on the HIV-1 envelope glycoprotein. The third variable region (V3 is a crucial target on gp120, primarily due to its involvement in co-receptor (CXCR4 or CCR5 binding and presence of epitopes recognized by broadly neutralizing antibodies. Methods Thirty-three HIV-1 seropositive drug naive patients (18 males and 15 females within the age range of 20–57 years (median = 33 years were recruited in this study for mAb production. The mAbs were selected from EBV transformed cultures with conformationally constrained Cholera-toxin-B containing V3C (V3C-CTB fusion protein. We tested the mAbs for their binding with HIV-1 derived proteins and peptides by ELISA and for neutralization against HIV-1 viruses by TZM-bl assays. Results We isolated three anti-V3 mAbs, 277, 903 and 904 from the cells of different individuals. The ELISA binding revealed a subtype-C and subtype-A specific binding of antibody 277 and 903 while mAb 904 exhibited cross reactivity also with subtype-B V3. Epitope mapping of mAbs with overlapping V3 peptides showed exclusive binding to V3 crown. The antibodies displayed high and low neutralizing activity against 2/5 tier 1 and 1/6 tier 2 viruses respectively. Overall, we observed a resistance of the tier 2 viruses to neutralization by the anti-V3 mAbs, despite the exposure of the epitopes recognized by these antibodies on two representative native viruses (Du156.12 and JRFL, suggesting that the affinity of mAb might equally be crucial for neutralization, as the epitope recognition. Conclusions Our study suggests that the anti-V3 antibodies derived from subtype-C infected Indian patients display neutralization potential against tier 1 viruses while such activity may be limited against more resistant tier 2 viruses. Defining the fine epitope

  11. HIV rapid testing in the framework of an STI prevention project on a cohort of vulnerable Italians and immigrants.

    Science.gov (United States)

    Uccella, Ilaria; Petrelli, Alessio; Vescio, Maria Fenicia; De Carolis, Silvia; Fazioli, Cecilia; Pezzotti, Patrizio; Rezza, Gianni

    2017-08-01

    Uptake of HIV tests is a challenging issue in vulnerable populations including immigrants, normally using standard diagnostic tools. Objectives of this study were to evaluate the acceptability of HIV rapid test; estimate the percentage of newly HIV diagnoses and evaluate knowledge, attitudes and perception (KAP) about HIV/AIDS and other STIs in a specific set of immigrants and vulnerable population in Rome (Italy). All immigrant and Italian people, aged 16-70 years, attending the infectious disease outpatient clinic of the National Institute for Health, Migration and Poverty (INMP) in Rome (Italy), during the period December 2012 to December 2013 were enrolled. HIV rapid testing was provided for free and patients were asked to fill in a questionnaire evaluating KAP about HIV/STIs. All patients with risky sexual behaviours or with a recent diagnosis of STIs were invited to come back after 3-6 months and a post-counselling questionnaire was offered. Out of the total sample, 99.2% (n = 825) accepted the "rapid test" and 10 new HIV diagnoses were found (1.22%; 95% CI 0.58%-2.22%). Three hundred and eighty-five participants (47%) answered the entry questionnaire and 58 (15%) completed the follow-up. Overall, we found high knowledge about HIV/AIDS; however, lower educational level and immigrant status were associated with poor knowledge about HIV, other STIs and prevention methods. Immigrants have lower perception of sexual risk and higher prejudice than Italians. Our study showed high acceptance of rapid test in this specific vulnerable population and this allowed to identify new HIV diagnoses in unaware people. Socioeconomic inequalities observed in the KAP questionnaire suggest the need for actions to support the reduction of cultural differences in knowledge of HIV/AIDS and for policies aimed at improving access to health services and preventions programmes of marginalized populations.

  12. Evaluation of Calypte AWARE HIV-1/2 OMT antibody test as a screening test in an Indian setting

    Directory of Open Access Journals (Sweden)

    Ingole N

    2010-01-01

    Full Text Available Purpose: Integrated counselling and testing centres (ICTC provide counselling and blood testing facilities for HIV diagnosis. Oral fluid tests provide an alternative for people whodo not want blood to be drawn. Also, it avoids the risk of occupational exposure. The goal of this study was to evaluate the utility of Calypte AWARE HIV-1/2 OMT antibody test as a screening test in an Indian setting. Materials and Methods: A cross-sectional study was carried out after ethics committee approval in 250 adult ICTC clients. Blood was collected and tested from these clients for HIV diagnosis as per routine policy and the results were considered as the gold standard. Also, after another written informed consent, oral fluid was collected from the clients and tested for the presence of HIV antibodies. Twenty five clients who had and 25 clients who had not completed their secondary school education (Group A and Group B, respectively were also asked to perform and interpret the test on their own and their findings and experiences were noted. Result: The sensitivity, specificity, PPV and NPV of the oral fluid antibody test were 100%, 98.51%, 94.11% and 100%, respectively. Seventy six percent of clients preferred oral fluid testing. Group B found it difficult to perform the test as compared to Group A and this difference was statistically significant (P ≤ 0.05. Conclusion: Oral fluid testing can be used as a screening test for HIV diagnosis; however, confirmation of reactive results by blood-based tests is a must.

  13. Characterization of broadly neutralizing antibody responses to HIV-1 in a cohort of long term non-progressors.

    Science.gov (United States)

    González, Nuria; McKee, Krisha; Lynch, Rebecca M; Georgiev, Ivelin S; Jimenez, Laura; Grau, Eulalia; Yuste, Eloísa; Kwong, Peter D; Mascola, John R; Alcamí, José

    2018-01-01

    Only a small fraction of HIV-1-infected patients develop broadly neutralizing antibodies (bNAbs), a process generally associated to chronic antigen stimulation. It has been described that rare aviremic HIV-1-infected patients can generate bNAbs but this issue remains controversial. To address this matter we have assessed bNAb responses in a large cohort of long-term non-progressors (LTNPs) with low or undetectable viremia. Samples from the LTNP cohort of the Spanish AIDS Research Network (87 elite and 42 viremic controllers) and a control population of 176 viremic typical-progressors (TPs) were screened for bNAbs using Env-recombinant viruses. bNAb specificities were studied by ELISA using mutated gp120, neutralization assays with mutated viruses, and peptide competition. Epitope specificities were also elucidated from the serum pattern of neutralization against a panel of diverse HIV-1 isolates. Broadly neutralizing sera were found among 9.3% LTNPs, both elite (7%) and viremic controllers (14%). Within the broadly neutralizing sera, CD4 binding site antibodies were detected by ELISA in 4/12 LTNPs (33%), and 16/33 of TPs (48%). Anti-MPER antibodies were detected in 6/12 LTNPs (50%) and 14/33 TPs (42%) whereas glycan-dependent HIV-1 bNAbs were more frequent in LTNPs (11/12, 92%) as compared to TPs (12/33, 36%). A good concordance between standard serum mapping and neutralization-based mapping was observed. LTNPs, both viremic and elite controllers, showed broad humoral immune responses against HIV-1, including activity against many major epitopes involved in bNAbs-mediated protection.

  14. Rapid identification of vibrio-cholerae O1 by coaglutination test using mono-specifis antibody

    Directory of Open Access Journals (Sweden)

    Bazargan SA

    1996-07-01

    Full Text Available In our investigation, rabbit hyper-immune serum to V.cholerae ogawa was absorbed with V.cholerae inaba whole-cells and vice versa. Applying ammonium sulphate precipitation method, mono-specific g globulins were purified and concentrated from the absorbed whole serum. These antibodies were fixed on staphylococcus cowan 1 NCTC-8325 whole-cells, using different chemical fixatives. It was observed that maximum fixation of g globulin to protein-A was achieved by 1-propanol 50% at 3 hours, which revealed through single radial immuno-diffusion techniqe. The rectal swab samples were cultured in an enrichment bile-peptons broth. After 5 hours 37°C while agitations, one drop of each sample was mixed with one drop of vibrio-cholerae bivalent mono-specific coagglutination reagent (VBCR. The results were read after 2 to 3 minutes. Finally though statistical analysis sensitivity and specificity of coagglutination test were calculated to be 95.1% and 99.2% respectively, when compared to positive & negative controls and conventional culture methods. Using VBCR, coagglutination test can be therefore considered as a simple, reliable and rapid method to detect V.cholerae O1 in the stool of patients in endemic area and less equipped laboratories

  15. Rapid drug desensitization for hypersensitivity reactions to chemotherapy and monoclonal antibodies in the 21st century.

    Science.gov (United States)

    Castells Guitart, M C

    2014-01-01

    The frequency of hypersensitivity reactions (HSR) to drugs has risen in the last 10 years owing to increased exposure to better and more allergenic medications including monoclonal antibodies. HSRs prevent patients from using their first-line therapy, leading to decreased quality of life and life expectancy. Although premedication with antihistamines, leukotriene blockers, and corticosteroids can protect against mild-to-moderate HSR, none of these medications has provided protection against anaphylaxis. Rapid drug desensitization is a treatment option for patients with HSR to their first-line medication that protects against anaphylaxis.Although the mechanisms of drug desensitization are not completely understood, in vitro mast cell models of IgE antigen desensitization have led to the design of safe and effective in vivo protocols aimed at protecting highly sensitized patients from hypersensitivity reactions and anaphylaxis. This review provides an insight into the mechanisms of IgE/mast cell desensitization, the principles and practice of drug desensitization, and an overview of the different desensitization protocols and their safety and efficacy profiles. Drug desensitization should only be performed by allergists, trained nurses, and experienced pharmacists, since this high-risk procedure involves reintroducing allergenic medication to highly sensitized patients, with the consequent potential for severe or fatal HSRs.

  16. Radiometric cytolysis inhibition assay, a new rapid test for neutralizing antibodies to intact and trypsin-cleaved poliovirus

    International Nuclear Information System (INIS)

    Hovi, T.; Roivainen, M.

    1989-01-01

    We have developed a new rapid test, the radiometric cytolysis inhibition assay (RACINA), for the determination of neutralizing poliovirus antibodies. HeLa cells prelabeled with 51 Cr, [ 3 H]leucine, or, preferentially, with [ 3 H]uridine are used as sensitive quantitative indicators of residual infectious virus. Both suspensions and monolayer cultures of the indicator cells can be used. Neutralization of a fraction of a high-titer virus preparation can be scored after the first replication cycle at 8 to 10 h. By lowering the incubation temperature to 30 degree C, the completion of the cytolysis due to the first replication cycle of poliovirus was delayed beyond 21 h. This makes it possible to use the RACINA, unlike the standard microneutralization assay, for measuring antibodies to trypsin-cleaved polioviruses. The RACINA was found to be as sensitive as and more reproducible than the standard microneutralization assay in the measurement of neutralizing poliovirus antibodies. The RACINA is a rapid and reliable test for neutralizing antibodies and in principle it may be applicable for quantitation of neutralizing antibodies to other cytolytic agents as well

  17. Development of microLIPS (Luciferase Immunoprecipitation Systems): a novel microfluidic assay for rapid serum antibody detection

    Science.gov (United States)

    Chandrangsu, Matt; Burbelo, Peter D.; Iadarola, Michael J.; Smith, Paul D.; Morgan, Nicole Y.

    2012-06-01

    There is considerable interest in the development of rapid, point-of-care antibody detection for the diagnosis of infectious and auto-immune diseases. In this paper, we present work on the development of a self-contained microfluidic format for the Luciferase Immunoprecipitation Systems (LIPS) assay. Whereas the majority of immunoassays for antigen-specific antibodies employ either bacteria- or yeast-expressed proteins and require the use of secondary antibodies, the LIPS technique uses a fusion protein comprised of a Renilla luciferase reporter and the antigen of interest produced via mammalian cell culture, ensuring the addition of mammalian post-translational modifications. Patient serum is mixed with the fusion protein and passed over immobilized Protein A/G; after washing, the only remaining luciferase-tagged antigens are those retained by specific antibodies. These can be quantitatively measured using chemiluminescence upon the introduction of coelenterazine. The assay has been successfully employed for a wide variety of diseases in a microwell format. We report on a recent demonstration of rapid HSV-2 diagnosis with the LIPS assay in a microfluidic format, using one microliter of serum and obtaining results in under ten minutes. We will also discuss recent progress on two fronts, both aimed at the deployment of this technology in the field: first, simplifying assay operation through the automation of flow control using power-free means; and second, efforts to increase signal levels, primarily through strategies to increase antibody binding capacity, in order to move towards portable battery powered electronics.

  18. DEPIVIH 2: Use of three HIV testing methods in French primary care settings - ELISA laboratory screening versus two rapid point-of-care HIV tests.

    Science.gov (United States)

    Papadima, D; Gauthier, R; Prévoteau du Clary, F; Bouée, S; Conort, G; Livrozet, J-M; Taulera, O; Wajsbrot, A; Majerholc, C; Peter, J-M; Aubert, J-P

    2018-03-01

    The primary endpoint was to evaluate the use of HIV testing methods by French primary care providers: Elisa laboratory screening, instant result HIV diagnostic test and rapid result HIV diagnostic test. The secondary endpoints were the population screening rate of unknown HIV status consulting during the study period, reasons for screening and for choosing the specific screening method, the investigators' satisfaction with the rapid diagnostic test (RDT) and problems encountered. National prospective interventional study with French family physicians (FP) from December 2013 to December 2014. FPs enrolled all consenting adults consulting for an HIV screening test during a 6-month period: the choice was an Elisa laboratory test or one of the two RDTs. During the study period, 43 FPs included 981 patients. HIV screening was performed for the first time for 31.6% of patients; 767 (78.2%) Elisa laboratory test prescriptions and 214 (21.8%) RDTs were performed, leading to a screening rate of 1.3%. For 120 (15.7%) of the Elisa laboratory tests, the result was not reported and six RDTs were not valid. Nine patients were diagnosed as HIV-infected (0.9%): five with Elisa laboratory test and four with RDT. Almost 90% of FPs were willing to keep on using RDTs in their daily practice. In general practice, RDTs may be an important additional tool to traditional HIV screening. They could account for one in five tests prescribed in this context. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  19. Performance of 3 Rapid Tests for Discrimination Between HIV-1 and HIV-2 in Guinea-Bissau, West Africa

    DEFF Research Database (Denmark)

    Hønge, Bo Langhoff; Bjarnason Obinah, Magnús Pétur; Jespersen, Sanne

    2014-01-01

    As HIV-2 is intrinsically resistant to nonnucleoside reverse transcriptase inhibitors, it is mandatory to discriminate between HIV types before initiating antiretroviral treatment. Guinea-Bissau has the world's highest prevalence of HIV-2 and HIV-1/HIV-2 dually infected individuals. We evaluated ...... (agreement 90.9%) and SD Bioline HIV-1/2 3.0 (agreement 84.5%). Our results underscore the need for evaluation of tests in relevant populations before implementation....

  20. Operational feasibility of using whole blood in the rapid HIV testing algorithm of a resource-limited settings like Bangladesh.

    Science.gov (United States)

    Munshi, Saif U; Oyewale, Tajudeen O; Begum, Shahnaz; Uddin, Ziya; Tabassum, Shahina

    2016-03-01

    Serum-based rapid HIV testing algorithm in Bangladesh constitutes operational challenge to scaleup HIV testing and counselling (HTC) in the country. This study explored the operational feasibility of using whole blood as alternative to serum for rapid HIV testing in Bangladesh. Whole blood specimens were collected from two study groups. The groups included HIV-positive patients (n = 200) and HIV-negative individuals (n = 200) presenting at the reference laboratory in Dhaka, Bangladesh. The specimens were subjected to rapid HIV tests using the national algorithm with A1 = Alere Determine (United States), A2 = Uni-Gold (Ireland), and A3 = First Response (India). The sensitivity and specificity of the test results, and the operational cost were compared with current serum-based testing. The sensitivities [95% of confidence interval (CI)] for A1, A2, and A3 tests using whole blood were 100% (CI: 99.1-100%), 100% (CI: 99.1-100%), and 97% (CI: 96.4-98.2%), respectively, and specificities of all test kits were 100% (CI: 99.1-100%). Significant (P < 0.05) reduction in the cost of establishing HTC centre and consumables by 94 and 61%, respectively, were observed. The cost of administration and external quality assurance reduced by 39 and 43%, respectively. Overall, there was a 36% cost reduction in total operational cost of rapid HIV testing with blood when compared with serum. Considering the similar sensitivity and specificity of the two specimens, and significant cost reduction, rapid HIV testing with whole blood is feasible. A review of the national HIV rapid testing algorithm with whole blood will contribute toward improving HTC coverage in Bangladesh.

  1. A rapid approach for characterization of thiol-conjugated antibody-drug conjugates and calculation of drug-antibody ratio by liquid chromatography mass spectrometry.

    Science.gov (United States)

    Firth, David; Bell, Leonard; Squires, Martin; Estdale, Sian; McKee, Colin

    2015-09-15

    We present the demonstration of a rapid "middle-up" liquid chromatography mass spectrometry (LC-MS)-based workflow for use in the characterization of thiol-conjugated maleimidocaproyl-monomethyl auristatin F (mcMMAF) and valine-citrulline-monomethyl auristatin E (vcMMAE) antibody-drug conjugates. Deconvoluted spectra were generated following a combination of deglycosylation, IdeS (immunoglobulin-degrading enzyme from Streptococcus pyogenes) digestion, and reduction steps that provide a visual representation of the product for rapid lot-to-lot comparison-a means to quickly assess the integrity of the antibody structure and the applied conjugation chemistry by mass. The relative abundance of the detected ions also offer information regarding differences in drug conjugation levels between samples, and the average drug-antibody ratio can be calculated. The approach requires little material (<100 μg) and, thus, is amenable to small-scale process development testing or as an early component of a complete characterization project facilitating informed decision making regarding which aspects of a molecule might need to be examined in more detail by orthogonal methodologies. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Laboratory evaluation of three dual rapid diagnostic tests for HIV and syphilis in China and Nigeria.

    Science.gov (United States)

    Yin, Yue-Ping; Ngige, Evelyn; Anyaike, Chukwuma; Ijaodola, Gbenga; Oyelade, Taiwo A; Vaz, Rui Gama; Newman, Lori M; Chen, Xiang-Sheng

    2015-06-01

    To determine the laboratory-based performance and operational characteristics of three dual rapid diagnostic tests (RDTs) for testing HIV and syphilis. Three dual RDTs (SD Bioline, Chembio, and MedMira) were evaluated using 1514 serum specimens archived at laboratories or collected from clinics in China and Nigeria to determine sensitivity and specificity, with 95% confidence intervals. Concordance of testing results read by two technicians, stability of testing results read at two time points, and test operation characteristics were also assessed. All three of the evaluated RDTs gave excellent performance with a combined sensitivity ranging from 99.0%-99.6% for HIV and 98.3%-99.0% for syphilis, and a combined specificity ranging from 97.9%-99.0% for HIV and 97.2%-99.6% for syphilis. Concordance of testing results between two technicians and stability of testing results read within and one hour past the recommended reading period showed excellent agreement, with Kappa greater than or equal to 0.98. All the tests were found to be very or fairly easy to use and easy to interpret the results. Further evaluations of these dual RDTs with whole blood in field settings, and more studies on the implication of introduction of these tests in HIV and syphilis control programs are needed. Copyright © 2015. Published by Elsevier Ireland Ltd.

  3. A rapid microassay for detecting antibodies against poliovirus based on [14C]thymidine uptake of treated cell cultures

    International Nuclear Information System (INIS)

    Hilfenhaus, J.; Damm, H.; Ziegelmaier, R.; Gruschkau, H.

    1977-01-01

    DNA synthesis of mammalian cells propagated in microplates can easily be measured if cell cultures incubated with [ 14 C]thymidine are harvested on to glass fibre filters by a semiautomatic harvesting technique. Soon after infection with poliovirus, [ 14 C]thymidine uptake of U cells (established, human amniotic cell line) is inhibited. This inhibition can be prevented by previous virus neutralization with antibody. Based on this effect a rapid, precise assay method was set up to determine neutralizing antibody titres against poliovirus. There was a good correlation between titres obtained by this assay and those obtained by 50% endpoint titrations in cytopathogenic effect inhibition assays

  4. A rapid one-step radiometric assay for hepatitis B surface antigen utilising monoclonal antibodies

    International Nuclear Information System (INIS)

    Goodall, A.H.; Meek, F.L.; Waters, J.A.; Miescher, G.C.; Janossy, G.; Thomas, H.C.

    1982-01-01

    A two-site antigen assay for HBsAg has been developed that employs 3 monoclonal antibodies. The antibodies were selected for their high affinity and their particular epitope specificity to establish an assay with a sensitivity for the antigen comparable with that of a conventional assay with heterologous antisera. In addition, by selecting a monoclonal antibody for use as a tracer which does not compete for antigenic binding sites with the solid-phase monoclonal antibodies, it has been possible to perform a two-site assay in a single 1 h incubation step, achieving the same degree of sensitivity. This principle of using monoclonal antibodies in a one-step assay therefore gives advantages of speed and simplicity over assays using heterologous antisera and would be applicable to a variety of antigen assays for which appropriate monoclonal antibodies are available. (Auth.)

  5. IGHV1-69 B cell chronic lymphocytic leukemia antibodies cross-react with HIV-1 and hepatitis C virus antigens as well as intestinal commensal bacteria.

    Directory of Open Access Journals (Sweden)

    Kwan-Ki Hwang

    Full Text Available B-cell chronic lymphocytic leukemia (B-CLL patients expressing unmutated immunoglobulin heavy variable regions (IGHVs use the IGHV1-69 B cell receptor (BCR in 25% of cases. Since HIV-1 envelope gp41 antibodies also frequently use IGHV1-69 gene segments, we hypothesized that IGHV1-69 B-CLL precursors may contribute to the gp41 B cell response during HIV-1 infection. To test this hypothesis, we rescued 5 IGHV1-69 unmutated antibodies as heterohybridoma IgM paraproteins and as recombinant IgG1 antibodies from B-CLL patients, determined their antigenic specificities and analyzed BCR sequences. IGHV1-69 B-CLL antibodies were enriched for reactivity with HIV-1 envelope gp41, influenza, hepatitis C virus E2 protein and intestinal commensal bacteria. These IGHV1-69 B-CLL antibodies preferentially used IGHD3 and IGHJ6 gene segments and had long heavy chain complementary determining region 3s (HCDR3s (≥21 aa. IGHV1-69 B-CLL BCRs exhibited a phenylalanine at position 54 (F54 of the HCDR2 as do rare HIV-1 gp41 and influenza hemagglutinin stem neutralizing antibodies, while IGHV1-69 gp41 antibodies induced by HIV-1 infection predominantly used leucine (L54 allelic variants. These results demonstrate that the B-CLL cell population is an expansion of members of the innate polyreactive B cell repertoire with reactivity to a number of infectious agent antigens including intestinal commensal bacteria. The B-CLL IGHV1-69 B cell usage of F54 allelic variants strongly suggests that IGHV1-69 B-CLL gp41 antibodies derive from a restricted B cell pool that also produces rare HIV-1 gp41 and influenza hemagglutinin stem antibodies.

  6. Mode of inhibition of HIV-1 Integrase by a C-terminal domain-specific monoclonal antibody*

    Directory of Open Access Journals (Sweden)

    Merkel George

    2006-06-01

    Full Text Available Abstract Background To further our understanding of the structure and function of HIV-1 integrase (IN we developed and characterized a library of monoclonal antibodies (mAbs directed against this protein. One of these antibodies, mAb33, which is specific for the C-terminal domain, was found to inhibit HIV-1 IN processing activity in vitro; a corresponding Fv fragment was able to inhibit HIV-1 integration in vivo. Our subsequent studies, using heteronuclear nuclear magnetic resonance spectroscopy, identified six solvent accessible residues on the surface of the C-terminal domain that were immobilized upon binding of the antibody, which were proposed to comprise the epitope. Here we test this hypothesis by measuring the affinity of mAb33 to HIV-1 proteins that contain Ala substitutions in each of these positions. To gain additional insight into the mode of inhibition we also measured the DNA binding capacity and enzymatic activities of the Ala substituted proteins. Results We found that Ala substitution of any one of five of the putative epitope residues, F223, R224, Y226, I267, and I268, caused a decrease in the affinity of the mAb33 for HIV-1 IN, confirming the prediction from NMR data. Although IN derivatives with Ala substitutions in or near the mAb33 epitope exhibited decreased enzymatic activity, none of the epitope substitutions compromised DNA binding to full length HIV-1 IN, as measured by surface plasmon resonance spectroscopy. Two of these derivatives, IN (I276A and IN (I267A/I268A, exhibited both increased DNA binding affinity and uncharacteristic dissociation kinetics; these proteins also exhibited non-specific nuclease activity. Results from these investigations are discussed in the context of current models for how the C-terminal domain interacts with substrate DNA. Conclusion It is unlikely that inhibition of HIV-1 IN activity by mAb33 is caused by direct interaction with residues that are essential for substrate binding. Rather

  7. Acceptability of rapid oral fluid HIV testing among male injection drug users in Taiwan, 1997 and 2007.

    Science.gov (United States)

    Lyu, Shu-Yu; Morisky, Donald E; Yeh, Ching-Ying; Twu, Shiing-Jer; Peng, Eugene Yu-Chang; Malow, Robert M

    2011-04-01

    Rapid oral fluid HIV testing (rapid oral testing) is in the process of being adapted in Taiwan and elsewhere given its advantages over prior HIV testing methods. To guide this process, we examined the acceptability of rapid oral testing at two time points (i.e., 1997 and 2007) among one of the highest risk populations, male injection drug users (IDUs). For this purpose, an anonymous self-administered survey was completed by HIV-negative IDUs involved in the criminal justice system in 1997 (N (1)=137 parolees) and 2007 (N (2)=106 prisoners). A social marketing model helped guide the design of our questionnaire to assess the acceptability of rapid oral testing. This included assessing a new product, across four marketing dimensions: product, price, promotion, and place. Results revealed that in both 1997 and 2007, over 90% indicated that rapid oral testing would be highly acceptable, particularly if the cost was under US$6, and that a pharmacy would be the most appropriate and accessible venue for selling the rapid oral testing kits. The vast majority of survey respondents believed that the cost of rapid oral testing should be federally subsidized and that television and newspaper advertisements would be the most effective media to advertise for rapid oral testing. Both the 1997 and 2007 surveys suggested that rapid oral HIV testing would be particularly accepted in Taiwan by IDUs after release from the criminal justice system.

  8. Rapid solid-phase radioimmunoassay for detection of equine infectious anemia viral antigen and antibodies: parameters involved in standardization

    International Nuclear Information System (INIS)

    Horenstein, A.L.; Feinstein, R.E.

    1985-01-01

    Solid-phase radioimmunoassays (SPRIA) are described for the detection of equine infectious anemia (EIA) viral antigen and antibodies. Protein-antigen P29 currently used in the agar-gel immunodiffusion (AGID) test was used as antigen in the SPRIA. The specificity of the reaction was assessed by inhibition with the antigen. The reaction of immune serum against EIA-virus antigen adsorbed to the wells, was completely inhibited by the antigen in solution. This property was applied in an indirect competitive SPRIA for the detection of viral protein P29. The detection threshold of the SPRIA for EIA virus protein was about 5 ng and about 1 ng of antibody can be detected. The assay is rapid, specific and sensitive and allows the testing of multiple serum samples with the advantage of employing a single secondary labelled antibody. (orig.)

  9. A cross sectional survey of the barriers for implementing rapid HIV testing among French general practitioners.

    Science.gov (United States)

    Fraisse, Thibaut; Fourcade, Camille; Brazes-Sanz, Julie; Koumar, Yatrika; Lavigne, Jean Philippe; Sotto, Albert; Laureillard, Didier

    2016-10-01

    In France, almost 30,000 people are unaware of their HIV-positive status. Innovative screening strategies are essential to reach this population. The aim of this study was to describe the acceptability of rapid HIV testing (RHT) among French general practitioners (GPs) working in the south of France and barriers for implementing this strategy. We analysed an anonymous questionnaire sent by mail to GPs about demographic data, routine practice, knowledge of RHT and barriers to its use. Between 1 April and 30 September 2013, out of the 165 GPs contacted, 78 returned the questionnaires. The GPs' mean age was 52 years; 49 were men. Fifty-one GPs reported that their registered patients included at least one HIV-infected person and 70 GPs reported taking care of high-risk patients. Sixty-three percent of GPs reported being interested in using RHT in their daily practice. The main reasons reported by uninterested GPs were: greater confidence in standard HIV testing, difficulties including RHT during the routine consultation, difficulties to screen for other sexually transmitted infections simultaneously, and difficulties to deliver a positive result. French National Authorities for Health propose to screen the population at least once in their lifetime and high-risk people at least once a year. In order to achieve this aim, RHT should be included in the GPs' arsenal for HIV testing. We showed a high acceptability of RHT by GPs. If specific and adapted training is developed, and if solutions to barriers reported by GPs are found, RHT could be implemented in to their routine activity. © The Author(s) 2016.

  10. HIV-TRACE (Transmission Cluster Engine): a tool for large scale molecular epidemiology of HIV-1 and other rapidly evolving pathogens.

    Science.gov (United States)

    Kosakovsky Pond, Sergei L; Weaver, Steven; Leigh Brown, Andrew J; Wertheim, Joel O

    2018-01-31

    In modern applications of molecular epidemiology, genetic sequence data are routinely used to identify clusters of transmission in rapidly evolving pathogens, most notably HIV-1. Traditional 'shoeleather' epidemiology infers transmission clusters by tracing chains of partners sharing epidemiological connections (e.g., sexual contact). Here, we present a computational tool for identifying a molecular transmission analog of such clusters: HIV-TRACE (TRAnsmission Cluster Engine). HIV-TRACE implements an approach inspired by traditional epidemiology, by identifying chains of partners whose viral genetic relatedness imply direct or indirect epidemiological connections. Molecular transmission clusters are constructed using codon-aware pairwise alignment to a reference sequence followed by pairwise genetic distance estimation among all sequences. This approach is computationally tractable and is capable of identifying HIV-1 transmission clusters in large surveillance databases comprising tens or hundreds of thousands of sequences in near real time, i.e., on the order of minutes to hours. HIV-TRACE is available at www.hivtrace.org and from github.com/veg/hivtrace, along with the accompanying result visualization module from github.com/veg/hivtrace-viz. Importantly, the approach underlying HIV-TRACE is not limited to the study of HIV-1 and can be applied to study outbreaks and epidemics of other rapidly evolving pathogens. © The Author 2018. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Evolution of the HIV-1 Envelope Glycoprotein Genes and Neutralizing Antibody Response in an Individual with Broadly Cross Neutralizing Antibodies

    Science.gov (United States)

    2010-08-31

    1994, 140: 1 05-130. 51. Pantaleo G, Graziosi C, Demarest JF, Butini L, Montroni M, Fox CH, Orenstein JM, Kotler DP, Fauci AS: HIV infection is...Pizzo PA, Schnittman SM, Kotler DP, Fauci AS: Lymphoid organs function as major reservoirs for human immunodeficiency virus. Proc Natl Acad Sci US

  12. A Rapid Detection Method of Brucella with Quantum Dots and Magnetic Beads Conjugated with Different Polyclonal Antibodies

    Science.gov (United States)

    Song, Dandan; Qu, Xiaofeng; Liu, Yushen; Li, Li; Yin, Dehui; Li, Juan; Xu, Kun; Xie, Renguo; Zhai, Yue; Zhang, Huiwen; Bao, Hao; Zhao, Chao; Wang, Juan; Song, Xiuling; Song, Wenzhi

    2017-03-01

    Brucella spp. are facultative intracellular bacteria that cause zoonotic disease of brucellosis worldwide. Traditional methods for detection of Brucella spp. take 48-72 h that does not meet the need of rapid detection. Herein, a new rapid detection method of Brucella was developed based on polyclonal antibody-conjugating quantum dots and antibody-modified magnetic beads. First, polyclonal antibodies IgG and IgY were prepared and then the antibody conjugated with quantum dots (QDs) and immunomagnetic beads (IMB), respectively, which were activated by N-(3-dimethylaminopropyl)- N'-ethylcar-bodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) to form probes. We used the IMB probe to separate the Brucella and labeled by the QD probe, and then detected the fluorescence intensity with a fluorescence spectrometer. The detection method takes 105 min with a limit of detection of 103 CFU/mL and ranges from 10 to 105 CFU/mL ( R 2 = 0.9983), and it can be well used in real samples.

  13. Comparative effectiveness of single and dual rapid diagnostic tests for syphilis and HIV in antenatal care services in Colombia.

    Science.gov (United States)

    Gaitán-Duarte, Hernando Guillermo; Newman, Lori; Laverty, Maura; Habib, Ndema Abu; González-Gordon, Lina María; Ángel-Müller, Edith; Abella, Catleya; Barros, Esther Cristina; Rincón, Carlos; Caicedo, Sidia; Gómez, Bertha; Pérez, Freddy

    2016-12-01

    To assess the effectiveness of a dual rapid test compared to a single rapid test for syphilis and HIV screening. A cluster-randomized open-label clinical trial was performed in 12 public antenatal care (ANC) centers in the cities of Bogotá and Cali, Colombia. Pregnant women who were over 14 years of age at their first antenatal visit and who had not been previously tested for HIV and syphilis during the current pregnancy were included. Pregnant women were randomized to single HIV and single syphilis rapid diagnostic tests (Arm A) or to dual HIV and syphilis rapid diagnostic tests (Arm B). The four main outcomes measured were: (1) acceptability of the test, (2) uptake in testing, (3) treatment on the same day (that is, timely treatment), and (4) treatment at any time for positive rapid test cases. Bivariate and multivariate analyses were calculated to adjust for the clustering effect and the period. A total of 1 048 patients were analyzed in Arm A, and 1 166 in Arm B. Acceptability of the rapid tests was 99.8% in Arm A and 99.6% in Arm B. The prevalence of positive rapid tests was 2.21% for syphilis and 0.36% for HIV. Timely treatment was provided to 20 of 29 patients (69%) in Arm A and 16 of 20 patients (80%) in Arm B (relative risk (RR), 1.10; 95% confidence interval (CI): (1.00 -1.20). Treatment at any time was given to 24 of 29 patients (83%) in Arm A and to 20 of 20 (100%) in Arm B (RR, 1.11; 95% CI: 1.01-1.22). There were no differences in patient acceptability, testing and timely treatment between dual rapid tests and single rapid tests for HIV and syphilis screening in the ANC centers. Same-day treatment depends also on the interpretation of and confidence in the results by the health providers.

  14. Neutralizing antibody and anti-retroviral drug sensitivities of HIV-1 isolates resistant to small molecule CCR5 inhibitors

    International Nuclear Information System (INIS)

    Pugach, Pavel; Ketas, Thomas J.; Michael, Elizabeth; Moore, John P.

    2008-01-01

    The small molecule CCR5 inhibitors are a new class of drugs for treating infection by human immunodeficiency virus type 1 (HIV-1). They act by binding to the CCR5 co-receptor and preventing its use during HIV-1-cell fusion. Escape mutants can be raised against CCR5 inhibitors in vitro and will arise when these drugs are used clinically. Here, we have assessed the responses of CCR5 inhibitor-resistant viruses to other anti-retroviral drugs that act by different mechanisms, and their sensitivities to neutralizing antibodies (NAbs). The rationale for the latter study is that the resistance pathway for CCR5 inhibitors involves changes in the HIV-1 envelope glycoproteins (Env), which are also targets for NAbs. The escape mutants CC101.19 and D1/85.16 were selected for resistance to AD101 and vicriviroc (VVC), respectively, from the primary R5 HIV-1 isolate CC1/85. Each escape mutant was cross-resistant to other small molecule CCR5 inhibitors (aplaviroc, maraviroc, VVC, AD101 and CMPD 167), but sensitive to protein ligands of CCR5: the modified chemokine PSC-RANTES and the humanized MAb PRO-140. The resistant viruses also retained wild-type sensitivity to the nucleoside reverse transcriptase inhibitor (RTI) zidovudine, the non-nucleoside RTI nevirapine, the protease inhibitor atazanavir and other attachment and fusion inhibitors that act independently of CCR5 (BMS-806, PRO-542 and enfuvirtide). Of note is that the escape mutants were more sensitive than the parental CC1/85 isolate to a subset of neutralizing monoclonal antibodies and to some sera from HIV-1-infected people, implying that sequence changes in Env that confer resistance to CCR5 inhibitors can increase the accessibility of some NAb epitopes. The need to preserve NAb resistance may therefore be a constraint upon how escape from CCR5 inhibitors occurs in vivo

  15. Multimeric scaffolds displaying the HIV-1 envelope MPER induce MPER-specific antibodies and cross-neutralizing antibodies when co-immunized with gp160 DNA.

    Directory of Open Access Journals (Sweden)

    Shelly J Krebs

    Full Text Available Developing a vaccine that overcomes the diversity of HIV-1 is likely to require a strategy that directs antibody (Ab responses toward conserved regions of the viral Envelope (Env. However, the generation of neutralizing Abs (NAbs targeting these regions through vaccination has proven to be difficult. One conserved region of particular interest is the membrane proximal external region (MPER of Env located within the gp41 ectodomain. In order to direct the immune response to this region, the MPER and gp41 ectodomain were expressed separately as N-terminal fusions to the E2 protein of Geobacillus stearothermophilus. The E2 protein acts as a scaffold by self-assembling into 60-mer particles, displaying up to 60 copies of the fused target on the surface. Rabbits were immunized with E2 particles displaying MPER and/or the gp41 ectodomain in conjunction with DNA encoding full-length gp160. Only vaccines including E2 particles displaying MPER elicited MPER-specific Ab responses. NAbs were elicited after two immunizations that largely targeted the V3 loop. To overcome V3 immunodominance in the DNA component, E2 particles displaying MPER were used in conjunction with gp160 DNA lacking hypervariable regions V2, V3, or combined V1V2V3. All rabbits had HIV binding Ab responses and NAbs following the second vaccination. Using HIV-2/HIV-1 MPER chimeric viruses as targets, NAbs were detected in 12/16 rabbits after three immunizations. Low levels of NAbs specific for Tier 1 and 2 viruses were observed in all groups. This study provides evidence that co-immunizing E2 particles displaying MPER and gp160 DNA can focus Ab responses toward conserved regions of Env.

  16. Accuracy in HIV Rapid Testing among Laboratory and Non-laboratory Personnel in Zambia: Observations from the National HIV Proficiency Testing System.

    Directory of Open Access Journals (Sweden)

    Sheila Mwangala

    Full Text Available Despite rapid task-shifting and scale-up of HIV testing services in high HIV prevalence countries, studies evaluating accuracy remain limited. This study aimed to assess overall accuracy level and factors associated with accuracy in HIV rapid testing in Zambia.Accuracy was investigated among rural and urban HIV testing sites participating in two annual national HIV proficiency testing (PT exercises conducted in 2009 (n = 282 sites and 2010 (n = 488 sites. Testers included lay counselors, nurses, laboratory personnel and others. PT panels of five dry tube specimens (DTS were issued to testing sites by the national reference laboratory (NRL. Site accuracy level was assessed by comparison of reported results to the expected results. Non-parametric rank tests and multiple linear regression models were used to assess variation in accuracy between PT cycles and between tester groups, and to examine factors associated with accuracy respectively.Overall accuracy level was 93.1% (95% CI: 91.2-94.9 in 2009 and 96.9% (95% CI: 96.1-97.8 in 2010. Differences in accuracy were seen between the tester groups in 2009 with laboratory personnel being more accurate than non-laboratory personnel, while in 2010 no differences were seen. In both PT exercises, lay counselors and nurses had more difficulties interpreting results, with more occurrences of false-negative, false-positive and indeterminate results. Having received the standard HIV rapid testing training and adherence to the national HIV testing algorithm were positively associated with accuracy.The study showed an improvement in tester group and overall accuracy from the first PT exercise to the next. Average number of incorrect test results per 1000 tests performed was reduced from 69 to 31. Further improvement is needed, however, and the national HIV proficiency testing system seems to be an important tool in this regard, which should be continued and needs to be urgently strengthened.

  17. Serodiagnostic profiles of HIV and HIV pathogenesis in vivo

    NARCIS (Netherlands)

    Goudsmit, J.; Lange, J. M.; Smit, L.; Bakker, M.; Klaver, B.; Danner, S. A.; Coutinho, R. A.

    1988-01-01

    Different stages of HIV infection are marked by expression of HIV genes, production of HIV antibodies, formation of antigen/antibody complexes and clearance of such complexes. Transient HIV antigenemia appearing generally 6-8 weeks prior to HIV antibody (HIV-Ab) seroconversion and lasting 3-4 months

  18. Decreased Fc receptor expression on innate immune cells is associated with impaired antibody-mediated cellular phagocytic activity in chronically HIV-1 infected individuals.

