Quantification of infectious HIV-1 plasma viral load using a boosted in vitro infection protocol.


:Methods currently used for HIV-1 viral load measurements are very sensitive, but cannot distinguish between infectious and noninfectious particles. Here we describe the development of a novel, sensitive, and highly reproducible method that allows rapid isolation and quantification of infectious particles from patient plasma. By immobilizing HIV-1 particles in human plasma to platelets using polybrene, we observed a 10- to 1000-fold increase in infectivity over infection protocols using free virus particles. Using this method, we evaluated infectivity in plasma from 52 patients at various disease stages. At plasma viral loads of 1000-10000 HIV-1 RNA copies/ml 18%, at 10,000-50,000 copies/ml 73%, at 50,000-100,000 copies/ml 90%, and above 100,000 copies 96% of cultures were positive. We found that infectious titers among patients vary distinctively but are characteristic for a patient over extended time periods. Furthermore, we demonstrate that by evaluating infectious titers in conjunction with total HIV RNA loads, subtle effects of treatment intervention on viremia levels can be detected. The immobilization procedure does not interfere with viral entry and does not restore the infectivity of neutralized virus. Therefore, this assay system can be utilized to investigate the influence of substances that specifically affect virion infectivity such as neutralizing antibodies, soluble CD4, or protease inhibitors. Measuring viral infectivity may thereby function as an additional, useful marker in monitoring disease progression and evaluating efficacy of antivirals in vivo.






Rusert P,Fischer M,Joos B,Leemann C,Kuster H,Flepp M,Bonhoeffer S,Günthard HF,Trkola A




Has Abstract


2004-08-15 00:00:00
















  • Adoptive transfer of infectious bronchitis virus primed alphabeta T cells bearing CD8 antigen protects chicks from acute infection.

    abstract::Infectious bronchitis virus (IBV) infection and associated illness may be dramatically modified by passive transfer of immune T lymphocytes. Lymphocytes collected 10 days postinfection were transferred to naive chicks before challenge with virus. As determined by respiratory illness and viral load, transfer of syngene...


    pub_type: 杂志文章


    authors: Seo SH,Pei J,Briles WE,Dzielawa J,Collisson EW

    更新日期:2000-03-30 00:00:00

  • Umbravirus-encoded proteins both stabilize heterologous viral RNA and mediate its systemic movement in some plant species.

    abstract::The proteins encoded by open reading frame 3 (ORF3) of the umbraviruses pea enation mosaic virus-2 and tobacco mottle virus, like that of groundnut rosette virus, mediated the movement of viral RNA through the phloem of infected Nicotiana benthamiana or N. clevelandii plants when they were expressed from chimeric toba...


    pub_type: 杂志文章


    authors: Ryabov EV,Robinson DJ,Taliansky M

    更新日期:2001-09-30 00:00:00

  • Hepatitis C virus RNA polymerase and NS5A complex with a SNARE-like protein.

    abstract::Hepatitis C virus (HCV) NS5A is a phosphoprotein that possesses a cryptic trans-activation activity. To investigate its potential role in viral replication, we searched for the cellular proteins interacting with NS5A protein by yeast two-hybrid screening of a human hepatocyte cDNA library. We identified a newly discov...


    pub_type: 杂志文章


    authors: Tu H,Gao L,Shi ST,Taylor DR,Yang T,Mircheff AK,Wen Y,Gorbalenya AE,Hwang SB,Lai MM

    更新日期:1999-10-10 00:00:00

  • Construction and characterisation of a full-length infectious molecular clone from a fast replicating, X4-tropic HIV-1 CRF02.AG primary isolate.

    abstract::Based on our previous analysis of HIV-1 isolates from Cameroon, we constructed a full-length infectious molecular clone from a primary isolate belonging to the CRF02.AG group of recombinant viruses which dominate the HIV-epidemic in West and Central Africa. The virus derived by transfection of the proviral clone pBD6-...


    pub_type: 杂志文章


    authors: Tebit DM,Zekeng L,Kaptué L,Kräusslich HG,Herchenröder O

    更新日期:2003-09-01 00:00:00

  • Cell killing by ultraviolet-inactivated human immunodeficiency virus.

    abstract::Extensive cell killing and cytopathology were observed within 24 hr after exposure of a clonal cell line of human T-4 lymphocytes (RH9) to culture supernatants containing human immunodeficiency virus (HIV). Ultraviolet-irradiated HIV-containing culture fluids were also capable of killing RH9 cells and of inducing spec...


    pub_type: 杂志文章


    authors: Rasheed S,Gottlieb AA,Garry RF

    更新日期:1986-10-30 00:00:00

  • Development of plaque assays for hepatitis C virus-JFH1 strain and isolation of mutants with enhanced cytopathogenicity and replication capacity.

    abstract::HCV culture in vitro results in massive cell death, which suggests the presence of HCV-induced cytopathic effects. Therefore, we investigated its mechanisms and viral nucleotide sequences involved in this effect using HCV-JFH1 cell culture and a newly developed HCV plaque assay technique. The plaque assay developed cy...


    pub_type: 杂志文章


    authors: Sekine-Osajima Y,Sakamoto N,Mishima K,Nakagawa M,Itsui Y,Tasaka M,Nishimura-Sakurai Y,Chen CH,Kanai T,Tsuchiya K,Wakita T,Enomoto N,Watanabe M

    更新日期:2008-02-05 00:00:00

  • Nonhomologous recombination between the hemagglutinin gene and the nucleoprotein gene of an influenza virus.

    abstract::Mutants of the influenza virus A/seal/Mass/1/80 (H7N7) are described which contain an insertion of 60 nucleotides in the hemagglutinin (HA) gene, derived most probably by recombination between the HA gene and the nucleoprotein gene of the same virus. The nonhomologous RNA recombination resulted in an enhanced hemagglu...


    pub_type: 杂志文章


    authors: Orlich M,Gottwald H,Rott R

    更新日期:1994-10-01 00:00:00

  • The herpes simplex virus immediate-early protein ICP27 shuttles between nucleus and cytoplasm.

    abstract::ICP27 is an essential herpes simplex virus type 1 (HSV-1) nuclear protein which regulates viral early and late genes during infection. The exact mechanism by which ICP27 modulates viral gene expression is unknown, but considerable evidence suggests that it functions posttranscriptionally. In this study, we have asked ...


    pub_type: 杂志文章


    authors: Mears WE,Rice SA

    更新日期:1998-03-01 00:00:00

  • Characterization of two chitinase genes and one chitosanase gene encoded by Chlorella virus PBCV-1.

    abstract::Chlorella virus PBCV-1 encodes two putative chitinase genes, a181/182r and a260r, and one chitosanase gene, a292l. The three genes were cloned and expressed in Escherichia coli. The recombinant A181/182R protein has endochitinase activity, recombinant A260R has both endochitinase and exochitinase activities, and recom...


    pub_type: 杂志文章


    authors: Sun L,Adams B,Gurnon JR,Ye Y,Van Etten JL

    更新日期:1999-10-25 00:00:00

  • Deletion analysis of a replication origin of human cytomegalovirus by a novel assay system with a combination of microinjection and polymerase chain reaction.

    abstract::We have developed a sensitive assay for DNA replication in mammalian cells that enables us to detect replicated DNA fragments of human cytomegalovirus. A 1/100 portion of DNA extracted from 1000 microinjected cells was subjected to polymerase chain reaction after digestion with appropriate restriction enzymes to diffe...


    pub_type: 杂志文章


    authors: Watanabe S,Yamaguchi N

    更新日期:1993-01-01 00:00:00

  • Establishment and characterization of plasmid-driven minigenome rescue systems for Nipah virus: RNA polymerase I- and T7-catalyzed generation of functional paramyxoviral RNA.