    Science.gov (United States)

    Dugast, Anne-Sophie; Tonelli, Andrew; Berger, Christoph T; Ackerman, Margaret E; Sciaranghella, Gaia; Liu, Qingquan; Sips, Magdalena; Toth, Ildiko; Piechocka-Trocha, Alicja; Ghebremichael, Musie; Alter, Galit

    2011-07-05

    In addition to neutralization, antibodies mediate other antiviral activities including antibody-dependent cellular phagocytosis (ADCP), antibody-dependent cellular cytotoxicity (ADCC), as well as complement deposition. While it is established that progressive HIV infection is associated with reduced ADCC and ADCP, the underlying mechanism for this loss of function is unknown. Here we report considerable changes in FcR expression over the course of HIV infection on both mDCs and monocytes, including elevated FcγRI expression in acute HIV infection and reduced expression of FcγRII and FcγRIIIa in chronic HIV infection. Furthermore, selective blockade of FcγRII alone was associated with a loss in ADCP activity, suggesting that FcγRII plays a central role in modulating ADCP. Overall, HIV infection is associated with a number of changes in FcR expression on phagocytic cells that are associated with changes in their ability to respond to antibody-opsonized targets, potentially contributing to a failure in viral clearance in progressive HIV-1 infection. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. Decreased Fc-Receptor expression on innate immune cells is associated with impaired antibody mediated cellular phagocytic activity in chronically HIV-1 infected individuals

    Science.gov (United States)

    Dugast, Anne-Sophie; Tonelli, Andrew; Berger, Christoph T.; Ackerman, Margaret E.; Sciaranghella, Gaia; Liu, Qingquan; Sips, Magdalena; Toth, Ildiko; Piechocka-Trocha, Alicja; Ghebremichael, Musie; Alter, Galit

    2011-01-01

    In addition to neutralization, antibodies mediate other antiviral activities including antibody-dependent cellular-phagocytosis (ADCP), antibody dependent cellular-cytotoxicity (ADCC), as well as complement deposition. While it is established that progressive HIV infection is associated with reduced ADCC and ADCP, the underlying mechanism for this loss of function is unknown. Here we report considerable changes in FcR expression over the course of HIV infection on both mDCs and monocytes, including elevated FcγRI expression in acute HIV infection and reduced expression of FcγRII and FcγRIIIa in chronic HIV infection. Furthermore, selective blockade of FcγRII alone was associated with a loss in ADCP activity, suggesting that FcγRII plays a central role in modulating ADCP. Overall, HIV infection is associated with a number of changes in FcR expression on phagocytic cells that are associated with changes in their ability to respond to antibody-opsonized targets, potentially contributing to a failure in viral clearance in progressive HIV-1 infection. PMID:21565376

  20. Diagnostic accuracy and acceptability of rapid HIV oral testing among adults attending an urban public health facility in Kampala, Uganda.

    Directory of Open Access Journals (Sweden)

    Joanita Nangendo

    Full Text Available The prevalence of HIV in Uganda is 7.3%, and yet nearly 40% of people living with HIV are unaware of their status. The current HIV testing policy which is strictly blood-based poses several challenges including: a need for high level laboratory skills, stringent waste disposal needs, and painful sample collection. It is envisaged that introduction of a rapid, painless HIV oral fluid test as a potential alternative is likely to increase the number of people testing. The aim of this study was to determine the diagnostic accuracy and acceptability of rapid HIV oral testing among adults attending Kisenyi Health Centre IV in Kampala.We conducted a cross-sectional study among 440 adults recruited consecutively at Kisenyi Health Centre IV from January to March 2016. The diagnostic accuracy of the HIV oral test was assessed by comparing to the national HIV serial testing algorithm. We also assessed for acceptability among patients and health care workers (HCWs by triangulating responses from a structured questionnaire, three focus group discussions and seven key informant interviews. Acceptability was defined as willingness to take the test at the time of the study and intention for future use of the test if it was availed. The prevalence of HIV infection among study participants was 14.8%. The HIV oral fluid test was highly accurate with sensitivity of 100% (95% CI; 94.5-100.0, specificity of 100% (95% CI; 99.0-100.0, positive predictive value (PPV of 100% (95% CI; 94.5-100.0 and negative predictive value (NPV of 100% (95% CI; 99.0-100.0. Acceptability of HIV oral testing was also high at 87.0% (95% CI; 83.6-89.9. Participants preferred HIV oral testing because it was: pain free (91%, n = 399 and did not require blood draw (82%, n = 360.The HIV oral fluid test has high diagnostic accuracy and acceptability. HIV oral testing is a suitable addition to the national HIV testing strategies with the potential of increasing access to HIV testing services in

  1. Dilution testing using rapid diagnostic tests in a HIV diagnostic algorithm: a novel alternative for confirmation testing in resource limited settings.

    Science.gov (United States)

    Shanks, Leslie; Siddiqui, M Ruby; Abebe, Almaz; Piriou, Erwan; Pearce, Neil; Ariti, Cono; Masiga, Johnson; Muluneh, Libsework; Wazome, Joseph; Ritmeijer, Koert; Klarkowski, Derryck

    2015-05-14

    Current WHO testing guidelines for resource limited settings diagnose HIV on the basis of screening tests without a confirmation test due to cost constraints. This leads to a potential risk of false positive HIV diagnosis. In this paper, we evaluate the dilution test, a novel method for confirmation testing, which is simple, rapid, and low cost. The principle of the dilution test is to alter the sensitivity of a rapid diagnostic test (RDT) by dilution of the sample, in order to screen out the cross reacting antibodies responsible for falsely positive RDT results. Participants were recruited from two testing centres in Ethiopia where a tiebreaker algorithm using 3 different RDTs in series is used to diagnose HIV. All samples positive on the initial screening RDT and every 10th negative sample underwent testing with the gold standard and dilution test. Dilution testing was performed using Determine™ rapid diagnostic test at 6 different dilutions. Results were compared to the gold standard of Western Blot; where Western Blot was indeterminate, PCR testing determined the final result. 2895 samples were recruited to the study. 247 were positive for a prevalence of 8.5 % (247/2895). A total of 495 samples underwent dilution testing. The RDT diagnostic algorithm misclassified 18 samples as positive. Dilution at the level of 1/160 was able to correctly identify all these 18 false positives, but at a cost of a single false negative result (sensitivity 99.6 %, 95 % CI 97.8-100; specificity 100 %, 95 % CI: 98.5-100). Concordance between the gold standard and the 1/160 dilution strength was 99.8 %. This study provides proof of concept for a new, low cost method of confirming HIV diagnosis in resource-limited settings. It has potential for use as a supplementary test in a confirmatory algorithm, whereby double positive RDT results undergo dilution testing, with positive results confirming HIV infection. Negative results require nucleic acid testing to rule out false

  2. An Integrated Solution-Based Rapid Sample Preparation Procedure for the Analysis of N-Glycans From Therapeutic Monoclonal Antibodies.

    Science.gov (United States)

    Aich, Udayanath; Liu, Aston; Lakbub, Jude; Mozdzanowski, Jacek; Byrne, Michael; Shah, Nilesh; Galosy, Sybille; Patel, Pramthesh; Bam, Narendra

    2016-03-01

    Consistent glycosylation in therapeutic monoclonal antibodies is a major concern in the biopharmaceutical industry as it impacts the drug's safety and efficacy and manufacturing processes. Large numbers of samples are created for the analysis of glycans during various stages of recombinant proteins drug development. Profiling and quantifying protein N-glycosylation is important but extremely challenging due to its microheterogeneity and more importantly the limitations of existing time-consuming sample preparation methods. Thus, a quantitative method with fast sample preparation is crucial for understanding, controlling, and modifying the glycoform variance in therapeutic monoclonal antibody development. Presented here is a rapid and highly quantitative method for the analysis of N-glycans from monoclonal antibodies. The method comprises a simple and fast solution-based sample preparation method that uses nontoxic reducing reagents for direct labeling of N-glycans. The complete work flow for the preparation of fluorescently labeled N-glycans takes a total of 3 h with less than 30 min needed for the release of N-glycans from monoclonal antibody samples. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  3. A rapid radioimmunoassay using 125I-labeled staphylococcal protein A for antibody to varicella-zoster virus

    International Nuclear Information System (INIS)

    Richman, D.D.; Cleveland, P.H.; Oxman, M.N.; Zaia, J.A.

    1981-01-01

    A sensitive radioimmunoassay for serum antibody to varicella-zoster virus is described; it uses 125I-labeled staphylococcal protein A and a specially designed immunofiltration apparatus. The assay accurately distinguishes between individuals who are susceptible and those who are immune to infection with varicella-zoster virus. In addition, it can detect passive antibody in recipients of varicella-zoster immune globulin. This radioimmunoassay also detects the heterologous antibody responses that occasionally occur in patients infected with herpes simplex virus, which also have been detected by other antibody assays. The particular advantages of this assay are the use of noninfectious reagents, the speed of execution (less than 3 hr), the requirement for only small quantities of serum (30 microliters), the objectivity of end-point determination, and the capability of screening large numbers of sera. Consequently, this radioimmunoassay is especially useful for the rapid identification of susceptible individuals, which is essential for the appropriate management of patients and hospital personnel after exposure to varicella

  4. Prevalence of XMRV Nucleic Acid and Antibody in HIV-1-Infected Men and in Men at Risk for HIV-1 Infection

    Directory of Open Access Journals (Sweden)

    J. Spindler

    2011-01-01

    Full Text Available Xenotropic MLV-Related Virus (XMRV was recently reported to be associated with prostate cancer and chronic fatigue syndrome (CFS. Infection was also reported in 3.7% of healthy individuals. These highly reported frequencies of infection prompted concerns about the possibility of a new, widespread retroviral epidemic. The Multicenter AIDS Cohort Study (MACS provides an opportunity to assess the prevalence of XMRV infection and its association with HIV-1 infection among men who have sex with men. Reliable detection of XMRV infection requires the application of multiple diagnostic methods, including detection of human antibodies to XMRV and detection of XMRV nucleic acid. We, therefore, tested 332 patient plasma and PBMC samples obtained from recent visits in a subset of patients in the MACS cohort for XMRV antibodies using Abbott prototype ARCHITECT chemiluminescent immunoassays (CMIAs and for XMRV RNA and proviral DNA using a XMRV single-copy qPCR assay (X-SCA. Although 9 of 332 (2.7% samples showed low positive reactivity against a single antigen in the CMIA, none of these samples or matched controls were positive for plasma XMRV RNA or PBMC XMRV DNA by X-SCA. Thus, we found no evidence of XMRV infection among men in the MACS regardless of HIV-1 serostatus.

  5. Differences in Allelic Frequency and CDRH3 Region Limit the Engagement of HIV Env Immunogens by Putative VRC01 Neutralizing Antibody Precursors

    Directory of Open Access Journals (Sweden)

    Christina Yacoob

    2016-11-01

    Full Text Available Elicitation of broadly neutralizing antibodies remains a long-standing goal of HIV vaccine research. Although such antibodies can arise during HIV-1 infection, gaps in our knowledge of their germline, pre-immune precursor forms, as well as on their interaction with viral Env, limit our ability to elicit them through vaccination. Studies of broadly neutralizing antibodies from the VRC01-class provide insight into progenitor B cell receptors (BCRs that could develop into this class of antibodies. Here, we employed high-throughput heavy chain variable region (VH/light chain variable region (VL deep sequencing, combined with biophysical, structural, and modeling antibody analyses, to interrogate circulating potential VRC01-progenitor BCRs in healthy individuals. Our study reveals that not all humans are equally predisposed to generate VRC01-class antibodies, not all predicted progenitor VRC01-expressing B cells can bind to Env, and the CDRH3 region of germline VRC01 antibodies influence their ability to recognize HIV-1. These findings will be critical to the design of optimized immunogens that should consider CDRH3 interactions.

  6. A Lateral Flow Protein Microarray for Rapid and Sensitive Antibody Assays

    Directory of Open Access Journals (Sweden)

    Helene Andersson-Svahn

    2011-11-01

    Full Text Available Protein microarrays are useful tools for highly multiplexed determination of presence or levels of clinically relevant biomarkers in human tissues and biofluids. However, such tools have thus far been restricted to laboratory environments. Here, we present a novel 384-plexed easy to use lateral flow protein microarray device capable of sensitive (< 30 ng/mL determination of antigen-specific antibodies in ten minutes of total assay time. Results were developed with gold nanobeads and could be recorded by a cell-phone camera or table top scanner. Excellent accuracy with an area under curve (AUC of 98% was achieved in comparison with an established glass microarray assay for 26 antigen-specific antibodies. We propose that the presented framework could find use in convenient and cost-efficient quality control of antibody production, as well as in providing a platform for multiplexed affinity-based assays in low-resource or mobile settings.

  7. The HIV-1 V3 domain on field isolates: participation in generation of escape virus in vivo and accessibility to neutralizing antibodies

    DEFF Research Database (Denmark)

    Arendrup, M; Akerblom, L; Heegaard, P M

    1995-01-01

    The V3 domain is highly variable and induces HIV neutralizing antibodies (NA). Here we addressed the issues of 1) the participation of mutations in V3 in generation of neutralization resistant escape virus in vivo and 2) the applicability of synthetic V3 peptides corresponding to field isolates...... to induce neutralizing immune sera. Seven peptides corresponding to the V3 region of primary and escape virus from 3 HIV-1 infected patients were synthesized and used for antibody (Abs) studies and immunizations. The anti-V3 Abs titre in patient serum was generally low against peptides corresponding...... to autologous virus isolated later than the serum sample in contrast to the titre against peptides corresponding to virus isolated earlier than the serum sample. Furthermore, neutralizing anti-V3 monoclonal antibodies (MAbs) raised against V3 peptides from laboratory strains of HIV-1 showed distinct binding...

  8. A radioimmunoassay method for the rapid detection of Candida antibodies is experimental systematic candidiasis

    International Nuclear Information System (INIS)

    Huang, Y.; Berry, W.; Cooper, H.; Zachariah, Y.; Newman, T.

    1979-01-01

    Rabbits were employed as experimental models to evaluate a solid-phase radioimmunoassay (RIA) method for the diagnosis of systematic candidiasis. Ten rabbits were incubated subcutaneously to mimic superficial candidiasis and were found to produce no antibodies to Candida as determined by both immunodiffusion and RIA procedures. However, 94 per cent of 18 rabbits systematically infected by intravenous injection of Candida cells were observed to produce antibody as assessed by the RIA technique. These data encourage further tests with human sera and the continued development of this RIA procedure as a useful tool in the early serodiagnosis of systematic candidiasis. (Auth.)

  9. The neuromyelitis optica presentation and the aquaporin-4 antibody in HIV-seropositive and seronegative patients in KwaZulu-Natal, South Africa

    Directory of Open Access Journals (Sweden)

    Ahmed I. Bhigjee

    2017-01-01

    Full Text Available Background: The association of the anti-aquaporin-4 (AQP-4 water channel antibody with neuromyelitis optica (NMO syndrome has been described from various parts of the world. There has been no large study describing this association from southern Africa, an HIV endemic area. HIV patients often present with visual disturbance or features of a myelopathy but seldom both either simultaneously or consecutively. We report our experience of NMO in the era of AQP-4 testing in HIV-positive and HIV-negative patients seen in KwaZulu-Natal, South Africa. Methods: A retrospective chart review was undertaken of NMO cases seen from January 2005 to April 2016 in two neurology units serving a population of 7.1 million adults. The clinical, radiological and relevant laboratory data were extracted from the files and analysed. Results: There were 12 HIV-positive patients (mean age 33 years, 9 (75% were women and all 12 were black patients. Of the 17 HIV-negative patients (mean age 32 years, 15 (88% were women and 10 (59% were black people. The clinical features in the two groups ranged from isolated optic neuritis, isolated longitudinally extensive myelitis or combinations. Recurrent attacks were noted in six HIV-positive patients and six HIV-negative patients. The AQP-4 antibody was positive in 4/10 (40% HIV-positive patients and 11/13 (85% HIV-negative patients. The radiological changes ranged from longitudinal hyperintense spinal cord lesions and long segment enhancing lesions of the optic nerves. Three patients, all HIV-positive, had tumefactive lesions with incomplete ring enhancement. Conclusion: This study confirms the presence of AQP-4-positive NMO in southern Africa in both HIV-positive and HIV-negative patients. The simultaneous or consecutive occurrence of optic neuritis and myelitis in an HIV-positive patient should alert the clinician to test for the AQP-4 antibody. It is important to recognise this clinical syndrome as specific therapy is available

  10. Rapid Active Assay for the Detection of Antibodies to West Nile Virus in Chickens

    National Research Council Canada - National Science Library

    Groves, Stephanie S; Turell, Michael J; Bailey, Charles L; Morozov, Victor N

    2008-01-01

    ... by detection of bound IgM molecules with functionalized magnetic beads as active labels. This assay takes only 15 minutes and has the same sensitivity as a commercially available human WNV IgM antibody-capture enzyme-linked immunosorbent assay...

  11. Development of a Rapid Qualitative Assay for Determining Elevated Antibody Levels to Periodontopathic Organisms

    Science.gov (United States)

    1990-01-01

    stemic antibody titers to ".actinomycetemcornitans, B.gingivalis, Cochracea, and Eubacterium saburreum either de(., cased or remained similar to...1984b) Serological identification of oral Bacteroides spp . by enzyme-linked immunosorbent assay. J. Clin. Microbiol. 19: 639-644. Ebersole, J.L

  12. Boosting of HIV-1 neutralizing antibody responses by a distally related retroviral envelope protein

    DEFF Research Database (Denmark)

    Uchtenhagen, Hannes; Schiffner, Torben; Bowles, Emma

    2014-01-01

    Our knowledge of the binding sites for neutralizing Abs (NAb) that recognize a broad range of HIV-1 strains (bNAb) has substantially increased in recent years. However, gaps remain in our understanding of how to focus B cell responses to vulnerable conserved sites within the HIV-1 envelope glycop...

  13. Anti-HCV antibody among newly diagnosed HIV patients in Ughelli ...

    African Journals Online (AJOL)

    Background: Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) share common routes of infection and ... drug users (IDU)7. HCV occurrence among people living with HIV has long been reported. This is of great medical impor- tance as 80% HCV infection are ..... before transfusion or organ transplantation.

  14. Clients of sex workers in Switzerland: it makes sense to counsel and propose rapid test for HIV on the street, a preliminary report.

    Science.gov (United States)

    Diserens, Esther-Amélie; Bodenmann, Patrick; N'Garambe, Chantal; Ansermet-Pagot, Anne; Vannotti, Marco; Masserey, Eric; Cavassini, Matthias

    2010-03-19

    Clients of street sex workers may be at higher risk for HIV infection than the general population. Furthermore, there is a lack of knowledge regarding HIV testing of clients of sex workers in developed countries. This pilot study assessed the feasibility and acceptance of rapid HIV testing by the clients of street-based sex workers in Lausanne, Switzerland. For 5 evenings, clients in cars were stopped by trained field staff for face-to-face interviews focusing on sex-related HIV risk behaviors and HIV testing history. The clients were then offered a free anonymous rapid HIV test in a bus parked nearby. Rapid HIV testing and counselling were performed by experienced nurse practitioners. Clients with reactive tests were offered confirmatory testing, medical evaluation, and care in our HIV clinic. We intercepted 144 men, 112 (77.8%) agreed to be interviewed. Among them, 50 (46.6%) had never been tested for HIV. A total of 31 (27.7%) rapid HIV tests were performed, 16 (51.6%) in clients who had not previously been tested. None were reactive. Initially, 19 (16.9%) additional clients agreed to HIV testing but later declined due to the 40-minute queue for testing. This pilot study showed that rapid HIV testing in the red light district of Lausanne was feasible, and that the clients of sex workers accepted testing at an unexpectedly high rate. This setting seems particularly appropriate for targeted HIV screening, since more than 40% of the clients had not previously been tested for HIV even though they engaged in sex-related HIV risk behaviour.

  15. Modified wick method using Weck-Cel sponges for collection of human rectal secretions and analysis of mucosal HIV antibody.

    Science.gov (United States)

    Kozlowski, P A; Lynch, R M; Patterson, R R; Cu-Uvin, S; Flanigan, T P; Neutra, M R

    2000-08-01

    Weck-Cel sponges were examined for suitability as an absorbent material for nontraumatic collection of rectal secretions in humans. Sponges were tested in vitro and determined by quantitative enzyme-linked immunosorbent assay (ELISA) to be capable of releasing 100% of absorbed albumin and all immunoglobulin subtypes after treatment with detergent-supplemented buffer. Protein composition in rectal secretions collected from normal women with dry sponges (DS) or with sponges previously softened by moistening with saline (MS) was subsequently compared. DS secretions showed evidence of contamination with blood and interstitial fluid-derived albumin, immunoglobulin G (IgG), and monomeric IgA. MS secretions appeared to represent local mucosal secretions more accurately because they contained negligible blood, a greater percentage of secretory IgA within the total IgA, and both lower albumin/IgG ratios and more dramatic alterations in IgG subclass distribution compared with corresponding serum. Anti-HIV IgG, IgM, IgA, and antibodies with secretory component could be demonstrated by ELISA in rectal secretions collected with moist sponges from 8 of 8, 1 of 8, 5 of 8, and 3 of 8 HIV-infected women, respectively. The data show that Weck-Cel sponges, if premoistened, can be used to collect rectal fluids nontraumatically and to obtain quantitative information about concentrations of immunoglobulins and specific antibodies on rectal mucosal surfaces.

  16. Rapid selection of escape mutants by the first CD8 T cell responses in acute HIV-1 infection

    Energy Technology Data Exchange (ETDEWEB)

    Korber, Bette Tina Marie [Los Alamos National Laboratory

    2008-01-01

    The recent failure of a vaccine that primes T cell responses to control primary HIV-1 infection has raised doubts about the role of CD8+ T cells in early HIV-1 infection. We studied four patients who were identified shortly after HIV-1 infection and before seroconversion. In each patient there was very rapid selection of multiple HIV-1 escape mutants in the transmitted virus by CD8 T cells, including examples of complete fixation of non-synonymous substitutions within 2 weeks. Sequencing by single genome amplification suggested that the high rate of virus replication in acute infection gave a selective advantage to virus molecules that contained simultaneous and gained sequential T cell escape mutations. These observations show that whilst early HIV-1 specific CD8 T cells can act against virus, rapid escape means that these T cell responses are unlikely to benefit the patient and may in part explain why current HIV-1 T cell vaccines may not be protective.

  17. Evaluating quality management systems for HIV rapid testing services in primary healthcare clinics in rural KwaZulu-Natal, South Africa

    OpenAIRE

    Jaya, Ziningi; Drain, Paul K.; Mashamba-Thompson, Tivani P.

    2017-01-01

    Introduction Rapid HIV tests have improved access to HIV diagnosis and treatment by providing quick and convenient testing in rural clinics and resource-limited settings. In this study, we evaluated the quality management system for voluntary and provider-initiated point-of-care HIV testing in primary healthcare (PHC) clinics in rural KwaZulu-Natal (KZN), South Africa. Material and methods We conducted a quality assessment audit in eleven PHC clinics that offer voluntary HIV testing and couns...

  18. The Isolation of Novel Phage Display-Derived Human Recombinant Antibodies Against CCR5, the Major Co-Receptor of HIV

    Science.gov (United States)

    Shimoni, Moria; Herschhorn, Alon; Britan-Rosich, Yelena; Kotler, Moshe; Benhar, Itai

    2013-01-01

    Abstract Selecting for antibodies against specific cell-surface proteins is a difficult task due to many unrelated proteins that are expressed on the cell surface. Here, we describe a method to screen antibody-presenting phage libraries against native cell-surface proteins. We applied this method to isolate antibodies that selectively recognize CCR5, which is the major co-receptor for HIV entry (consequently, playing a pivotal role in HIV transmission and pathogenesis). We employed a phage screening strategy by using cells that co-express GFP and CCR5, along with an excess of control cells that do not express these proteins (and are otherwise identical to the CCR5-expressing cells). These control cells are intended to remove most of the phages that bind the cells nonspecifically; thus leading to an enrichment of the phages presenting anti-CCR5-specific antibodies. Subsequently, the CCR5-presenting cells were quantitatively sorted by flow cytometry, and the bound phages were eluted, amplified, and used for further successive selection rounds. Several different clones of human single-chain Fv antibodies that interact with CCR5-expressing cells were identified. The most specific monoclonal antibody was converted to a full-length IgG and bound the second extracellular loop of CCR5. The experimental approach presented herein for screening for CCR5-specific antibodies can be applicable to screen antibody-presenting phage libraries against any cell-surface expressed protein of interest. PMID:23941674

  19. Analysis of V2 antibody responses induced in vaccinees in the ALVAC/AIDSVAX HIV-1 vaccine efficacy trial.

    Directory of Open Access Journals (Sweden)

    Susan Zolla-Pazner

    Full Text Available The RV144 clinical trial of a prime/boost immunizing regimen using recombinant canary pox (ALVAC-HIV and two gp120 proteins (AIDSVAX B and E was previously shown to have a 31.2% efficacy rate. Plasma specimens from vaccine and placebo recipients were used in an extensive set of assays to identify correlates of HIV-1 infection risk. Of six primary variables that were studied, only one displayed a significant inverse correlation with risk of infection: the antibody (Ab response to a fusion protein containing the V1 and V2 regions of gp120 (gp70-V1V2. This finding prompted a thorough examination of the results generated with the complete panel of 13 assays measuring various V2 Abs in the stored plasma used in the initial pilot studies and those used in the subsequent case-control study. The studies revealed that the ALVAC-HIV/AIDSVAX vaccine induced V2-specific Abs that cross-react with multiple HIV-1 subgroups and recognize both conformational and linear epitopes. The conformational epitope was present on gp70-V1V2, while the predominant linear V2 epitope mapped to residues 165-178, immediately N-terminal to the putative α4β7 binding motif in the mid-loop region of V2. Odds ratios (ORs were calculated to compare the risk of infection with data from 12 V2 assays, and in 11 of these, the ORs were ≤1, reaching statistical significance for two of the variables: Ab responses to gp70-V1V2 and to overlapping V2 linear peptides. It remains to be determined whether anti-V2 Ab responses were directly responsible for the reduced infection rate in RV144 and whether anti-V2 Abs will prove to be important with other candidate HIV vaccines that show efficacy, however, the results support continued dissection of Ab responses to the V2 region which may illuminate mechanisms of protection from HIV-1 infection and may facilitate the development of an effective HIV-1 vaccine.

  20. Feasibility of implementing rapid oral fluid HIV testing in an urban University Dental Clinic: a qualitative study

    Directory of Open Access Journals (Sweden)

    Hutchinson M

    2012-05-01

    Full Text Available Abstract Background More than 1 million individuals in the U.S. are infected with HIV; approximately 20% of whom do not know they are infected. Early diagnosis of HIV infection results in earlier access to treatment and reductions in HIV transmission. In 2006, the CDC recommended that health care providers offer routine HIV screening to all adolescent and adult patients, regardless of community seroprevalence or patient lifestyle. Dental providers are uniquely positioned to implement these recommendations using rapid oral fluid HIV screening technology. However, thus far, uptake into dental practice has been very limited. Methods The study utilized a qualitative descriptive approach with convenience samples of dental faculty and students. Six in-depth one-on-one interviews were conducted with dental faculty and three focus groups were conducted with fifteen dental students. Results Results were fairly consistent and indicated relatively high levels of acceptability. Barriers and facilitators of oral fluid HIV screening were identified in four primary areas: scope of practice/practice enhancement, skills/knowledge/training, patient service/patient reactions and logistical issues. Conclusions Oral fluid HIV screening was described as having benefits for patients, dental practitioners and the public good. Many of the barriers to implementation that were identified in the study could be addressed through training and interdisciplinary collaborations.

  1. Safety and pharmacokinetics of the Fc-modified HIV-1 human monoclonal antibody VRC01LS: A Phase 1 open-label clinical trial in healthy adults

    OpenAIRE

    Gaudinski, Martin R.; Coates, Emily E.; Houser, Katherine V.; Chen, Grace L.; Yamshchikov, Galina; Saunders, Jamie G.; Holman, LaSonji A.; Gordon, Ingelise; Plummer, Sarah; Hendel, Cynthia S.; Conan-Cibotti, Michelle; Lorenzo, Margarita Gomez; Sitar, Sandra; Carlton, Kevin; Laurencot, Carolyn

    2018-01-01

    Background VRC01 is a human broadly neutralizing monoclonal antibody (bnMAb) against the CD4-binding site of the HIV-1 envelope glycoprotein (Env) that is currently being evaluated in a Phase IIb adult HIV-1 prevention efficacy trial. VRC01LS is a modified version of VRC01, designed for extended serum half-life by increased binding affinity to the neonatal Fc receptor. Methods and findings This Phase I dose-escalation study of VRC01LS in HIV-negative healthy adults was conducted by the Vaccin...

  2. The initial antibody response to HIV-1: induction of ineffective early B cell responses against GP41 by the transmitted/founder virus

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, Leslie L [Los Alamos National Laboratory; Perelson, Alan [Los Alamos National Laboratory

    2008-01-01

    A window of opportunity for immune responses to extinguish HIV -1 exists from the moment of transmission through establishment of the latent pool of HIV -I-infected cells. A critical time to study the initial immune responses to the transmitted/founder virus is the eclipse phase of HIV-1 infection (time from transmission to the first appearance of plasma virus) but, to date, this period has been logistically difficult to analyze. Studies in non-human primates challenged with chimeric simianhuman immunodeficiency virus have shown that neutralizing antibodies, when present at the time of infection, can prevent virus infection.

  3. HIV Viral Load

    Science.gov (United States)

    ... PF4 Antibody Hepatitis A Testing Hepatitis B Testing Hepatitis C Testing HER2/neu Herpes Testing High-sensitivity C-reactive Protein (hs-CRP) Histamine Histone Antibody HIV Antibody and HIV Antigen (p24) HIV Antiretroviral Drug Resistance Testing, Genotypic HIV Viral Load HLA Testing HLA- ...

  4. Seroprevalence of Toxoplasma gondii IgG antibody in HIV/AIDS-infected individuals in Maputo, Mozambique

    Directory of Open Access Journals (Sweden)

    Abílio Domingos

    2013-10-01

    Full Text Available OBJECTIVE To analyze the prevalence of IgG antibodies to Toxoplasma gondii in patients infected with HIV/AIDS and the association of demographic and social variables. METHODS Descriptive cross-sectional study that included the analysis of sociodemographic data and laboratory findings of 200 patients infected with HIV/AIDS treated in a laboratory unit in Maputo, Mozambique, in 2010. Individual data for all participants were collected with a self-administered questionnaire. Plasma samples were tested for IgG testing of anti- T. gondii using hemagglutination for the analysis of antibodies. RESULTS The seroprevalence of IgG anti- T. gondii was 46.0% (95%CI 39.2;52.9, 39.3% (95%CI 29.5;50.0 in men and 50.9% (95%CI 41.9;59.8 in women, with no difference between sex (OR 1.30; 95%CI 0.95;1.77; p = 0.12. Ages ranged from 10 to 60 years, with a higher prevalence of infection in older age groups, but with no significant difference between them. Regularly consuming cattle meat (OR 1.74; 95%CI 1.04;2.89, p = 0.05, breeding cats/dogs (OR 6.18; 95%CI 3.60;10.62, p < 0.000 and having regular contact with soil (OR 3.38; 95%CI 2.19;5.21; p < 0.000 were significantly associated with risk of latent infection. CONCLUSIONS Toxoplasmosis is an infection with high prevalence in Mozambique. Cultural and behavioral aspects increase the risk. Toxoplasmosis can be responsible in our environment by the great burden of morbidity and mortality associated with meningoencephalic injuries in patients with HIV/AIDS.

  5. Nef decreases HIV-1 sensitivity to neutralizing antibodies that target the membrane-proximal external region of TMgp41.

    Directory of Open Access Journals (Sweden)

    Rachel P J Lai

    2011-12-01

    Full Text Available Primate lentivirus nef is required for sustained virus replication in vivo and accelerated progression to AIDS. While exploring the mechanism by which Nef increases the infectivity of cell-free virions, we investigated a functional link between Nef and Env. Since we failed to detect an effect of Nef on the quantity of virion-associated Env, we searched for qualitative changes by examining whether Nef alters HIV-1 sensitivity to agents that target distinct features of Env. Nef conferred as much as 50-fold resistance to 2F5 and 4E10, two potent neutralizing monoclonal antibodies (nAbs that target the membrane proximal external region (MPER of TMgp41. In contrast, Nef had no effect on HIV-1 neutralization by MPER-specific nAb Z13e1, by the peptide inhibitor T20, nor by a panel of nAbs and other reagents targeting gp120. Resistance to neutralization by 2F5 and 4E10 was observed with Nef from a diverse range of HIV-1 and SIV isolates, as well as with HIV-1 virions bearing Env from CCR5- and CXCR4-tropic viruses, clade B and C viruses, or primary isolates. Functional analysis of a panel of Nef mutants revealed that this activity requires Nef myristoylation but that it is genetically separable from other Nef functions such as the ability to enhance virus infectivity and to downregulate CD4. Glycosylated-Gag from MoMLV substituted for Nef in conferring resistance to 2F5 and 4E10, indicating that this activity is conserved in a retrovirus that does not encode Nef. Given the reported membrane-dependence of MPER-recognition by 2F5 and 4E10, in contrast to the membrane-independence of Z13e1, the data here is consistent with a model in which Nef alters MPER recognition in the context of the virion membrane. Indeed, Nef and Glycosylated-Gag decreased the efficiency of virion capture by 2F5 and 4E10, but not by other nAbs. These studies demonstrate that Nef protects lentiviruses from one of the most broadly-acting classes of neutralizing antibodies. This newly

  6. Rapid Identification of Dengue Virus Serotypes Using Monoclonal Antibodies in an Indirect Immunofluorescence Test.

    Science.gov (United States)

    1982-06-18

    encephalitis(TBH-28), West Nile(E-101), Yellow fever(French neurotropic and 17D strains), and Zika . Two Sandfly Fever viruses (213452 and Candiru) were...were provided as first passage isolates ( Aedes pseudoscutellaris cells, AP-61) or human serum from recent dengue virus patients. African isolates... viruses of the Phlebovirus genus (Table 1). Several monoclonal antibody preparations reacted solely with dengue virus serotypes. Two preparations (13E7 and

  7. Neutralizing Activity of Broadly Neutralizing Anti-HIV-1 Antibodies against Clade B Clinical Isolates Produced in Peripheral Blood Mononuclear Cells.

    Science.gov (United States)

    Cohen, Yehuda Z; Lorenzi, Julio C C; Seaman, Michael S; Nogueira, Lilian; Schoofs, Till; Krassnig, Lisa; Butler, Allison; Millard, Katrina; Fitzsimons, Tomas; Daniell, Xiaoju; Dizon, Juan P; Shimeliovich, Irina; Montefiori, David C; Caskey, Marina; Nussenzweig, Michel C

    2018-03-01

    Recently discovered broadly neutralizing antibodies (bNAbs) against HIV-1 demonstrate extensive breadth and potency against diverse HIV-1 strains and represent a promising approach for the treatment and prevention of HIV-1 infection. The breadth and potency of these antibodies have primarily been evaluated by using panels of HIV-1 Env-pseudotyped viruses produced in 293T cells expressing molecularly cloned Env proteins. Here we report on the ability of five bNAbs currently in clinical development to neutralize circulating primary HIV-1 isolates derived from peripheral blood mononuclear cells (PBMCs) and compare the results to those obtained with the pseudovirus panels used to characterize the bNAbs. The five bNAbs demonstrated significantly less breadth and potency against clinical isolates produced in PBMCs than against Env-pseudotyped viruses. The magnitude of this difference in neutralizing activity varied, depending on the antibody epitope. Glycan-targeting antibodies showed differences of only 3- to 4-fold, while antibody 10E8, which targets the membrane-proximal external region, showed a nearly 100-fold decrease in activity between published Env-pseudotyped virus panels and PBMC-derived primary isolates. Utilizing clonal PBMC-derived primary isolates and molecular clones, we determined that the observed discrepancy in bNAb performance is due to the increased sensitivity to neutralization exhibited by 293T-produced Env-pseudotyped viruses. We also found that while full-length molecularly cloned viruses produced in 293T cells exhibit greater sensitivity to neutralization than PBMC-derived viruses do, Env-pseudotyped viruses produced in 293T cells generally exhibit even greater sensitivity to neutralization. As the clinical development of bNAbs progresses, it will be critical to determine the relevance of each of these in vitro neutralization assays to in vivo antibody performance. IMPORTANCE Novel therapeutic and preventive strategies are needed to contain the

  8. Boosting of HIV-1 neutralizing antibody responses by a distally related retroviral envelope protein.

    Science.gov (United States)

    Uchtenhagen, Hannes; Schiffner, Torben; Bowles, Emma; Heyndrickx, Leo; LaBranche, Celia; Applequist, Steven E; Jansson, Marianne; De Silva, Thushan; Back, Jaap Willem; Achour, Adnane; Scarlatti, Gabriella; Fomsgaard, Anders; Montefiori, David; Stewart-Jones, Guillaume; Spetz, Anna-Lena

    2014-06-15

    Our knowledge of the binding sites for neutralizing Abs (NAb) that recognize a broad range of HIV-1 strains (bNAb) has substantially increased in recent years. However, gaps remain in our understanding of how to focus B cell responses to vulnerable conserved sites within the HIV-1 envelope glycoprotein (Env). In this article, we report an immunization strategy composed of a trivalent HIV-1 (clade B envs) DNA prime, followed by a SIVmac239 gp140 Env protein boost that aimed to focus the immune response to structurally conserved parts of the HIV-1 and simian immunodeficiency virus (SIV) Envs. Heterologous NAb titers, primarily to tier 1 HIV-1 isolates, elicited during the trivalent HIV-1 env prime, were significantly increased by the SIVmac239 gp140 protein boost in rabbits. Epitope mapping of Ab-binding reactivity revealed preferential recognition of the C1, C2, V2, V3, and V5 regions. These results provide a proof of concept that a distally related retroviral SIV Env protein boost can increase pre-existing NAb responses against HIV-1. Copyright © 2014 by The American Association of Immunologists, Inc.

  9. Comparison of patient comprehension of rapid HIV pre-test fundamentals by information delivery format in an emergency department setting

    Directory of Open Access Journals (Sweden)

    Clark Melissa A

    2007-09-01

    Full Text Available Abstract Background Two trials were conducted to compare emergency department patient comprehension of rapid HIV pre-test information using different methods to deliver this information. Methods Patients were enrolled for these two trials at a US emergency department between February 2005 and January 2006. In Trial One, patients were randomized to a no pre-test information or an in-person discussion arm. In Trial Two, a separate group of patients were randomized to an in-person discussion arm or a Tablet PC-based video arm. The video, "Do you know about rapid HIV testing?", and the in-person discussion contained identical Centers for Disease Control and Prevention-suggested pre-test information components as well as information on rapid HIV testing with OraQuick®. Participants were compared by information arm on their comprehension of the pre-test information by their score on a 26-item questionnaire using the Wilcoxon rank-sum test. Results In Trial One, 38 patients completed the no-information arm and 31 completed the in-person discussion arm. Of these 69 patients, 63.8% had twelve years or fewer of formal education and 66.7% had previously been tested for HIV. The mean score on the questionnaire for the in-person discussion arm was higher than for the no information arm (18.7 vs. 13.3, p ≤ 0.0001. In Trial Two, 59 patients completed the in-person discussion and 55 completed the video arms. Of these 114 patients, 50.9% had twelve years or fewer of formal education and 68.4% had previously been tested for HIV. The mean score on the questionnaire for the video arm was similar to the in-person discussion arm (20.0 vs. 19.2; p ≤ 0.33. Conclusion The video "Do you know about rapid HIV testing?" appears to be an acceptable substitute for an in-person pre-test discussion on rapid HIV testing with OraQuick®. In terms of adequately informing ED patients about rapid HIV testing, either form of pre-test information is preferable than for patients

  10. Seroprevalence of transplacentally acquired measles antibodies in HIV-exposed versus HIV-unexposed infants at six months of age

    Directory of Open Access Journals (Sweden)

    Sneha Jain

    2017-01-01

    Interpretation & conclusions: Most HEI lacked measles antibodies at six months age and were, therefore, more vulnerable to measles than HUnI. Seroconversion in response to a single dose of measles vaccine administered at six months age was low in these infants, signifying the need of additional dose(s of measles/measles-containing vaccine.

  11. Self-paired monoclonal antibody lateral flow immunoassay strip for rapid detection of Acidovorax avenae subsp. citrulli.

    Science.gov (United States)

    Zeng, Haijuan; Guo, Wenbo; Liang, Beibei; Li, Jianwu; Zhai, Xuzhao; Song, Chunmei; Zhao, Wenjun; Fan, Enguo; Liu, Qing

    2016-09-01

    We screened a highly specific monoclonal antibody (McAb), named 6D, against Acidovorax avenae subsp. citrulli (Aac). Single McAb 6D was used as both nanogold-labeled antibody and test antibody to develop a single self-paired colloidal gold immunochromatographic test strip (Sa-GICS). The detection limit achieved using the Sa-GICS approach was 10(5) CFU/mL, with a result that can be observed by the naked eye within 10 min. Moreover, Sa-GICS can detect eight strains of Aac and display no cross-reactions with other pathogenic plant microorganisms. Artificial contamination experiments demonstrated that Sa-GICS would not be affected by impurities in the leaves or stems of the plants and were consistent with the PCR results. This is the first report on the development of a colloidal gold immunoassay strip with self-paired single McAb for the rapid detection of Aac. Graphical Abstract Schematic representation of the test strip.

  12. Diphtheria Antibodies and T lymphocyte Counts in Patients Infected with HIV-1

    Directory of Open Access Journals (Sweden)

    Francisco A. B. Speranza

    2012-09-01

    Full Text Available We assessed the IgG levels anti-diphtheria (D-Ab and T cell counts (CD4+ and CD8+ in HIV-1 infected subjects undergoing or not highly active antiretroviral therapy (HAART. Approximately 70% of all HIV-1 patients were unprotected against diphtheria. There were no differences in D-Ab according to CD4 counts. Untreated patients had higher D-Ab (geometric mean of 0.62 IU/ml than HAART-patients (geometric mean of 0.39 IU/ml. The data indicated the necessity of keeping all HIV-1 patients up-to-date with their vaccination.

  13. Evaluating HIV Prevention Programs: Herpes Simplex Virus Type 2 Antibodies as Biomarker for Sexual Risk Behavior in Young Adults in Resource-Poor Countries.

    Directory of Open Access Journals (Sweden)

    Juliane Behling

    Full Text Available Measuring effectiveness of HIV prevention interventions is challenged by bias when using self-reported knowledge, attitude or behavior change. HIV incidence is an objective marker to measure effectiveness of HIV prevention interventions, however, because new infection rates are relatively low, prevention studies require large sample sizes. Herpes simplex virus type 2 (HSV-2 is similarly transmitted and more prevalent and could thus serve as a proxy marker for sexual risk behavior and therefore HIV infection.HSV-2 antibodies were assessed in a sub-study of 70,000 students participating in an education intervention in Western Province, Kenya. Feasibility of testing for HSV-2 antibodies was assessed comparing two methods using Fisher's exact test. Three hundred and ninety four students (aged 18 to 22 years were randomly chosen from the cohort and tested for HIV, Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis. Out of these, 139 students were tested for HSV-2 with ELISA and surveyed for sexual risk behavior and 89 students were additionally tested for HSV-2 with a point-of-contact (POC test.Prevalence rates were 0.5%, 1.8%, 0.3% and 2.3% for HIV, Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis, respectively. Prevalence of HSV-2 antibodies was 3.4 % as measured by POC test (n=89 and 14.4 % by ELISA (n=139. Specificity of the POC test compared with ELISA was 100%, and the sensitivity only 23.1%. Associations between self-reported sexual behavior and HSV-2 serostatus could not be shown.Associations between self-reported sexual risk behavior and HSV-2 serostatus could not be shown, probably due to social bias in interviews since its transmission is clearly linked. HSV-2 antibody testing is feasible in resource-poor settings and shows higher prevalence rates than other sexually transmitted diseases thus representing a potential biomarker for evaluation of HIV prevention interventions.

  14. Cutting edge: Rapid recovery of NKT cells upon institution of highly active antiretroviral therapy for HIV-1 infection

    NARCIS (Netherlands)

    van der Vliet, Hans J. J.; van Vonderen, Marit G. A.; Molling, Johan W.; Bontkes, Hetty J.; Reijm, Martine; Reiss, Peter; van Agtmael, Michiel A.; Danner, Sven A.; van den Eertwegh, Alfons J. M.; von Blomberg, B. Mary E.; Scheper, Rik J.

    2006-01-01

    CD1d-restricted NKT cells play important regulatory roles in various immune responses and are rapidly and selectively depleted upon infection with HIV-1. The cause of this selective depletion is incompletely understood, although it is in part due to the high susceptibility of CD4+ NKT cells to

  15. Polyclonal B cell differentiation and loss of gastrointestinal tract germinal centers in the earliest stages of HIV-1 infection.

    Directory of Open Access Journals (Sweden)

    Marc C Levesque

    2009-07-01

    Full Text Available The antibody response to HIV-1 does not appear in the plasma until approximately 2-5 weeks after transmission, and neutralizing antibodies to autologous HIV-1 generally do not become detectable until 12 weeks or more after transmission. Moreover, levels of HIV-1-specific antibodies decline on antiretroviral treatment. The mechanisms of this delay in the appearance of anti-HIV-1 antibodies and of their subsequent rapid decline are not known. While the effect of HIV-1 on depletion of gut CD4(+ T cells in acute HIV-1 infection is well described, we studied blood and tissue B cells soon after infection to determine the effect of early HIV-1 on these cells.In human participants, we analyzed B cells in blood as early as 17 days after HIV-1 infection, and in terminal ileum inductive and effector microenvironments beginning at 47 days after infection. We found that HIV-1 infection rapidly induced polyclonal activation and terminal differentiation of B cells in blood and in gut-associated lymphoid tissue (GALT B cells. The specificities of antibodies produced by GALT memory B cells in acute HIV-1 infection (AHI included not only HIV-1-specific antibodies, but also influenza-specific and autoreactive antibodies, indicating very early onset of HIV-1-induced polyclonal B cell activation. Follicular damage or germinal center loss in terminal ileum Peyer's patches was seen with 88% of follicles exhibiting B or T cell apoptosis and follicular lysis.Early induction of polyclonal B cell differentiation, coupled with follicular damage and germinal center loss soon after HIV-1 infection, may explain both the high rate of decline in HIV-1-induced antibody responses and the delay in plasma antibody responses to HIV-1. Please see later in the article for Editors' Summary.

  16. Comparative effectiveness of single and dual rapid diagnostic tests for syphilis and HIV in antenatal care services in Colombia

    Directory of Open Access Journals (Sweden)

    Hernando Guillermo Gaitán-Duarte

    Full Text Available ABSTRACT Objective To assess the effectiveness of a dual rapid test compared to a single rapid test for syphilis and HIV screening. Methods A cluster-randomized open-label clinical trial was performed in 12 public antenatal care (ANC centers in the cities of Bogotá and Cali, Colombia. Pregnant women who were over 14 years of age at their first antenatal visit and who had not been previously tested for HIV and syphilis during the current pregnancy were included. Pregnant women were randomized to single HIV and single syphilis rapid diagnostic tests (Arm A or to dual HIV and syphilis rapid diagnostic tests (Arm B. The four main outcomes measured were: (1 acceptability of the test, (2 uptake in testing, (3 treatment on the same day (that is, timely treatment, and (4 treatment at any time for positive rapid test cases. Bivariate and multivariate analyses were calculated to adjust for the clustering effect and the period. Results A total of 1 048 patients were analyzed in Arm A, and 1 166 in Arm B. Acceptability of the rapid tests was 99.8% in Arm A and 99.6% in Arm B. The prevalence of positive rapid tests was 2.21% for syphilis and 0.36% for HIV. Timely treatment was provided to 20 of 29 patients (69% in Arm A and 16 of 20 patients (80% in Arm B (relative risk (RR, 1.10; 95% confidence interval (CI: (1.00 −1.20. Treatment at any time was given to 24 of 29 patients (83% in Arm A and to 20 of 20 (100% in Arm B (RR, 1.11; 95% CI: 1.01−1.22. Conclusions There were no differences in patient acceptability, testing and timely treatment between dual rapid tests and single rapid tests for HIV and syphilis screening in the ANC centers. Same-day treatment depends also on the interpretation of and confidence in the results by the health providers.

  17. A recombinant mimetics of the HIV-1 gp41 prehairpin fusion intermediate fused with human IgG Fc fragment elicits neutralizing antibody response in the vaccinated mice

    International Nuclear Information System (INIS)

    Qi, Zhi; Pan, Chungen; Lu, Hong; Shui, Yuan; Li, Lin; Li, Xiaojuan; Xu, Xueqing; Liu, Shuwen; Jiang, Shibo

    2010-01-01

    Research highlights: → One recombinant mimetics of gp41 prehairpin fusion intermediate (PFI) consisting of gp41 N46 sequence, foldon and IgG Fc, designated N46FdFc, was expressed. → N46FdFc-induced antibodies in mice that neutralized HIV-1 infection, inhibited PIE7 binding to PFI, blocked gp41 six-helix bundle formation, and suppressed HIV-1 mediated cell-cell fusion. → These findings provide an important clue for developing recombinant gp41 PFI mimetics-based HIV vaccines. -- Abstract: HIV-1 gp41 prehairpin fusion intermediate (PFI) composed of three N-terminal heptad repeats (NHR) plays a crucial role in viral fusion and entry and represents an attractive target for anti-HIV therapeutics (e.g., enfuvirtide) and vaccines. In present study, we constructed and expressed two recombinant gp41 PFI mimetics, designated N46Fd and N46FdFc. N46Fd consists of N46 (residues 536-581) in gp41 NHR and foldon (Fd), a trimerization motif. N46FdFc is composed of N46Fd fused with human IgG Fc fragment as an immunoenhancer. We immunized mice with N46 peptide, N46Fd and N46FdFc, respectively, and found that only N46FdFc elicited neutralizing antibody response in mice against infection by HIV-1 strains IIIB (clade B, X4), 92US657 (clade B, R5), and 94UG103 (clade A, X4R5). Anti-N46FdFc antibodies inhibited PIE7 binding to PFI, blocked gp41 six-helix bundle formation, and suppressed HIV-1 mediated cell-cell fusion. These findings provide an important clue for developing recombinant gp41 PFI mimetics-based HIV vaccines.

  18. Characterization of HIV-1 gp120 antibody specificities induced in anogenital secretions of RV144 vaccine recipients after late boost immunizations.

    Directory of Open Access Journals (Sweden)

    Siriwat Akapirat

    Full Text Available Sexual transmission is the principal driver of the human immunodeficiency virus (HIV pandemic. Understanding HIV vaccine-induced immune responses at mucosal surfaces can generate hypotheses regarding mechanisms of protection, and may influence vaccine development. The RV144 (ClinicalTrials.gov NCT00223080 efficacy trial showed protection against HIV infections but mucosal samples were not collected, therefore, the contribution of mucosal antibodies to preventing HIV-1 acquisition is unknown. Here, we report the generation, magnitude and persistence of antibody responses to recombinant gp120 envelope and antigens including variable one and two loop scaffold antigens (gp70V1V2 previously shown to correlate with risk in RV144. We evaluated antibody responses to gp120 A244gD and gp70V1V2 92TH023 (both CRF01_AE and Case A2 (subtype B in cervico-vaginal mucus (CVM, seminal plasma (SP and rectal secretions (RS from HIV-uninfected RV144 vaccine recipients, who were randomized to receive two late boosts of ALVAC-HIV/AIDSVAX®B/E, AIDSVAX®B/E, or ALVAC-HIV alone at 0 and 6 months. Late vaccine boosting increased IgG geometric mean titers (GMT to gp120 A244gD in AIDSVAX®B/E and ALVAC-HIV/AIDSVAX®B/E CVM (28 and 17 fold, respectively, followed by SP and RS. IgG to gp70V1V2 92TH023 increased in AIDSVAX®B/E and ALVAC-HIV/AIDSVAX®B/E CVM (11-17 fold and SP (2 fold two weeks post first boost. IgG to Case A2 was only detected in AIDSVAX®B/E and ALVAC-HIV/AIDSVAX®B/E CVM. Mucosal IgG to gp120 A244gD (CVM, SP, RS, gp70V1V2 92TH023 (CVM, SP, and Case A2 (CVM correlated with plasma IgG levels (p<0.001. Although the magnitude of IgG responses declined after boosting, anti-gp120 A244gD IgG responses in CVM persisted for 12 months post final vaccination. Further studies in localization, persistence and magnitude of envelope specific antibodies (IgG and dimeric IgA in anogenital secretions will help determine their role in preventing mucosal HIV acquisition.

  19. Human Papillomavirus neutralizing and cross-reactive antibodies induced in HIV-positive subjects after vaccination with quadrivalent and bivalent HPV vaccines

    DEFF Research Database (Denmark)

    Faust, Helena; Nielsen, Lars Toft; Sehr, Peter

    2016-01-01

    Ninety-one HIV-infected individuals (61 men and 30 women) were randomized to vaccination either with quadrivalent (Gardasil™) or bivalent (Cervarix™) HPV vaccine. Neutralizing and specific HPV-binding serum antibodies were measured at baseline and 12 months after the first vaccine dose. Presence...... of neutralizing and binding antibodies had good agreement (average Kappa for HPV types 6, 11, 16, 18, 31, 33 and 45 was 0.65). At baseline, 88% of subjects had antibodies against at least one genital HPV. Following vaccination with Cervarix™, all subjects became seropositive for HPV16 and 18. After Gardasil......™ vaccination, 96% of subjects seroconverted for HPV16 and 73% for HPV18. Levels of HPV16-specific antibodies were 10IU in 85% of study subjects after vaccination. Antibodies against non-vaccine HPV types appeared after Gardasil...

  20. The breadth and titer of maternal HIV-1-specific heterologous neutralizing antibodies are not associated with a lower rate of mother-to-child transmission of HIV-1.

    Science.gov (United States)

    Chaillon, Antoine; Wack, Thierry; Braibant, Martine; Mandelbrot, Laurent; Blanche, Stéphane; Warszawski, Josiane; Barin, Francis

    2012-10-01

    It has been hypothesized that neutralizing antibodies (NAbs) should have broad specificity to be effective in protection against diverse HIV-1 variants. The mother-to-child transmission model of HIV-1 provides the opportunity to examine whether the breadth of maternal NAbs is associated with protection of infants from infection. Samples were obtained at delivery from 57 transmitting mothers (T) matched with 57 nontransmitting mothers (NT) enrolled in the multicenter French perinatal cohort (ANRS EPF CO1) between 1990 and 1996. Sixty-eight (59.6%) and 46 (40.4%) women were infected by B and non-B viruses, respectively. Neutralization assays were carried out with TZM-bl cells, using a panel of 10 primary isolates of 6 clades (A, B, C, F, CRF01_AE, and CRF02_AG), selected for their moderate or low sensitivity to neutralization. Neutralization breadths were not statistically different between T and NT mothers. However, a few statistically significant differences were observed, with higher frequencies or titers of NAbs toward several individual strains for NT mothers when the clade B-infected or non-clade B-infected mothers were analyzed separately. Our study confirms that the breadth of maternal NAbs is not associated with protection of infants from infection.

  1. Repeated Vaccination of Cows with HIV Env gp140 during Subsequent Pregnancies Elicits and Sustains an Enduring Strong Env-Binding and Neutralising Antibody Response.

    Directory of Open Access Journals (Sweden)

    Behnaz Heydarchi

    Full Text Available An important feature of a potential vaccine against HIV is the production of broadly neutralising antibodies (BrNAbs capable of potentially blocking infectivity of a diverse array of HIV strains. BrNAbs naturally arise in some HIV infected individuals after several years of infection and their serum IgG can neutralise various HIV strains across different subtypes. We previously showed that vaccination of cows with HIV gp140 AD8 trimers resulted in a high titre of serum IgG against HIV envelope (Env that had strong BrNAb activity. These polyclonal BrNAbs concentrated into the colostrum during the late stage of pregnancy and can be harvested in vast quantities immediately after calving. In this study, we investigated the effect of prolonged HIV gp140 vaccination on bovine colostrum IgG HIV Env-binding and BrNAb activity over subsequent pregnancies. Repeated immunisation led to a maintained high titre of HIV Env specific IgG in the colostrum batches, but this did not increase through repeated cycles. Colostrum IgG from all batches also strongly competed with sCD4 binding to gp140 Env trimer and with human-derived monoclonal VRC01 and b12 BrNAbs that bind the CD4 binding site (CD4bs. Furthermore, competition neutralisation assays using RSC3 Env gp120 protein core and a derivative CD4bs mutant, RSC3 Δ371I/P363N, showed that CD4bs neutralising antibodies contribute to the neutralising activity of all batches of purified bovine colostrum IgG. This result indicates that the high IgG titre/avidity of anti-CD4bs antibodies with BrNAb activity was achieved during the first year of vaccination and was sustained throughout the years of repeated vaccinations in the cow tested. Although IgG of subsequent colostrum batches may have a higher avidity towards the CD4bs, the overall breadth in neutralisation was not enhanced. This implies that the boosting vaccinations over 4 years elicited a polyclonal antibody response that maintained the proportion of both

  2. The development of AIDS or AIDS-related conditions in a cohort of HIV antibody-positive homosexual men during a 3-year follow-up period

    DEFF Research Database (Denmark)

    Pedersen, C; Kolby, P; Sindrup, J

    1989-01-01

    One hundred and thirty-three homosexual men seropositive for the antibody against human immunodeficiency virus (HIV) were enrolled in a prospective study in 1984-85. The 3-year cumulative incidences of the acquired immunodeficiency syndrome (AIDS) and AIDS-related conditions, by life-table analyses...... with the development of AIDS. There was no association between disease progression and persistent generalized lymphadenopathy. When adjusted to the probable year of infection, these results are in accordance with previous cohort studies. It is concluded that most, or all, subjects seropositive for HIV will develop......, were 18% and 34%. The cumulative incidence of immune deficiency defined as CD4 lymphocytes less than 0.5 x 10(9) l-1 was 70% at 3 years. Absence of antibodies to p24 antigen, HIV antigenaemia, CD4 lymphocytes less than 0.3 x 10 l-1 and elevated serum level of IgA were significantly associated...

  3. Broad antibody mediated cross-neutralization and preclinical immunogenicity of new codon-optimized HIV-1 clade CRF02_AG and G primary isolates.

    Directory of Open Access Journals (Sweden)

    Simon M Agwale

    Full Text Available Creation of an effective vaccine for HIV has been an elusive goal of the scientific community for almost 30 years. Neutralizing antibodies are assumed to be pivotal to the success of a prophylactic vaccine but previous attempts to make an immunogen capable of generating neutralizing antibodies to primary "street strain" isolates have resulted in responses of very limited breadth and potency. The objective of the study was to determine the breadth and strength of neutralizing antibodies against autologous and heterologous primary isolates in a cohort of HIV-1 infected Nigerians and to characterize envelopes from subjects with particularly broad or strong immune responses for possible use as vaccine candidates in regions predominated by HIV-1 CRF02_AG and G subtypes. Envelope vectors from a panel of primary Nigerian isolates were constructed and tested with plasma/sera from the same cohort using the PhenoSense HIV neutralizing antibody assay (Monogram Biosciences Inc, USA to assess the breadth and potency of neutralizing antibodies. The immediate goal of this study was realized by the recognition of three broadly cross-neutralizing sera: (NG2-clade CRF02_AG, NG3-clade CRF02_AG and NG9- clade G. Based on these findings, envelope gp140 sequences from NG2 and NG9, complemented with a gag sequence (Clade G and consensus tat (CRF02_AG and G antigens have been codon-optimized, synthesized, cloned and evaluated in BALB/c mice. The intramuscular administration of these plasmid DNA constructs, followed by two booster DNA immunizations, induced substantial specific humoral response against all constructs and strong cellular responses against the gag and tat constructs. These preclinical findings provide a framework for the design of candidate vaccine for use in regions where the HIV-1 epidemic is driven by clades CRF02_AG and G.

  4. Broad antibody mediated cross-neutralization and preclinical immunogenicity of new codon-optimized HIV-1 clade CRF02_AG and G primary isolates.

    Science.gov (United States)

    Agwale, Simon M; Forbi, Joseph C; Notka, Frank; Wrin, Terri; Wild, Jens; Wagner, Ralf; Wolf, Hans

    2011-01-01

    Creation of an effective vaccine for HIV has been an elusive goal of the scientific community for almost 30 years. Neutralizing antibodies are assumed to be pivotal to the success of a prophylactic vaccine but previous attempts to make an immunogen capable of generating neutralizing antibodies to primary "street strain" isolates have resulted in responses of very limited breadth and potency. The objective of the study was to determine the breadth and strength of neutralizing antibodies against autologous and heterologous primary isolates in a cohort of HIV-1 infected Nigerians and to characterize envelopes from subjects with particularly broad or strong immune responses for possible use as vaccine candidates in regions predominated by HIV-1 CRF02_AG and G subtypes. Envelope vectors from a panel of primary Nigerian isolates were constructed and tested with plasma/sera from the same cohort using the PhenoSense HIV neutralizing antibody assay (Monogram Biosciences Inc, USA) to assess the breadth and potency of neutralizing antibodies. The immediate goal of this study was realized by the recognition of three broadly cross-neutralizing sera: (NG2-clade CRF02_AG, NG3-clade CRF02_AG and NG9- clade G). Based on these findings, envelope gp140 sequences from NG2 and NG9, complemented with a gag sequence (Clade G) and consensus tat (CRF02_AG and G) antigens have been codon-optimized, synthesized, cloned and evaluated in BALB/c mice. The intramuscular administration of these plasmid DNA constructs, followed by two booster DNA immunizations, induced substantial specific humoral response against all constructs and strong cellular responses against the gag and tat constructs. These preclinical findings provide a framework for the design of candidate vaccine for use in regions where the HIV-1 epidemic is driven by clades CRF02_AG and G.

  5. Broad-spectrum inhibition of HIV-1 by a monoclonal antibody directed against a gp120-induced epitope of CD4.

    Science.gov (United States)

    Burastero, Samuele E; Frigerio, Barbara; Lopalco, Lucia; Sironi, Francesca; Breda, Daniela; Longhi, Renato; Scarlatti, Gabriella; Canevari, Silvana; Figini, Mariangela; Lusso, Paolo

    2011-01-01

    To penetrate susceptible cells, HIV-1 sequentially interacts with two highly conserved cellular receptors, CD4 and a chemokine receptor like CCR5 or CXCR4. Monoclonal antibodies (MAbs) directed against such receptors are currently under clinical investigation as potential preventive or therapeutic agents. We immunized Balb/c mice with molecular complexes of the native, trimeric HIV-1 envelope (Env) bound to a soluble form of the human CD4 receptor. Sera from immunized mice were found to contain gp120-CD4 complex-enhanced antibodies and showed broad-spectrum HIV-1-inhibitory activity. A proportion of MAbs derived from these mice preferentially recognized complex-enhanced epitopes. In particular, a CD4-specific MAb designated DB81 (IgG1Κ) was found to preferentially bind to a complex-enhanced epitope on the D2 domain of human CD4. MAb DB81 also recognized chimpanzee CD4, but not baboon or macaque CD4, which exhibit sequence divergence in the D2 domain. Functionally, MAb DB81 displayed broad HIV-1-inhibitory activity, but it did not exert suppressive effects on T-cell activation in vitro. The variable regions of the heavy and light chains of MAb DB81 were sequenced. Due to its broad-spectrum anti-HIV-1 activity and lack of immunosuppressive effects, a humanized derivative of MAb DB81 could provide a useful complement to current preventive or therapeutic strategies against HIV-1.

  6. Broad-spectrum inhibition of HIV-1 by a monoclonal antibody directed against a gp120-induced epitope of CD4.

    Directory of Open Access Journals (Sweden)

    Samuele E Burastero

    Full Text Available To penetrate susceptible cells, HIV-1 sequentially interacts with two highly conserved cellular receptors, CD4 and a chemokine receptor like CCR5 or CXCR4. Monoclonal antibodies (MAbs directed against such receptors are currently under clinical investigation as potential preventive or therapeutic agents. We immunized Balb/c mice with molecular complexes of the native, trimeric HIV-1 envelope (Env bound to a soluble form of the human CD4 receptor. Sera from immunized mice were found to contain gp120-CD4 complex-enhanced antibodies and showed broad-spectrum HIV-1-inhibitory activity. A proportion of MAbs derived from these mice preferentially recognized complex-enhanced epitopes. In particular, a CD4-specific MAb designated DB81 (IgG1Κ was found to preferentially bind to a complex-enhanced epitope on the D2 domain of human CD4. MAb DB81 also recognized chimpanzee CD4, but not baboon or macaque CD4, which exhibit sequence divergence in the D2 domain. Functionally, MAb DB81 displayed broad HIV-1-inhibitory activity, but it did not exert suppressive effects on T-cell activation in vitro. The variable regions of the heavy and light chains of MAb DB81 were sequenced. Due to its broad-spectrum anti-HIV-1 activity and lack of immunosuppressive effects, a humanized derivative of MAb DB81 could provide a useful complement to current preventive or therapeutic strategies against HIV-1.

  7. Feasibility and acceptability of rapid HIV screening in a labour ward in Togo

    Science.gov (United States)

    Ekouevi, Didier K; Kariyiare, Benjamin G; Coffie, Patrick A; Jutand, Marthe-Aline; Akpadza, Koffi; Lawson-Evi, Annette; Tatagan, Albert; Dabis, François; Sibe, Mathieu; Pitche, Vincent P; Becquet, Renaud; David, Mireille

    2012-01-01

    Background HIV screening in a labour ward is the last opportunity to initiate an antiretroviral prophylaxis among pregnant women living with HIV to prevent mother-to-child HIV transmission. Little is known about the feasibility and acceptability of HIV screening during labour in West Africa. Findings A cross-sectional survey was conducted in the labour ward at the Tokoin Teaching Hospital in Lomé (Togo) between May and August 2010. Pregnant women admitted for labour were randomly selected to enter the study and were interviewed on the knowledge of their HIV status. Clinical and biological data were collected from the individual maternal health chart. HIV testing or re-testing was systematically proposed to all pregnant women. Among 1530 pregnant women admitted for labour, 508 (32.2%) were included in the study. Information on HIV screening was available in the charts of 359 women (71%). Overall, 467 women accepted HIV testing in the labour ward (92%). The HIV prevalence was 8.8% (95% confidence interval: 6.4 to 11.7%). Among the 41 women diagnosed as living with HIV during labour, 34% had not been tested for HIV during pregnancy and were missed opportunities. Antiretroviral prophylaxis had been initiated antenatally for 24 women living with HIV and 17 in the labour room. Conclusions This study is the first to show in West Africa that HIV testing in a labour room is feasible and well accepted by pregnant women. HIV screening in labour rooms needs to be routinely implemented to reduce missed opportunities for intervention aimed at HIV care and prevention, especially PMTCT. PMID:22905362

  8. The diagnostic sensitivity of dengue rapid test assays is significantly enhanced by using a combined antigen and antibody testing approach.

    Directory of Open Access Journals (Sweden)

    Scott R Fry

    2011-06-01

    Full Text Available BACKGROUND: Serological tests for IgM and IgG are routinely used in clinical laboratories for the rapid diagnosis of dengue and can differentiate between primary and secondary infections. Dengue virus non-structural protein 1 (NS1 has been identified as an early marker for acute dengue, and is typically present between days 1-9 post-onset of illness but following seroconversion it can be difficult to detect in serum. AIMS: To evaluate the performance of a newly developed Panbio® Dengue Early Rapid test for NS1 and determine if it can improve diagnostic sensitivity when used in combination with a commercial IgM/IgG rapid test. METHODOLOGY: The clinical performance of the Dengue Early Rapid was evaluated in a retrospective study in Vietnam with 198 acute laboratory-confirmed positive and 100 negative samples. The performance of the Dengue Early Rapid in combination with the IgM/IgG Rapid test was also evaluated in Malaysia with 263 laboratory-confirmed positive and 30 negative samples. KEY RESULTS: In Vietnam the sensitivity and specificity of the test was 69.2% (95% CI: 62.8% to 75.6% and 96% (95% CI: 92.2% to 99.8 respectively. In Malaysia the performance was similar with 68.9% sensitivity (95% CI: 61.8% to 76.1% and 96.7% specificity (95% CI: 82.8% to 99.9% compared to RT-PCR. Importantly, when the Dengue Early Rapid test was used in combination with the IgM/IgG test the sensitivity increased to 93.0%. When the two tests were compared at each day post-onset of illness there was clear differentiation between the antigen and antibody markers. CONCLUSIONS: This study highlights that using dengue NS1 antigen detection in combination with anti-glycoprotein E IgM and IgG serology can significantly increase the sensitivity of acute dengue diagnosis and extends the possible window of detection to include very early acute samples and enhances the clinical utility of rapid immunochromatographic testing for dengue.

  9. Genome-wide association study on the development of cross-reactive neutralizing antibodies in HIV-1 infected individuals.

    Directory of Open Access Journals (Sweden)

    Zelda Euler

    Full Text Available Broadly neutralizing antibodies may protect against HIV-1 acquisition. In natural infection, only 10-30% of patients have cross-reactive neutralizing humoral immunity which may relate to viral and or host factors. To explore the role of host genetic markers in the formation of cross-reactive neutralizing activity (CrNA in HIV-1 infected individuals, we performed a genome-wide association study (GWAS, in participants of the Amsterdam Cohort Studies with known CrNA in their sera. Single-nucleotide polymorphisms (SNPs with the strongest P-values are located in the major histocompatibility complex (MHC region, close to MICA (P = 7.68 × 10(-7, HLA-B (P = 6.96 × 10(-6 and in the coding region of HCP5 (P = 1.34 × 10(-5. However, none of the signals reached genome-wide significance. Our findings underline the potential involvement of genes close or within the MHC region with the development of CrNA.

  10. Genome-Wide Association Study on the Development of Cross-Reactive Neutralizing Antibodies in HIV-1 Infected Individuals

    Science.gov (United States)

    Euler, Zelda; van Gils, Marit J.; Boeser-Nunnink, Brigitte D.; Schuitemaker, Hanneke; van Manen, Daniëlle

    2013-01-01

    Broadly neutralizing antibodies may protect against HIV-1 acquisition. In natural infection, only 10–30% of patients have cross-reactive neutralizing humoral immunity which may relate to viral and or host factors. To explore the role of host genetic markers in the formation of cross-reactive neutralizing activity (CrNA) in HIV-1 infected individuals, we performed a genome-wide association study (GWAS), in participants of the Amsterdam Cohort Studies with known CrNA in their sera. Single-nucleotide polymorphisms (SNPs) with the strongest P-values are located in the major histocompatibility complex (MHC) region, close to MICA (P = 7.68×10−7), HLA-B (P = 6.96×10−6) and in the coding region of HCP5 (P = 1.34×10−5). However, none of the signals reached genome-wide significance. Our findings underline the potential involvement of genes close or within the MHC region with the development of CrNA. PMID:23372753

  11. Quantitative analyses reveal distinct sensitivities of the capture of HIV-1 primary viruses and pseudoviruses to broadly neutralizing antibodies.

    Science.gov (United States)

    Kim, Jiae; Jobe, Ousman; Peachman, Kristina K; Michael, Nelson L; Robb, Merlin L; Rao, Mangala; Rao, Venigalla B

    2017-08-01

    Development of vaccines capable of eliciting broadly neutralizing antibodies (bNAbs) is a key goal to controlling the global AIDS epidemic. To be effective, bNAbs must block the capture of HIV-1 to prevent viral acquisition and establishment of reservoirs. However, the role of bNAbs, particularly during initial exposure of primary viruses to host cells, has not been fully examined. Using a sensitive, quantitative, and high-throughput qRT-PCR assay, we found that primary viruses were captured by host cells and converted into a trypsin-resistant form in less than five minutes. We discovered, unexpectedly, that bNAbs did not block primary virus capture, although they inhibited the capture of pseudoviruses/IMCs and production of progeny viruses at 48h. Further, viruses escaped bNAb inhibition unless the bNAbs were present in the initial minutes of exposure of virus to host cells. These findings will have important implications for HIV-1 vaccine design and determination of vaccine efficacy. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  12. DNA vaccines expressing soluble CD4-envelope proteins fused to C3d elicit cross-reactive neutralizing antibodies to HIV-1

    International Nuclear Information System (INIS)

    Bower, Joseph F.; Green, Thomas D.; Ross, Ted M.

    2004-01-01

    DNA vaccines expressing the envelope (Env) of the human immunodeficiency virus type 1 (HIV-1) have been relatively ineffective at generating high-titer, long-lasting, neutralizing antibodies in a variety of animal models. In this study, DNA vaccines were constructed to express a fusion protein of the soluble human CD4 (sCD4) and the gp120 subunit of the HIV-1 envelope. To enhance the immunogenicity of the expressed fusion protein, three copies of the murine C3d (mC3d 3 ) were added to the carboxyl terminus of the complex. Monoclonal antibodies that recognize CD4-induced epitopes on gp120 efficiently bound to sCD4-gp120 or sCD4-gp120-mC3d 3 . In addition, both sCD4-gp120 and sCD4-gp120-mC3d 3 bound to cells expressing appropriate coreceptors in the absence of cell surface hCD4. Mice (BALB/c) vaccinated with DNA vaccines expressing either gp120-mC3d 3 or sCD4-gp120-mC3d 3 elicited antibodies that neutralized homologous virus infection. However, the use of sCD4-gp120-mC3d 3 -DNA elicited the highest titers of neutralizing antibodies that persisted after depletion of anti-hCD4 antibodies. Interestingly, only mice vaccinated with DNA expressing sCD4-gp120-mC3d 3 had antibodies that elicited cross-protective neutralizing antibodies. The fusion of sCD4 to the HIV-1 envelope exposes neutralizing epitopes that elicit broad protective immunity when the fusion complex is coupled with the molecular adjuvant, C3d

  13. Triple positivity of HBsAg, anti-HCV antibody, and HIV and their ...

    African Journals Online (AJOL)

    cy virus (HIV), hepatitis B and C viruses (HBV and ..... tive impact on the CD4+ lymphocytes cells on the basis of consistent rise in the ..... Locarnini S: Molecular virology of hepatitis B virus. .... hepatitis C virus by men with hemophilia. Journal of.

  14. Anti-HCV antibody among newly diagnosed HIV patients in Ughelli ...

    African Journals Online (AJOL)

    ingly well above several other studies done in the past in Nigeria and other countries of ... Keywords: HIV, HCV, Hepatitis, co-infection, intravenous drug use. ... African Health Sciences Vol 15 Issue 3, September 2015. 728 .... drugs or men that sleep with men (0.0%). .... association of the receipt of a blood transfusion before.

  15. Developing Guidelines for HIV Antibody Testing among Victims of Pediatric Sexual Abuse.

    Science.gov (United States)

    Gellert, George A.; And Others

    1990-01-01

    An interim set of human immunodeficiency virus (HIV) testing guidelines for victims of pediatric sexual abuse (PSA) is proposed. Guidelines are based on responses of 63 practitioners of PSA assessment to 7 hypothetical clinical profiles with 12 testing criteria. (Author/DB)

  16. Rapid Active Assay for the Detection of Antibodies to West Nile Virus in Chickens

    Science.gov (United States)

    2008-01-01

    and organ donations ,9 breast feeding,10 intrauterine exposure,11 and laboratory pro- cedures,12 emphasizing the importance of developing a rapid and... milk in 20 mmol/L Tris-HCl, 0.15 mol/L NaCl, and 0.05% Tween-20, pH 7.5) was applied to the plates, followed by incubation at room temperature for 30...884–895. 10. Centers for Disease Control and Prevention, 2002. Possible West Nile virus transmission to an infant through breast -feeding— Michigan, 2002

  17. A simple and rapid characterization of influenza virus isolates by monoclonal antibodies in radioimmunoassay

    International Nuclear Information System (INIS)

    Kostolansky, F.; Styk, B.; Russ, G.

    1986-01-01

    Radioimmunoassay is described with infectious allantoic fluid directly bound to solid phase, suitable for the detection and further characterization of influenza virus isolates. This simple and rapid method was applied for the description of isolates obtained from different regions of Czechoslovakia during the influenza epidemic in 1983. The results confirmed that all 13 examined isolates represented influenza A viruses possessing H3 subtype haemagglutinin very similar to haemagglutinin of influenza viruses A/Bangkok/1/79 (H3N2), A/Belgium/2/81 (H3N2) and A/Philippines/2/82 (H3N2). (author)

  18. Pharmacokinetics and Preliminary Safety of Pod-Intravaginal Rings Delivering the Monoclonal Antibody VRC01-N for HIV Prophylaxis in a Macaque Model.

    Science.gov (United States)

    Zhao, Chunxia; Gunawardana, Manjula; Villinger, Francois; Baum, Marc M; Remedios-Chan, Mariana; Moench, Thomas R; Zeitlin, Larry; Whaley, Kevin J; Bohorov, Ognian; Smith, Thomas J; Anderson, Deborah J; Moss, John A

    2017-07-01

    The broadly neutralizing antibody (bNAb) VRC01, capable of neutralizing 91% of known human immunodeficiency virus type 1 (HIV-1) isolates in vitro , is a promising candidate microbicide for preventing sexual HIV infection when administered topically to the vagina; however, accessibility to antibody-based prophylactic treatment by target populations in sub-Saharan Africa and other underdeveloped regions may be limited by the high cost of conventionally produced antibodies and the limited capacity to manufacture such antibodies. Intravaginal rings of the pod design (pod-IVRs) delivering Nicotiana -manufactured VRC01 (VRC01-N) over a range of release rates have been developed. The pharmacokinetics and preliminary safety of VRC01-N pod-IVRs were evaluated in a rhesus macaque model. The devices sustained VRC01-N release for up to 21 days at controlled rates, with mean steady-state VRC01-N levels in vaginal fluids in the range of 10 2 to 10 3 μg g -1 being correlated with in vitro release rates. No adverse safety indications were observed. These findings indicate that pod-IVRs are promising devices for the delivery of the candidate topical microbicide VRC01-N against HIV-1 infection and merit further preclinical evaluation. Copyright © 2017 American Society for Microbiology.

  19. A Cell Internalizing Antibody Targeting Capsid Protein (p24 Inhibits the Replication of HIV-1 in T Cells Lines and PBMCs: A Proof of Concept Study.

    Directory of Open Access Journals (Sweden)

    Syed A Ali

    Full Text Available There remains a need for newer therapeutic approaches to combat HIV/AIDS. Viral capsid protein p24 plays important roles in HIV pathogenesis. Peptides and small molecule inhibitors targeting p24 have shown to inhibit virus replication in treated cell. High specificity and biological stability of monoclonal antibodies (mAbs make them an attractive contender for in vivo treatments. However, mAbs do not enter into cells, thus are restricted to target surface molecules. This also makes targeting intracellular HIV-1 p24 a challenge. A mAb specific to p24 that can internalize into the HIV-infected cells is hypothesized to inhibit the virus replication. We selected a mAb that has previously shown to inhibit p24 polymerization in an in vitro assay and chemically conjugated it with cell penetrating peptides (CPP to generate cell internalizing anti-p24 mAbs. Out of 8 CPPs tested, κFGF-MTS -conjugated mAbs internalized T cells most efficiently. At nontoxic concentration, the κFGF-MTS-anti-p24-mAbs reduced the HIV-1 replication up to 73 and 49% in T-lymphocyte and PBMCs respectively. Marked inhibition of HIV-1 replication in relevant cells by κFGF-MTS-anti-p24-mAbs represents a viable strategy to target HIV proteins present inside the cells.

  20. Recent advances in the characterization of HIV-1 neutralization assays for standardized evaluation of the antibody response to infection and vaccination.

    Science.gov (United States)

    Polonis, Victoria R; Brown, Bruce K; Rosa Borges, Andrew; Zolla-Pazner, Susan; Dimitrov, Dimiter S; Zhang, Mei-Yun; Barnett, Susan W; Ruprecht, Ruth M; Scarlatti, Gabriella; Fenyö, Eva-Maria; Montefiori, David C; McCutchan, Francine E; Michael, Nelson L

    2008-06-05

    In AIDS vaccine development the pendulum has swung towards a renewed emphasis on the potential role for neutralizing antibodies in a successful global vaccine. It is recognized that vaccine-induced antibody performance, as assessed in the available neutralization assays, may well serve as a "gatekeeper" for HIV-1 subunit vaccine prioritization and advancement. As a result, development of a standardized platform for reproducible measurement of neutralizing antibodies has received considerable attention. Here we review current advancements in our knowledge of the performance of different types of antibodies in a traditional primary cell neutralization assay and the newer, more standardized TZM-bl reporter cell line assay. In light of recently revealed differences (see accompanying article) in the results obtained in these two neutralization formats, parallel evaluation with both platforms should be contemplated as an interim solution until a better understanding of immune correlates of protection is achieved.

  1. Llama Antibody Fragments Recognizing Various Epitopes of the CD4bs Neutralize a Broad Range of HIV-1 Subtypes A, B and C

    Science.gov (United States)

    Aasa-Chapman, Marlèn; Gorlani, Andrea; Forsman Quigley, Anna; Hulsik, David Lutje; Chen, Lei; Weiss, Robin; de Haard, Hans; Verrips, Theo

    2012-01-01

    Many of the neutralising antibodies, isolated to date, display limited activities against the globally most prevalent HIV-1 subtypes A and C. Therefore, those subtypes are considered to be an important target for antibody-based therapy. Variable domains of llama heavy chain antibodies (VHH) have some superior properties compared with classical antibodies. Therefore we describe the application of trimeric forms of envelope proteins (Env), derived from HIV-1 of subtype A and B/C, for a prolonged immunization of two llamas. A panel of VHH, which interfere with CD4 binding to HIV-1 Env were selected with use of panning. The results of binding and competition assays to various Env, including a variant with a stabilized CD4-binding state (gp120Ds2), cross-competition experiments, maturation analysis and neutralisation assays, enabled us to classify the selected VHH into three groups. The VHH of group I were efficient mainly against viruses of subtype A, C and B′/C. The VHH of group II resemble the broadly neutralising antibody (bnmAb) b12, neutralizing mainly subtype B and C viruses, however some had a broader neutralisation profile. A representative of the third group, 2E7, had an even higher neutralization breadth, neutralizing 21 out of the 26 tested strains belonging to the A, A/G, B, B/C and C subtypes. To evaluate the contribution of certain amino acids to the potency of the VHH a small set of the mutants were constructed. Surprisingly this yielded one mutant with slightly improved neutralisation potency against 92UG37.A9 (subtype A) and 96ZM651.02 (subtype C). These findings and the well-known stability of VHH indicate the potential application of these VHH as anti-HIV-1 microbicides. PMID:22438910

  2. Structure and function of broadly reactive antibody PG16 reveal an H3 subdomain that mediates potent neutralization of HIV-1

    Energy Technology Data Exchange (ETDEWEB)

    Pejchal, Robert; Walker, Laura M.; Stanfield, Robyn L.; Phogat, Sanjay K.; Koff, Wayne C.; Poignard, Pascal; Burton, Dennis R.; Wilson, Ian A. (Scripps); (IAVI)

    2010-11-15

    Development of an effective vaccine against HIV-1 will likely require elicitation of broad and potent neutralizing antibodies against the trimeric surface envelope glycoprotein (Env). Monoclonal antibodies (mAbs) PG9 and PG16 neutralize {approx}80% of HIV-1 isolates across all clades with extraordinary potency and target novel epitopes preferentially expressed on Env trimers. As these neutralization properties are ideal for a vaccine-elicited antibody response to HIV-1, their structural basis was investigated. The crystal structure of the antigen-binding fragment (Fab) of PG16 at 2.5 {angstrom} resolution revealed its unusually long, 28-residue, complementarity determining region (CDR) H3 forms a unique, stable subdomain that towers above the antibody surface. A 7-residue 'specificity loop' on the 'hammerhead' subdomain was identified that, when transplanted from PG16 to PG9 and vice versa, accounted for differences in the fine specificity and neutralization of these two mAbs. The PG16 electron density maps also revealed that a CDR H3 tyrosine was sulfated, which was confirmed for both PG9 (doubly) and PG16 (singly) by mass spectral analysis. We further showed that tyrosine sulfation plays a role in binding and neutralization. An N-linked glycan modification is observed in the variable light chain, but not required for antigen recognition. Further, the crystal structure of the PG9 light chain at 3.0 {angstrom} facilitated homology modeling to support the presence of these unusual features in PG9. Thus, PG9 and PG16 use unique structural features to mediate potent neutralization of HIV-1 that may be of utility in antibody engineering and for high-affinity recognition of a variety of therapeutic targets.