    abstract::In this study we report the development and optimization of two minigenome rescue systems for Nipah virus, a member of the Paramyxoviridae family. One is mediated by the T7 RNA polymerase supplied either by a constitutively expressing cell line or by transfection of expression plasmids and is thus independent from inf...


    pub_type: 杂志文章


    authors: Freiberg A,Dolores LK,Enterlein S,Flick R

    更新日期:2008-01-05 00:00:00

  • Site-directed mutagenesis of the P2 region of the Rous sarcoma virus gag gene: effects on Gag polyprotein processing.

    abstract::The Pr76Gag and Pr180Gag-Pol polyprotein precursors of Rous sarcoma virus contain a 22-amino-acid spacer peptide, called p2, located between the amino acid sequences of the mature Gag proteins MA and p10. This spacer peptide is present in stoichiometric amounts in the virion, albeit cleaved into two parts, but its fun...


    pub_type: 杂志文章


    authors: Bowles N,Bonnet D,Mulhauser F,Spahr PF

    更新日期:1994-08-15 00:00:00

  • K562 cell strains differ in their response to poliovirus infection.

    abstract::Poliovirus readily establishes a persistent infection in the K562-Mu erythroleukemia cell strain. In this study, three additional K562 cell strains were analyzed for their responses to poliovirus infection and found to be quite variable. K562 cells obtained from the ATCC established a persistent infection, similar to ...


    pub_type: 杂志文章


    authors: Benton PA,Murphy JW,Lloyd RE

    更新日期:1995-10-20 00:00:00

  • An EBNA-negative, EBV-genome-positive human lymphoblast cell line in which superinfecting EBV DNA is not maintained.

    abstract::A human B-lymphoid cell line, designated TG8, which does not express detectable levels of the EBV (Epstein-Barr virus)-associated nuclear antigen (EBNA), yet carries an average of one to two plasmid copies of the P3HR-1 EBV genome has been identified. TG8 can be superinfected by B95-8 EBV, resulting in up to 60-70% of...


    pub_type: 杂志文章


    authors: Reisman D,Sugden B

    更新日期:1984-08-01 00:00:00

  • Characterization of human papillomavirus-11 mRNAs expressed in the context of autonomously replicating viral genomes.

    abstract::We have previously adapted an experimental system which supports autonomous replication of human papillomavirus-11 (HPV-11) genomic DNA in a human squamous carcinoma cell line (SCC-4) following electroporation of linearized viral DNA. This system allows evaluation of HPV-11 transcription in the context of replicating ...


    pub_type: 杂志文章


    authors: Renaud KJ,Cowsert LM

    更新日期:1996-06-01 00:00:00

  • Mapping early transcription products of Autographa californica nuclear polyhedrosis virus.

    abstract::The regions of the AcMNPV genome represented as cytoplasmic transcripts early after infection of Spodoptera frugiperda cells prior to and encompassing the initiation of DNA replication were mapped. In vivo(32)P pulse-labeled cytoplasmic RNA from infected cells at various times postinfection was used to probe Southern ...


    pub_type: 杂志文章


    authors: Erlandson MA,Carstens EB

    更新日期:1983-04-15 00:00:00

  • Molecular basis for naturally occurring elevated readthrough transcription across the M-F junction of the paramyxovirus SV5.

    abstract::Transcription of the paramyxovirus RNA genome is thought to involve a sequential stop-start mechanism whereby monocistronic mRNAs are produced by polyadenylation and termination of 3' upstream gene followed by reinitiation at the downstream start site. For a number of paramyxoviruses, transcription across the M-F gene...


    pub_type: 杂志文章


    authors: Rassa JC,Parks GD

    更新日期:1998-08-01 00:00:00

  • Flanders virus replication and protein synthesis.