  3. Structure of an N276-Dependent HIV-1 Neutralizing Antibody Targeting a Rare V5 Glycan Hole Adjacent to the CD4 Binding Site

    Energy Technology Data Exchange (ETDEWEB)

    Wibmer, Constantinos Kurt; Gorman, Jason; Anthony, Colin S.; Mkhize, Nonhlanhla N.; Druz, Aliaksandr; York, Talita; Schmidt, Stephen D.; Labuschagne, Phillip; Louder, Mark K.; Bailer, Robert T.; Karim, Salim S. Abdool; Mascola, John R.; Williamson, Carolyn; Moore, Penny L.; Kwong, Peter D.; Morris, Lynn (NHLS-South Africa); (NIH); (Witwatersrand); (KwaZulu-Natal)

    2016-08-31

    ABSTRACT

    All HIV-1-infected individuals develop strain-specific neutralizing antibodies to their infecting virus, which in some cases mature into broadly neutralizing antibodies. Defining the epitopes of strain-specific antibodies that overlap conserved sites of vulnerability might provide mechanistic insights into how broadly neutralizing antibodies arise. We previously described an HIV-1 clade C-infected donor, CAP257, who developed broadly neutralizing plasma antibodies targeting an N276 glycan-dependent epitope in the CD4 binding site. The initial CD4 binding site response potently neutralized the heterologous tier 2 clade B viral strain RHPA, which was used to design resurfaced gp120 antigens for single-B-cell sorting. Here we report the isolation and structural characterization of CAP257-RH1, an N276 glycan-dependent CD4 binding site antibody representative of the early CD4 binding site plasma response in donor CAP257. The cocrystal structure of CAP257-RH1 bound to RHPA gp120 revealed critical interactions with the N276 glycan, loop D, and V5, but not with aspartic acid 368, similarly to HJ16 and 179NC75. The CAP257-RH1 monoclonal antibody was derived from the immunoglobulin-variable IGHV3-33 and IGLV3-10 genes and neutralized RHPA but not the transmitted/founder virus from donor CAP257. Its narrow neutralization breadth was attributed to a binding angle that was incompatible with glycosylated V5 loops present in almost all HIV-1 strains, including the CAP257 transmitted/founder virus. Deep sequencing of autologous CAP257 viruses, however, revealed minority variants early in infection that lacked V5 glycans. These glycan-free V5 loops are unusual holes in the glycan shield that may have been necessary for initiating this N276 glycan-dependent CD4 binding site B-cell lineage.

    IMPORTANCEThe conserved CD4 binding site on gp120 is a major target for HIV-1 vaccine design, but key events in the elicitation and maturation of

  4. MABGEL 1: first phase 1 trial of the anti-HIV-1 monoclonal antibodies 2F5, 4E10 and 2G12 as a vaginal microbicide.

    Directory of Open Access Journals (Sweden)

    Georgina C Morris

    Full Text Available BACKGROUND: Monoclonal antibodies (mAbs which potently neutralize a broad range of HIV isolates are potential microbicide candidates. To date, topical application of mAbs in humans and their stability in vaginal secretions has not been studied. OBJECTIVES: To assess the pharmacokinetics and safety of the mAbs 2F5, 4E10 and 2G12 when applied vaginally in women. DESIGN: A randomized, double-blind, placebo-controlled phase 1 trial. METHODS: Twenty-eight healthy, sexually abstinent women administered 2.5 g of gel daily for 12 days containing either 10 or 20 mg/g of each mAb (MABGEL or placebo. Main clinical evaluations and sampling occurred at baseline, 1, 8, and 24 hours post-1st dose and 12 and 36 hours post-12th dose. RESULTS: After adjustment for dilution factors, median levels of 2F5, 4E10 and 2G12 in vaginal secretions at 1 hour post high-dose MABGEL were 7.74, 5.28 and 7.48 mg/ml respectively. Levels of 2F5 and 4E10 declined exponentially thereafter with similar estimated half-lives (4.6 and 4.3 hours. In contrast, 2G12 levels declined more rapidly in the first 8 hours, with an estimated half-life of 1.4 hours during this period. There was no evidence of systemic absorption. There were no significant differences in local or systemic adverse event rates or vaginal flora changes (by qPCR between active and placebo gel arms. Whilst at least 1 adverse event was recorded in 96% of participants, 95% were mild and none were serious. CONCLUSIONS: Vaginal application of 50 mg of each mAb daily was safe over a 12 day period. Median mAb concentrations detected at 8 hours post dose were potentially sufficient to block HIV transmission.2G12 exhibited more rapid elimination from the human vagina than 4E10 and 2F5, likely due to poor stability of 2G12 in acidic human vaginal secretions. Further research is needed to develop mAb-based vaginal microbicides and delivery systems. TRIAL REGISTRATION: ISRCTN 64808733 UK CRN Portfolio 6470.

  5. Rapid testing may not improve uptake of HIV testing and same day results in a rural South African community: a cohort study of 12,000 women.

    Directory of Open Access Journals (Sweden)

    Ntombizodumo B Mkwanazi

    Full Text Available Rapid testing of pregnant women aims to increase uptake of HIV testing and results and thus optimize care. We report on the acceptability of HIV counselling and testing, and uptake of results, before and after the introduction of rapid testing in this area.HIV counsellors offered counselling and testing to women attending 8 antenatal clinics, prior to enrolment into a study examining infant feeding and postnatal HIV transmission. From August 2001 to April 2003, blood was sent for HIV ELISA testing in line with the Prevention of Mother-to-Child Transmission (PMTCT programme in the district. From May 2003 to September 2004 women were offered a rapid HIV test as part of the PMTCT programme, but also continued to have ELISA testing for study purposes. Of 12,323 women counselled, 5,879 attended clinic prior to May 2003, and 6,444 after May 2003 when rapid testing was introduced; of whom 4,324 (74.6% and 4,810 (74.6% agreed to have an HIV test respectively. Of the 4,810 women who had a rapid HIV test, only 166 (3.4% requested to receive their results on the same day as testing, the remainder opted to return for results at a later appointment. Women with secondary school education were less likely to agree to testing than those with no education (AOR 0.648, p35 years (AOR 0.756, p<0.01 compared to those <20 years.Contrary to other reports, few women who had rapid tests accepted their HIV results the same day. Finding strategies to increase the proportion of pregnant women knowing their HIV results is critical so that appropriate care can be given.

  6. Structural Changes in Stx1 Engineering Monoclonal Antibody Improves Its Functionality as Diagnostic Tool for a Rapid Latex Agglutination Test

    Directory of Open Access Journals (Sweden)

    Daniela Luz

    2018-02-01

    Full Text Available Stx1 toxin is one of the AB5 toxins of Shiga toxin-producing Escherichia coli (STEC responsible for foodborne intoxication during outbreaks. The single-chain variable fragment (scFv is the most common recombinant antibody format; it consists of both variable chains connected by a peptide linker with conserved specificity and affinity for antigen. The drawbacks of scFv production in bacteria are the heterologous expression, conformation and stability of the molecule, which could change the affinity for the antigen. In this work, we obtained a stable and functional scFv-Stx1 in bacteria, starting from IgG produced by hybridoma cells. After structural modifications, i.e., change in protein orientation, vector and linker, its solubility for expression in bacteria was increased as well as the affinity for its antigen, demonstrated by a scFv dissociation constant (KD of 2.26 × 10−7 M. Also, it was able to recognize purified Stx1 and cross-reacted with Stx2 toxin by ELISA (Enzyme-Linked Immunosorbent Assay, and detected 88% of Stx1-producing strains using a rapid latex agglutination test. Thus, the scFv fragment obtained in the present work is a bacteria-produced tool for use in a rapid diagnosis test, providing an alternative for STEC diagnosis.

  7. Subsets of memory CD4+ T cell and bactericidal antibody response to Neisseria meningitidis serogroup C after immunization of HIV-infected children and adolescents.

    Directory of Open Access Journals (Sweden)

    Lucimar G Milagres

    Full Text Available Meningococcal disease is endemic in Brazil, with periodic outbreaks and case fatality rates reach as high as 18 to 20% of cases. Conjugate vaccines against meningococci are immunogenic in healthy children. However, we have previously shown a poor bactericidal antibody response to a Men C conjugate vaccine in Brazilian HIV-infected children and adolescents after a single vaccine administration. The goal of the present work was to investigate associations between bactericidal antibody response induced by MenC vaccine and the frequency and activation profile (expression of CD38, HLA-DR and CCR5 molecules of total CD4+ memory T cell sub-populations in HIV-1-infected children and adolescents. Responders to vaccination against MenC had a predominance (about 44% of CD4+ TINTERMEDIATE subset followed by TTRANSITIONAL memory subset (23 to 26%. Importantly, CD4+ TINT frequency was positively associated with bactericidal antibody response induced by vaccination. The positive correlation persisted despite the observation that the frequency TINT CD38+HLA-DR+ was higher in responders. In contrast, CD4+ TCENTRAL MEMORY (TCM subset negatively correlated with bactericidal antibodies. In conclusion, these data indicate that less differentiated CD+ T cells, like TCM may be constantly differentiating into intermediate and later differentiated CD4+ T cell subsets. These include CD4 TINT subset which showed a positive association with bactericidal antibodies.

  8. Feasibility of supervised self-testing using an oral fluid-based HIV rapid testing method: a cross-sectional, mixed method study among pregnant women in rural India.

    Science.gov (United States)

    Sarkar, Archana; Mburu, Gitau; Shivkumar, Poonam Varma; Sharma, Pankhuri; Campbell, Fiona; Behera, Jagannath; Dargan, Ritu; Mishra, Surendra Kumar; Mehra, Sunil

    2016-01-01

    HIV self-testing can increase coverage of essential HIV services. This study aimed to establish the acceptability, concordance and feasibility of supervised HIV self-testing among pregnant women in rural India. A cross-sectional, mixed methods study was conducted among 202 consenting pregnant women in a rural Indian hospital between August 2014 and January 2015. Participants were provided with instructions on how to self-test using OraQuick(®) HIV antibody test, and subsequently asked to self-test under supervision of a community health worker. Test results were confirmed at a government-run integrated counselling and testing centre. A questionnaire was used to obtain information on patient demographics and the ease, acceptability and difficulties of self-testing. In-depth interviews were conducted with a sub-sample of 35 participants to understand their experiences. In total, 202 participants performed the non-invasive, oral fluid-based, rapid test under supervision for HIV screening. Acceptance rate was 100%. Motivators for self-testing included: ease of testing (43.4%), quick results (27.3%) and non-invasive procedure (23.2%). Sensitivity and specificity were 100% for 201 tests, and one test was invalid. Concordance of test result interpretation between community health workers and participants was 98.5% with a Cohen's Kappa (k) value of k=0.566 with pwomen in rural India. Participants were supportive of making self-testing publicly available. Policy guidelines and implementation research are required to advance HIV self-testing for larger populations at scale.

  9. Sex, drugs, and HIV: rapid assessment of HIV risk behaviors among street-based drug using sex workers in Durban, South Africa.

    Science.gov (United States)

    Needle, Richard; Kroeger, Karen; Belani, Hrishikesh; Achrekar, Angeli; Parry, Charles D; Dewing, Sarah

    2008-11-01

    South Africa is experiencing significant changes in patterns of illicit drug use, including increasing injection and non-injection drug use, and the use of drugs by persons engaged in sex work, both of which could further expand the HIV/AIDS epidemic. In 2005, a rapid ethnographic assessment was conducted in Durban, South Africa, to learn more about patterns of drug use and HIV risk behaviors among drug-using, street-based sex workers. Field teams recruited 52 current injection and non-injection drug users for key informant interviews and focus groups, and they conducted mapping and observation in identified high-risk neighborhoods. Key informants were offered free, voluntary counseling and HIV rapid testing. The results of the assessment indicate that in this population, drugs play an organizing role in patterns of daily activities, with sex work closely linked to the buying, selling, and using of drugs. Participants reported using multiple drugs including crack cocaine, heroin, Ecstasy and Mandrax, and their choices were based on their expectations about the functional role and behavioral and pharmacological properties of the drugs. The organization of sex work and patterns of drug use differ by gender, with males exercising more control over daily routines and drug and sexual transactions than females. Activities of female sex workers are subject to considerable control by individual pimps, many of whom also function as landlords and drug dealers. A strong hold over the overlapping economies of drugs and sex work by a few individuals extends to control of the physical and social settings in which sex is exchanged and drugs are sold and used as well as the terms under which sex work is carried out. The potential for accelerated HIV spread is considerable given the evidence of overlapping drug-using and sexual risk behaviors and the mixing patterns across drug and sexual risk networks.

  10. Fluorescent protein-tagged Vpr dissociates from HIV-1 core after viral fusion and rapidly enters the cell nucleus.

    Science.gov (United States)

    Desai, Tanay M; Marin, Mariana; Sood, Chetan; Shi, Jiong; Nawaz, Fatima; Aiken, Christopher; Melikyan, Gregory B

    2015-10-29

    HIV-1 Vpr is recruited into virions during assembly and appears to remain associated with the viral core after the reverse transcription and uncoating steps of entry. This feature has prompted the use of fluorescently labeled Vpr to visualize viral particles and to follow trafficking of post-fusion HIV-1 cores in the cytoplasm. Here, we tracked single pseudovirus entry and fusion and observed that fluorescently tagged Vpr gradually dissociates from post-fusion viral cores over the course of several minutes and accumulates in the nucleus. Kinetics measurements showed that fluorescent Vpr released from the cores very rapidly entered the cell nucleus. More than 10,000 Vpr molecules can be delivered into the cell nucleus within 45 min of infection by HIV-1 particles pseudotyped with the avian sarcoma and leukosis virus envelope glycoprotein. The fraction of Vpr from cell-bound viruses that accumulated in the nucleus was proportional to the extent of virus-cell fusion and was fully blocked by viral fusion inhibitors. Entry of virus-derived Vpr into the nucleus occurred independently of envelope glycoproteins or target cells. Fluorescence correlation spectroscopy revealed two forms of nuclear Vpr-monomers and very large complexes, likely involving host factors. The kinetics of viral Vpr entering the nucleus after fusion was not affected by point mutations in the capsid protein that alter the stability of the viral core. The independence of Vpr shedding of capsid stability and its relatively rapid dissociation from post-fusion cores suggest that this process may precede capsid uncoating, which appears to occur on a slower time scale. Our results thus demonstrate that a bulk of fluorescently labeled Vpr incorporated into HIV-1 particles is released shortly after fusion. Future studies will address the question whether the quick and efficient nuclear delivery of Vpr derived from incoming viruses can regulate subsequent steps of HIV-1 infection.

  11. HIV Rapid Testing in Substance Abuse Treatment: Implementation Following a Clinical Trial

    Science.gov (United States)

    Haynes, L. F.; Korte, J. E.; Holmes, B. E.; Gooden, L.; Matheson, T.; Feaster, D. J.; Leff, J. A.; Wilson, L.; Metsch, L. R.; Schackman, B. R.

    2011-01-01

    The Substance Abuse Mental Health Services Administration has promoted HIV testing and counseling as an evidence-based practice. Nevertheless, adoption of HIV testing in substance abuse treatment programs has been slow. This article describes the experience of a substance abuse treatment agency where, following participation in a clinical trial,…

  12. Rapid Quantification of the Toxic Alga Prymnesium parvum in Natural Samples by Use of a Specific Monoclonal Antibody and Solid-Phase Cytometry

    DEFF Research Database (Denmark)

    West, N. J.; Bacchieri, R.; Hansen, Gert

    2006-01-01

    The increasing incidence of harmful algal blooms around the world and their associated health and economic effects require the development of methods to rapidly and accurately detect and enumerate the target species. Here we describe use of a solid-phase cytometer to detect and enumerate the toxi......-phase cytometer can be used to rapidly enumerate natural P. parvum cells and that it could be used to detect other toxic algae, with an appropriate antibody or DNA probe....

  13. A Novel, Rapid Assay for Detection and Differentiation of Serotype-Specific Antibodies to Venezuelan Equine Encephalitis Complex Alphaviruses

    National Research Council Canada - National Science Library

    Wang, Eryu; Paessler, Slobodan; Smith, Darci R; Coffey, Lark L; Kang, Wenli; Estrada-Franco, Jose; Weaver, Scott C; Aguilar, Patricia V; Pfeffer, Martin; Olson, James

    2005-01-01

    ... of Venezuelan equine encephalitis (VEE) virus. Two monoclonal antibodies that differentially recognize epizootic versus enzootic VEE virus epitopes were used to measure the serotype-specific blocking abilities of antibodies in sera of naturally...

  14. Feasibility of supervised self-testing using an oral fluid-based HIV rapid testing method: a cross-sectional, mixed method study among pregnant women in rural India

    OpenAIRE

    Sarkar, Archana; Mburu, Gitau; Shivkumar, Poonam Varma; Sharma, Pankhuri; Campbell, Fiona; Behera, Jagannath; Dargan, Ritu; Mishra, Surendra Kumar; Mehra, Sunil

    2016-01-01

    Introduction: HIV self-testing can increase coverage of essential HIV services. This study aimed to establish the acceptability, concordance and feasibility of supervised HIV self-testing among pregnant women in rural India. Methods: A cross-sectional, mixed methods study was conducted among 202 consenting pregnant women in a rural Indian hospital between August 2014 and January 2015. Participants were provided with instructions on how to self-test using OraQuick® HIV antibody test, and subse...

  15. The HIV-1 V3 domain on field isolates: participation in generation of escape virus in vivo and accessibility to neutralizing antibodies

    DEFF Research Database (Denmark)

    Arendrup, M; Akerblom, L; Heegaard, P M

    1995-01-01

    The V3 domain is highly variable and induces HIV neutralizing antibodies (NA). Here we addressed the issues of 1) the participation of mutations in V3 in generation of neutralization resistant escape virus in vivo and 2) the applicability of synthetic V3 peptides corresponding to field isolates...... patterns against V3 peptides corresponding to sequential primary and escape field isolates, with the strongest reactivity against late isolated escape virus. These observations suggest that the neutralization epitope was influenced by the appearance of mutations. When used as immunogen in rabbits, V3...... to induce neutralizing immune sera. Seven peptides corresponding to the V3 region of primary and escape virus from 3 HIV-1 infected patients were synthesized and used for antibody (Abs) studies and immunizations. The anti-V3 Abs titre in patient serum was generally low against peptides corresponding...

  16. High risk exposure to HIV among sexually active individuals who tested negative on rapid HIV Tests in the Tshwane District of South Africa-The importance of behavioural prevention measures.

    Directory of Open Access Journals (Sweden)

    Simnikiwe H Mayaphi

    Full Text Available To assess the prevalence of HIV risk behaviour among sexually active HIV sero-negative individuals in the Tshwane district of South Africa (SA.Demographic and HIV risk behaviour data were collected on a questionnaire from participants of a cross-sectional study that screened for early HIV infection using pooled nucleic acid amplification testing (NAAT. The study enrolled individuals who tested negative on rapid HIV tests performed at five HIV counseling and testing (HCT clinics, which included four antenatal clinics and one general HCT clinic.The study enrolled 9547 predominantly black participants (96.6% with a median age of 27 years (interquartile range [IQR]: 23-31. There were 1661 non-pregnant and 7886 pregnant participants largely enrolled from the general and antenatal HCT clinics, respectively. NAAT detected HIV infection in 61 participants (0.6%; 95% confidence interval [CI]: 0.4-0.8 in the whole study. A high proportion of study participants, 62.8% and 63.0%, were unaware of their partner's HIV status; and also had high prevalence, 88.5% and 99.5%, of recent unprotected sex in the general and pregnant population, respectively. Consistent use of condoms was associated with protection against HIV infection in the general population. Trends of higher odds for HIV infection were observed with most demographic and HIV risk factors at univariate analysis, however, multivariate analysis did not show statistical significance for almost all these factors. A significantly lower risk of HIV infection was observed in circumcised men (p <0.001.These data show that a large segment of sexually active people in the Tshwane district of SA have high risk exposure to HIV. The detection of newly diagnosed HIV infections in all study clinics reflects a wide distribution of individuals who are capable of sustaining HIV transmission in the setting where HIV risk behaviour is highly prevalent. A questionnaire that captures HIV risk behaviour would be useful

  17. Comparison of two enzyme-linked immunosorbent assays and one rapid immunoblot assay for detection of herpes simplex virus type 2-specific antibodies in serum

    NARCIS (Netherlands)

    Groen, J; Van Dijk, G; Niesters, H G; Van Der Meijden, W I; Osterhaus, A D

    The sensitivities and specificities of three immunoassays for the detection of herpes simplex virus type 2 (HSV-2)-specific immunoglobulin G antibodies in serum, including the one-strip rapid immunoblot assay (RIBA; Chiron Corporation) and two indirect enzyme immunosorbent assays (EIA; Gull

  18. Bispecific engineered antibody domains (nanoantibodies that interact noncompetitively with an HIV-1 neutralizing epitope and FcRn.

    Directory of Open Access Journals (Sweden)

    Rui Gong

    Full Text Available Libraries based on an isolated human immunoglobulin G1 (IgG1 constant domain 2 (CH2 have been previously diversified by random mutagenesis. However, native isolated CH2 is not very stable and the generation of many mutations could lead to an increase in immunogenicity. Recently, we demonstrated that engineering an additional disulfide bond and removing seven N-terminal residues results in an engineered antibody domain (eAd (m01s with highly increased stability and enhanced binding to human neonatal Fc receptor (FcRn (Gong et al, JBC, 2009 and 2011. We and others have also previously shown that grafting of the heavy chain complementarity region 3 (CDR-H3 (H3 onto cognate positions of the variable domain leads to highly diversified libraries from which a number of binders to various antigens have been selected. However, grafting of H3s to non-cognate positions in constant domains results in additional residues at the junctions of H3s and the CH2 framework. Here we describe a new method based on multi-step PCR that allows the precise replacement of loop FG (no changes in its flanking sequences by human H3s from another library. Using this method and limited mutagenesis of loops BC and DE we generated an eAd phage-displayed library. Panning of this library against an HIV-1 gp41 MPER peptide resulted in selection of a binder, m2a1, which neutralized HIV-1 isolates from different clades with modest activity and retained the m01s capability of binding to FcRn. This result provides a proof of concept that CH2-based antigen binders that also mimic to certain extent other functions of full-size antibodies (binding to FcRn can be generated; we have previously hypothesized that such binders can be made and coined the term nanoantibodies (nAbs. Further studies in animal models and in humans will show how useful nAbs could be as therapeutics and diagnostics.

  19. Randomized Cross-Sectional Study to Compare HIV-1 Specific Antibody and Cytokine Concentrations in Female Genital Secretions Obtained by Menstrual Cup and Cervicovaginal Lavage.

    Science.gov (United States)

    Archary, Derseree; Liebenberg, Lenine J; Werner, Lise; Tulsi, Sahil; Majola, Nelisile; Naicker, Nivashnee; Dlamini, Sarah; Hope, Thomas J; Samsunder, Natasha; Abdool Karim, Salim S; Morris, Lynn; Passmore, Jo-Ann S; Garrett, Nigel J

    2015-01-01

    Optimizing methods for genital specimen collection to accurately characterize mucosal immune responses is a priority for the HIV prevention field. The menstrual cup (MC) has been proposed as an alternative to other methods including cervicovaginal lavage (CVL), but no study has yet formally compared these two methods. Forty HIV-infected, antiretroviral therapy-naïve women from the CAPRISA 002 acute HIV infection cohort study were randomized to have genital fluid collected using the MC with subsequent CVL, or by CVL alone. Qualitative data, which assessed levels of comfort and acceptability of MC using a 5-point Likert scale, was collected. Luminex multiplex assays were used to measure HIV-specific IgG against multiple gene products and 48 cytokines. The majority (94%) of participants indicated that insertion, wearing and removal of the MC was comfortable. Nineteen MCs with 18 matching, subsequent CVLs and 20 randomized CVLs were available for analysis. Mucosal IgG responses against four HIV-antigens were detected in 99% of MCs compared to only 80% of randomized CVLs (p = 0.029). Higher specific antibody activity and total antibodies were observed in MCs compared to CVL (all p<0.001). In MCs, 42/48 (88%) cytokines were in the detectable range in all participants compared to 27/48 (54%) in CVL (p<0.001). Concentrations of 22/41 cytokines (53.7%) were significantly higher in fluid collected by MC. Both total IgG (r = 0.63; p = 0.005) and cytokine concentrations (r = 0.90; p<0.001) correlated strongly between MC and corresponding post-MC CVL. MC sampling improves the detection of mucosal cytokines and antibodies, particularly those present at low concentrations. MC may therefore represent an ideal tool to assess immunological parameters in genital secretions, without interfering with concurrent collection of conventional CVL samples.

  20. Randomized Cross-Sectional Study to Compare HIV-1 Specific Antibody and Cytokine Concentrations in Female Genital Secretions Obtained by Menstrual Cup and Cervicovaginal Lavage.

    Directory of Open Access Journals (Sweden)

    Derseree Archary

    Full Text Available Optimizing methods for genital specimen collection to accurately characterize mucosal immune responses is a priority for the HIV prevention field. The menstrual cup (MC has been proposed as an alternative to other methods including cervicovaginal lavage (CVL, but no study has yet formally compared these two methods.Forty HIV-infected, antiretroviral therapy-naïve women from the CAPRISA 002 acute HIV infection cohort study were randomized to have genital fluid collected using the MC with subsequent CVL, or by CVL alone. Qualitative data, which assessed levels of comfort and acceptability of MC using a 5-point Likert scale, was collected. Luminex multiplex assays were used to measure HIV-specific IgG against multiple gene products and 48 cytokines.The majority (94% of participants indicated that insertion, wearing and removal of the MC was comfortable. Nineteen MCs with 18 matching, subsequent CVLs and 20 randomized CVLs were available for analysis. Mucosal IgG responses against four HIV-antigens were detected in 99% of MCs compared to only 80% of randomized CVLs (p = 0.029. Higher specific antibody activity and total antibodies were observed in MCs compared to CVL (all p<0.001. In MCs, 42/48 (88% cytokines were in the detectable range in all participants compared to 27/48 (54% in CVL (p<0.001. Concentrations of 22/41 cytokines (53.7% were significantly higher in fluid collected by MC. Both total IgG (r = 0.63; p = 0.005 and cytokine concentrations (r = 0.90; p<0.001 correlated strongly between MC and corresponding post-MC CVL.MC sampling improves the detection of mucosal cytokines and antibodies, particularly those present at low concentrations. MC may therefore represent an ideal tool to assess immunological parameters in genital secretions, without interfering with concurrent collection of conventional CVL samples.

  1. Antithyroglobulin antibody

    Science.gov (United States)

    Thyroglobulin antibody; Thyroiditis - thyroglobulin antibody; Hypothyroidism - thyroglobulin antibody; Thyroiditis - thyroglobulin antibody; Graves disease - thyroglobulin antibody; Underactive thyroid - thyroglobulin antibody

  2. Investigation of Sequence Clipping and Structural Heterogeneity of an HIV Broadly Neutralizing Antibody by a Comprehensive LC-MS Analysis

    Science.gov (United States)

    Ivleva, Vera B.; Schneck, Nicole A.; Gollapudi, Deepika; Arnold, Frank; Cooper, Jonathan W.; Lei, Q. Paula

    2018-05-01

    CAP256 is one of the highly potent, broadly neutralizing monoclonal antibodies (bNAb) designed for HIV-1 therapy. During the process development of one of the constructs, an unexpected product-related impurity was observed via microfluidics gel electrophoresis. A panel of complementary LC-MS analyses was applied for the comprehensive characterization of CAP256 which included the analysis of the intact and reduced protein, the middle-up approach, and a set of complementary peptide mapping techniques and verification of the disulfide bonds. The designed workflow allowed to identify a clip within a protruding acidic loop in the CDR-H3 region of the heavy chain, which can lead to the decrease of bNAb potency. This characterization explained the origin of the additional species reflected by the reducing gel profile. An intra-loop disulfide bond linking the two fragments was identified, which explained why the non-reducing capillary electrophoresis (CE) profile was not affected. The extensive characterization of CAP256 post-translational modifications was performed to investigate a possible cause of CE profile complexity and to illustrate other structural details related to this molecule's biological function. Two sites of the engineered Tyr sulfation were verified in the antigen-binding loop, and pyroglutamate formation was used as a tool for monitoring the extent of antibody clipping. Overall, the comprehensive LC-MS study was crucial to (1) identify the impurity as sequence clipping, (2) pinpoint the clipping location and justify its susceptibility relative to the molecular structure, (3) lead to an upstream process optimization to mitigate product quality risk, and (4) ultimately re-engineer the sequence to be clip-resistant. [Figure not available: see fulltext.

  3. Specific Antibody Production by Blood B Cells is Retained in Late Stage Drug-naïve HIV-infected Africans

    Directory of Open Access Journals (Sweden)

    Lydie Béniguel

    2004-01-01

    Full Text Available Unseparated peripheral blood mononuclear cells (PBMCs obtained from drug-naïve African individuals living in a context of multi-infections and presenting with high viral load (VL, were cultured in vitro and tested for their ability to produce antibodies (Abs reacting with HIV-1 antigens. Within these PBMCs, circulating B cells were differentiated in vitro and produced IgG Abs against not only ENV, but also GAG and POL proteins. Under similar experimental conditions, HAART treated patients produced Abs to ENV proteins only. The in vitro antibody production by drug-naïve individuals' PBMCs depended on exogenous cytokines (IL-2 and IL-10 but neither on the re-stimulation of reactive cells in cultures by purified HIV-1-gp 160 antigen nor on the re-engagement of CD40 surface molecules. Further, it was not abrogated by the addition of various monoclonal Abs (mAbs to co-stimulatory molecules. This suggests that the in vitro antibody production by drug-naïve individuals' PBMCs resulted from the maturation of already envelope and core antigen-primed, differentiated B cells, presumably pre-plasma cells, which are not known to circulate at homeostasy. As in vitro produced Abs retained the capacity of binding antigen and forming complexes, this study provides pre-clinical support for functional humoral responses despite major HIV- and other tropical pathogen-induced B cell perturbations.

  4. Triggering HIV polyprotein processing by light using rapid photodegradation of a tight-binding protease inhibitor

    Czech Academy of Sciences Publication Activity Database

    Schimer, Jiří; Pávová, Marcela; Anders, M.; Pachl, Petr; Šácha, Pavel; Cígler, Petr; Weber, Jan; Majer, Pavel; Řezáčová, Pavlína; Kräusslich, H. G.; Müller, B.; Konvalinka, Jan

    2015-01-01

    Roč. 6, Mar (2015), 6461/1-6461/8 ISSN 2041-1723 R&D Projects: GA ČR GBP208/12/G016; GA MŠk LO1302 Grant - others:GA MŠk(CZ) ED1.1.00/02.0109 Program:ED Institutional support: RVO:61388963 Keywords : HIV maturation * HIV PR photodegradable inhibitor * HIV PR caging Subject RIV: CE - Biochemistry Impact factor: 11.329, year: 2015 http://www.nature.com/ncomms/2015/150309/ncomms7461/pdf/ncomms7461.pdf

  5. The effect of daily co-trimoxazole prophylaxis on natural development of antibody-mediated immunity against P. falciparum malaria infection in HIV-exposed uninfected Malawian children.

    Directory of Open Access Journals (Sweden)

    Herbert Longwe

    Full Text Available Co-trimoxazole prophylaxis, currently recommended in HIV-exposed, uninfected (HEU children as protection against opportunistic infections, also has some anti-malarial efficacy. We determined whether daily co-trimoxazole prophylaxis affects the natural development of antibody-mediated immunity to blood-stage Plasmodium falciparum malaria infection.Using an enzyme-linked immunosorbent assay, we measured antibodies to 8 Plasmodium falciparum antigens (AMA-1, MSP-119, MSP-3, PfSE, EBA-175RII, GLURP R0, GLURP R2 and CSP in serum samples from 33 HEU children and 31 HIV-unexposed, uninfected (HUU children, collected at 6, 12 and 18 months of age.Compared to HIV-uninfected children, HEU children had significantly lower levels of specific IgG against AMA-1 at 6 months (p = 0.001, MSP-119 at 12 months (p = 0.041 and PfSE at 6 months (p = 0.038, 12 months (p = 0.0012 and 18 months (p = 0.0097. No differences in the IgG antibody responses against the rest of the antigens were observed between the two groups at all time points. The breadth of specificity of IgG response was reduced in HEU children compared to HUU children during the follow up period.Co-trimoxazole prophylaxis seems to reduce IgG antibody responses to P. falciparum blood stage antigens, which could be as a result of a reduction in exposure of those children under this regime. Although antibody responses were regarded as markers of exposure in this study, further studies are required to establish whether these responses are correlated in any way to clinical immunity to malaria.

  6. The effect of daily co-trimoxazole prophylaxis on natural development of antibody-mediated immunity against P. falciparum malaria infection in HIV-exposed uninfected Malawian children.

    Science.gov (United States)

    Longwe, Herbert; Jambo, Kondwani C; Phiri, Kamija S; Mbeye, Nyanyiwe; Gondwe, Thandile; Hall, Tom; Tetteh, Kevin K A; Drakeley, Chris; Mandala, Wilson L

    2015-01-01

    Co-trimoxazole prophylaxis, currently recommended in HIV-exposed, uninfected (HEU) children as protection against opportunistic infections, also has some anti-malarial efficacy. We determined whether daily co-trimoxazole prophylaxis affects the natural development of antibody-mediated immunity to blood-stage Plasmodium falciparum malaria infection. Using an enzyme-linked immunosorbent assay, we measured antibodies to 8 Plasmodium falciparum antigens (AMA-1, MSP-119, MSP-3, PfSE, EBA-175RII, GLURP R0, GLURP R2 and CSP) in serum samples from 33 HEU children and 31 HIV-unexposed, uninfected (HUU) children, collected at 6, 12 and 18 months of age. Compared to HIV-uninfected children, HEU children had significantly lower levels of specific IgG against AMA-1 at 6 months (p = 0.001), MSP-119 at 12 months (p = 0.041) and PfSE at 6 months (p = 0.038), 12 months (p = 0.0012) and 18 months (p = 0.0097). No differences in the IgG antibody responses against the rest of the antigens were observed between the two groups at all time points. The breadth of specificity of IgG response was reduced in HEU children compared to HUU children during the follow up period. Co-trimoxazole prophylaxis seems to reduce IgG antibody responses to P. falciparum blood stage antigens, which could be as a result of a reduction in exposure of those children under this regime. Although antibody responses were regarded as markers of exposure in this study, further studies are required to establish whether these responses are correlated in any way to clinical immunity to malaria.

  7. Prevalence, risk factors, and impact of isolated antibody to hepatitis B core antigen and occult hepatitis B virus infection in HIV-1-infected pregnant women.

    Science.gov (United States)

    Khamduang, Woottichai; Ngo-Giang-Huong, Nicole; Gaudy-Graffin, Catherine; Jourdain, Gonzague; Suwankornsakul, Weerapong; Jarupanich, Tapnarong; Chalermpolprapa, Veeradate; Nanta, Sirisak; Puarattana-Aroonkorn, Noossara; Tonmat, Sakchai; Lallemant, Marc; Goudeau, Alain; Sirirungsi, Wasna

    2013-06-01

    Prevalence and risk factors for isolated antibody to hepatitis B core antigen (anti-HBc) and occult hepatitis B virus (HBV) infection are not well known in human immunodeficiency virus type 1 (HIV-1)-infected pregnant women. It is unclear if women with occult infections are at risk of transmitting HBV to their infants. HIV-1-infected and HBV surface antigen (HBsAg)-negative pregnant women were tested for antibody to HBsAg (anti-HBs) and anti-HBc using enzyme immunoassay. Women with isolated anti-HBc were assessed for occult HBV infection, defined as HBV DNA levels >15 IU/mL, using the Abbott RealTime HBV DNA assay. Infants born to women with isolated anti-HBc and detectable HBV DNA were tested at 4 months of age for HBV DNA. Logistic regression analysis was used to identify factors associated with isolated anti-HBc and occult HBV infection. Among 1812 HIV-infected pregnant women, 1682 were HBsAg negative. Fourteen percent (95% confidence interval [CI], 12%-15%) of HBsAg-negative women had an isolated anti-HBc that was independently associated with low CD4 count, age >35 years, birth in northern Thailand, and positive anti-hepatitis C virus serology. Occult HBV infection was identified in 24% (95% CI, 18%-30%) of women with isolated anti-HBc, representing 2.6% (95% CI, 1.9%-3.5%) of HIV-1-infected pregnant women, and was inversely associated with HIV RNA levels. None of the women with isolated anti-HBc and occult HBV infection transmitted HBV to their infants. HIV-1-infected pregnant women with isolated anti-HBc and occult HBV infection have very low HBV DNA levels and are thus at very low risk to transmit HBV to their infants.

  8. Situation of Linkage between Sexual and Reproductive Health and HIV-Related Policies in Islamic Republic of Iran – A Rapid Assessment in 2011–2

    Directory of Open Access Journals (Sweden)

    Ghobad Moradi

    2015-03-01

    Full Text Available The number of sexual transmission of HIV is increasing globally. Sexual and Reproductive Health (SRH issues and HIV/AIDS related problems are rooted in common grounds such as poverty, gender inequality, and social exclusion. As a result, international health organizations have suggested the integration of SRH services with HIV/AIDS services as a strategy to control HIV and to improve people’s access to SRH services. The aim of this study was to evaluate the relationship between reproductive health and HIV/AIDS services at policy-making level in Islamic Republic of Iran (IRI. This study was conducted in 2011–2 and was a rapid assessment based on guidelines provided by the World Health Organization (WHO, United Nations Programme on HIV/AIDS (UNAIDS, Family Health International Association, and some other international organizations. In this rapid assessment we used different methods such as a review of literature and documents, visiting and interviewing professionals and experts in family health and HIV/AIDS programs, and experts working in some NonGovernmental Organizations (NGOs. Overall, based on the results obtained in this study, in most cases there was not much linkage between HIV/AIDS policies and SRH policies in Iran. Since integration of HIV/AIDS services and SRH services is recommended as a model and an appropriate response to HIV epidemics worldwide, likewise to control the HIV/AIDS epidemic in Iran it is required to integrate HIV/AIDS and SRH services at all levels, particularly at the policy-making level.

  9. Evaluation du test rapide oral aware™ omt HIV 1/2 pour le ...

    African Journals Online (AJOL)

    Chaque participant a fourni un échantillon de fluide oral pour la réalisation du test Aware™ OMT HIV-1/2 et du sang testé suivant l'algorithme séquentiel de tests ELISAs Murex® HIV-1.2.0 (Laboratoires Abbott, Japon) et Test ELISA peptidique maison du CeDReS. Résultats : la sensibilité, la spécificité, la Valeur Prédictive ...

  10. Evaluation of HIV-1 rapid tests and identification of alternative testing algorithms for use in Uganda.

    Science.gov (United States)

    Kaleebu, Pontiano; Kitandwe, Paul Kato; Lutalo, Tom; Kigozi, Aminah; Watera, Christine; Nanteza, Mary Bridget; Hughes, Peter; Musinguzi, Joshua; Opio, Alex; Downing, Robert; Mbidde, Edward Katongole

    2018-02-27

    The World Health Organization recommends that countries conduct two phase evaluations of HIV rapid tests (RTs) in order to come up with the best algorithms. In this report, we present the first ever such evaluation in Uganda, involving both blood and oral based RTs. The role of weak positive (WP) bands on the accuracy of the individual RT and on the algorithms was also investigated. In total 11 blood based and 3 oral transudate kits were evaluated. All together 2746 participants from seven sites, covering the four different regions of Uganda participated. Two enzyme immunoassays (EIAs) run in parallel were used as the gold standard. The performance and cost of the different algorithms was calculated, with a pre-determined price cut-off of either cheaper or within 20% price of the current algorithm of Determine + Statpak + Unigold. In the second phase, the three best algorithms selected in phase I were used at the point of care for purposes of quality control using finger stick whole blood. We identified three algorithms; Determine + SD Bioline + Statpak; Determine + Statpak + SD Bioline, both with the same sensitivity and specificity of 99.2% and 99.1% respectively and Determine + Statpak + Insti, with sensitivity and specificity of 99.1% and 99% respectively as having performed better and met the cost requirements. There were 15 other algorithms that performed better than the current one but rated more than the 20% price. None of the 3 oral mucosal transudate kits were suitable for inclusion in an algorithm because of their low sensitivities. Band intensity affected the performance of individual RTs but not the final algorithms. We have come up with three algorithms we recommend for public or Government procurement based on accuracy and cost. In case one algorithm is preferred, we recommend to replace Unigold, the current tie breaker with SD Bioline. We further recommend that all the 18 algorithms that have shown better performance than the current one are made

  11. Measuring enzymatic HIV-1 susceptibility to two reverse transcriptase inhibitors as a rapid and simple approach to HIV-1 drug-resistance testing.

    Directory of Open Access Journals (Sweden)

    Dieter Hoffmann

    Full Text Available Simple and cost-effective approaches for HIV drug-resistance testing are highly desirable for managing increasingly expanding HIV-1 infected populations who initiate antiretroviral therapy (ART, particularly in resource-limited settings. Non-nucleoside reverse trancriptase inhibitor (NNRTI-based regimens with an NRTI backbone containing lamivudine (3TC or emtricitabine (FTC are preferred first ART regimens. Failure with these drug combinations typically involves the selection of NNRTI- and/or 3TC/FTC-resistant viruses. Therefore, the availability of simple assays to measure both types of drug resistance is critical. We have developed a high throughput screening test for assessing enzymatic resistance of the HIV-1 RT in plasma to 3TC/FTC and NNRTIs. The test uses the sensitive "Amp-RT" assay with a newly-developed real-time PCR format to screen biochemically for drug resistance in single reactions containing either 3TC-triphosphate (3TC-TP or nevirapine (NVP. Assay cut-offs were defined based on testing a large panel of subtype B and non-subtype B clinical samples with known genotypic profiles. Enzymatic 3TC resistance correlated well with the presence of M184I/V, and reduced NVP susceptibility was strongly associated with the presence of K103N, Y181C/I, Y188L, and G190A/Q. The sensitivity and specificity for detecting resistance were 97.0% and 96.0% in samples with M184V, and 97.4% and 96.2% for samples with NNRTI mutations, respectively. We further demonstrate the utility of an HIV capture method in plasma by using magnetic beads coated with CD44 antibody that eliminates the need for ultracentifugation. Thus our results support the use of this simple approach for distinguishing WT from NNRTI- or 3TC/FTC-resistant viruses in clinical samples. This enzymatic testing is subtype-independent and can assist in the clinical management of diverse populations particularly in resource-limited settings.

  12. Development of a definition for Rapid Progression (RP) of renal function in HIV-positive persons : the D:A:D study

    NARCIS (Netherlands)

    Kamara, David A; Ryom, Lene; Ross, Michael; Kirk, Ole; Reiss, Peter; Morlat, Philippe; Moranne, Olivier; Fux, Christoph A; Mocroft, Amanda; Sabin, Caroline; Lundgren, Jens D; Smith, Colette J; Schölvinck, Elisabeth H.

    2014-01-01

    BACKGROUND: No consensus exists on how to define abnormally rapid deterioration in renal function (Rapid Progression, RP). We developed an operational definition of RP in HIV-positive persons with baseline estimated glomerular filtration rate (eGFR) >90 ml/min/1.73 m2 (using Cockcroft Gault) in the

  13. Development of a definition for Rapid Progression (RP) of renal function in HIV-positive persons: the D:A:D study

    NARCIS (Netherlands)

    Kamara, David A.; Ryom, Lene; Ross, Michael; Kirk, Ole; Reiss, Peter; Morlat, Philippe; Moranne, Olivier; Fux, Christoph A.; Mocroft, Amanda; Sabin, Caroline; Lundgren, Jens D.; Smith, Colette J.; Powderly, B.; Shortman, N.; Moecklinghoff, C.; Reilly, G.; Franquet, X.; Ryom, L.; Sabin, C. A.; Kamara, D.; Smith, C.; Phillips, A.; Mocroft, A.; Tverland, J.; Mansfeld, M.; Nielsen, J.; Raben, D.; Lundgren, J. D.; Brandt, R. Salbøl; Rickenbach, M.; Fanti, I.; Krum, E.; Hillebregt, M.; Geffard, S.; Sundström, A.; Prins, J. M.; Kuijpers, T. W.; Scherpbier, H. J.; van der Meer, J. T. M.; Wit, F. W. M. N.; Godfried, M. H.; Nellen, F. J. B.; Lange, J. M. A.; Geerlings, S. E.; van Vugt, M.; Pajkrt, D.; Grijsen, M. L.; Wiersinga, W. J.; Goorhuis, A.; Hovius, J. W. R.

    2014-01-01

    No consensus exists on how to define abnormally rapid deterioration in renal function (Rapid Progression, RP). We developed an operational definition of RP in HIV-positive persons with baseline estimated glomerular filtration rate (eGFR) >90 ml/min/1.73 m2 (using Cockcroft Gault) in the Data

  14. Development of a definition for Rapid Progression (RP) of renal function in HIV-positive persons: the D:A:D study

    NARCIS (Netherlands)

    Kamara, D.A.; Ryom, L.; Ross, M.; Kirk, O.; Reiss, P.; Morlat, P.; Moranne, O.; Fux, C.A.; Mocroft, A.; Sabin, C.; Lundgren, J.D.; Smith, C.J.; Koopmans †, P.P.; Keuter, M.; Ven, A.J.A.M. van der; Hofstede, H.J.M. ter; Dofferhoff, A.S.M.; Warris, A.; Crevel, R. van; et al.,

    2014-01-01

    BACKGROUND: No consensus exists on how to define abnormally rapid deterioration in renal function (Rapid Progression, RP). We developed an operational definition of RP in HIV-positive persons with baseline estimated glomerular filtration rate (eGFR) >90 ml/min/1.73 m2 (using Cockcroft Gault) in the

  15. Repeat confirmatory testing for persons with discordant whole blood and oral fluid rapid HIV test results: findings from post marketing surveillance.

    Science.gov (United States)

    Wesolowski, Laura G; Mackellar, Duncan A; Ethridge, Steven F; Zhu, Julia H; Owen, S Michele; Sullivan, Patrick S

    2008-02-06

    Reactive oral fluid and whole blood rapid HIV tests must be followed with a confirmatory test (Western blot (WB), immunofluorescent assay (IFA) or approved nucleic acid amplification test (NAAT)). When the confirmatory result is negative or indeterminate (i.e. discordant with rapid result), repeat confirmatory testing should be conducted using a follow-up specimen. Previous reports have not described whether repeat testing adequately resolves the HIV-infection status of persons with discordant results. Post-marketing surveillance was conducted in 368 testing sites affiliated with 14 state and 2 city health departments from August 11, 2004 to June 30, 2005 and one health department through December 31, 2005. For persons with discordant results, data were collected on demographics, risk behaviors, HIV test results and specimen types. Persons with repeat confirmatory results were classified as HIV-infected or uninfected. Regression models were created to assess risk factors for not having repeat testing. Of 167,371 rapid tests conducted, 2589 (1.6%) were reactive: of these, 2417 (93%) had positive WB/IFA, 172 (7%) had negative or indeterminate WB/IFA. Of 89/172 (52%) persons with a repeat confirmatory test: 17 (19%) were HIV-infected, including 3 with indeterminate WB and positive NAAT; 72 (81%) were uninfected, including 12 with repeat indeterminate WB. Factors associated with HIV-infection included having an initial indeterminate WB/IFA (vs. negative) (ptest [adjusted OR 2.6, 95% CI (1.3, 4.9)]. Though only half of persons with discordant results had repeat confirmatory testing, of those who did, nearly one in five were HIV-infected. These findings underscore the need for rapid HIV testing programs to increase repeat confirmatory testing for persons with discordant results. Because of the lower sensitivity of oral fluid WBs, confirmatory testing following a reactive rapid test should be conducted using serum or plasma, when possible.

  16. 2012 HIV Diagnostics Conference: the molecular diagnostics perspective.

    Science.gov (United States)

    Branson, Bernard M; Pandori, Mark

    2013-04-01

    2012 HIV Diagnostic Conference Atlanta, GA, USA, 12-14 December 2012. This report highlights the presentations and discussions from the 2012 National HIV Diagnostic Conference held in Atlanta (GA, USA), on 12-14 December 2012. Reflecting changes in the evolving field of HIV diagnostics, the conference provided a forum for evaluating developments in molecular diagnostics and their role in HIV diagnosis. In 2010, the HIV Diagnostics Conference concluded with the proposal of a new diagnostic algorithm which included nucleic acid testing to resolve discordant screening and supplemental antibody test results. The 2012 meeting, picking up where the 2010 meeting left off, focused on scientific presentations that assessed this new algorithm and the role played by RNA testing and new developments in molecular diagnostics, including detection of total and integrated HIV-1 DNA, detection and quantification of HIV-2 RNA, and rapid formats for detection of HIV-1 RNA.

  17. Validation of the rapid fluorescent focus inhibition test for rabies virus-neutralizing antibodies in clinical samples

    NARCIS (Netherlands)

    Kostense, Stefan; Moore, Susan; Companjen, Arjen; Bakker, Alexander B. H.; Marissen, Wilfred E.; von Eyben, Rie; Weverling, Gerrit Jan; Hanlon, Cathleen; Goudsmit, Jaap

    2012-01-01

    Monoclonal antibodies are successful biologics in treating a variety of diseases, including the prevention or treatment of viral infections. CL184 is a 1:1 combination of two human monoclonal IgG1 antibodies (CR57 and CR4098) against rabies virus, produced in the PER.C6 human cell line. The two

  18. The diagnostic performance evaluation of the SD BIOLINE HIV/syphilis Duo rapid test in southern Ethiopia: a cross-sectional study.

    Science.gov (United States)

    Shimelis, Techalew; Tadesse, Endale

    2015-04-23

    To determine the diagnostic performance of the SD BIOLINE HIV/syphilis Duo rapid test. A hospital-based cross-sectional study. This evaluation was conducted at one of the largest hospitals in southern Ethiopia. Serum samples obtained from clients attending the antiretroviral therapy and voluntary counselling and testing centres were used. Sera were originally collected for the purpose of investigating syphilis epidemiology. The performance of the test to detect HIV was evaluated using 400 sera (200 HIV positives and 200 HIV negatives). Also, its performance to detect syphilis was evaluated using 85 syphilis positive and 100 syphilis negative serum samples. Individuals tiebreaker to determine the result. We also used ELISA to resolve discordant HIV results. Syphilis serostatus was determined using the Treponema pallidum haemagglutination assay (TPHA). The respective sensitivity, specificity, positive predictive value and negative predictive value of the SD BIOLINE HIV/syphilis Duo test were 100, 99.5, 99.5 and 100% for HIV and 97.6, 96, 95.4 and 98% for syphilis testing, respectively. In reference to TPHA, the test kit reported 4 false positives and 2 false negative results for syphilis. The κ values were 0.99 for HIV testing and 0.94 for syphilis testing. The excellent performance of the SD BIOLINE HIV/syphilis Duo test to detect HIV as well as syphilis facilitates the integration of syphilis testing and treatment to the already established HIV prevention programme, ultimately contributing to the dual HIV and syphilis elimination goal. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  19. Structure and Recognition of a Novel HIV-1 gp120-gp41 Interface Antibody that Caused MPER Exposure through Viral Escape

    Energy Technology Data Exchange (ETDEWEB)

    Wibmer, Constantinos Kurt; Gorman, Jason; Ozorowski, Gabriel; Bhiman, Jinal N.; Sheward, Daniel J.; Elliott, Debra H.; Rouelle, Julie; Smira, Ashley; Joyce, M. Gordon; Ndabambi, Nonkululeko; Druz, Aliaksandr; Asokan, Mangai; Burton, Dennis R.; Connors, Mark; Abdool Karim, Salim S.; Mascola, John R.; Robinson, James E.; Ward, Andrew B.; Williamson, Carolyn; Kwong, Peter D.; Morris, Lynn; Moore, Penny L.; Desrosiers, Ronald C.

    2017-01-11

    A comprehensive understanding of the regions on HIV-1 envelope trimers targeted by broadly neutralizing antibodies may contribute to rational design of an HIV-1 vaccine. We previously identified a participant in the CAPRISA cohort, CAP248, who developed trimer-specific antibodies capable of neutralizing 60% of heterologous viruses at three years post-infection. Here, we report the isolation by B cell culture of monoclonal antibody CAP248-2B, which targets a novel membrane proximal epitope including elements of gp120 and gp41. Despite low maximum inhibition plateaus, often below 50% inhibitory concentrations, the breadth of CAP248-2B significantly correlated with donor plasma. Site-directed mutagenesis, X-ray crystallography, and negative-stain electron microscopy 3D reconstructions revealed how CAP248-2B recognizes a cleavage-dependent epitope that includes the gp120 C terminus. While this epitope is distinct, it overlapped in parts of gp41 with the epitopes of broadly neutralizing antibodies PGT151, VRC34, 35O22, 3BC315, and 10E8. CAP248-2B has a conformationally variable paratope with an unusually long 19 amino acid light chain third complementarity determining region. Two phenylalanines at the loop apex were predicted by docking and mutagenesis data to interact with the viral membrane. Neutralization by CAP248-2B is not dependent on any single glycan proximal to its epitope, and low neutralization plateaus could not be completely explained by N- or O-linked glycosylation pathway inhibitors, furin co-transfection, or pre-incubation with soluble CD4. Viral escape from CAP248-2B involved a cluster of rare mutations in the gp120-gp41 cleavage sites. Simultaneous introduction of these mutations into heterologous viruses abrogated neutralization by CAP248-2B, but enhanced neutralization sensitivity to 35O22, 4E10, and 10E8 by 10-100-fold. Altogether, this study expands the region of the HIV-1 gp120-gp41 quaternary interface that is a target for broadly neutralizing

  20. Patients' Willingness to Participate in Rapid HIV Testing: A pilot study in three New York City dental hygiene clinics.

    Science.gov (United States)

    Davide, Susan H; Santella, Anthony J; Furnari, Winnie; Leuwaisee, Petal; Cortell, Marilyn; Krishnamachari, Bhuma

    2017-12-01

    Purpose: One in eight people living with an HIV infection in the United States is unaware of their status. Rapid HIV testing (RHT) is an easily used and accepted screening tool that has been introduced in a limited number of clinical settings. The purpose of this study was to investigate patient acceptability, certainty of their decision, and willingness to pay for screening if RHT was offered in university-based dental hygiene clinics. Methods: A cross-sectional survey was administered to 426 patients at three dental hygiene clinics in New York City over a period of four months. The survey questionnaire was based on the decisional conflict scale measuring personal perceptions; with zero indicating extremely high conflict to four indicating no conflict. Patients were assessed for their acceptance of RHT, provider preference for administration of the test and their willingness to pay for RHT. Results: Over half (72.2%) indicated acceptance of HIV testing in a dental hygiene clinic setting; with 85.3% choosing oral RHT, 4.9% fingerstick RHT, and 8.8% venipuncture. Respondents were amenable to testing when offered by dental hygienists (71.7%) and dentists (72.4%). Over 30% indicated their willingness to receive HIV testing in the dental setting when offered at no additional cost. The mean decisional conflict score was 3.42/4.0 indicating no decisional conflict. Conclusions: Patients are willing to undergo oral RHT when offered as a service and provided by dental hygienists in the dental setting. Patients appear to be aware of the benefits and risks associated with RHT. Further research is needed to evaluate the public health benefits and logistical challenges facing the delivery of RHT within in the dental setting. Copyright © 2017 The American Dental Hygienists’ Association.

  1. Large sharing networks and unusual injection practices explain the rapid rise in HIV among IDUs in Sargodha, Pakistan

    Directory of Open Access Journals (Sweden)

    Qureshi Salman U

    2009-06-01

    Full Text Available Abstract Background Of the nearly 100,000 street-based IDUs in Pakistan, 20% have HIV. We investigated the recent rise in HIV prevalence from 12 to 52% among IDUs in Sargodha despite > 70% coverage with syringe exchanges. Methods We interviewed approximately 150 IDUs and 30 outreach workers in focus group discussions. Results We found six rural and 28 urban injecting locations. Urban locations have about 20–30 people at any time and about 100 daily; rural locations have twice as many (national average: 4–15. About half of the IDUs started injecting within the past 2 years and are not proficient at injecting themselves. They use street injectors, who have 15–16 clients daily. Heroin is almost exclusively the drug used. Most inject 5–7 times daily. Nearly all injectors claim to use fresh syringes. However, they load, inject and share using a locally developed method called scale. Most Pakistani IDUs prefer to double pump drug the syringe, which allows mixing of blood with drug in the syringe. The injector injects 3 ml and keeps 2 ml (the scale as injection fee. The injector usually pools all the leftover scale (now with some blood mixed with drug either for his own use or to sell it. Most IDUs backload the scale they buy into their own fresh syringes. Discussion Use of an unprecedented method of injecting drugs that largely bypasses fresh syringes, larger size of sharing networks, higher injection frequency and near universal use of street injectors likely explain for the rapid rise in HIV prevalence among IDUs in Sargodha despite high level provision of fresh syringes. This had been missed by us and the national surveillance, which is quantitative. We have addressed this by hiring injectors as peer outreach workers and increasing syringe supply. Our findings highlight both the importance of qualitative research and operations research to enrich the quality of HIV prevention programs.

  2. The quality of rapid HIV testing in South Africa: an assessment of ...

    African Journals Online (AJOL)

    100%, which was higher than laboratory technicians who scored 99.3%.10 In this study, human error in recording results was considered to be a potential reason for the discrepancy.10 The proficiency of personnel administer- ing HIV testing has an impact on the sensitivity (ability of the kit to correctly detect specimens ...

  3. Estimating the probability of polyreactive antibodies 4E10 and 2F5 disabling a gp41 trimer after T cell-HIV adhesion.

    Directory of Open Access Journals (Sweden)

    Bin Hu

    2014-01-01

    Full Text Available A few broadly neutralizing antibodies, isolated from HIV-1 infected individuals, recognize epitopes in the membrane proximal external region (MPER of gp41 that are transiently exposed during viral entry. The best characterized, 4E10 and 2F5, are polyreactive, binding to the viral membrane and their epitopes in the MPER. We present a model to calculate, for any antibody concentration, the probability that during the pre-hairpin intermediate, the transient period when the epitopes are first exposed, a bound antibody will disable a trivalent gp41 before fusion is complete. When 4E10 or 2F5 bind to the MPER, a conformational change is induced that results in a stably bound complex. The model predicts that for these antibodies to be effective at neutralization, the time to disable an epitope must be shorter than the time the antibody remains bound in this conformation, about five minutes or less for 4E10 and 2F5. We investigate the role of avidity in neutralization and show that 2F5 IgG, but not 4E10, is much more effective at neutralization than its Fab fragment. We attribute this to 2F5 interacting more stably than 4E10 with the viral membrane. We use the model to elucidate the parameters that determine the ability of these antibodies to disable epitopes and propose an extension of the model to analyze neutralization data. The extended model predicts the dependencies of IC50 for neutralization on the rate constants that characterize antibody binding, the rate of fusion of gp41, and the number of gp41 bridging the virus and target cell at the start of the pre-hairpin intermediate. Analysis of neutralization experiments indicate that only a small number of gp41 bridges must be disabled to prevent fusion. However, the model cannot determine the exact number from neutralization experiments alone.

  4. Structural defects and variations in the HIV-1 nef gene from rapid, slow and non-progressor children.

    Science.gov (United States)

    Casartelli, Nicoletta; Di Matteo, Gigliola; Argentini, Claudio; Cancrini, Caterina; Bernardi, Stefania; Castelli, Guido; Scarlatti, Gabriella; Plebani, Anna; Rossi, Paolo; Doria, Margherita

    2003-06-13

    Evaluation of sequence evolution as well as structural defects and mutations of the human immunodeficiency virus-type 1 (HIV-1) nef gene in relation to disease progression in infected children. We examined a large number of nef alleles sequentially derived from perinatally HIV-1-infected children with different rates of disease progression: six non-progressors (NPs), four rapid progressors (RPs), and three slow progressors (SPs). Nef alleles (182 total) were isolated from patients' peripheral blood mononuclear cells (PBMCs), sequenced and analysed for their evolutionary pattern, frequency of mutations and occurrence of amino acid variations associated with different stages of disease. The evolution rate of the nef gene apparently correlated with CD4+ decline in all progression groups. Evidence for rapid viral turnover and positive selection for changes were found only in two SPs and two RPs respectively. In NPs, a higher proportion of disrupted sequences and mutations at various functional motifs were observed. Furthermore, NP-derived Nef proteins were often changed at residues localized in the folded core domain at cytotoxic T lymphocytes (CTL) epitopes (E(105), K(106), E(110), Y(132), K(164), and R(200)), while other residues outside the core domain are more often changed in RPs (A(43)) and SPs (N(173) and Y(214)). Our results suggest a link between nef gene functions and the progression rate in HIV-1-infected children. Moreover, non-progressor-associated variations in the core domain of Nef, together with the genetic analysis, suggest that nef gene evolution is shaped by an effective immune system in these patients.

  5. Development of antibody-modified chitosan nanoparticles for the targeted delivery of siRNA across the blood-brain barrier as a strategy for inhibiting HIV replication in astrocytes.

    Science.gov (United States)

    Gu, Jijin; Al-Bayati, Karam; Ho, Emmanuel A

    2017-08-01

    RNA interference (RNAi)-mediated gene silencing offers a novel treatment and prevention strategy for human immunodeficiency virus (HIV) infection. HIV was found to infect and replicate in human brain cells and can cause neuroinfections and neurological deterioration. We designed dual-antibody-modified chitosan/small interfering RNA (siRNA) nanoparticles to deliver siRNA across the blood-brain barrier (BBB) targeting HIV-infected brain astrocytes as a strategy for inhibiting HIV replication. We hypothesized that transferrin antibody and bradykinin B2 antibody could specifically bind to the transferrin receptor (TfR) and bradykinin B2 receptor (B2R), respectively, and deliver siRNA across the BBB into astrocytes as potential targeting ligands. In this study, chitosan nanoparticles (CS-NPs) were prepared by a complex coacervation method in the presence of siRNA, and antibody was chemically conjugated to the nanoparticles. The antibody-modified chitosan nanoparticles (Ab-CS-NPs) were spherical in shape, with an average particle size of 235.7 ± 10.2 nm and a zeta potential of 22.88 ± 1.78 mV. The therapeutic potential of the nanoparticles was evaluated based on their cellular uptake and gene silencing efficiency. Cellular accumulation and gene silencing efficiency of Ab-CS-NPs in astrocytes were significantly improved compared to non-modified CS-NPs and single-antibody-modified CS-NPs. These results suggest that the combination of anti-Tf antibody and anti-B2 antibody significantly increased the knockdown effect of siRNA-loaded nanoparticles. Thus, antibody-mediated dual-targeting nanoparticles are an efficient and promising delivery strategy for inhibiting HIV replication in astrocytes. Graphical abstract Graphic representation of dual-antibody-conjugated chitosan nanoparticles for the targeted delivery of siRNA across the blood-brain barrier (BBB) for inhibiting HIV replication in astrocytes. a Nanoparticle delivery to the BBB and penetration. b Tf

  6. High-sensitive and rapid detection of Mycobacterium tuberculosis infection by IFN-γ release assay among HIV-infected individuals in BCG-vaccinated area

    Directory of Open Access Journals (Sweden)

    Jiang Weimin

    2009-05-01

    Full Text Available Abstract Background An accurate test for Mycobacterium tuberculosis infection is urgently needed in immunosuppressed populations. The aim of this study was to investigate the diagnostic power of enzyme-linked immunospot (ELISPOT-based IFN-γ release assay in detecting active and latent tuberculosis in HIV-infected population in bacillus Calmette-Guerin (BCG-vaccinated area. A total of 100 HIV-infected individuals including 32 active tuberculosis patients were recruited. An ELISPOT-based IFN-γ release assay, T-SPOT.TB, was used to evaluate the M. tuberculosis ESAT-6 and CFP-10 specific IFN-γ response. Tuberculin skin test (TST was performed for all recruited subjects. Results The subjects were divided into group HIV+ATB (HIV-infected individuals with active tuberculosis, n = 32, group HIV+LTB (HIV-infected individuals with positive results of T-SPOT.TB assay, n = 46 and group HIV only (HIV-infected individuals with negative results of T-SPOT.TB assay and without evidence of tuberculosis infection, n = 22. In group HIV+ATB and HIV+LTB, T-SPOT.TB positive rate in subjects with TST P 85% in patients with TB treatment for less than 1 month and CD4+ T cells ≥200/μl, while for patients treated for more than 3 months and CD4+ T cells Conclusion ELISPOT-based IFN-γ release assay is more sensitive and rapid for the diagnosis of TB infection in Chinese HIV-infected individuals with history of BCG vaccination, and could be an effective tool for guiding preventive treatment with isoniazid in latently infected people and for TB control in China.

  7. Env-glycoprotein heterogeneity as a source of apparent synergy and enhanced cooperativity in inhibition of HIV-1 infection by neutralizing antibodies and entry inhibitors

    Science.gov (United States)

    Ketas, Thomas J.; Holuigue, Sophie; Matthews, Katie; Moore, John P.

    2011-01-01

    We measured the inhibition of infectivity of HIV-1 isolates and derivative clones by combinations of neutralizing antibodies (NAbs) and other entry inhibitors in a single-cycle-replication assay. Synergy was analyzed both by the current linear and a new nonlinear method. The new method reduced spurious indications of synergy and antagonism. Synergy between NAbs was overall weaker than between other entry inhibitors, and no stronger where one ligand is known to enhance the binding of another. However, synergy was stronger for a genetically heterogeneous HIV-1 R5 isolate than for its derivative clones. Enhanced cooperativity in inhibition by combinations, compared with individual inhibitors, correlated with increased synergy at higher levels of inhibition, while being less variable. Again, cooperativity enhancement was stronger for isolates than clones. We hypothesize that genetic, post-translational or conformational heterogeneity of the Env protein and of other targets for inhibitors can yield apparent synergy and increased cooperativity between inhibitors. PMID:22018634

  8. Hidden Lineage Complexity of Glycan-Dependent HIV-1 Broadly Neutralizing Antibodies Uncovered by Digital Panning and Native-Like gp140 Trimer

    Directory of Open Access Journals (Sweden)

    Linling He

    2017-08-01

    Full Text Available Germline precursors and intermediates of broadly neutralizing antibodies (bNAbs are essential to the understanding of humoral response to HIV-1 infection and B-cell lineage vaccine design. Using a native-like gp140 trimer probe, we examined antibody libraries constructed from donor-17, the source of glycan-dependent PGT121-class bNAbs recognizing the N332 supersite on the HIV-1 envelope glycoprotein. To facilitate this analysis, a digital panning method was devised that combines biopanning of phage-displayed antibody libraries, 900 bp long-read next-generation sequencing, and heavy/light (H/L-paired antibodyomics. In addition to single-chain variable fragments resembling the wild-type bNAbs, digital panning identified variants of PGT124 (a member of the PGT121 class with a unique insertion in the heavy chain complementarity-determining region 1, as well as intermediates of PGT124 exhibiting notable affinity for the native-like trimer and broad HIV-1 neutralization. In a competition assay, these bNAb intermediates could effectively compete with mouse sera induced by a scaffolded BG505 gp140.681 trimer for the N332 supersite. Our study thus reveals previously unrecognized lineage complexity of the PGT121-class bNAbs and provides an array of library-derived bNAb intermediates for evaluation of immunogens containing the N332 supersite. Digital panning may prove to be a valuable tool in future studies of bNAb diversity and lineage development.

  9. Hidden Lineage Complexity of Glycan-Dependent HIV-1 Broadly Neutralizing Antibodies Uncovered by Digital Panning and Native-Like gp140 Trimer.

    Science.gov (United States)

    He, Linling; Lin, Xiaohe; de Val, Natalia; Saye-Francisco, Karen L; Mann, Colin J; Augst, Ryan; Morris, Charles D; Azadnia, Parisa; Zhou, Bin; Sok, Devin; Ozorowski, Gabriel; Ward, Andrew B; Burton, Dennis R; Zhu, Jiang

    2017-01-01

    Germline precursors and intermediates of broadly neutralizing antibodies (bNAbs) are essential to the understanding of humoral response to HIV-1 infection and B-cell lineage vaccine design. Using a native-like gp140 trimer probe, we examined antibody libraries constructed from donor-17, the source of glycan-dependent PGT121-class bNAbs recognizing the N332 supersite on the HIV-1 envelope glycoprotein. To facilitate this analysis, a digital panning method was devised that combines biopanning of phage-displayed antibody libraries, 900 bp long-read next-generation sequencing, and heavy/light (H/L)-paired antibodyomics. In addition to single-chain variable fragments resembling the wild-type bNAbs, digital panning identified variants of PGT124 (a member of the PGT121 class) with a unique insertion in the heavy chain complementarity-determining region 1, as well as intermediates of PGT124 exhibiting notable affinity for the native-like trimer and broad HIV-1 neutralization. In a competition assay, these bNAb intermediates could effectively compete with mouse sera induced by a scaffolded BG505 gp140.681 trimer for the N332 supersite. Our study thus reveals previously unrecognized lineage complexity of the PGT121-class bNAbs and provides an array of library-derived bNAb intermediates for evaluation of immunogens containing the N332 supersite. Digital panning may prove to be a valuable tool in future studies of bNAb diversity and lineage development.

  10. Lymphocyte transformation response to pokeweed mitogen as a predictive marker for development of AIDS and AIDS related symptoms in homosexual men with HIV antibodies

    DEFF Research Database (Denmark)

    Hofmann, B; Lindhardt, B O; Gerstoft, J

    1987-01-01

    To identify factors that may predict the development of the acquired immune deficiency syndrome (AIDS) or AIDS related symptoms various immunological measurements were studied in a group of homosexual men attending screening clinics for AIDS in Copenhagen. Fifty seven men whose ratio of T helper...... lymphocytes to T suppressor lymphocytes (CD4:CD8 ratio) was less than 1.0 before the study began were included. Forty two were positive for antibody to the human immunodeficiency virus (HIV), of whom 38 were reinvestigated after a median observation period of 10 months. Among the seropositive men...

  11. A cross-reacting material CRM197 conjugate vaccine induces diphtheria toxin neutralizing antibody response in children and adolescents infected or not with HIV.

    Science.gov (United States)

    Silva, Giselle P; Santos, Rafaela S; Pereira-Manfro, Wânia F; Ferreira, Bianca; Barreto, Daniella M; Frota, Ana Cristina C; Hofer, Cristina B; Milagres, Lucimar G

    2017-07-05

    Anti-diphtheria antibody levels decrease with aging, and frequent booster vaccinations are required to maintain herd immunity. We analyzed the diphtheria toxin neutralizing antibody (DT-Nab) response induced by a conjugate vaccine (meningococcal C polysaccharide-CRM 197 ) in HIV-vertically infected (HI) children and adolescents and healthy controls (HC) with matched age. We report the association of DT-Nab with the bactericidal antibodies to serogroup C meningococcus (MenC). Before vaccination, 21 HI patients (50%) had no protection against diphtheria (≤0.01IU/ml of antibody) and only 8 (19%) showed complete protection (≥0.1IU/ml). About half of the HC (56%) had complete protection before immunization and 6 subjects (12%) had no protection against diphtheria. After one and two vaccine injections, 96% of HC and 64% of HI vaccinees, respectively, showed full protection against diphtheria. These data indicate that CRM 197 was able to induce primary and/or booster response in both groups of individuals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Pesquisa de anticorpos contra o sarampo em crianças infectadas pelo HIV, após a imunização básica Search of antimeasles antibodies in HIV-infected children after basic immunization

    Directory of Open Access Journals (Sweden)

    Claudia R. Lindgren-Alves

    2001-12-01

    Full Text Available OBJETIVO: verificar a presença de anticorpos contra o sarampo em crianças com infecção perinatal pelo HIV e devidamente imunizadas. MÉTODOS: estudo de coorte retrospectivo realizado em Belo Horizonte, entre 1995 e 1996. Foram incluídas 21 crianças com infecção perinatal pelo HIV e 29 crianças imunocompetentes não-infectadas. Informações acerca da vacina contra o sarampo foram obtidas do cartão de imunizações dos pacientes. A pesquisa de anticorpos contra o sarampo foi realizada pelos testes de neutralização por redução de placa e dosagem de IgM pela técnica de ELISA. Adotou-se nível de significância de 5% em todas as análises estatísticas realizadas. RESULTADOS: a mediana de idade dos pacientes infectados pelo HIV foi de 44,5 meses, e das crianças não-infectadas, de 62,0 meses (P=0,64.Os grupos receberam em média 2 doses da vacina contra o sarampo. Todos os pacientes soronegativos para o HIV apresentaram títulos de anticorpos contra o sarampo superiores a 50 mUI/ml, enquanto 57,1% das crianças infectadas apresentaram títulos acima deste valor (P=0,0001. O título geométrico médio de anticorpos neutralizantes foi significativamente menor no grupo de crianças com infecção pelo HIV (433,5 mUI/ml do que no grupo de não-infectados(1668,1 mUI/ml, P=0,001. Todos os pacientes dos dois grupos foram negativos para a pesquisa de IgM contra o sarampo. CONCLUSÃO: as crianças infectadas pelo HIV apresentaram menor soroprevalência de anticorpos contra o sarampo após a imunização do que as crianças não-infectadas. Esses resultados alertam para o risco potencial de aquisição do vírus do sarampo, e apontam a necessidade de avaliar alternativas para a imunização das crianças infectadas pelo HIV, no sentido de maximizar a proteção contra o sarampo nesse grupo de pacientes.OBJECTIVE: to determine the presence of antimeasles antibodies in children perinatally infected with HIV and properly immunized. METHODS: a

  13. Synthetic biocompatible polymers are an effective delivery platform that elicits potent antibody responses against HIV-1 glycopeptide immunogens

    Czech Academy of Sciences Publication Activity Database

    Francica, J.; Lynn, G.; Laga, Richard; Aussedat, B.; Meyerhoff, R.; Alam, M.; Danishefsky, S.; Haynes, B.; Seder, R.

    2016-01-01

    Roč. 32, Supplement 1 (2016), s. 221-P07.27 ISSN 0889-2229. [Conference on HIV Research for Prevention - HIV R4P. 17.10.2016-21.10.2016, Chicago] Institutional support: RVO:61389013 Keywords : biocompatible polymers * druh delivery Subject RIV: CD - Macromolecular Chemistry

  14. Evaluating quality management systems for HIV rapid testing services in primary healthcare clinics in rural KwaZulu-Natal, South Africa.

    Directory of Open Access Journals (Sweden)

    Ziningi Jaya

    Full Text Available Rapid HIV tests have improved access to HIV diagnosis and treatment by providing quick and convenient testing in rural clinics and resource-limited settings. In this study, we evaluated the quality management system for voluntary and provider-initiated point-of-care HIV testing in primary healthcare (PHC clinics in rural KwaZulu-Natal (KZN, South Africa.We conducted a quality assessment audit in eleven PHC clinics that offer voluntary HIV testing and counselling in rural KZN, South Africa from August 2015 to October 2016. All the participating clinics were purposively selected from the province-wide survey of diagnostic services. We completed an on-site monitoring checklist, adopted from the WHO guidelines for assuring accuracy and reliability of HIV rapid tests, to assess the quality management system for HIV rapid testing at each clinic. To determine clinic's compliance to WHO quality standards for HIV rapid testing the following quality measure was used, a 3-point scale (high, moderate and poor. A high score was defined as a percentage rating of 90 to 100%, moderate was defined as a percentage rating of 70 to 90%, and poor was defined as a percentage rating of less than 70%. Clinic audit scores were summarized and compared. We employed Pearson pair wise correlation coefficient to determine correlations between clinics audit scores and clinic and clinics characteristics. Linear regression model was computed to estimate statistical significance of the correlates. Correlations were reported as significant at p ≤0.05.Nine out of 11 audited rural PHC clinics are located outside 20Km of the nearest town and hospital. Majority (18.2% of the audited rural PHC clinics reported that HIV rapid test was performed by HIV lay counsellors. Overall, ten clinics were rated moderate, in terms of their compliance to the stipulated WHO guidelines. Audit results showed that rural PHC clinics' average rating score for compliance to the WHO guidelines ranged

  15. Evaluating quality management systems for HIV rapid testing services in primary healthcare clinics in rural KwaZulu-Natal, South Africa.

    Science.gov (United States)

    Jaya, Ziningi; Drain, Paul K; Mashamba-Thompson, Tivani P

    2017-01-01

    Rapid HIV tests have improved access to HIV diagnosis and treatment by providing quick and convenient testing in rural clinics and resource-limited settings. In this study, we evaluated the quality management system for voluntary and provider-initiated point-of-care HIV testing in primary healthcare (PHC) clinics in rural KwaZulu-Natal (KZN), South Africa. We conducted a quality assessment audit in eleven PHC clinics that offer voluntary HIV testing and counselling in rural KZN, South Africa from August 2015 to October 2016. All the participating clinics were purposively selected from the province-wide survey of diagnostic services. We completed an on-site monitoring checklist, adopted from the WHO guidelines for assuring accuracy and reliability of HIV rapid tests, to assess the quality management system for HIV rapid testing at each clinic. To determine clinic's compliance to WHO quality standards for HIV rapid testing the following quality measure was used, a 3-point scale (high, moderate and poor). A high score was defined as a percentage rating of 90 to 100%, moderate was defined as a percentage rating of 70 to 90%, and poor was defined as a percentage rating of less than 70%. Clinic audit scores were summarized and compared. We employed Pearson pair wise correlation coefficient to determine correlations between clinics audit scores and clinic and clinics characteristics. Linear regression model was computed to estimate statistical significance of the correlates. Correlations were reported as significant at p ≤0.05. Nine out of 11 audited rural PHC clinics are located outside 20Km of the nearest town and hospital. Majority (18.2%) of the audited rural PHC clinics reported that HIV rapid test was performed by HIV lay counsellors. Overall, ten clinics were rated moderate, in terms of their compliance to the stipulated WHO guidelines. Audit results showed that rural PHC clinics' average rating score for compliance to the WHO guidelines ranged between 64.4% (CI

  16. Use of task-shifting to rapidly scale-up HIV treatment services: experiences from Lusaka, Zambia

    Directory of Open Access Journals (Sweden)

    Chi Harmony F

    2009-01-01

    Full Text Available Abstract The World Health Organization advocates task-shifting, the process of delegating clinical care functions from more specialized to less specialized health workers, as a strategy to achieve the United Nations Millennium Development Goals. However, there is a dearth of literature describing task shifting in sub-Saharan Africa, where services for antiretroviral therapy (ART have scaled up rapidly in the face of generalized human resource crises. As part of ART services expansion in Lusaka, Zambia, we implemented a comprehensive task-shifting program among existing health providers and community-based workers. Training begins with didactic sessions targeting specialized skill sets. This is followed by an intensive period of practical mentorship, where providers are paired with trainers before working independently. We provide on-going quality assessment using key indicators of clinical care quality at each site. Program performance is reviewed with clinic-based staff quarterly. When problems are identified, clinic staff members design and implement specific interventions to address targeted areas. From 2005 to 2007, we trained 516 health providers in adult HIV treatment; 270 in pediatric HIV treatment; 341 in adherence counseling; 91 in a specialty nurse "triage" course, and 93 in an intensive clinical mentorship program. On-going quality assessment demonstrated improvement across clinical care quality indicators, despite rapidly growing patient volumes. Our task-shifting strategy was designed to address current health care worker needs and to sustain ART scale-up activities. While this approach has been successful, long-term solutions to the human resource crisis are also urgently needed to expand the number of providers and to slow staff migration out of the region.

  17. A rapid assessment of post-disclosure experiences of urban HIV-positive and HIV-negative school-aged children in Kenya

    Directory of Open Access Journals (Sweden)

    Grace Gachanja

    2015-06-01

    Full Text Available There has been limited involvement of HIV-negative children in HIV disclosure studies; most studies conducted on the effects of disclosure on children have been with HIV-positive children and HIV-positive mother-child dyads. Seven HIV-positive and five HIV-negative children participated in a larger study conducted to understand the lived experiences of HIV-positive parents and their children during the disclosure process in Kenya. In this study, the experiences of these 12 children after receiving disclosure of their own and their parents’ illnesses respectively are presented. Each child underwent an in-depth qualitative semi-structured digitally recorded interview. The recorded interviews were transcribed and loaded into NVivo8 for phenomenological data analysis. Five themes emerged from the data, indicating that HIV-positive and negative children appear to have differing post-disclosure experiences revolving around acceptance of illness, stigma and discrimination, medication consumption, sexual awareness, and use of coping mechanisms. Following disclosure, HIV-negative children accepted their parents’ illnesses within a few hours to a few weeks; HIV-positive children took weeks to months to accept their own illnesses. HIV-negative children knew of high levels of stigma and discrimination within the community; HIV-positive children reported experiencing indirect incidences of stigma and discrimination. HIV-negative children wanted their parents to take their medications, stay healthy, and pay their school fees so they could have a better life in the future; HIV-positive children viewed medication consumption as an ordeal necessary to keep them healthy. HIV-negative children wanted their parents to speak to them about sexual-related matters; HIV-positive children had lingering questions about relationships, use of condoms, marriage, and childbearing options. All but one preadolescent HIV-positive child had self-identified a person to speak

  18. Induction of a protein-targeted catalytic response in autoimmune prone mice: antibody-mediated cleavage of HIV-1 glycoprotein GP120.