    abstract::The prototype strain of Flanders virus (61-7484) has been adapted to grow in Vero cell cultures and a plaque assay has been developed. Electron micrographs of infected cells revealed rod-shaped virions budding in clusters from the plasma membrane, consistent with the tentative classification of Flanders virus as a mem...


    pub_type: 杂志文章


    authors: Boyd KR,Whitaker-Dowling P

    更新日期:1988-04-01 00:00:00

  • Domain structure of herpes simplex virus 1 glycoprotein B: neutralizing epitopes map in regions of continuous and discontinuous residues.

    abstract::Herpes simplex virus 1 (HSV-1) glycoprotein B (gB) is a multifunctional glycoprotein required for infectivity; it is thought to promote fusion of the viral envelope with the cell membrane and entry of virions into cells. To map the antigenic and functional domains on gB, we constructed amino terminal derivatives lacki...


    pub_type: 杂志文章


    authors: Pereira L,Ali M,Kousoulas K,Huo B,Banks T

    更新日期:1989-09-01 00:00:00

  • Analysis of the complete genome sequence of two Korean sacbrood viruses in the Honey bee, Apis mellifera.

    abstract::The complete genomic RNAs of two Korean sacbrood virus (SBV) strains, which infect the honey bee, Apis mellifera, were sequenced. The two sequences (AmSBV-Kor19, AmSBV-Kor21) were distinguished by the presence or absence of a PstI restriction site. These strains comprised of 8784 bp and 8835 bp; contained a single lar...


    pub_type: 杂志文章


    authors: Choe SE,Nguyen LT,Noh JH,Kweon CH,Reddy KE,Koh HB,Chang KY,Kang SW

    更新日期:2012-10-10 00:00:00

  • Effects of sequences of prokaryotic origin on titer and transgene expression in retroviral vectors.

    abstract::Transcriptionally targeted MLV-based ProCon vectors allow expression of the transduced gene in a promoter-specific manner by replacement of the viral U3 region with a heterologous promoter. In order to evaluate the effects of sequence elements present in ProCon vectors on transgene expression (enhanced green fluoresce...


    pub_type: 杂志文章


    authors: Hlavaty J,Portsmouth D,Stracke A,Salmons B,Günzburg WH,Renner M

    更新日期:2004-12-05 00:00:00

  • Two regions of simian virus 40 large T-antigen independently extend the life span of primary C57BL/6 mouse embryo fibroblasts and cooperate in immortalization.

    abstract::Expression of the SV40 large T-antigen allows primary cells to escape senescence and thereby become immortalized. Immortalization occurs in two steps, extension of life span and acquisition of unlimited cell division potential. By following the increase in expression of a senescence-associated marker with increased ce...


    pub_type: 杂志文章


    authors: Tevethia MJ,Lacko HA,Conn A

    更新日期:1998-04-10 00:00:00

  • Combination of Adt-O1Manisa and Ad5-boIFNλ3 induces early protective immunity against foot-and-mouth disease in cattle.

    abstract::Foot-and-mouth-disease (FMD) remains the most infectious livestock disease worldwide. Although commercially available inactivated or adenovirus-vectored-vaccines (Ad5-FMD) are effective, they require 5-7 days to induce protection. Therefore, new control strategies that stimulate rapid immune responses are needed. Expr...


    pub_type: 杂志文章


    authors: Diaz-San Segundo F,Montiel NA,Sturza DF,Perez-Martin E,Hickman D,Ramirez-Medina E,Grubman MJ,de Los Santos T

    更新日期:2016-12-01 00:00:00

  • Identification of two independent neutralization domains on the VP4 trypsin cleavage products VP5* and VP8* of human rotavirus ST3.

    abstract::The antigenic structure of the VP4 protein of human rotavirus (HRV) strains Wa and ST3 was studied by using a panel of Wa- and ST3-derived VP4-specific neutralizing monoclonal antibodies (NMAbs) and NMAb-resistant variants. The VP4-coding genes from three Wa and three ST3 variants were sequenced. For Wa VP4, one homot...