    Science.gov (United States)

    Ponomarenko, Natalia A; Vorobiev, Ivan I; Alexandrova, Elena S; Reshetnyak, Andrew V; Telegin, Georgy B; Khaidukov, Sergey V; Avalle, Bérangère; Karavanov, Alexander; Morse, Herbert C; Thomas, Daniel; Friboulet, Alain; Gabibov, Alexander G

    2006-01-10

    We have induced a polyclonal IgG that degrades the HIV-1 surface antigen, glycoprotein gp120, by taking advantage of the susceptibility of SJL mice to a peptide-induced autoimmune disorder, experimental autoimmune encephalomyelitis (EAE). Specific pathogen-free SJL mice were immunized with structural fragments of gp120, fused in-frame with encephalitogenic peptide MBP(85-101). It has resulted in a pronounced disease-associated immune response against antigens. A dramatic increase of gp120 degradation level by purified polyclonal IgG from immunized versus nonimmunized mice has been demonstrated by a newly developed fluorescence-based assay. This activity was inhibited by anti-mouse immunoglobulin antibodies as well as by Ser- and His-reactive covalent inhibitors. A dominant proteolysis site in recombinant gp120 incubated with purified polyclonal IgG from immunized mice was shown by SDS-PAGE. The SELDI-based mass spectrometry revealed that these antibodies exhibited significant specificity toward the Pro484-Leu485 peptide bond. The sequence surrounding this site is present in nearly half of the HIV-I variants. This novel strategy can be generalized for creating a catalytic vaccine against viral pathogens.

  19. Side chain requirements for affinity and specificity in D5, an HIV-1 antibody derived from the VH1-69 germline segment.

    Science.gov (United States)

    Stewart, Alex; Harrison, Joseph S; Regula, Lauren K; Lai, Jonathan R

    2013-04-08

    Analysis of factors contributing to high affinity antibody-protein interactions provides insight into natural antibody evolution, and guides the design of antibodies with new or enhanced function. We previously studied the interaction between antibody D5 and its target, a designed protein based on HIV-1 gp41 known as 5-Helix, as a model system [Da Silva, G. F.; Harrison, J. S.; Lai, J. R., Biochemistry, 2010, 49, 5464-5472]. Antibody D5 represents an interesting case study because it is derived from the VH1-69 germline segment; this germline segment is characterized by a hydrophobic second heavy chain complementarity determining region (HCDR2) that constitutes the major functional paratope in D5 and several antibodies derived from the same progenitor. Here we explore side chain requirements for affinity and specificity in D5 using phage display. Two D5-based libraries were prepared that contained diversity in all three light chain complementarity determining regions (LCDRs 1-3), and in the third HCDR (HCDR3). The first library allowed residues to vary among a restricted set of six amino acids (Tyr/Ala/Asp/Ser/His/Pro; D5-Lib-I). The second library was designed based on a survey of existing VH1-69 antibody structures (D5-Lib-II). Both libraries were subjected to multiple rounds of selection against 5-Helix, and individual clones characterized. We found that selectants from D5-Lib-I generally had moderate affinity and specificity, while many clones from D5-Lib-II exhibited D5-like properties. Additional analysis of the D5-Lib-II functional population revealed position-specific biases for particular amino acids, many that differed from the identity of those side chains in D5. Together these results suggest that there is some permissiveness for alternative side chains in the LCDRs and HCDR3 of D5, but that replacement with a minimal set of residues is not tolerated in this scaffold for 5-Helix recognition. This work provides novel information about this high

  20. A simple electroelution method for rapid protein purification: isolation and antibody production of alpha toxin from Clostridium septicum

    Directory of Open Access Journals (Sweden)

    Lorena Vázquez-Iglesias

    2017-06-01

    Full Text Available Clostridium septicum produces a number of diseases in human and farm animals which, in most of the cases, are fatal without clinical intervention. Alpha toxin is an important agent and the unique lethal virulent factor produced by Clostridium septicum. This toxin is haemolytic, highly lethal and necrotizing activities but is being used as an antigen to develop animal vaccines. The aim of this study was to isolate the alpha toxin of Clostridium septicum and produce highly specific antibodies against it. In this work, we have developed a simple and efficient method for alpha toxin purification, based on electroelution that can be used as a time-saving method for purifying proteins. This technique avoids contamination by other proteins that could appear during other protein purification techniques such chromatography. The highly purified toxin was used to produce polyclonal antibodies. The specificity of the antibodies was tested by western blot and these antibodies can be applied to the quantitative determination of alpha toxin by slot blot.

  1. Increased carotid intima-media thickness associated with antibody responses to varicella-zoster virus and cytomegalovirus in HIV-infected patients.

    Directory of Open Access Journals (Sweden)

    Mar Masiá

    Full Text Available OBJECTIVE: We investigated the relationship of the Herpesviridiae with inflammation and subclinical atherosclerosis in HIV-infected patients. METHODS: Prospective study including virologically suppressed HIV-infected patients. IgG antibodies against herpesviruses, carotid intima-media thickness (cIMT, endothelial function through flow-mediated dilatation (FMD of the brachial artery, and blood atherosclerosis biomarkers (hsCRP, TNF-α, IL-6, MCP-1, MDA, sCD14, sCD163, VCAM-1, ICAM-1, D-dimer, and PAI-1 were measured. RESULTS: 136 patients with HIV viral load <200 copies/ml were included. 93.4% patients were infected with herpes simplex virus type-1, 55.9% with herpes simplex virus type-2, 97.1% with varicella-zoster virus, 65.4% with human herpesvirus-6, 91.2% with cytomegalovirus, and 99.3% with Epstein-Barr virus. Previous AIDS diagnosis was associated with higher cytomegalovirus IgG titers (23,000 vs 17,000 AU, P = 0.011 and higher varicella-zoster virus IgG titers (3.19 vs 2.88 AU, P = 0.047, and there was a positive correlation of the Framingham risk score with IgG levels against cytomegalovirus (Spearman's Rho 0.216, P = 0.016 and Herpes simplex virus-2 (Spearman's Rho 0.293, P = 0.001. IgG antibodies against cytomegalovirus correlated in adjusted analysis with the cIMT (P = 0.030. High seropositivity for varicella-zoster virus (OR 2.91, 95% CI 1.05-8.01, P = 0.039, and for cytomegalovirus (OR 3.79, 95% CI 1.20-11.97, P = 0.023 were predictors for the highest quartile of the cIMT in adjusted analyses. PAI-1 levels were independently associated with cytomegalovirus IgG titers (P = 0.041, IL-6 and ICAM-1 levels with varicella-zoster virus IgG (P = 0.046 and P = 0.035 respectively, and hsCRP levels with Herpes simplex virus-2 IgG (P = 0.035. CONCLUSION: In virologically suppressed HIV-infected patients, antibody responses against herpesviruses are associated with subclinical atherosclerosis, and with increased inflammation and coagulation

  2. Repeat confirmatory testing for persons with discordant whole blood and oral fluid rapid HIV test results: findings from post marketing surveillance.

    Directory of Open Access Journals (Sweden)

    Laura G Wesolowski

    Full Text Available BACKGROUND: Reactive oral fluid and whole blood rapid HIV tests must be followed with a confirmatory test (Western blot (WB, immunofluorescent assay (IFA or approved nucleic acid amplification test (NAAT. When the confirmatory result is negative or indeterminate (i.e. discordant with rapid result, repeat confirmatory testing should be conducted using a follow-up specimen. Previous reports have not described whether repeat testing adequately resolves the HIV-infection status of persons with discordant results. METHODOLOGY: Post-marketing surveillance was conducted in 368 testing sites affiliated with 14 state and 2 city health departments from August 11, 2004 to June 30, 2005 and one health department through December 31, 2005. For persons with discordant results, data were collected on demographics, risk behaviors, HIV test results and specimen types. Persons with repeat confirmatory results were classified as HIV-infected or uninfected. Regression models were created to assess risk factors for not having repeat testing. PRINCIPAL FINDINGS: Of 167,371 rapid tests conducted, 2589 (1.6% were reactive: of these, 2417 (93% had positive WB/IFA, 172 (7% had negative or indeterminate WB/IFA. Of 89/172 (52% persons with a repeat confirmatory test: 17 (19% were HIV-infected, including 3 with indeterminate WB and positive NAAT; 72 (81% were uninfected, including 12 with repeat indeterminate WB. Factors associated with HIV-infection included having an initial indeterminate WB/IFA (vs. negative (p<0.001 and having an initial oral fluid WB (vs. serum (p<0.001. Persons who had male-female sex (vs. male-male sex were at increased risk for not having a repeat test [adjusted OR 2.6, 95% CI (1.3, 4.9]. CONCLUSIONS: Though only half of persons with discordant results had repeat confirmatory testing, of those who did, nearly one in five were HIV-infected. These findings underscore the need for rapid HIV testing programs to increase repeat confirmatory testing for

  3. Sensitivity of HIV-1 to neutralization by antibodies against O-linked carbohydrate epitopes despite deletion of O-glycosylation signals in the V3 loop

    DEFF Research Database (Denmark)

    Hansen, J E; Jansson, B; Gram, G J

    1996-01-01

    It has been suggested that threonine or serine residues in the V3 loop of HIV-1 gp120 are glycosylated with the short-chain O-linked oligosaccharides Tn or sialosyl-Tn that function as epitopes for broadly neutralizing carbohydrate specific antibodies. In this study we examined whether mutation....... Additionally, one of these T-A mutants (T308A) also abrogated the signal for N-glycosylation at N306 inside the V3-loop. The mutant clones were compared with the wild type virus as to sensitivity to neutralization with monoclonal and polyclonal antibodies specific for the tip of the V3 loop of BRU or for the O......-linked oligosaccharides Tn or sialosyl-Tn. Deletion of the N-linked oligosaccharide at N306 increased the neutralization sensitivity to antibodies specific for the tip of the loop, which indicates that N-linked glycosylation modulates the accessibility to this immunodominant epitope. However, none of the mutants...

  4. Rapid profiling of the antigen regions recognized by serum antibodies using massively parallel sequencing of antigen-specific libraries.

    KAUST Repository

    Domina, Maria; Lanza Cariccio, Veronica; Benfatto, Salvatore; D'Aliberti, Deborah; Venza, Mario; Borgogni, Erica; Castellino, Flora; Biondo, Carmelo; D'Andrea, Daniel; Grassi, Luigi; Tramontano, Anna; Teti, Giuseppe; Felici, Franco; Beninati, Concetta

    2014-01-01

    There is a need for techniques capable of identifying the antigenic epitopes targeted by polyclonal antibody responses during deliberate or natural immunization. Although successful, traditional phage library screening is laborious and can map only some of the epitopes. To accelerate and improve epitope identification, we have employed massive sequencing of phage-displayed antigen-specific libraries using the Illumina MiSeq platform. This enabled us to precisely identify the regions of a model antigen, the meningococcal NadA virulence factor, targeted by serum antibodies in vaccinated individuals and to rank hundreds of antigenic fragments according to their immunoreactivity. We found that next generation sequencing can significantly empower the analysis of antigen-specific libraries by allowing simultaneous processing of dozens of library/serum combinations in less than two days, including the time required for antibody-mediated library selection. Moreover, compared with traditional plaque picking, the new technology (named Phage-based Representation OF Immuno-Ligand Epitope Repertoire or PROFILER) provides superior resolution in epitope identification. PROFILER seems ideally suited to streamline and guide rational antigen design, adjuvant selection, and quality control of newly produced vaccines. Furthermore, this method is also susceptible to find important applications in other fields covered by traditional quantitative serology.

  5. Rapid profiling of the antigen regions recognized by serum antibodies using massively parallel sequencing of antigen-specific libraries.

    Directory of Open Access Journals (Sweden)

    Maria Domina

    Full Text Available There is a need for techniques capable of identifying the antigenic epitopes targeted by polyclonal antibody responses during deliberate or natural immunization. Although successful, traditional phage library screening is laborious and can map only some of the epitopes. To accelerate and improve epitope identification, we have employed massive sequencing of phage-displayed antigen-specific libraries using the Illumina MiSeq platform. This enabled us to precisely identify the regions of a model antigen, the meningococcal NadA virulence factor, targeted by serum antibodies in vaccinated individuals and to rank hundreds of antigenic fragments according to their immunoreactivity. We found that next generation sequencing can significantly empower the analysis of antigen-specific libraries by allowing simultaneous processing of dozens of library/serum combinations in less than two days, including the time required for antibody-mediated library selection. Moreover, compared with traditional plaque picking, the new technology (named Phage-based Representation OF Immuno-Ligand Epitope Repertoire or PROFILER provides superior resolution in epitope identification. PROFILER seems ideally suited to streamline and guide rational antigen design, adjuvant selection, and quality control of newly produced vaccines. Furthermore, this method is also susceptible to find important applications in other fields covered by traditional quantitative serology.

  6. Rapid profiling of the antigen regions recognized by serum antibodies using massively parallel sequencing of antigen-specific libraries.

    KAUST Repository

    Domina, Maria

    2014-12-04

    There is a need for techniques capable of identifying the antigenic epitopes targeted by polyclonal antibody responses during deliberate or natural immunization. Although successful, traditional phage library screening is laborious and can map only some of the epitopes. To accelerate and improve epitope identification, we have employed massive sequencing of phage-displayed antigen-specific libraries using the Illumina MiSeq platform. This enabled us to precisely identify the regions of a model antigen, the meningococcal NadA virulence factor, targeted by serum antibodies in vaccinated individuals and to rank hundreds of antigenic fragments according to their immunoreactivity. We found that next generation sequencing can significantly empower the analysis of antigen-specific libraries by allowing simultaneous processing of dozens of library/serum combinations in less than two days, including the time required for antibody-mediated library selection. Moreover, compared with traditional plaque picking, the new technology (named Phage-based Representation OF Immuno-Ligand Epitope Repertoire or PROFILER) provides superior resolution in epitope identification. PROFILER seems ideally suited to streamline and guide rational antigen design, adjuvant selection, and quality control of newly produced vaccines. Furthermore, this method is also susceptible to find important applications in other fields covered by traditional quantitative serology.

  7. Rapid Transient Production of a Monoclonal Antibody Neutralizing the Porcine Epidemic Diarrhea Virus (PEDV) in Nicotiana benthamiana and Lactuca sativa.

    Science.gov (United States)

    Rattanapisit, Kaewta; Srijangwad, Anchalee; Chuanasa, Taksina; Sukrong, Suchada; Tantituvanont, Angkana; Mason, Hugh S; Nilubol, Dachrit; Phoolcharoen, Waranyoo

    2017-12-01

    Porcine epidemic diarrhea virus (PEDV) causes acute diarrhea, vomiting, dehydration, weight loss, and high mortality rate in neonatal piglets. Porcine epidemic diarrhea (PED) has been reported in Europe, America, and Asia including Thailand. The disease causes substantial losses to the swine industry in many countries. Presently, there is no effective PEDV vaccine available. In this study, we developed a plant-produced monoclonal antibody (mAb) 2C10 as a prophylactic candidate to prevent the PEDV infection. Recently, plant expression systems have gained interest as an alternative for the production of antibodies because of many advantages, such as low production cost, lack of human and animal pathogen, large scalability, etc. The 2C10 mAb was transiently expressed in Nicotiana benthamiana and lettuce using geminiviral vector. After purification by protein A affinity chromatography, the antibody was tested for the binding and neutralizing activity against PEDV. Our result showed that the plant produced 2C10 mAb can bind to the virus and also inhibit PEDV infection in vitro . These results show excellent potential for a plant-expressed 2C10 as a PEDV prophylaxis and a diagnostic for PEDV infection. Georg Thieme Verlag KG Stuttgart · New York.

  8. Rapid Detection of Human Immunodeficiency Virus Types 1 and 2 by Use of an Improved Piezoelectric Biosensor

    Science.gov (United States)

    Severns, Virginia; Branch, Darren W.; Edwards, Thayne L.; Larson, Richard S.

    2013-01-01

    Disasters can create situations in which blood donations can save lives. However, in emergency situations and when resources are depleted, on-site blood donations require the rapid and accurate detection of blood-borne pathogens, including human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2). Techniques such as PCR and antibody capture by an enzyme-linked immunosorbent assay (ELISA) for HIV-1 and HIV-2 are precise but time-consuming and require sophisticated equipment that is not compatible with emergency point-of-care requirements. We describe here a prototype biosensor based on piezoelectric materials functionalized with specific antibodies against HIV-1 and HIV-2. We show the rapid and accurate detection of HIV-1 and HIV-2 in both simple and complex solutions, including human serum, and in the presence of a cross-confounding virus. We report detection limits of 12 50% tissue culture infective doses (TCID50s) for HIV-1 and 87 TCID50s for HIV-2. The accuracy, precision of measurements, and operation of the prototype biosensor compared favorably to those for nucleic acid amplification. We conclude that the biosensor has significant promise as a successful point-of-care diagnostic device for use in emergency field applications requiring rapid and reliable testing for blood-borne pathogens. PMID:23515541

  9. Detection of Acute and Early HIV-1 Infections in an HIV Hyper-Endemic Area with Limited Resources.

    Directory of Open Access Journals (Sweden)

    Simnikiwe H Mayaphi

    Full Text Available Two thirds of the world's new HIV infections are in sub-Saharan Africa. Acute HIV infection (AHI is the time of virus acquisition until the appearance of HIV antibodies. Early HIV infection, which includes AHI, is the interval between virus acquisition and establishment of viral load set-point. This study aimed to detect acute and early HIV infections in a hyper-endemic setting.This was a cross-sectional diagnostic study that enrolled individuals who had negative rapid HIV results in five clinics in South Africa. Pooled nucleic acid amplification testing (NAAT was performed, followed by individual sample testing in positive pools. NAAT-positive participants were recalled to the clinics for confirmatory testing and appropriate management. HIV antibody, p24 antigen, Western Blot and avidity tests were performed for characterization of NAAT-positive samples.The study enrolled 6910 individuals with negative rapid HIV results. Median age was 27 years (interquartile range {IQR}: 23-31. NAAT was positive in 55 samples, resulting in 0.8% newly diagnosed HIV-infected individuals (95% confidence interval {CI}: 0.6-1.0. The negative predictive value for rapid HIV testing was 99.2% (95% CI: 99.0-99.4. Characterization of NAAT-positive samples revealed that 0.04% (95% CI: 0.000-0.001 had AHI, 0.3% (95% CI: 0.1-0.4 had early HIV infection, and 0.5% (95% CI: 0.5-0.7 had chronic HIV infection. Forty-seven (86% of NAAT-positive participants returned for follow-up at a median of 4 weeks (IQR: 2-8. Follow-up rapid tests were positive in 96% of these participants.NAAT demonstrated that a substantial number of HIV-infected individuals are misdiagnosed at South African points-of-care. Follow-up rapid tests done within a 4 week interval detected early and chronic HIV infections initially missed by rapid HIV testing. This may be a practical and affordable strategy for earlier detection of these infections in resource-constrained settings. Newer molecular tests that can

  10. Development of a rapid agglutination latex test for diagnosis of enteropathogenic and enterohemorrhagic Escherichia coli infection in developing world: defining the biomarker, antibody and method.

    Directory of Open Access Journals (Sweden)

    Letícia B Rocha

    2014-09-01

    Full Text Available Enteropathogenic and enterohemorrhagic Escherichia coli (EPEC/EHEC are human intestinal pathogens responsible for diarrhea in both developing and industrialized countries. In research laboratories, EPEC and EHEC are defined on the basis of their pathogenic features; nevertheless, their identification in routine laboratories is expensive and laborious. Therefore, the aim of the present work was to develop a rapid and simple assay for EPEC/EHEC detection. Accordingly, the EPEC/EHEC-secreted proteins EspA and EspB were chosen as target antigens.First, we investigated the ideal conditions for EspA/EspB production/secretion by ELISA in a collection of EPEC/EHEC strains after cultivating bacterial isolates in Dulbecco's modified Eagle's medium (DMEM or DMEM containing 1% tryptone or HEp-2 cells-preconditioned DMEM, employing either anti-EspA/anti-EspB polyclonal or monoclonal antibodies developed and characterized herein. Subsequently, a rapid agglutination latex test (RALT was developed and tested with the same collection of bacterial isolates.EspB was defined as a biomarker and its corresponding monoclonal antibody as the tool for EPEC/EHEC diagnosis; the production of EspB was better in DMEM medium. RALT assay has the sensitivity and specificity required for high-impact diagnosis of neglected diseases in the developing world.RALT assay described herein can be considered an alternative assay for diarrhea diagnosis in low-income countries since it achieved 97% sensitivity, 98% specificity and 97% efficiency.

  11. Identification of early HIV infections using the fourth generation Abbott ARCHITECT HIV Ag/Ab Combo chemiluminescent microparticle immunoassay (CIA) in San Diego County.

    Science.gov (United States)

    Manlutac, Anna Liza M; Giesick, Jill S; McVay, Patricia A

    2013-12-01

    HIV screening assays have gone through several generations of development in an effort to narrow the "window period" of detection. Utilizing a fourth generation HIV screening assay has the potential to detect earlier HIV infection, thus reducing HIV-1 transmission. To identify acute infections to decrease HIV transmission in San Diego County. Serum specimens were collected from clients seen by multiple submitters in San Diego County. All acceptable specimens were screened using the 4th Gen Combo Assay. Initially reactive specimens were repeated in duplicate and if repeatedly reactive, were confirmed by HIV-1 Immunofluorescent Antibody Assay (IFA). IFA negative/inconclusive specimens were sent for HIV-1 NAT and HIV-2 antibody testing to referral laboratories. BioRad Multispot HIV-1/HIV-2 Rapid Test was also performed on a subset of specimens. Of 14,559 specimens received in 20 months, 14,517 specimens were tested. Of the 14,517 specimens that were tested, a total of 279 (1.9%) specimens were CIA repeatedly reactive and 240 of the 279 confirmed by HIV-1 IFA. Thirty-nine gave IFA negative/inconclusive result and 30 were further tested for HIV-1 NAT and 36 for HIV-2 antibody. Thirteen specimens were considered false positives by CIA and 17 specimens were classified as acute infections. Eleven of 39 IFA negative/inconclusive specimens were further tested by Multispot. Five of the 11 were positive by Multispot. The fourth generation Abbott ARCHITECT HIV Ag/Ab Combo Assay identified 17 patients who may have been missed by the prior HIV-1 screening assay used at San Diego County Public Health Laboratory. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Monoclonal Antibodies, Derived from Humans Vaccinated with the RV144 HIV Vaccine Containing the HVEM Binding Domain of Herpes Simplex Virus (HSV) Glycoprotein D, Neutralize HSV Infection, Mediate Antibody-Dependent Cellular Cytotoxicity, and Protect Mice from Ocular Challenge with HSV-1.

    Science.gov (United States)

    Wang, Kening; Tomaras, Georgia D; Jegaskanda, Sinthujan; Moody, M Anthony; Liao, Hua-Xin; Goodman, Kyle N; Berman, Phillip W; Rerks-Ngarm, Supachai; Pitisuttithum, Punnee; Nitayapan, Sorachai; Kaewkungwal, Jaranit; Haynes, Barton F; Cohen, Jeffrey I

    2017-10-01

    The RV144 HIV vaccine trial included a recombinant HIV glycoprotein 120 (gp120) construct fused to a small portion of herpes simplex virus 1 (HSV-1) glycoprotein D (gD) so that the first 40 amino acids of gp120 were replaced by the signal sequence and the first 27 amino acids of the mature form of gD. This region of gD contains most of the binding site for HVEM, an HSV receptor important for virus infection of epithelial cells and lymphocytes. RV144 induced antibodies to HIV that were partially protective against infection, as well as antibodies to HSV. We derived monoclonal antibodies (MAbs) from peripheral blood B cells of recipients of the RV144 HIV vaccine and showed that these antibodies neutralized HSV-1 infection in cells expressing HVEM, but not the other major virus receptor, nectin-1. The MAbs mediated antibody-dependent cellular cytotoxicity (ADCC), and mice that received the MAbs and were then challenged by corneal inoculation with HSV-1 had reduced eye disease, shedding, and latent infection. To our knowledge, this is the first description of MAbs derived from human recipients of a vaccine that specifically target the HVEM binding site of gD. In summary, we found that monoclonal antibodies derived from humans vaccinated with the HVEM binding domain of HSV-1 gD (i) neutralized HSV-1 infection in a cell receptor-specific manner, (ii) mediated ADCC, and (iii) reduced ocular disease in virus-infected mice. IMPORTANCE Herpes simplex virus 1 (HSV-1) causes cold sores and neonatal herpes and is a leading cause of blindness. Despite many trials, no HSV vaccine has been approved. Nectin-1 and HVEM are the two major cellular receptors for HSV. These receptors are expressed at different levels in various tissues, and the role of each receptor in HSV pathogenesis is not well understood. We derived human monoclonal antibodies from persons who received the HIV RV144 vaccine that contained the HVEM binding domain of HSV-1 gD fused to HIV gp120. These antibodies were

  13. Simple, rapid 125I-labeled cyclosporine double antibody/polyethylene glycol radioimmunoassay used in a pediatric cardiac transplant program

    International Nuclear Information System (INIS)

    Berk, L.S.; Webb, G.; Imperio, N.C.; Nehlsen-Cannarella, S.L.; Eby, W.C.

    1986-01-01

    We modified the Sandoz cyclosporine radioimmunoassay because of our need for frequent clinical monitoring of cyclosporine drug levels in allo- and xenograft pediatric cardiac transplant patients. With application of a commercially available [ 125 I]cyclosporine label in place of [ 3 H]cyclosporine and a second antibody/polyethylene glycol (PEG) method of separation in place of charcoal separation, we simplified and enhanced the speed and precision of assay performance. Studies of 140 whole blood samples comparing this new method to the [ 3 H]cyclosporine radioimmunoassay (RIA) method of Berk and colleagues yielded a coefficient of correlation of 0.96 (p less than 0.00001) with means of 626 and 667 ng/ml for [ 3 H]RIA and [ 125 I]RIA, respectively, and a regression equation of y = 28 + 1.02x. The major advantages are that total assay time is reduced to approximately 1 h; [ 125 I]cyclosporine label is used, avoiding the problems associated with liquid scintillation counting; and precision is enhanced by separating bound and free fractions with second antibody/PEG. These modifications should provide for greater ease of assay performance and improved clinical utility of cyclosporine monitoring not only in the pediatric but also in the adult transplant patient

  14. Provider-related barriers to rapid HIV testing in U.S. urban non-profit community clinics, community-based organizations (CBOs) and hospitals.

    Science.gov (United States)

    Bogart, Laura M; Howerton, Devery; Lange, James; Setodji, Claude Messan; Becker, Kirsten; Klein, David J; Asch, Steven M

    2010-06-01

    We examined provider-reported barriers to rapid HIV testing in U.S. urban non-profit community clinics, community-based organizations (CBOs), and hospitals. 12 primary metropolitan statistical areas (PMSAs; three per region) were sampled randomly, with sampling weights proportional to AIDS case reports. Across PMSAs, all 671 hospitals and a random sample of 738 clinics/CBOs were telephoned for a survey on rapid HIV test availability. Of the 671 hospitals, 172 hospitals were randomly selected for barriers questions, for which 158 laboratory and 136 department staff were eligible and interviewed in 2005. Of the 738 clinics/CBOs, 276 were randomly selected for barriers questions, 206 were reached, and 118 were eligible and interviewed in 2005-2006. In multivariate models, barriers regarding translation of administrative/quality assurance policies into practice were significantly associated with rapid HIV testing availability. For greater rapid testing diffusion, policies are needed to reduce administrative barriers and provide quality assurance training to non-laboratory staff.

  15. Safety and pharmacokinetics of the Fc-modified HIV-1 human monoclonal antibody VRC01LS: A Phase 1 open-label clinical trial in healthy adults.

    Directory of Open Access Journals (Sweden)

    Martin R Gaudinski

    2018-01-01

    Full Text Available VRC01 is a human broadly neutralizing monoclonal antibody (bnMAb against the CD4-binding site of the HIV-1 envelope glycoprotein (Env that is currently being evaluated in a Phase IIb adult HIV-1 prevention efficacy trial. VRC01LS is a modified version of VRC01, designed for extended serum half-life by increased binding affinity to the neonatal Fc receptor.This Phase I dose-escalation study of VRC01LS in HIV-negative healthy adults was conducted by the Vaccine Research Center (VRC at the National Institutes of Health (NIH Clinical Center (Bethesda, MD. The age range of the study volunteers was 21-50 years; 51% of study volunteers were male and 49% were female. Primary objectives were safety and tolerability of VRC01LS intravenous (IV infusions at 5, 20, and 40 mg/kg infused once, 20 mg/kg given three times at 12-week intervals, and subcutaneous (SC delivery at 5 mg/kg delivered once, or three times at 12-week intervals. Secondary objectives were pharmacokinetics (PK, serum neutralization activity, and development of antidrug antibodies. Enrollment began on November 16, 2015, and concluded on August 23, 2017. This report describes the safety data for the first 37 volunteers who received administrations of VRC01LS. There were no serious adverse events (SAEs or dose-limiting toxicities. Mild malaise and myalgia were the most common adverse events (AEs. There were six AEs assessed as possibly related to VRC01LS administration, and all were mild in severity and resolved during the study. PK data were modeled based on the first dose of VRC01LS in the first 25 volunteers to complete their schedule of evaluations. The mean (±SD serum concentration 12 weeks after one IV administration of 20 mg/kg or 40 mg/kg were 180 ± 43 μg/mL (n = 7 and 326 ± 35 μg/mL (n = 5, respectively. The mean (±SD serum concentration 12 weeks after one IV and SC administration of 5 mg/kg were 40 ± 3 μg/mL (n = 2 and 25 ± 5 μg/mL (n = 9, respectively. Over the 5-40 mg

  16. Hepatitis C Viremia Is Associated with Cytomegalovirus IgG Antibody Levels in HIV-Infected Women

    Science.gov (United States)

    Kuniholm, Mark H.; Parrinello, Christina M.; Anastos, Kathryn; Augenbraun, Michael; Plankey, Michael; Nowicki, Marek; Peters, Marion; Golub, Elizabeth T.; Lurain, Nell; Landay, Alan L.; Strickler, Howard D.; Kaplan, Robert C.

    2013-01-01

    Background Individuals with HIV infection exhibit high cytomegalovirus (CMV) IgG levels, but there are few data regarding the association of hepatitis C virus (HCV) with the immune response against CMV. Methods Associations of HCV with CMV seropositivity and CMV IgG levels were studied in 635 HIV-infected women, 187 of whom were HCV-seropositive, with adjustment in multivariable models for age, race/ethnicity, and HIV disease characteristics. Eighty one percent of the women reported receipt of highly active antiretroviral therapy (HAART) prior to or at CMV testing. Results In adjusted models women with chronic HCV had higher CMV IgG levels than those without HCV RNA (β = 2.86, 95% CI:0.89 – 4.83; P = 0.004). The association of HCV RNA with CMV IgG differed by age (P interaction = 0.0007), with a strong association observed among women in the low and middle age tertiles (≤45.3 years of age; β = 6.21, 95% CI:3.30 – 9.11, P<0.0001) but not among women in the high age tertile. CMV IgG levels were not associated with non-invasive measures of liver disease, APRI and FIB-4, or with HCV RNA level and adjustment for Epstein-Barr virus (EBV) IgG levels did not affect the association between HCV and CMV. Conclusions CMV IgG levels are higher in HCV/HIV co-infected women than in HIV mono-infected women. Further research on the association of HCV with CMV IgG is indicated because prior studies have found CMV IgG to be associated with morbidity and mortality in the general population and subclinical carotid artery disease in HIV-infected patients. PMID:23613990

  17. Hepatitis C viremia is associated with cytomegalovirus IgG antibody levels in HIV-infected women.

    Directory of Open Access Journals (Sweden)

    Mark H Kuniholm

    Full Text Available Individuals with HIV infection exhibit high cytomegalovirus (CMV IgG levels, but there are few data regarding the association of hepatitis C virus (HCV with the immune response against CMV.Associations of HCV with CMV seropositivity and CMV IgG levels were studied in 635 HIV-infected women, 187 of whom were HCV-seropositive, with adjustment in multivariable models for age, race/ethnicity, and HIV disease characteristics. Eighty one percent of the women reported receipt of highly active antiretroviral therapy (HAART prior to or at CMV testing.In adjusted models women with chronic HCV had higher CMV IgG levels than those without HCV RNA (β = 2.86, 95% CI:0.89 - 4.83; P = 0.004. The association of HCV RNA with CMV IgG differed by age (P(interaction = 0.0007, with a strong association observed among women in the low and middle age tertiles (≤ 45.3 years of age; β = 6.21, 95% CI:3.30 - 9.11, P<0.0001 but not among women in the high age tertile. CMV IgG levels were not associated with non-invasive measures of liver disease, APRI and FIB-4, or with HCV RNA level and adjustment for Epstein-Barr virus (EBV IgG levels did not affect the association between HCV and CMV.CMV IgG levels are higher in HCV/HIV co-infected women than in HIV mono-infected women. Further research on the association of HCV with CMV IgG is indicated because prior studies have found CMV IgG to be associated with morbidity and mortality in the general population and subclinical carotid artery disease in HIV-infected patients.

  18. Evaluation of Performance of Two Rapid Tests for Detection of HIV-1 and -2 in High- and Low-Prevalence Populations in Nigeria.

    Science.gov (United States)

    Manak, Mark M; Njoku, Ogbonnaya S; Shutt, Ashley; Malia, Jennifer; Jagodzinski, Linda L; Milazzo, Mark; Suleiman, Aminu; Ogundeji, Amos A; Nelson, Robert; Ayemoba, Ojor R; O'Connell, Robert J; Singer, Darrell E; Michael, Nelson L; Peel, Sheila A

    2015-11-01

    The availability of reliable human immunodeficiency virus types 1 and 2 (HIV-1/2) rapid tests in resource-limited settings represents an important advancement in the accurate diagnosis of HIV infection and presents opportunities for implementation of effective prevention and treatment interventions among vulnerable populations. A study of the potential target populations for future HIV vaccine studies examined the prevalence of HIV infections at six selected sites in Nigeria and evaluated the use of two rapid diagnostic tests (RDTs) for HIV. The populations included market workers at sites adjacent to military installations and workers at highway settlements (truck stops) who may have a heightened risk of HIV exposure. Samples from 3,187 individuals who provided informed consent were tested in parallel using the Determine (DT) and Stat-Pak (SP) RDTs; discordant results were subjected to the Uni-Gold (UG) RDT as a tiebreaker. The results were compared to those of a third-generation enzyme immunoassay screen with confirmation of repeat reactive samples by HIV-1 Western blotting. One participant was HIV-2 infected, yielding positive results on both RDTs. Using the laboratory algorithm as a gold standard, we calculated sensitivities of 98.5% (confidence interval [CI], 97.1 to 99.8%) for DT and 98.1% (CI, 96.7 to 99.6%) for SP and specificities of 98.7% (CI, 98.3 -99.1%) for DT and 99.8% (CI, 99.6 to 100%) for SP. Similar results were obtained when the sites were stratified into those of higher HIV prevalence (9.4% to 22.8%) versus those of lower prevalence (3.2% to 7.3%). A parallel two-test algorithm requiring both DT and SP to be positive resulted in the highest sensitivity (98.1%; CI, 96.7 to 99.6%) and specificity (99.97%; CI, 99.9 to 100%) relative to those for the reference laboratory algorithm. Copyright © 2015, Manak et al.

  19. Cross-Neutralizing Antibodies in HIV-1 Individuals Infected by Subtypes B, F1, C or the B/Bbr Variant in Relation to the Genetics and Biochemical Characteristics of the env Gene.

    Directory of Open Access Journals (Sweden)

    Dalziza Victalina de Almeida

    Full Text Available Various HIV-1 env genetic and biochemical features impact the elicitation of cross-reactive neutralizing antibodies in natural infections. Thus, we aimed to investigate cross-neutralizing antibodies in individuals infected with HIV-1 env subtypes B, F1, C or the B/Bbr variant as well as env characteristics. Therefore, plasma samples from Brazilian chronically HIV-1 infected individuals were submitted to the TZM-bl neutralization assay. We also analyzed putative N-glycosylation sites (PNGLs and the size of gp120 variable domains in the context of HIV-1 subtypes prevalent in Brazil. We observed a greater breadth and potency of the anti-Env neutralizing response in individuals infected with the F1 or B HIV-1 subtypes compared with the C subtype and the variant B/Bbr. We observed greater V1 B/Bbr and smaller V4 F1 than those of other subtypes (p<0.005, however neither was there a correlation verified between the variable region length and neutralization potency, nor between PNLG and HIV-1 subtypes. The enrichment of W at top of V3 loop in weak neutralizing response viruses and the P in viruses with higher neutralization susceptibility was statistically significant (p = 0.013. Some other signatures sites were associated to HIV-1 subtype-specific F1 and B/Bbr samples might influence in the distinct neutralizing response. These results indicate that a single amino acid substitution may lead to a distinct conformational exposure or load in the association domain of the trimer of gp120 and interfere with the induction power of the neutralizing response, which affects the sensitivity of the neutralizing antibody and has significant implications for vaccine design.

  20. A novel non-rapid-eye movement and rapid-eye-movement parasomnia with sleep breathing disorder associated with antibodies to IgLON5: a case series, characterisation of the antigen, and post-mortem study.

    Science.gov (United States)

    Sabater, Lidia; Gaig, Carles; Gelpi, Ellen; Bataller, Luis; Lewerenz, Jan; Torres-Vega, Estefanía; Contreras, Angeles; Giometto, Bruno; Compta, Yaroslau; Embid, Cristina; Vilaseca, Isabel; Iranzo, Alex; Santamaría, Joan; Dalmau, Josep; Graus, Francesc

    2014-06-01

    Autoimmunity might be associated with or implicated in sleep and neurodegenerative disorders. We aimed to describe the features of a novel neurological syndrome associated with prominent sleep dysfunction and antibodies to a neuronal antigen. In this observational study, we used clinical and video polysomnography to identify a novel sleep disorder in three patients referred to the Sleep Unit of Hospital Clinic, University of Barcelona, Spain, for abnormal sleep behaviours and obstructive sleep apnoea. These patients had antibodies against a neuronal surface antigen, which were also present in five additional patients referred to our laboratory for antibody studies. These five patients had been assessed with polysomnography, which was done in our sleep unit in one patient and the recording reviewed in a second patient. Two patients underwent post-mortem brain examination. Immunoprecipitation and mass spectrometry were used to characterise the antigen and develop an assay for antibody testing. Serum or CSF from 298 patients with neurodegenerative, sleep, or autoimmune disorders served as control samples. All eight patients (five women; median age at disease onset 59 years [range 52-76]) had abnormal sleep movements and behaviours and obstructive sleep apnoea, as confirmed by polysomnography. Six patients had chronic progression with a median duration from symptom onset to death or last visit of 5 years (range 2-12); in four the sleep disorder was the initial and most prominent feature, and in two it was preceded by gait instability followed by dysarthria, dysphagia, ataxia, or chorea. Two patients had a rapid progression with disequilibrium, dysarthria, dysphagia, and central hypoventilation, and died 2 months and 6 months, respectively, after symptom onset. In five of five patients, video polysomnography showed features of obstructive sleep apnoea, stridor, and abnormal sleep architecture (undifferentiated non-rapid-eye-movement [non-REM] sleep or poorly structured

  1. Performance and diagnostic usefulness of commercially available enzyme linked immunosorbent assay and rapid kits for detection of HIV, HBV and HCV in India.

    Science.gov (United States)

    Maity, Susmita; Nandi, Srijita; Biswas, Subrata; Sadhukhan, Salil Kumar; Saha, Malay Kumar

    2012-11-26

    HIV, HBV and HCV pose a major public health problem throughout the world. Detection of infection markers for these agents is a major challenge for testing laboratories in a resource poor setting. As blood transfusion is an important activity saving millions of live every year, it also carries a risk of transfusion transmissible infections caused by these fatal blood borne pathogens if the quality of testing is compromised. Conventional ELISA is regarded as the mostly used screening technique but due to limitations like high cost, unavailability in many blood banks and testing sites, involvement of costly instruments, time taking nature and requirement of highly skilled personnel for interpretation, rapid tests are gaining more importance and warrants comparison of performance. A comparative study between these two techniques has been performed using commercially available diagnostic kits to assess their efficacy for detection of HIV, HBV and HCV infections. Rapid kits were more efficient in specificity with synthetic antigens along with high PPV than ELISA in most cases. Comparison between different ELISA kits revealed that Microlisa HIV and Hepalisa (J. Mitra & Co. Pvt. Ltd.); ERBA LISA HIV1 + 2, ERBA LISA Hepatitis B and ERBA LISA HCV (Transasia Bio-medicals Ltd.) gives uniform result with good performance in terms of sensitivity, specificity, PPV, NPV and efficiency, whereas, Microlisa HCV (J. Mitra & Co. Pvt. Ltd.), Microscreen HBsAg ELISA and INNOVA HCV (Span Diagnostics Ltd.) did not perform well. Rapid kits were also having high degree of sensitivity and specificity (100%) except in HIV Comb and HCV Comb (J. Mitra & Co. Pvt. Ltd.). The kit efficiency didn't vary significantly among different companies and lots in all the cases except for HCV ELISA showing statistically significant variation (p bank. For availability of quality commercial diagnostic assays, evaluation of kit may be helpful.

  2. Rapid Screening Assay for the Detection of Nivalenol and Deoxynivalenol using Monoclonal Antibody and Surface Plasmon Resonance

    Science.gov (United States)

    Nivalenol (NIV) and Deoxynivalenol (DON) are trichothecene mycotoxins produced by Fusarium spp that contaminate mainly cereal crops, such as wheat, barley, and maize. These mycotoxins are serious health hazards to human and domestic animals. The study reports a rapid screening method of NIV and DO...

  3. Rapid point-of-care CD4 testing at mobile HIV testing sites to increase linkage to care: an evaluation of a pilot program in South Africa.