    pub_type: 杂志文章


    authors: Padilla-Noriega L,Dunn SJ,López S,Greenberg HB,Arias CF

    更新日期:1995-01-10 00:00:00

  • Extensive immune-mediated hippocampal damage in mice surviving infection with neuroadapted Sindbis virus.

    abstract::Viral infections of the central nervous system and immune responses to these infections cause a variety of neurological diseases. Infection of weanling mice with Sindbis virus causes acute nonfatal encephalomyelitis followed by clearance of infectious virus, but persistence of viral RNA. Infection with a neuroadapted ...


    pub_type: 杂志文章


    authors: Kimura T,Griffin DE

    更新日期:2003-06-20 00:00:00

  • Expression and antiviral function of ARGONAUTE 2 in Nicotiana benthamiana plants infected with two isolates of tomato ringspot virus with varying degrees of virulence.

    abstract::ARGONAUTEs (notably AGO1 and AGO2) are effectors of plant antiviral RNA silencing. AGO1 was shown to be required for the temperature-dependent symptom recovery of Nicotiana benthamiana plants infected with tomato ringspot virus (isolate ToRSV-Rasp1) at 27 °C. In this study, we show that symptom recovery from isolate T...


    pub_type: 杂志文章


    authors: Paudel DB,Ghoshal B,Jossey S,Ludman M,Fatyol K,Sanfaçon H

    更新日期:2018-11-01 00:00:00

  • The outer capsid protein VP4 of murine rotavirus strain Eb represents a tentative new P type.

    abstract::The nucleotide and deduced amino acid sequence of the gene 4 of murine rotavirus strain Eb were determined. The gene is 2359 nucleotides in length and encodes for a protein of 775 amino acids. Comparison of the VP4 amino acid sequence of the Eb strain with several human and animal rotavirus strains which represent all...


    pub_type: 杂志文章


    authors: Sereno MM,Gorziglia MI

    更新日期:1994-03-01 00:00:00

  • Murine AIDS requires CD154/CD40L expression by the CD4 T cells that mediate retrovirus-induced disease: Is CD4 T cell receptor ligation needed?

    abstract::LP-BM5, a retroviral isolate, induces a disease featuring an acquired immunodeficiency syndrome termed murine AIDS (MAIDS). Many of the features of the LP-BM5-initiated disease are shared with HIV/AIDS. Our lab has shown that the interaction of B and CD4 T cells that is central to MAIDS pathogenesis requires ligation ...


    pub_type: 杂志文章


    authors: Li W,Green WR

    更新日期:2007-03-30 00:00:00

  • Epitopes of the G1 glycoprotein of La Crosse virus form overlapping clusters within a single antigenic site.

    abstract::Antigenic sites on the G1 glycoprotein of La Crosse bunyavirus were defined by constructing a panel of neutralizing and nonneutralizing monoclonal antibodies (F. Gonzalez-Scarano, R. E. Shope, C. H. Calisher, and N. Nathanson (1982), Virology 120, 42-53). To analyze the relationship between the individual epitopes del...


    pub_type: 杂志文章


    authors: Najjar JA,Gentsch JR,Nathanson N,Gonzalez-Scarano F

    更新日期:1985-07-30 00:00:00

  • Mapping of the red clover necrotic mosaic virus subgenomic RNA.

    abstract::The red clover necrotic mosaic dianthovirus capsid protein is expressed in vivo from a subgenomic RNA (sgRNA) identical to the 3'-terminal 1.5 kb of RNA-1. The 5' leader sequence of the capsid protein sgRNA is 62 nucleotides, contains a 14-nucleotide putative promoter sequence homologous to the RNA-1 5' terminus, and ...


    pub_type: 杂志文章


    authors: Zavriev SK,Hickey CM,Lommel SA

    更新日期:1996-02-15 00:00:00