    Science.gov (United States)

    Larson, Bruce A; Schnippel, Kathryn; Ndibongo, Buyiswa; Xulu, Thembisile; Brennan, Alana; Long, Lawrence; Fox, Matthew P; Rosen, Sydney

    2012-10-01

    A mobile HIV counseling and testing (HCT) program around Johannesburg piloted the integration of point-of-care (POC) CD4 testing, using the Pima analyzer, to improve linkages to HIV care. We report results from this pilot program for patients testing positive (n = 508) from May to October 2010. We analyzed 3 primary outcomes: assignment to testing group (offered POC CD4 or not), successful follow-up (by telephone), and completed the referral visit for HIV care within 8 weeks after HIV testing if successfully followed up. Proportions for each outcome were calculated, and relative risks were estimated using a modified Poisson approach. Three hundred eleven patients were offered the POC CD4 test, and 197 patients were not offered the test. No differences in patient characteristics were observed between the 2 groups. Approximately 62.7% of patients were successfully followed up 8 weeks after HIV testing, with no differences observed between testing groups. Among those followed up, 54.4% reported completing their referral visit. Patients offered the POC CD4 test were more likely to complete the referral visit for further HIV care (relative risk 1.25, 95% confidence interval: 1.00 to 1.57). In this mobile HCT setting, patients offered POC CD4 testing as part of the HCT services were more likely to visit a referral clinic after testing, suggesting that rapid CD4 testing technology may improve linkage to HIV care. Future research can evaluate options for adjusting HCT services if POC CD4 testing was included permanently and the cost-effectiveness of the POC CD4 testing compared with other approaches for improving linkage of care.

  4. Antibody to histo-blood group A antigen neutralizes HIV produced by lymphocytes from blood group A donors but not from blood group B or O donors

    DEFF Research Database (Denmark)

    Arendrup, M; Hansen, J E; Clausen, H

    1991-01-01

    Three virus isolates HTLV-IIIB/lyA, HTLV-IIIB/lyB and HTLV-IIIB/lyO, obtained by passaging and propagating the HTLV-IIIB/H9 isolate in three separate cultures of mixed peripheral blood mononuclear cells (PBMC) from donors of blood type A, B or O, respectively, were tested for susceptibility...... for virus neutralization by the monoclonal antibody (MAb) AH16 directed against the blood group A epitope. MAb AH16 was previously shown to inhibit cell-free virus infection using HTLV-IIIB propagated in H9 cells. AH16 showed a concentration-dependent inhibition of the HTLV-IIIB/lyA isolate but did...... not inhibit the HTLV-IIIB/lyB or the HTLV-IIIB/lyO isolate. Specificity of the MAb-mediated inhibition was shown using A-antigen (tetrasaccharide). Thus, HIV infection of PBMC from donors with blood type A appears to induce expression of host-cell-encoded carbohydrate blood group A epitope on HIV which can...

  5. Antibody to histo-blood group A antigen neutralizes HIV produced by lymphocytes from blood group A donors but not from blood group B or O donors

    DEFF Research Database (Denmark)

    Arendrup, M; Hansen, J E; Clausen, H

    1991-01-01

    Three virus isolates HTLV-IIIB/lyA, HTLV-IIIB/lyB and HTLV-IIIB/lyO, obtained by passaging and propagating the HTLV-IIIB/H9 isolate in three separate cultures of mixed peripheral blood mononuclear cells (PBMC) from donors of blood type A, B or O, respectively, were tested for susceptibility...... not inhibit the HTLV-IIIB/lyB or the HTLV-IIIB/lyO isolate. Specificity of the MAb-mediated inhibition was shown using A-antigen (tetrasaccharide). Thus, HIV infection of PBMC from donors with blood type A appears to induce expression of host-cell-encoded carbohydrate blood group A epitope on HIV which can...... for virus neutralization by the monoclonal antibody (MAb) AH16 directed against the blood group A epitope. MAb AH16 was previously shown to inhibit cell-free virus infection using HTLV-IIIB propagated in H9 cells. AH16 showed a concentration-dependent inhibition of the HTLV-IIIB/lyA isolate but did...

  6. Vaccine-Elicited Tier 2 HIV-1 Neutralizing Antibodies Bind to Quaternary Epitopes Involving Glycan-Deficient Patches Proximal to the CD4 Binding Site.

    Directory of Open Access Journals (Sweden)

    Ema T Crooks

    2015-05-01

    Full Text Available Eliciting broad tier 2 neutralizing antibodies (nAbs is a major goal of HIV-1 vaccine research. Here we investigated the ability of native, membrane-expressed JR-FL Env trimers to elicit nAbs. Unusually potent nAb titers developed in 2 of 8 rabbits immunized with virus-like particles (VLPs expressing trimers (trimer VLP sera and in 1 of 20 rabbits immunized with DNA expressing native Env trimer, followed by a protein boost (DNA trimer sera. All 3 sera neutralized via quaternary epitopes and exploited natural gaps in the glycan defenses of the second conserved region of JR-FL gp120. Specifically, trimer VLP sera took advantage of the unusual absence of a glycan at residue 197 (present in 98.7% of Envs. Intriguingly, removing the N197 glycan (with no loss of tier 2 phenotype rendered 50% or 16.7% (n = 18 of clade B tier 2 isolates sensitive to the two trimer VLP sera, showing broad neutralization via the surface masked by the N197 glycan. Neutralizing sera targeted epitopes that overlap with the CD4 binding site, consistent with the role of the N197 glycan in a putative "glycan fence" that limits access to this region. A bioinformatics analysis suggested shared features of one of the trimer VLP sera and monoclonal antibody PG9, consistent with its trimer-dependency. The neutralizing DNA trimer serum took advantage of the absence of a glycan at residue 230, also proximal to the CD4 binding site and suggesting an epitope similar to that of monoclonal antibody 8ANC195, albeit lacking tier 2 breadth. Taken together, our data show for the first time that strain-specific holes in the glycan fence can allow the development of tier 2 neutralizing antibodies to native spikes. Moreover, cross-neutralization can occur in the absence of protecting glycan. Overall, our observations provide new insights that may inform the future development of a neutralizing antibody vaccine.

  7. Setting of methods for analysis of mucosal antibodies in seminal and vaginal fluids of HIV seropositive subjects from Cambodian and Italian cohorts.

    Directory of Open Access Journals (Sweden)

    Carla Donadoni

    2010-03-01

    Full Text Available Genital mucosae play a key role in protection from STD and HIV infection, due to their involvement in both horizontal and vertical disease transmission. High variability of published observations concerning IgA isolation and quantification underlies the strong requirement of specific methods able to maximize investigation on HIV-specific IgA.Genital fluids from 109 subjects, including male and female cohorts from Italy and Cambodia, were collected, aliquoted and processed with different techniques, to assess optimal conditions maximizing mucosal antibody recovery. Three sampling techniques, up to sixteen preservation conditions, six ELISA methods and four purifications protocols were compared.The optimal method here described took advantage of Weck-Cel sampling of female mucosal fluids. Immediate processing of genital fluids, with the addition of antibiotics and EDTA, improved recovery of vaginal IgA, while the triple addition of EDTA, antibiotics and protease inhibitors provided the highest amount of seminal IgA. Due to low amount of IgA in mucosal fluids, a high sensitive sandwich ELISA assay was set; sensitivity was enhanced by milk-based overcoating buffer and by a two-step biotin-streptavidin signal amplification. Indeed, commercial antisera to detect human immunoglobulins showed weak cross-reactivity to different antibody types. Three-step affinity purification provided reproducible immunoglobulin recovery from genital specimens, while conventional immuno-affinity IgA purification was found poorly manageable. Affinity columns were suitable to isolate mucosal IgA, which are ten-fold less concentrated than IgG in genital specimens, and provided effective separation of IgA monomers, dimers, and J-chains. Jacalin-bound resin successfully separated IgA1 from IgA2 subfraction.Specific, effective and reliable methods to study local immunity are key items in understanding host mucosal response. The sequence of methods here described is effective

  8. Rapid electrochemical quantification of Salmonella Pullorum and Salmonella Gallinarum based on glucose oxidase and antibody-modified silica nanoparticles.

    Science.gov (United States)

    Luo, Yiheng; Dou, Wenchao; Zhao, Guangying

    2017-07-01

    In this article, a facile and sensitive electrochemical method for quantification of Salmonella Pullorum and Salmonella Gallinarum (S. Pullorum and S. Gallinarum) was established by monitoring glucose consumption with a personal glucose meter (PGM). Antibody-functionalized magnetic nanoparticles (IgG-MNPs) were used to capture and enrich S. Pullorum and S. Gallinarum, and IgG-MNPs-S. Pullorum and IgG-MNPs-S. Gallinarum complexes were magnetically separated from a sample using a permanent magnet. The trace tag was prepared by loading polyclonal antibodies and high-content glucose oxidase on amino-functionalized silica nanoparticles (IgG-SiNPs-GOx). With a sandwich-type immunoassay format, IgG-SiNPs-GOx were added into the above mixture solution and conjugated to the complexes, forming sandwich composites IgG-MNPs/S. Pullorum and S. Gallinarum/IgG-SiNPs-GOx. The above sandwich composites were dispersed in glucose solution. Before and after the hydrolysis of glucose, the concentration of glucose was measured using PGM. Under optimal conditions, a linear relationship between the decrease of glucose concentration and the logarithm of S. Pullorum and S. Gallinarum concentration was obtained in the concentration range from 1.27 × 10 2 to 1.27 × 10 5  CFU mL -1 , with a detection limit of 7.2 × 10 1  CFU mL -1 (S/N = 3). This study provides a portable, low-cost, and quantitative analytical method for bacteria detection; thus, it has a great potential in the prevention of disease caused by S. Pullorum and S. Gallinarum in poultry. Graphical abstract A schematic illustration of the fabrication process of IgG-SiNPs-GOD nanomaterials (A) and IgG-MNPs (B) and experimental procedure of detection of S. Pullorum and S. Gallinarum using GOD-functionalized silica nanospheres as trace tags based on PGM (C).

  9. New sensitive and specific assay for human immunodeficiency virus antibodies using labeled recombinant fusion protein and time-resolved fluoroimmunoassay.

    OpenAIRE

    Siitari, H; Turunen, P; Schrimsher, J; Nunn, M

    1990-01-01

    A new, rapid method for the detection of human immunodeficiency virus type 1 (HIV-1) antibody by time-resolved fluoroimmunoassay (TR-FIA) was developed. In this assay format, microtitration strips were coated with a recombinant fusion protein, and the same protein was labeled with europium and added into the wells simultaneously with the test specimens. The recombinant fusion protein contained the HIV-1 p24 gag protein sequence that carried an insertion, near the carboxyl terminus, of a 23-am...

  10. Rapid analysis of charge variants of monoclonal antibodies using non-linear salt gradient in cation-exchange high performance liquid chromatography.

    Science.gov (United States)

    Joshi, Varsha; Kumar, Vijesh; Rathore, Anurag S

    2015-08-07

    A method is proposed for rapid development of a short, analytical cation exchange high performance liquid chromatography method for analysis of charge heterogeneity in monoclonal antibody products. The parameters investigated and optimized include pH, shape of elution gradient and length of the column. It is found that the most important parameter for development of a shorter method is the choice of the shape of elution gradient. In this paper, we propose a step by step approach to develop a non-linear sigmoidal shape gradient for analysis of charge heterogeneity for two different monoclonal antibody products. The use of this gradient not only decreases the run time of the method to 4min against the conventional method that takes more than 40min but also the resolution is retained. Superiority of the phosphate gradient over sodium chloride gradient for elution of mAbs is also observed. The method has been successfully evaluated for specificity, sensitivity, linearity, limit of detection, and limit of quantification. Application of this method as a potential at-line process analytical technology tool has been suggested. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Comparison of the efficiency of antibody selection from semi-synthetic scFv and non-immune Fab phage display libraries against protein targets for rapid development of diagnostic immunoassays.

    Science.gov (United States)

    Chan, Conrad E Z; Chan, Annie H Y; Lim, Angeline P C; Hanson, Brendon J

    2011-10-28

    Rapid development of diagnostic immunoassays against novel emerging or genetically modified pathogens in an emergency situation is dependent on the timely isolation of specific antibodies. Non-immune antibody phage display libraries are an efficient in vitro method for selecting monoclonal antibodies and hence ideal in these circumstances. Such libraries can be constructed from a variety of sources e.g. B cell cDNA or synthetically generated, and use a variety of antibody formats, typically scFv or Fab. However, antibody source and format can impact on the quality of antibodies generated and hence the effectiveness of this methodology for the timely production of antibodies. We have carried out a comparative screening of two antibody libraries, a semi-synthetic scFv library and a human-derived Fab library against the protective antigen toxin component of Bacillus anthracis and the epsilon toxin of Clostridium botulinum. We have shown that while the synthetic library produced a diverse collection of specific scFv-phage, these contained a high frequency of unnatural amber stops and glycosylation sites which limited their conversion to IgG, and also a high number which lost specificity when expressed as IgG. In contrast, these limitations were overcome by the use of a natural human library. Antibodies from both libraries could be used to develop sandwich ELISA assays with similar sensitivity. However, the ease and speed with which full-length IgG could be generated from the human-derived Fab library makes screening this type of library the preferable method for rapid antibody generation for diagnostic assay development. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Elevated Basal Pre-infection CXCL10 in Plasma and in the Small Intestine after Infection Are Associated with More Rapid HIV/SIV Disease Onset.

    Directory of Open Access Journals (Sweden)

    Mickaël J Ploquin

    2016-08-01

    Full Text Available Elevated blood CXCL10/IP-10 levels during primary HIV-1 infection (PHI were described as an independent marker of rapid disease onset, more robust than peak viremia or CD4 cell nadir. IP-10 enhances the recruitment of CXCR3+ cells, which include major HIV-target cells, raising the question if it promotes the establishment of viral reservoirs. We analyzed data from four cohorts of HIV+ patients, allowing us to study IP-10 levels before infection (Amsterdam cohort, as well as during controlled and uncontrolled viremia (ANRS cohorts. We also addressed IP-10 expression levels with regards to lymphoid tissues (LT and blood viral reservoirs in patients and non-human primates. Pre-existing elevated IP-10 levels but not sCD63 associated with rapid CD4 T-cell loss upon HIV-1 infection. During PHI, IP-10 levels and to a lesser level IL-18 correlated with cell-associated HIV DNA, while 26 other inflammatory soluble markers did not. IP-10 levels tended to differ between HIV controllers with detectable and undetectable viremia. IP-10 was increased in SIV-exposed aviremic macaques with detectable SIV DNA in tissues. IP-10 mRNA was produced at higher levels in the small intestine than in colon or rectum. Jejunal IP-10+ cells corresponded to numerous small and round CD68neg cells as well as to macrophages. Blood IP-10 response negatively correlated with RORC (Th17 marker gene expression in the small intestine. CXCR3 expression was higher on memory CD4+ T cells than any other immune cells. CD4 T cells from chronically infected animals expressed extremely high levels of intra-cellular CXCR3 suggesting internalization after ligand recognition. Elevated systemic IP-10 levels before infection associated with rapid disease progression. Systemic IP-10 during PHI correlated with HIV DNA. IP-10 production was regionalized in the intestine during early SIV infection and CD68+ and CD68neg haematopoietic cells in the small intestine appeared to be the major source of IP-10.

  13. Development toward rapid and efficient screening for high performance hydrolysate lots in a recombinant monoclonal antibody manufacturing process.

    Science.gov (United States)

    Luo, Ying; Pierce, Karisa M

    2012-07-01

    Plant-derived hydrolysates are widely used in mammalian cell culture media to increase yields of recombinant proteins and monoclonal antibodies (mAbs). However, these chemically varied and undefined raw materials can have negative impact on yield and/or product quality in large-scale cell culture processes. Traditional methods that rely on fractionation of hydrolysates yielded little success in improving hydrolysate quality. We took a holistic approach to develop an efficient and reliable method to screen intact soy hydrolysate lots for commercial recombinant mAb manufacturing. Combined high-resolution (1) H nuclear magnetic resonance (NMR) spectroscopy and partial least squares (PLS) analysis led to a prediction model between product titer and NMR fingerprinting of soy hydrolysate with cross-validated correlation coefficient R(2) of 0.87 and root-mean-squared-error of cross-validation RMSECV% of 11.2%. This approach screens for high performance hydrolysate lots, therefore ensuring process consistency and product quality in the mAb manufacturing process. Furthermore, PLS analysis was successful in discerning multiple markers (DL-lactate, soy saccharides, citrate and succinate) among hydrolysate components that positively and negatively correlate with titer. Interestingly, these markers correlate to the metabolic characteristics of some strains of taxonomically diverse lactic acid bacteria (LAB). Thus our findings indicate that LAB strains may exist during hydrolysate manufacturing steps and their biochemical activities may attribute to the titer enhancement effect of soy hydrolysates. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

  14. Self-Reported HIV-Positive Status But Subsequent HIV-Negative Test Result Using Rapid Diagnostic Testing Algorithms Among Seven Sub-Saharan African Military Populations

    Science.gov (United States)

    2017-07-07

    analysis, data interpretation, or writing of the report. Leidos provided support in the form of salaries for JH, BRT, AGT, MBJ and JM but did not have any...have data on a QA process. The survey used for all seven partner mili- taries was based on a standardized modular survey, which assessed HIV risk... Technical considerations Technical limitations have been shown to increase false-positive HIV test results in voluntary counseling and testing centers

  15. Glycans Flanking the Hypervariable Connecting Peptide between the A and B Strands of the V1/V2 Domain of HIV-1 gp120 Confer Resistance to Antibodies That Neutralize CRF01_AE Viruses

    Science.gov (United States)

    O’Rourke, Sara M.; Sutthent, Ruengpung; Phung, Pham; Mesa, Kathryn A.; Frigon, Normand L.; To, Briana; Horthongkham, Navin; Limoli, Kay; Wrin, Terri; Berman, Phillip W.

    2015-01-01

    Understanding the molecular determinants of sensitivity and resistance to neutralizing antibodies is critical for the development of vaccines designed to prevent HIV infection. In this study, we used a genetic approach to characterize naturally occurring polymorphisms in the HIV envelope protein that conferred neutralization sensitivity or resistance. Libraries of closely related envelope genes, derived from virus quasi-species, were constructed from individuals infected with CRF01_AE viruses. The libraries were screened with plasma containing broadly neutralizing antibodies, and neutralization sensitive and resistant variants were selected for sequence analysis. In vitro mutagenesis allowed us to identify single amino acid changes in three individuals that conferred resistance to neutralization by these antibodies. All three mutations created N-linked glycosylation sites (two at N136 and one at N149) proximal to the hypervariable connecting peptide between the C-terminus of the A strand and the N-terminus of the B strand in the four-stranded V1/V2 domain β-sheet structure. Although N136 has previously been implicated in the binding of broadly neutralizing monoclonal antibodies, this glycosylation site appears to inhibit the binding of neutralizing antibodies in plasma from HIV-1 infected subjects. Previous studies have reported that the length of the V1/V2 domain in transmitted founder viruses is shorter and possesses fewer glycosylation sites compared to viruses isolated from chronic infections. Our results suggest that vaccine immunogens based on recombinant envelope proteins from clade CRF01_AE viruses might be improved by inclusion of envelope proteins that lack these glycosylation sites. This strategy might improve the efficacy of the vaccines used in the partially successful RV144 HIV vaccine trial, where the two CRF01_AE immunogens (derived from the A244 and TH023 isolates) both possessed glycosylation sites at N136 and N149. PMID:25793890

  16. Performance and diagnostic usefulness of commercially available enzyme linked immunosorbent assay and rapid kits for detection of HIV, HBV and HCV in India

    Directory of Open Access Journals (Sweden)

    Maity Susmita

    2012-11-01

    Full Text Available Abstract Background HIV, HBV and HCV pose a major public health problem throughout the world. Detection of infection markers for these agents is a major challenge for testing laboratories in a resource poor setting. As blood transfusion is an important activity saving millions of live every year, it also carries a risk of transfusion transmissible infections caused by these fatal blood borne pathogens if the quality of testing is compromised. Conventional ELISA is regarded as the mostly used screening technique but due to limitations like high cost, unavailability in many blood banks and testing sites, involvement of costly instruments, time taking nature and requirement of highly skilled personnel for interpretation, rapid tests are gaining more importance and warrants comparison of performance. Results A comparative study between these two techniques has been performed using commercially available diagnostic kits to assess their efficacy for detection of HIV, HBV and HCV infections. Rapid kits were more efficient in specificity with synthetic antigens along with high PPV than ELISA in most cases. Comparison between different ELISA kits revealed that Microlisa HIV and Hepalisa (J. Mitra & Co. Pvt. Ltd.; ERBA LISA HIV1 + 2, ERBA LISA Hepatitis B and ERBA LISA HCV (Transasia Bio-medicals Ltd. gives uniform result with good performance in terms of sensitivity, specificity, PPV, NPV and efficiency, whereas, Microlisa HCV (J. Mitra & Co. Pvt. Ltd., Microscreen HBsAg ELISA and INNOVA HCV (Span Diagnostics Ltd. did not perform well. Rapid kits were also having high degree of sensitivity and specificity (100% except in HIV Comb and HCV Comb (J. Mitra & Co. Pvt. Ltd.. The kit efficiency didn’t vary significantly among different companies and lots in all the cases except for HCV ELISA showing statistically significant variation (p  Conclusions ELISA is a good screening assay for markers of HIV, HBV and HCV infections. Rapid tests are useful for

  17. A comparative analysis of costs of single and dual rapid HIV and syphilis diagnostics: results from a randomised controlled trial in Colombia.

    Science.gov (United States)

    Obure, Carol Dayo; Gaitan-Duarte, Hernando; Losada Saenz, Ricardo; Gonzalez, Lina; Angel-Muller, Edith; Laverty, Maura; Perez, Freddy

    2017-11-01

    HIV and congenital syphilis are major public health burdens contributing to substantial perinatal morbidity and mortality globally. Although studies have reported on the costs and cost-effectiveness of rapid diagnostic tests (RDTs) for syphilis screening within antenatal care in a number of resource-constrained settings, empirical evidence on country-specific cost and estimates of single RDTs compared with dual RDTs for HIV and syphilis are limited. A cluster randomised controlled study design was used to compare the incremental costs of two testing algorithms: (1) single RDTs for HIV and syphilis and (2) dual RDTs for HIV and syphilis, in 12 health facilities in Bogota and Cali, Colombia. The costs of single HIV and syphilis RDTs and dual HIV and syphilis RDTs were collected from each of the health facilities. The economic costs per woman tested for HIV and syphilis and costs per woman treated for syphilis defined as the total costs required to test and treat one woman for syphilis were estimated. A total of 2214 women were tested in the study facilities. Cost per pregnant woman tested and cost per woman treated for syphilis were US$10.26 and US$607.99, respectively in the single RDT arm. For the dual RDTs, the cost per pregnant woman tested for HIV and syphilis and cost per woman treated for syphilis were US$15.89 and US$1859.26, respectively. Overall costs per woman tested for HIV and syphilis and cost per woman treated for syphilis were lower in Cali compared with Bogota across both intervention arms. Staff costs accounted for the largest proportion of costs while treatment costs comprised <1% of the preventive programme. Findings show lower average costs for single RDTs compared with dual RDTs with costs sensitive to personnel costs and the scale of output at the health facilities. NCT02454816; results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  18. Evaluation of rapid immuno chromatographic assay kit using monoclonal mpt64 antibodies for identification of mycobacterium tuberculosis complex

    International Nuclear Information System (INIS)

    Satti, L.; Ikram, A.; Malik, N.

    2010-01-01

    To evaluate the performance of rapid immuno chromatographic kit MPT64 Ag for the identification of Mycobacterium tuberculosis complex from various Mycobacterium tuberculosis culture positive specimens. Department of Microbiology, Armed Forces Institute of Pathology Rawalpindi, from August 2008 through March 2009. Eighty four Mycobacterium tuberculosis positive cultures on I BACTEC 460 and MGIT 960, one ATCC 25177 MTB strain, three institutional control MTB strains, two institutional control MOTT strains and 20 different bacterial isolates were tested. Tests were performed according to the instructional manual. Out of total 84 tested samples, MPT64 showed positive result in 80 cultures. Only four positive cultures did not display any band on MPT64 kit. These four strains were reconfirmed as Mycobacterium tuberculosis by PCR method. MOTT control strains and all the 20 bacterial isolates were negative for band. The sensitivity and specificity of ICT assay in our study was 95.2% and 100% respectively. Rapid MPT64 Kit is a good diagnostic tool to differentiate between Mycobacterium tuberculosis complex and MOTT with 100% specificity. The technique is simple and can provide prompt information to the clinicians to initiate early and appropriate antituberculosis therapy. (author)

  19. Assessing stakeholder perceptions of the acceptability and feasibility of national scale-up for a dual HIV/syphilis rapid diagnostic test in Malawi.

    Science.gov (United States)

    Maddox, Brandy L Peterson; Wright, Shauntā S; Namadingo, Hazel; Bowen, Virginia B; Chipungu, Geoffrey A; Kamb, Mary L

    2017-12-01

    The WHO recommends pregnant women receive both HIV and syphilis testing at their first antenatal care visit, as untreated maternal infections can lead to severe, adverse pregnancy outcomes. One strategy for increasing testing for both HIV and syphilis is the use of point-of-care (rapid) diagnostic tests that are simple, proven effective and inexpensive. In Malawi, pregnant women routinely receive HIV testing, but only 10% are tested for syphilis at their first antenatal care visit. This evaluation explores stakeholder perceptions of a novel, dual HIV/syphilis rapid diagnostic test and potential barriers to national scale-up of the dual test in Malawi. During June and July 2015, we conducted 15 semistructured interviews with 25 healthcare workers, laboratorians, Ministry of Health leaders and partner agency representatives working in prevention of mother-to-child transmission in Malawi. We asked stakeholders about the importance of a dual rapid diagnostic test, concerns using and procuring the dual test and recommendations for national expansion. Stakeholders viewed the test favourably, citing the importance of a dual rapid test in preventing missed opportunities for syphilis diagnosis and treatment, improving infant outcomes and increasing syphilis testing coverage. Primary technical concerns were about the additional procedural steps needed to perform the test, the possibility that testers may not adhere to required waiting times before interpreting results and difficulty reading and interpreting test results. Stakeholders thought national scale-up would require demonstration of cost-savings, uniform coordination, revisions to testing guidelines and algorithms, training of testers and a reliable supply chain. Stakeholders largely support implementation of a dual HIV/syphilis rapid diagnostic test as a feasible alternative to current antenatal testing. Scale-up will require addressing perceived barriers; negotiating changes to existing algorithms and guidelines

  20. Age-associated changes in monocyte and innate immune activation markers occur more rapidly in HIV infected women.

    Directory of Open Access Journals (Sweden)

    Genevieve E Martin

    Full Text Available Aging is associated with immune dysfunction and the related development of conditions with an inflammatory pathogenesis. Some of these immune changes are also observed in HIV infection, but the interaction between immune changes with aging and HIV infection are unknown. Whilst sex differences in innate immunity are recognized, little research into innate immune aging has been performed on women.This cross-sectional study of HIV positive and negative women used whole blood flow cytometric analysis to characterize monocyte and CD8(+ T cell subsets. Plasma markers of innate immune activation were measured using standard ELISA-based assays.HIV positive women exhibited elevated plasma levels of the innate immune activation markers CXCL10 (p<0.001, soluble CD163 (sCD163, p = 0.001, sCD14 (p = 0.022, neopterin (p = 0.029 and an increased proportion of CD16(+ monocytes (p = 0.009 compared to uninfected controls. Levels of the innate immune aging biomarkers sCD163 and the proportion of CD16(+ monocytes were equivalent to those observed in HIV negative women aged 14.5 and 10.6 years older, respectively. CXCL10 increased with age at an accelerated rate in HIV positive women (p = 0.002 suggesting a synergistic effect between HIV and aging on innate immune activation. Multivariable modeling indicated that age-related increases in innate immune biomarkers CXCL10 and sCD163 are independent of senescent changes in CD8(+ T lymphocytes.Quantifying the impact of HIV on immune aging reveals that HIV infection in women confers the equivalent of a 10-14 year increase in the levels of innate immune aging markers. These changes may contribute to the increased risk of inflammatory age-related diseases in HIV positive women.

  1. Age-associated changes in monocyte and innate immune activation markers occur more rapidly in HIV infected women.

    Science.gov (United States)

    Martin, Genevieve E; Gouillou, Maelenn; Hearps, Anna C; Angelovich, Thomas A; Cheng, Allen C; Lynch, Fiona; Cheng, Wan-Jung; Paukovics, Geza; Palmer, Clovis S; Novak, Richard M; Jaworowski, Anthony; Landay, Alan L; Crowe, Suzanne M

    2013-01-01

    Aging is associated with immune dysfunction and the related development of conditions with an inflammatory pathogenesis. Some of these immune changes are also observed in HIV infection, but the interaction between immune changes with aging and HIV infection are unknown. Whilst sex differences in innate immunity are recognized, little research into innate immune aging has been performed on women. This cross-sectional study of HIV positive and negative women used whole blood flow cytometric analysis to characterize monocyte and CD8(+) T cell subsets. Plasma markers of innate immune activation were measured using standard ELISA-based assays. HIV positive women exhibited elevated plasma levels of the innate immune activation markers CXCL10 (p<0.001), soluble CD163 (sCD163, p = 0.001), sCD14 (p = 0.022), neopterin (p = 0.029) and an increased proportion of CD16(+) monocytes (p = 0.009) compared to uninfected controls. Levels of the innate immune aging biomarkers sCD163 and the proportion of CD16(+) monocytes were equivalent to those observed in HIV negative women aged 14.5 and 10.6 years older, respectively. CXCL10 increased with age at an accelerated rate in HIV positive women (p = 0.002) suggesting a synergistic effect between HIV and aging on innate immune activation. Multivariable modeling indicated that age-related increases in innate immune biomarkers CXCL10 and sCD163 are independent of senescent changes in CD8(+) T lymphocytes. Quantifying the impact of HIV on immune aging reveals that HIV infection in women confers the equivalent of a 10-14 year increase in the levels of innate immune aging markers. These changes may contribute to the increased risk of inflammatory age-related diseases in HIV positive women.

  2. Inhibition of human immunodeficiency virus (HIV) infection in vitro by anticarbohydrate monoclonal antibodies: peripheral glycosylation of HIV envelope glycoprotein gp120 may be a target for virus neutralization

    DEFF Research Database (Denmark)

    Hansen, J E; Clausen, H; Nielsen, C

    1990-01-01

    Carbohydrate structures are often involved in the initial adhesion of pathogens to target cells. In the present study, a panel of anticarbohydrate monoclonal antibodies (MAbs) was tested for their ability to inhibit in vitro human immunodeficiency virus infectivity. MAbs against three different N......- and O-linked carbohydrate epitopes (LeY, A1, and sialyl-Tn) were able to block infection by cell-free virus as well as inhibit syncytium formation. Inhibition of virus infectivity was independent of virus strain (HTLVIIIB or patient isolate SSI-002), the cell line used for virus propagation (H9 or MT4...

  3. Probing hydrogen bonds in the antibody-bound HIV-1 gp120 V3 loop by solid state NMR REDOR measurements

    Energy Technology Data Exchange (ETDEWEB)

    Balbach, John J. [National Institutes of Health, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases (United States); Yang Jun; Weliky, David P. [Michigan State University, Department of Chemistry (United States); Steinbach, Peter J. [National Institutes of Health, Center for Molecular Modeling, Center for Information Technology (United States); Tugarinov, Vitali; Anglister, Jacob [Weizmann Institute of Science, Department of Structural Biology (Israel); Tycko, Robert [National Institutes of Health, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases (United States)

    2000-04-15

    We describe solid state NMR measurements on frozen solutions of the complex of the 24-residue HIV-1 gp120 V3 loop peptide RP135 with the Fab fragment of the anti-gp120 antibody 0.5{beta}, using rotational echo double resonance (REDOR). In order to probe possible hydrogen bonding between arginine side chains and glycine backbone carbonyls in the region of the conserved Gly-Pro-Gly-Arg (GPGR) motif of the V3 loop, RP135 samples were prepared with {sup 15}N labels at the {eta} nitrogen positions of arginine side chains and {sup 13}C labels at glycine carbonyl positions and {sup 13}C-detected {sup 13}C-{sup 15}N REDOR measurements were performed on peptide/antibody complexes of these labeled samples. Such hydrogen bonding was previously observed in a crystal structure of the V3 loop peptide/antibody complex RP142/59.1 [Ghiara et al. (1994) Science, 264, 82-85], but is shown by the REDOR measurements to be absent in the RP135/0.5{beta} complex. These results confirm the antibody-dependent conformational differences in the GPGR motif suggested by previously reported solid state NMR measurements of {phi} and {psi} backbone dihedral angles in the RP135/0.5{beta} complex. In addition, we describe REDOR measurements on the helical synthetic peptide MB(i+4)EK in frozen solution that establish our ability to detect {sup 13}C-{sup 15}N dipole-dipole couplings in the distance range appropriate to these hydrogen bonding studies. We also report the results of molecular modeling calculations on the central portion RP135, using a combination of the solid state NMR restraints of Weliky et al. [Nat. Struct. Biol., 6, 141-145, 1999] and the liquid state NMR restraints of Tugarinov et al. (Nat. Struct. Biol., 6, 331-335, 1999]. The dynamics calculations demonstrate the mutual compatibility of the two sets of experimental structural restraints and reduce ambiguities in the solid state NMR restraints that result from symmetry and signal-to-noise considerations.

  4. Probing hydrogen bonds in the antibody-bound HIV-1 gp120 V3 loop by solid state NMR REDOR measurements

    International Nuclear Information System (INIS)

    Balbach, John J.; Yang Jun; Weliky, David P.; Steinbach, Peter J.; Tugarinov, Vitali; Anglister, Jacob; Tycko, Robert

    2000-01-01

    We describe solid state NMR measurements on frozen solutions of the complex of the 24-residue HIV-1 gp120 V3 loop peptide RP135 with the Fab fragment of the anti-gp120 antibody 0.5β, using rotational echo double resonance (REDOR). In order to probe possible hydrogen bonding between arginine side chains and glycine backbone carbonyls in the region of the conserved Gly-Pro-Gly-Arg (GPGR) motif of the V3 loop, RP135 samples were prepared with 15 N labels at the η nitrogen positions of arginine side chains and 13 C labels at glycine carbonyl positions and 13 C-detected 13 C- 15 N REDOR measurements were performed on peptide/antibody complexes of these labeled samples. Such hydrogen bonding was previously observed in a crystal structure of the V3 loop peptide/antibody complex RP142/59.1 [Ghiara et al. (1994) Science, 264, 82-85], but is shown by the REDOR measurements to be absent in the RP135/0.5β complex. These results confirm the antibody-dependent conformational differences in the GPGR motif suggested by previously reported solid state NMR measurements of φ and Ψ backbone dihedral angles in the RP135/0.5β complex. In addition, we describe REDOR measurements on the helical synthetic peptide MB(i+4)EK in frozen solution that establish our ability to detect 13 C- 15 N dipole-dipole couplings in the distance range appropriate to these hydrogen bonding studies. We also report the results of molecular modeling calculations on the central portion RP135, using a combination of the solid state NMR restraints of Weliky et al. [Nat. Struct. Biol., 6, 141-145, 1999] and the liquid state NMR restraints of Tugarinov et al. (Nat. Struct. Biol., 6, 331-335, 1999]. The dynamics calculations demonstrate the mutual compatibility of the two sets of experimental structural restraints and reduce ambiguities in the solid state NMR restraints that result from symmetry and signal-to-noise considerations

  5. Acceptability of using electronic vending machines to deliver oral rapid HIV self-testing kits: a qualitative study.

    Directory of Open Access Journals (Sweden)

    Sean D Young

    Full Text Available Rates of unrecognized HIV infection are significantly higher among Latino and Black men who have sex with men (MSM. Policy makers have proposed that HIV self-testing kits and new methods for delivering self-testing could improve testing uptake among minority MSM. This study sought to conduct qualitative assessments with MSM of color to determine the acceptability of using electronic vending machines to dispense HIV self-testing kits.African American and Latino MSM were recruited using a participant pool from an existing HIV prevention trial on Facebook. If participants expressed interest in using a vending machine to receive an HIV self-testing kit, they were emailed a 4-digit personal identification number (PIN code to retrieve the test from the machine. We followed up with those who had tested to assess their willingness to participate in an interview about their experience.Twelve kits were dispensed and 8 interviews were conducted. In general, participants expressed that the vending machine was an acceptable HIV test delivery method due to its novelty and convenience.Acceptability of this delivery model for HIV testing kits was closely associated with three main factors: credibility, confidentiality, and convenience. Future research is needed to address issues, such as user-induced errors and costs, before scaling up the dispensing method.

  6. Acceptability of using electronic vending machines to deliver oral rapid HIV self-testing kits: a qualitative study.

    Science.gov (United States)

    Young, Sean D; Daniels, Joseph; Chiu, ChingChe J; Bolan, Robert K; Flynn, Risa P; Kwok, Justin; Klausner, Jeffrey D

    2014-01-01

    Rates of unrecognized HIV infection are significantly higher among Latino and Black men who have sex with men (MSM). Policy makers have proposed that HIV self-testing kits and new methods for delivering self-testing could improve testing uptake among minority MSM. This study sought to conduct qualitative assessments with MSM of color to determine the acceptability of using electronic vending machines to dispense HIV self-testing kits. African American and Latino MSM were recruited using a participant pool from an existing HIV prevention trial on Facebook. If participants expressed interest in using a vending machine to receive an HIV self-testing kit, they were emailed a 4-digit personal identification number (PIN) code to retrieve the test from the machine. We followed up with those who had tested to assess their willingness to participate in an interview about their experience. Twelve kits were dispensed and 8 interviews were conducted. In general, participants expressed that the vending machine was an acceptable HIV test delivery method due to its novelty and convenience. Acceptability of this delivery model for HIV testing kits was closely associated with three main factors: credibility, confidentiality, and convenience. Future research is needed to address issues, such as user-induced errors and costs, before scaling up the dispensing method.

  7. Obtaining of a rapid diagnostic test for Cholera, based on latex particles coupled with a monoclonal antibody against Vibrio cholera O1 lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Fátima Reyes-López

    2015-08-01

    Full Text Available Cholera is an acute contagious intestinal disease caused by ingestion of food or water contaminated with O1 and O139 serotypes of the bacterium Vibrio cholerae. Cholera is characterized by abundant secretory diarrhea leading to dehydration. Death occurs within hours without treatment, so early diagnosis is very important, especially at the beginning of the disease, because it is difficult to differentiate from other acute diarrheal diseases. The diagnostic golden test is the stool culture; however, it does not guarantee a rapid detection of the disease. Rapid tests have been recently developed; they are based on test strips and agglutination with latex particles, which are very effective, but difficult to acquire for their high prices. The objective of this research was to obtain a quick assay based on latex particles coupled with a monoclonal antibody (mAb against V. cholerae O1 lipopolysaccharide obtained in Finlay Institute. Latex particles of 0.8 µm were used in a 10% suspension, and they were coupled to the mAb (0.25 mg/ml for 2 hours at 37°C. The sensitivity, specificity and performance were evaluated in 84 stool samples from patients with presumptive diagnosis of cholera. The diagnostic test obtained showed no cross-reactivity against no-O1 strains and other enteropathogens. Latex diagnostic test showed values of sensitivity, specificity and efficacy of 97.87; 97.29 and 97.6% respectively, very similar to the commercial diagnostic test CTK- Biotech. The latex reagent obtained can be used in the rapid diagnosis of the disease.

  8. Characterization of functional antibody and memory B-cell responses to pH1N1 monovalent vaccine in HIV-infected children and youth.

    Directory of Open Access Journals (Sweden)

    Donna J Curtis

    Full Text Available We investigated immune determinants of antibody responses and B-cell memory to pH1N1 vaccine in HIV-infected children.Ninety subjects 4 to <25 years of age received two double doses of pH1N1 vaccine. Serum and cells were frozen at baseline, after each vaccination, and at 28 weeks post-immunization. Hemagglutination inhibition (HAI titers, avidity indices (AI, B-cell subsets, and pH1N1 IgG and IgA antigen secreting cells (ASC were measured at baseline and after each vaccination. Neutralizing antibodies and pH1N1-specific Th1, Th2 and Tfh cytokines were measured at baseline and post-dose 1.At entry, 26 (29% subjects had pH1N1 protective HAI titers (≥1:40. pH1N1-specific HAI, neutralizing titers, AI, IgG ASC, IL-2 and IL-4 increased in response to vaccination (p<0.05, but IgA ASC, IL-5, IL-13, IL-21, IFNγ and B-cell subsets did not change. Subjects with baseline HAI ≥1:40 had significantly greater increases in IgG ASC and AI after immunization compared with those with HAI <1:40. Neutralizing titers and AI after vaccination increased with older age. High pH1N1 HAI responses were associated with increased IgG ASC, IFNγ, IL-2, microneutralizion titers, and AI. Microneutralization titers after vaccination increased with high IgG ASC and IL-2 responses. IgG ASC also increased with high IFNγ responses. CD4% and viral load did not predict the immune responses post-vaccination, but the B-cell distribution did. Notably, vaccine immunogenicity increased with high CD19+CD21+CD27+% resting memory, high CD19+CD10+CD27+% immature activated, low CD19+CD21-CD27-CD20-% tissue-like, low CD19+CD21-CD27-CD20-% transitional and low CD19+CD38+HLADR+% activated B-cell subsets.HIV-infected children on HAART mount a broad B-cell memory response to pH1N1 vaccine, which was higher for subjects with baseline HAI≥1:40 and increased with age, presumably due to prior exposure to pH1N1 or to other influenza vaccination/infection. The response to the vaccine was dependent

  9. Soil transmitted helminth infections are not associated with compromised antibody responses to previously administered measles and tetanus vaccines among HIV-1 infected, ART naïve Kenyan adults

    Directory of Open Access Journals (Sweden)

    Helen L. Storey

    2017-02-01

    Full Text Available In many regions of sub-Saharan Africa, both HIV and helminth infections are prevalent. HIV-1 (human immunodeficiency virus type 1 and helminth infections can both compromise immune responses in humans. To determine whether the presence of helminth infection or the treatment of helminth infection alters unstimulated vaccine responses among HIV-1 infected individuals, we conducted two nested serologic studies. Blood samples were collected for HIV disease monitoring and vaccine-specific serologic assays, while stool was evaluated by direct microscopy methods. We compared antibody responses to measles and tetanus vaccines in helminth-infected (Ascaris, Trichuris, hookworm and/or Schistosoma mansoni and uninfected adults 18 years and older (n = 100. We also compared measles and tetanus antibody responses in Ascaris only-infected adults receiving 400 mg albendazole daily for 3 days (n = 16 vs. placebo (n = 19 in a separate study. In both cohorts, over 70% of participants had measles and tetanus responses above the protective threshold. Prevalence of measles responses were similar between helminth-infected and uninfected individuals (82%, 95% CI: 71–93% vs 72%, 95% CI: 59–85%, as well as log10 tetanus antibody levels (−0.133 IU/mL vs −0.190 IU/mL, p > 0.05, and did not differ by helminth species. In the Ascaris-infected cohort, changes in measles responses and tetanus responses did not differ between those who received anthelminthic vs. placebo (p > 0.05 for both. In these studies, neither helminth infection, nor deworming, appeared to affect previously administered vaccine responsiveness in HIV-1 infected, ART naïve, adults in Kenya.

  10. Evaluation of an Immunochromatographic Test for Rapid and Reliable Serodiagnosis of Human Tularemia and Detection of Francisella tularensis-Specific Antibodies in Sera from Different Mammalian Species ▿

    Science.gov (United States)

    Splettstoesser, W.; Guglielmo-Viret, V.; Seibold, E.; Thullier, P.

    2010-01-01

    Tularemia is a highly contagious infectious zoonosis caused by the bacterial agent Francisella tularensis. Serology is still considered to be a cornerstone in tularemia diagnosis due to the low sensitivity of bacterial culture and the lack of standardization in PCR methodology for the direct identification of the pathogen. We developed a novel immunochromatographic test (ICT) to efficiently detect F. tularensis-specific antibodies in sera from humans and other mammalian species (nonhuman primate, pig, and rabbit). This new tool requires none or minimal laboratory equipment, and the results are obtained within 15 min. When compared to the method of microagglutination, which was shown to be more specific than the enzyme-linked immunosorbent assay, the ICT had a sensitivity of 98.3% (58 positive sera were tested) and a specificity of 96.5% (58 negative sera were tested) on human sera. On animal sera, the overall sensitivity was 100% (22 positive sera were tested) and specificity was also 100% (70 negative sera were tested). This rapid test preferentially detects IgG antibodies that may occur early in the course of human tularemia, but further evaluation with human sera is important to prove that the ICT can be a valuable field test to support a presumptive diagnosis of tularemia. The ICT can also be a useful tool to monitor successful vaccination with subunit vaccines or live vaccine strains containing lipopolysaccharide (e.g., LVS) and to detect seropositive individuals or animals in outbreak situations or in the context of epidemiologic surveillance programs in areas of endemicity as recently recommended by the World Health Organization. PMID:20220165

  11. A novel sandwich enzyme-linked immunosorbent assay with covalently bound monoclonal antibody and gold probe for sensitive and rapid detection of bovine β-lactoglobulin.

    Science.gov (United States)

    He, Shengfa; Li, Xin; Wu, Yong; Wu, Shandong; Wu, Zhihua; Yang, Anshu; Tong, Ping; Yuan, Juanli; Gao, Jinyan; Chen, Hongbing

    2018-06-01

    Bovine milk is a recognized allergenic food source with β-lactoglobulin (BLG) as its major allergen. Reliable detection of BLG epitopes can, therefore, be a useful marker for the presence of milk in processed food products, and for potential allergenicity. At the present, enzyme-linked immunosorbent assays (ELISA) for the detection of BLG are time-consuming and generally not specific to BLG IgE epitopes. In this study, the 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide-activated anti-BLG IgE epitope monoclonal antibody (mAb 1G9) was covalently bound onto the KOH-treated microtiter plate surface. Using this mAb-bound plate in sandwich combination with biotinylated anti-BLG polyclonal antibody-labeled gold nanoparticles, a linear dynamic range between 31.25 and 64 × 10 3  ng mL -1 with a limit of detection for BLG of 0.49 ng mL -1 was obtained, which is 32 times wider and 16 times more sensitive than conventional sandwich ELISA (sELISA). Total recovery of BLG in spiked food samples was found, without matrix effects. Also in partially hydrolyzed infant formulas, the allergenic BLG residues were detected quantitatively. Compared with conventional and commercial BLG detection sELISAs, our sELISA is reliable, highly BLG epitope-specific, user-friendly, and time-saving and allows accurate detection of potentially allergenic residues in different types of processed foods. This improved sELISA protocol can be easily extended to detect other well-identified and characterized food allergens. Graphical abstract IgE epitope mAb-bound plate in sandwich combination with gold probe for sensitive and rapid detection of bovine β-lactoglobulin and its potentially allergenic residues.

  12. An Outdated Notion of Antibody Specificity is One of the Major Detrimental Assumptions of the Structure-Based Reverse Vaccinology Paradigm, Which Prevented It from Helping to Develop an Effective HIV-1 Vaccine.

    Science.gov (United States)

    Van Regenmortel, Marc H V

    2014-01-01

    The importance of paradigms for guiding scientific research is explained with reference to the seminal work of Karl Popper and Thomas Kuhn. A prevalent paradigm, followed for more than a decade in HIV-1 vaccine research, which gave rise to the strategy known as structure-based reverse vaccinology is described in detail. Several reasons why this paradigm did not allow the development of an effective HIV-1 vaccine are analyzed. A major reason is the belief shared by many vaccinologists that antibodies possess a narrow specificity for a single epitope and are not polyspecific for a diverse group of potential epitopes. When this belief is abandoned, it becomes obvious that the one particular epitope structure observed during the crystallographic analysis of a neutralizing antibody-antigen complex does not necessarily reveal, which immunogenic structure should be used to elicit the same type of neutralizing antibody. In the physical sciences, scientific explanations are usually presented as logical deductions derived from a relevant law of nature together with certain initial conditions. In immunology, causal explanations in terms of a single cause acting according to a law of nature are not possible because numerous factors always play a role in bringing about an effect. The implications of this state of affairs for the rational design of HIV vaccines are outlined. An alternative approach to obtain useful scientific understanding consists in intervening empirically in the immune system and it is suggested that manipulating the system experimentally is needed to learn to control it and achieve protective immunity by vaccination.

  13. Teste rápido para detecção da infecção pelo HIV-1 em gestantes Rapid test to detect HIV-1 infection among pregnant women

    Directory of Open Access Journals (Sweden)

    Geraldo Duarte

    2001-03-01

    Full Text Available Objetivos: avaliar os resultados do teste de diagnóstico rápido da infecção pelo HIV-1 disponibilizado pelo Ministério da Saúde, para identificação de gestantes contaminadas por este vírus. Métodos: avaliação prospectiva de 443 gestantes sem teste sorológico para HIV no pré-natal, atendidas no Departamento de Ginecologia e Obstetrícia da Faculdade de Medicina de Ribeirão Preto-Universidade de São Paulo (HCFMRP-USP, entre fevereiro e junho de 2000. As amostras destas pacientes foram submetidas ao teste rápido imunocromatográfico, sendo comparadas com ELISA e confirmadas pela aglutinação. Resultados: dentre as 443 gestantes submetidas ao teste rápido (20,1% dos partos no período, 16 apresentaram resultados positivos (3,6%. Nenhuma amostra negativa pelo teste rápido foi positiva pelo ELISA. Entretanto, das 16 amostras positivas pelo teste rápido, duas foram negativas pelos testes confirmatórios. Logo, a sensibilidade do teste rápido foi de 100,0%, especificidade 99,5%, valor preditivo positivo 87,5% e valor preditivo negativo 100,0%. Conclusões: os resultados obtidos na avaliação do teste para o diagnóstico rápido da infecção pelo HIV-1 em gestantes revelaram sensibilidade, especificidade e valores preditivos que o credenciam como recurso extremamente importante na indicação de medidas que reduzem a transmissão perinatal desse vírus.Purpose: to evaluate the results of a rapid diagnostic test for HIV-1 infection made available by the Health Ministry for the identification of pregnant women contaminated by this virus. Methods: we evaluated prospectively 443 pregnant women with no prenatal serologic anti-HIV test seen at the Department of Gynecology and Obstetrics of the Faculty of Medicine of Ribeirão Preto, University of São Paulo, from February to June, 2000. Samples from these patients were submitted to the rapid immunochromatographic test, which was compared with ELISA and submitted to a confirmatory

  14. Development and testing of monoclonal antibody-based rapid immunodiagnostic test kits for direct detection of Vibrio cholerae O139 synonym Bengal.

    Science.gov (United States)

    Hasan, J A; Huq, A; Nair, G B; Garg, S; Mukhopadhyay, A K; Loomis, L; Bernstein, D; Colwell, R R

    1995-11-01

    We report on the development and testing of two monoclonal antibody-based rapid immunodiagnostic test kits, BengalScreen, a coagglutination test, and Bengal DFA, a direct fluorescent-antibody test, for direct detection of Vibrio cholerae O139 synonym Bengal in clinical and environmental specimens. The BengalScreen test requires less than 5 min to complete and can be used in the field. Bengal DFA, being more sensitive than BengalScreen, requires only one reagent and less than 20 min for detection and enumeration of V. cholerae O139 synonym Bengal. In tests for specificity, all 40 strains of V. cholerae O139 reacted with both test kits, whereas 157 strains of heterologous species examined did not, yielding 100% specificity in this study. A field trial was conducted in with both BengalScreen and Bengal DFA, and the results were compared with those obtained by conventional culture methods. BengalScreen demonstrated a sensitivity of 95%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 94%. Results obtained by Bengal DFA, on the other hand, were 100% sensitive and 100% specific and yielded 100% positive and negative predictive values compared with culture methods. In a second evaluation, 93 stool specimens from Mexico that were negative for V. cholerae O139 by culture were also tested with both the BengalScreen and Bengal DFA kits. None of the 93 specimens were positive for V. cholerae O139 by both tests. A concentration method was optimized for screening of environmental water samples for V. cholerae O139 synonym Bengal with rapid test kits. BengalScreen results were unequivocally positive when water samples contained at least 2.0 x 10(3) CFU/ml, whereas Bengal DFA demonstrated an unequivocally positive reaction when the water sample contained at least 1.5 x 10(2) CFU/ml. When Bengal DFA was compared with conventional culture methods for enumeration of V. cholerae O139 synonym Bengal organisms, no difference was observed.

  15. Case Report: HIV test misdiagnosis

    African Journals Online (AJOL)

    Case Study: HIV test misdiagnosis 124. Case Report: HIV ... A positive rapid HIV test does not require ... 3 College of Medicine - Johns Hopkins Research Project, Blantyre,. Malawi ... test results: a pilot study of three community testing sites.

  16. Dual rapid lateral flow immunoassay fingerstick wholeblood testing for syphilis and HIV infections is acceptable and accurate, Port-au-Prince, Haiti.

    Science.gov (United States)

    Bristow, Claire C; Severe, Linda; Pape, Jean William; Javanbakht, Marjan; Lee, Sung-Jae; Comulada, Warren Scott; Klausner, Jeffrey D

    2016-06-18

    Dual rapid tests for HIV and syphilis infections allow for detection of HIV infection and syphilis at the point-of-care. Those tests have been evaluated in laboratory settings and show excellent performance but have not been evaluated in the field. We evaluated the field performance of the SD BIOLINE HIV/Syphilis Duo test in Port-au-Prince, Haiti using whole blood fingerprick specimens. GHESKIO (Haitian Study Group for Kaposi's Sarcoma and Opportunistic Infections) clinic attendees 18 years of age or older were invited to participate. Venipuncture blood specimens were used for reference testing with standard commercially available tests for HIV and syphilis in Haiti. The sensitivity and specificity of the Duo test compared to the reference standard were calculated. The exact binomial method was used to determine 95 % confidence intervals (CI). Of 298 study participants, 237 (79.5 %) were female, of which 49 (20.7 %) were pregnant. For the HIV test component, the sensitivity and specificity were 99.2 % (95 % CI: 95.8 %, 100 %) and 97.0 % (95 % CI: 93.2 %, 99.0 %), respectively; and for the syphilis component were 96.5 % (95 % CI: 91.2 %, 99.0 %) and 90.8 % (95 % CI: 85.7 %, 94.6 %), respectively. In pregnant women, the sensitivity and specificity of the HIV test component were 93.3 % (95 % CI: 68.0 %, 99.8 %) and 94.1 % (95 % CI: 80.3 %, 99.3 %), respectively; and for the syphilis component were 100 % (95 % CI:81.5 %, 100 %) and 96.8 % (95 % CI:83.3 %, 99.9 %), respectively. The Standard Diagnostics BIOLINE HIV/Syphilis Duo dual test performed well in a field setting in Haiti and should be considered for wider use.

  17. Complement and the control of HIV infection: an evolving story.

    Science.gov (United States)

    Frank, Michael M; Hester, Christopher; Jiang, Haixiang

    2014-05-01

    Thirty years ago, investigators isolated and later determined the structure of HIV-1 and its envelope proteins. Using techniques that were effective with other viruses, they prepared vaccines designed to generate antibody or T-cell responses, but they were ineffective in clinical trials. In this article, we consider the role of complement in host defense against enveloped viruses, the role it might play in the antibody response and why complement has not controlled HIV-1 infection. Complement consists of a large group of cell-bound and plasma proteins that are an integral part of the innate immune system. They provide a first line of defense against microbes and also play a role in the immune response. Here we review the studies of complement-mediated HIV destruction and the role of complement in the HIV antibody response. HIV-1 has evolved a complex defense to prevent complement-mediated killing reviewed here. As part of these studies, we have discovered that HIV-1 envelope, on administration into animals, is rapidly broken down into small peptides that may prove to be very inefficient at provident the type of antigenic stimulation that leads to an effective immune response. Improving complement binding and stabilizing envelope may improve the vaccine response.

  18. Screening of HIV-1 Protease Using a Combination of an Ultra-High-Throughput Fluorescent-Based Assay and RapidFire Mass Spectrometry.

    Science.gov (United States)

    Meng, Juncai; Lai, Ming-Tain; Munshi, Vandna; Grobler, Jay; McCauley, John; Zuck, Paul; Johnson, Eric N; Uebele, Victor N; Hermes, Jeffrey D; Adam, Gregory C

    2015-06-01

    HIV-1 protease (PR) represents one of the primary targets for developing antiviral agents for the treatment of HIV-infected patients. To identify novel PR inhibitors, a label-free, high-throughput mass spectrometry (HTMS) assay was developed using the RapidFire platform and applied as an orthogonal assay to confirm hits identified in a fluorescence resonance energy transfer (FRET)-based primary screen of > 1 million compounds. For substrate selection, a panel of peptide substrates derived from natural processing sites for PR was evaluated on the RapidFire platform. As a result, KVSLNFPIL, a new substrate measured to have a ~ 20- and 60-fold improvement in k cat/K m over the frequently used sequences SQNYPIVQ and SQNYPIV, respectively, was identified for the HTMS screen. About 17% of hits from the FRET-based primary screen were confirmed in the HTMS confirmatory assay including all 304 known PR inhibitors in the set, demonstrating that the HTMS assay is effective at triaging false-positives while capturing true hits. Hence, with a sampling rate of ~7 s per well, the RapidFire HTMS assay enables the high-throughput evaluation of peptide substrates and functions as an efficient tool for hits triage in the discovery of novel PR inhibitors. © 2015 Society for Laboratory Automation and Screening.

  19. Functional Antibody Response Against V1V2 and V3 of HIV gp120 in the VAX003 and VAX004 Vaccine Trials.

    Science.gov (United States)

    Balasubramanian, Preetha; Williams, Constance; Shapiro, Mariya B; Sinangil, Faruk; Higgins, Keith; Nádas, Arthur; Totrov, Maxim; Kong, Xiang-Peng; Fiore-Gartland, Andrew J; Haigwood, Nancy L; Zolla-Pazner, Susan; Hioe, Catarina E

    2018-01-11

    Immunization with HIV AIDSVAX gp120 vaccines in the phase III VAX003 and VAX004 trials did not confer protection. To understand the shortcomings in antibody (Ab) responses induced by these vaccines, we evaluated the kinetics of Ab responses to the V1V2 and V3 regions of gp120 and the induction of Ab-mediated antiviral functions during the course of 7 vaccinations over a 30.5-month period. Plasma samples from VAX003 and VAX004 vaccinees and placebo recipients were measured for ELISA-binding Abs and for virus neutralization, Ab-dependent cellular phagocytosis (ADCP), and Ab-dependent cellular cytotoxicity (ADCC). Ab responses to V1V2 and V3 peaked after 3 to 4 immunizations and declined after 5 to 7 immunizations. The deteriorating responses were most evident against epitopes in the underside of the V1V2 β-barrel and in the V3 crown. Correspondingly, vaccinees demonstrated higher neutralization against SF162 pseudovirus sensitive to anti-V1V2 and anti-V3 Abs after 3 or 4 immunizations than after 7 immunizations. Higher levels of ADCP and ADCC were also observed at early or mid-time points as compared with the final time point. Hence, VAX003 and VAX004 vaccinees generated V1V2- and V3-binding Abs and functional Abs after 3 to 4 immunizations, but subsequent boosts did not maintain these responses.

  20. Complementary factors contributing to the rapid spread of HIV-I in sub-Saharan Africa: a review.

    Science.gov (United States)

    Nyindo, M

    2005-01-01

    To examine and establish complementary factors that contribute to the alarmingly high prevalence of HIV-1 in sub-Saharan Africa (SSA) in order to create awareness and suggest possible measures to avert the spread of the pandemic. Review of literature via Medline, the Internet, articles in refereed journals, and un-refereed features from the East Africa media houses and personal communications. Most published data from 1981 to September 2004 found to have revealed an impact on the spread of HIV-1 in SSA were included in the review. Therefore, all selected articles were read and critically evaluated. Where possible the number of citations articles which had been received were sought to established the degree of impact. Abstracts of all articles identified were accessed, read and analysed to determined possible relevance to the spread of HIV-1. When relevance was established from the abstract the entire paper was read and important points were included in the review. A matrix was drawn to include all subtitles (e.g. polygamy, circumcision, poverty, etc). Below each subtitle all published works were included and prioritised. Published works that were found to have impact were included in the review. Finally a percent composite picture of all factors was drawn in an attempt to prioritise the factors, not withstanding the fact that most factors are interrelated and complementary. There are many reasons why the spread of HIV-1 in SSA has not been declining over the years. Main risk factors for HIV-1 infection and AIDS disease in SSA were found to include poverty, famine, low status of women in society, corruption, naive risk taking perception, resistance to sexual behaviour change, high prevalence of sexually transmitted infections (STI), internal conflicts and refugee status, antiquated beliefs, lack of recreational facilities, ignorance of individual's HIV status, child and adult prostitution, uncertainty of safety of blood intended for transfusion, widow inheritance

  1. gCUP: rapid GPU-based HIV-1 co-receptor usage prediction for next-generation sequencing.

    Science.gov (United States)

    Olejnik, Michael; Steuwer, Michel; Gorlatch, Sergei; Heider, Dominik

    2014-11-15

    Next-generation sequencing (NGS) has a large potential in HIV diagnostics, and genotypic prediction models have been developed and successfully tested in the recent years. However, albeit being highly accurate, these computational models lack computational efficiency to reach their full potential. In this study, we demonstrate the use of graphics processing units (GPUs) in combination with a computational prediction model for HIV tropism. Our new model named gCUP, parallelized and optimized for GPU, is highly accurate and can classify >175 000 sequences per second on an NVIDIA GeForce GTX 460. The computational efficiency of our new model is the next step to enable NGS technologies to reach clinical significance in HIV diagnostics. Moreover, our approach is not limited to HIV tropism prediction, but can also be easily adapted to other settings, e.g. drug resistance prediction. The source code can be downloaded at http://www.heiderlab.de d.heider@wz-straubing.de. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  2. Comparison of a Clinical Prediction Rule and a LAM Antigen-Detection Assay for the Rapid Diagnosis of TBM in a High HIV Prevalence Setting

    Science.gov (United States)

    Patel, Vinod B.; Singh, Ravesh; Connolly, Cathy; Kasprowicz, Victoria; Zumla, Allimudin; Ndungu, Thumbi; Dheda, Keertan

    2010-01-01

    Background/Objective The diagnosis of tuberculous meningitis (TBM) in resource poor TB endemic environments is challenging. The accuracy of current tools for the rapid diagnosis of TBM is suboptimal. We sought to develop a clinical-prediction rule for the diagnosis of TBM in a high HIV prevalence setting, and to compare performance outcomes to conventional diagnostic modalities and a novel lipoarabinomannan (LAM) antigen detection test (Clearview-TB®) using cerebrospinal fluid (CSF). Methods Patients with suspected TBM were classified as definite-TBM (CSF culture or PCR positive), probable-TBM and non-TBM. Results Of the 150 patients, 84% were HIV-infected (median [IQR] CD4 count = 132 [54; 241] cells/µl). There were 39, 55 and 54 patients in the definite, probable and non-TBM groups, respectively. The LAM sensitivity and specificity (95%CI) was 31% (17;48) and 94% (85;99), respectively (cut-point ≥0.18). By contrast, smear-microscopy was 100% specific but detected none of the definite-TBM cases. LAM positivity was associated with HIV co-infection and low CD4 T cell count (CD4200 cells/µl; p = 0.03). The sensitivity and specificity in those with a CD4<100 cells/µl was 50% (27;73) and 95% (74;99), respectively. A clinical-prediction rule ≥6 derived from multivariate analysis had a sensitivity and specificity (95%CI) of 47% (31;64) and 98% (90;100), respectively. When LAM was combined with the clinical-prediction-rule, the sensitivity increased significantly (p<0.001) to 63% (47;68) and specificity remained high at 93% (82;98). Conclusions Despite its modest sensitivity the LAM ELISA is an accurate rapid rule-in test for TBM that has incremental value over smear-microscopy. The rule-in value of LAM can be further increased by combination with a clinical-prediction rule, thus enhancing the rapid diagnosis of TBM in HIV-infected persons with advanced immunosuppression. PMID:21203513

  3. Postvaccination C-Reactive Protein and C5/gp41732-744 Antibody Level Fold-Changes Over Baseline Are Independent Predictors of Therapeutic HIV Vaccine Effect in a Phase 2 Clinical Study of Vacc-4x.

    Science.gov (United States)

    Huang, Yunda; Zhang, Lily; Jolliffe, Darren; Sanchez, Brittany; Stjernholm, Grete; Jelmert, Øyvind; Ökvist, Mats; Sommerfelt, Maja A

    2018-03-01

    Therapeutic vaccination has the potential to contribute to functional HIV cure strategies. However, to show functional HIV cure, study participants must be taken off combination antiretroviral therapy (cART). The availability of suitable biomarkers that can predict viral load (VL) or CD4 count outcomes following therapeutic HIV vaccination would reduce the risks associated with cART interruption in such studies. This report sought to determine baseline and postvaccination biomarker predictors of vaccine effect (VE) on VL and CD4 counts following cART interruption in a double-blind, randomized phase 2 study of the peptide-based therapeutic HIV vaccine, Vacc-4x (n = 93), versus placebo (n = 43). Antibody responses to a novel envelope glycoprotein antigen, C5/gp41 732-744 , and three safety marker measurements [C-reactive protein (CRP), white blood cell, and lactate dehydrogenase] were considered. Interaction tests in univariate and multivariate linear regression models were used to estimate the effect of biomarkers on VE, defined as the VL or CD4 count difference in Vacc-4x versus placebo groups. The reported q-values (considered significant for hypothesis-generating purposes if ≤0.2) accounted for multiple comparisons using the false discovery rate method. Data were analyzed from all available 58 Vacc-4x and 25 placebo recipients before cART resumption. Lower postvaccination fold-change over baseline of CRP concentration (interaction p- (q-) value = 0.005 (0.11) for VL) and higher fold-change of anti-C5/gp41 732-744 antibody levels (0.005 (0.11) for VL and 0.009 (0.20) for CD4) were associated with Vacc-4x benefit. These findings suggest potential roles for inflammation and immune activation markers in predicting therapeutic HIV VE.

  4. Comparison of Multispot EIA with Western blot for confirmatory serodiagnosis of HIV.

    Science.gov (United States)

    Torian, Lucia V; Forgione, Lisa A; Punsalang, Amado E; Pirillo, Robert E; Oleszko, William R

    2011-12-01

    Recent improvements in the sensitivity of immunoassays (IA) used for HIV screening, coupled with increasing recognition of the importance of rapid point-of-care testing, have led to proposals to adjust the algorithm for serodiagnosis of HIV so that screening and confirmation can be performed using a dual or triple IA sequence that does not require Western blotting for confirmation. One IA that has been proposed as a second or confirmatory test is the Bio-Rad Multispot(®) Rapid HIV-1/HIV-2 Test. This test would have the added advantage of differentiating between HIV-1 and HIV-2 antibodies. To compare the sensitivity and type-specificity of an algorithm combining a 3rd generation enzyme immunoassay (EIA) followed by a confirmatory Multispot with the conventional algorithm that combines a 3rd generation EIA (Bio-Rad GS HIV-1/HIV-2 Plus O EIA) followed by confirmatory Western blot (Bio-Rad GS HIV-1 WB). 8760 serum specimens submitted for HIV testing to the New York City Public Health Laboratory between May 22, 2007, and April 30, 2010, tested repeatedly positive on 3rd generation HIV-1-2+O EIA screening and received parallel confirmatory testing by WB and Multispot (MS). 8678/8760 (99.1%) specimens tested WB-positive; 82 (0.9%) tested WB-negative or indeterminate (IND). 8690/8760 specimens (99.2%) tested MS-positive, of which 14 (17.1%) had been classified as negative or IND by WB. Among the HIV-1 WB-positive specimens, MS classified 26 (0.29%) as HIV-2. Among the HIV-1 WB negative and IND, MS detected 12 HIV-2. MS detected an additional 14 HIV-1 infections among WB negative or IND specimens, differentiated 26 HIV-1 WB positives as HIV-2, and detected 12 additional HIV-2 infections among WB negative/IND. A dual 3rd generation EIA algorithm incorporating MS had equivalent HIV-1 sensitivity to the 3rd generation EIA-WB algorithm and had the added advantage of detecting 12 HIV-2 specimens that were not HIV-1 WB cross-reactors. In this series an algorithm using EIA

  5. Adolescents’ experience of a rapid HIV self-testing device in youth-friendly clinic settings in Cape Town South Africa: a cross-sectional community based usability study

    Science.gov (United States)

    Smith, Philip; Wallace, Melissa; Bekker, Linda-Gail

    2016-01-01

    Abstract Introduction: Since HIV testing in South African adolescents and young adults is sub-optimal, the objective of the current study was to investigate the feasibility and acceptability of an HIV rapid self-testing device in adolescents and young people at the Desmond Tutu HIV Foundation Youth Centre and Mobile Clinic. Methods: Self-presenting adolescents and young adults were invited to participate in a study investigating the fidelity, usability and acceptability of the AtomoRapid HIV Rapid self-testing device. Trained healthcare workers trained participants to use the device before the participant conducted the HIV self-test with device usage instructions. The healthcare worker then conducted a questionnaire-based survey to assess outcomes. Results: Of the 224 enrolled participants between 16 and 24 years of age, 155 (69,2%) were female. Overall, fidelity was high; 216 (96,4%) participants correctly completed the test and correctly read and interpreted the HIV test result. There were eight (3,6%) user errors overall; six participants failed to prick their finger even though the lancet fired correctly. There were two user errors where participants failed to use the capillary tube correctly. Participants rated acceptability and usability highly, with debut testers giving significantly higher ratings for both. Younger participants gave significantly higher ratings of acceptability. Conclusions: Adolescents and young adults found HIV self-testing highly acceptable with the AtomoRapid and they used the device accurately. Further research should investigate how, where and when to deploy HIV self-testing as a means to accompany existing strategies in reaching the UNAIDS goal to test 90% of all individuals worldwide. PMID:28406597

  6. Adolescents' experience of a rapid HIV self-testing device in youth-friendly clinic settings in Cape Town South Africa: a cross-sectional community based usability study.

    Science.gov (United States)

    Smith, Philip; Wallace, Melissa; Bekker, Linda-Gail

    2016-12-23

    Introduction : Since HIV testing in South African adolescents and young adults is sub-optimal, the objective of the current study was to investigate the feasibility and acceptability of an HIV rapid self-testing device in adolescents and young people at the Desmond Tutu HIV Foundation Youth Centre and Mobile Clinic. Methods : Self-presenting adolescents and young adults were invited to participate in a study investigating the fidelity, usability and acceptability of the AtomoRapid HIV Rapid self-testing device. Trained healthcare workers trained participants to use the device before the participant conducted the HIV self-test with device usage instructions. The healthcare worker then conducted a questionnaire-based survey to assess outcomes. Results : Of the 224 enrolled participants between 16 and 24 years of age, 155 (69,2%) were female. Overall, fidelity was high; 216 (96,4%) participants correctly completed the test and correctly read and interpreted the HIV test result. There were eight (3,6%) user errors overall; six participants failed to prick their finger even though the lancet fired correctly. There were two user errors where participants failed to use the capillary tube correctly. Participants rated acceptability and usability highly, with debut testers giving significantly higher ratings for both. Younger participants gave significantly higher ratings of acceptability. Conclusions : Adolescents and young adults found HIV self-testing highly acceptable with the AtomoRapid and they used the device accurately. Further research should investigate how, where and when to deploy HIV self-testing as a means to accompany existing strategies in reaching the UNAIDS goal to test 90% of all individuals worldwide.

  7. A gp41-based heteroduplex mobility assay provides rapid and accurate assessment of intrasubtype epidemiological linkage in HIV type 1 heterosexual transmission Pairs.

    Science.gov (United States)

    Manigart, Olivier; Boeras, Debrah I; Karita, Etienne; Hawkins, Paulina A; Vwalika, Cheswa; Makombe, Nathan; Mulenga, Joseph; Derdeyn, Cynthia A; Allen, Susan; Hunter, Eric

    2012-12-01

    A critical step in HIV-1 transmission studies is the rapid and accurate identification of epidemiologically linked transmission pairs. To date, this has been accomplished by comparison of polymerase chain reaction (PCR)-amplified nucleotide sequences from potential transmission pairs, which can be cost-prohibitive for use in resource-limited settings. Here we describe a rapid, cost-effective approach to determine transmission linkage based on the heteroduplex mobility assay (HMA), and validate this approach by comparison to nucleotide sequencing. A total of 102 HIV-1-infected Zambian and Rwandan couples, with known linkage, were analyzed by gp41-HMA. A 400-base pair fragment within the envelope gp41 region of the HIV proviral genome was PCR amplified and HMA was applied to both partners' amplicons separately (autologous) and as a mixture (heterologous). If the diversity between gp41 sequences was low (<5%), a homoduplex was observed upon gel electrophoresis and the transmission was characterized as having occurred between partners (linked). If a new heteroduplex formed, within the heterologous migration, the transmission was determined to be unlinked. Initial blind validation of gp-41 HMA demonstrated 90% concordance between HMA and sequencing with 100% concordance in the case of linked transmissions. Following validation, 25 newly infected partners in Kigali and 12 in Lusaka were evaluated prospectively using both HMA and nucleotide sequences. Concordant results were obtained in all but one case (97.3%). The gp41-HMA technique is a reliable and feasible tool to detect linked transmissions in the field. All identified unlinked results should be confirmed by sequence analyses.

  8. Low knowledge and anecdotal use of unauthorized online HIV self-test kits among attendees at a street-based HIV rapid testing programme in Spain.

    Science.gov (United States)

    Belza, M José; Figueroa, Carmen; Rosales-Statkus, M Elena; Ruiz, Mónica; Vallejo, Fernando; de la Fuente, Luis

    2014-08-01

    The objectives of this study were to estimate the percentage of potential users who know that unauthorized HIV self-tests can be purchased online and the percentage of those who have already used them, and to determine socio-demographic and behavioural correlates. A self-administered questionnaire was employed to collect data from attendees at a street-based HIV testing programme. Logistic regression for rare events was performed. Of the 3340 participants, 5.3% (95% confidence interval (CI) 4.5-6.0%) had knowledge of self-tests being sold online and 7.5% (95% CI 6.6-8.5%) thought they existed but had never seen them; only 0.6% (95% CI 0.3-0.9%) had ever used one. Knowing that self-tests are sold online (odds ratio (OR) 3.6, 95% CI 2.4-5.4) and using them (OR 7.3, 95% CI 2.2-23.8) were associated with having undergone more than two previous HIV tests. Use was also associated with being neither Spanish nor Latin American (OR 3.8, 95% CI 1.2-12.0) and with having a university degree (OR 0.2, 95% CI 0.1-0.7). At the time of the study, the impact on the population of issues related to the use of unauthorized tests was very low. However, media coverage following the approval of self-testing in the USA might have changed the situation. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Antibodies to H2a and H2b histones from the sera of HIV-infected patients catalyze site-specific degradation of these histones.

    Science.gov (United States)

    Baranova, Svetlana V; Dmitrienok, Pavel S; Ivanisenko, Nikita V; Buneva, Valentina N; Nevinsky, Georgy A

    2017-06-01

    Histones and their post-translational modifications have key roles in chromatin remodeling and gene transcription. Besides intranuclear functions, histones act as damage-associated molecules when they are released into the extracellular space. Administration of histones to animals leads to systemic inflammatory and toxic responses. Autoantibodies with enzymatic activities (abzymes) are distinctive features of some autoimmune and viral diseases. Electrophoretically homogeneous IgGs containing no canonical enzymes were isolated from the sera of HIV-infected patients by chromatography on several affinity sorbents including anti-histone Sepharose. In contrast to canonical proteases (trypsin, chymotrypsin, proteinase K), IgGs from HIV-infected patients specifically hydrolyzed only histones but not many other tested globular proteins. Using MALDI mass spectrometry the sites of H2a and H2b histone cleavage by anti-histone IgGs were determined for the first time. One cluster of H2a hydrolysis contains two major (↕) and four moderate (↓) cleavage sites: 31-H↓R↓L↓L↓R↕K G↕N-38. One major and two moderate sites of cleavage were revealed in the second cluster: 14-A↕KSRS↓SRA↓G-22. The third cluster corresponding to the H2a C-terminal part contains only five minor (†) sites of cleavage: 82-H†LQLAIRNDEELN†KLLG†RV†T†I-102. It was shown that two major and four moderate sites of cleavage were present in the main cluster of H2b hydrolysis: 46-K↕QvhpD↓TgiS↓SkA↓M↕GiM↓N-63. Two moderate sites of cleavage correspond to a relatively short 6-mer cluster: 12-K↓GskK↓A-17. The third relatively long 9-mer cluster contains one major and two minor sites of H2b cleavage: 80-L↕AHYN†KRS†T-88. In the nucleosome core particle, most of the major and moderate cleavage sites are located at the H2a/H2b interaction interface. Minor cleavage sites of H2a are involved in binding with H3 in the nucleosome core. Two moderate cleavage sites of H2b and one

  10. CCR5 antibodies HGS004 and HGS101 preferentially inhibit drug-bound CCR5 infection and restore drug sensitivity of Maraviroc-resistant HIV-1 in primary cells

    International Nuclear Information System (INIS)

    Latinovic, Olga; Reitz, Marvin; Le, Nhut M.; Foulke, James S.; Faetkenheuer, Gerd; Lehmann, Clara; Redfield, Robert R.; Heredia, Alonso

    2011-01-01

    R5 HIV-1 strains resistant to the CCR5 antagonist Maraviroc (MVC) can use drug-bound CCR5. We demonstrate that MVC-resistant HIV-1 exhibits delayed kinetics of coreceptor engagement and fusion during drug-bound versus free CCR5 infection of cell lines. Antibodies directed against the second extracellular loop (ECL2) of CCR5 had greater antiviral activity against MVC-bound compared to MVC-free CCR5 infection. However, in PBMCs, only ECL2 CCR5 antibodies HGS004 and HGS101, but not 2D7, inhibited infection by MVC resistant HIV-1 more potently with MVC-bound than with free CCR5. In addition, HGS004 and HGS101, but not 2D7, restored the antiviral activity of MVC against resistant virus in PBMCs. In flow cytometric studies, CCR5 binding by the HGS mAbs, but not by 2D7, was increased when PBMCs were treated with MVC, suggesting MVC increases exposure of the relevant epitope. Thus, HGS004 and HGS101 have antiviral mechanisms distinct from 2D7 and could help overcome MVC resistance.

  11. High prevalence of HIV-1 CRF01_AE viruses among female commercial sex workers residing in Surabaya, Indonesia.

    Science.gov (United States)

    Kotaki, Tomohiro; Khairunisa, Siti Qamariyah; Sukartiningrum, Septhia Dwi; Arfijanto, M Vitanata; Utsumi, Takako; Normalina, Irine; Handajani, Retno; Widiyanti, Prihartini; Rusli, Musofa; Rahayu, Retno Pudji; Lusida, Maria Inge; Hayashi, Yoshitake; Nasronudin; Kameoka, Masanori

    2013-01-01

    Human immunodeficiency virus (HIV) infection and acquired immune deficiency syndrome (AIDS) cause serious health problems and have an impact on the Indonesian economy. In addition, the rapid epidemic growth of HIV is continuing in Indonesia. Commercial sex plays a significant role in the spread of HIV; therefore, in order to reveal the current HIV prevalence rate among commercial sex workers (CSWs), we conducted an epidemiological study on HIV infection among CSWs residing in Surabaya, the capital of East Java province of Indonesia with large communities of CSWs. The prevalence of HIV infection among 200 CSWs was studied. In addition, the subtype of HIV type 1 (HIV-1) and the prevalence of other blood-borne viruses, hepatitis B virus (HBV), hepatitis C virus (HCV) and GB virus C (GBV-C), were studied. The prevalence rates of HIV, hepatitis B core antibody, hepatitis B surface antigen, anti-HCV antibodies and anti-GBV-C antibodies were 11%, 64%, 4%, 0.5% and 0% among CSWs involved in this study, respectively. HIV-1 CRF01_AE viral gene fragments were detected in most HIV-positive samples. In addition, most CSWs showed low awareness of sexually transmitted diseases and had unprotected sex with their clients. The HIV prevalence rate among CSWs was significantly higher than that among the general population in Indonesia (0.2-0.4%). In addition, CSWs were at a high risk of exposure to HBV, although chronic HBV infection was less frequently established. Our results suggest the necessity of efficient prevention programs for HIV and other blood-borne viral infections among CSWs in Surabaya, Indonesia.

  12. High prevalence of HIV-1 CRF01_AE viruses among female commercial sex workers residing in Surabaya, Indonesia.

    Directory of Open Access Journals (Sweden)

    Tomohiro Kotaki

    Full Text Available Human immunodeficiency virus (HIV infection and acquired immune deficiency syndrome (AIDS cause serious health problems and have an impact on the Indonesian economy. In addition, the rapid epidemic growth of HIV is continuing in Indonesia. Commercial sex plays a significant role in the spread of HIV; therefore, in order to reveal the current HIV prevalence rate among commercial sex workers (CSWs, we conducted an epidemiological study on HIV infection among CSWs residing in Surabaya, the capital of East Java province of Indonesia with large communities of CSWs.The prevalence of HIV infection among 200 CSWs was studied. In addition, the subtype of HIV type 1 (HIV-1 and the prevalence of other blood-borne viruses, hepatitis B virus (HBV, hepatitis C virus (HCV and GB virus C (GBV-C, were studied. The prevalence rates of HIV, hepatitis B core antibody, hepatitis B surface antigen, anti-HCV antibodies and anti-GBV-C antibodies were 11%, 64%, 4%, 0.5% and 0% among CSWs involved in this study, respectively. HIV-1 CRF01_AE viral gene fragments were detected in most HIV-positive samples. In addition, most CSWs showed low awareness of sexually transmitted diseases and had unprotected sex with their clients.The HIV prevalence rate among CSWs was significantly higher than that among the general population in Indonesia (0.2-0.4%. In addition, CSWs were at a high risk of exposure to HBV, although chronic HBV infection was less frequently established. Our results suggest the necessity of efficient prevention programs for HIV and other blood-borne viral infections among CSWs in Surabaya, Indonesia.

  13. Therapeutic Recombinant Monoclonal Antibodies

    Science.gov (United States)

    Bakhtiar, Ray

    2012-01-01

    During the last two decades, the rapid growth of biotechnology-derived techniques has led to a myriad of therapeutic recombinant monoclonal antibodies with significant clinical benefits. Recombinant monoclonal antibodies can be obtained from a number of natural sources such as animal cell cultures using recombinant DNA engineering. In contrast to…