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Genetic Variation of the Borrelia burgdorferi Gene vlsE Involves Cassette-Specific, Segmental Gene Conversion

The Lyme disease spirochete Borrelia burgdorferi possesses 15 silent vls cassettes and a vls expression site (vlsE) encoding a surface-exposed lipoprotein. Segments of the silent vls cassettes have been shown to recombine with the vlsE cassette region in the mammalian host, resul...

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Effects of vlsE Complementation on the Infectivity of Borrelia burgdorferi Lacking the Linear Plasmid lp28-1

The loss of linear plasmid lp28-1, which contains the vls antigenic variation locus, is associated with reduced infectivity of Borrelia burgdorferi in immunocompetent mice. The recombinant shuttle vector pBBE22, which includes the virulence determinant BBE22 from lp25 and restore...

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Evidence That the Variable Regions of the Central Domain of VlsE Are Antigenic during Infection with Lyme Disease Spirochetes

It has been postulated that the vls system of the Lyme disease spirochetes contributes to immune evasion through antigenic variation. While it is clear that vlsE undergoes sequence change within its variable regions at a high frequency during the early stages of infection, a defi...

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Evidence for the Contribution of Point Mutations to vlsE Variation and for Apparent Constraints on the Net Accumulation of Sequence Changes in vlsE during Infection with Lyme Disease Spirochetes

In the Lyme disease spirochetes, both the ospE and vlsE gene families have been demonstrated to undergo sequence variation during infection. To further investigate the mechanisms associated with the generation of vls variation, single-nucleotide polymorphism and subsequent DNA se...

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Human Antibody Responses to VlsE Antigenic Variation Protein of Borrelia burgdorferi

VlsE is a 35-kDa surface-exposed lipoprotein of Borrelia burgdorferi that was shown previously to undergo antigenic variation through segmental recombination of silent vls cassettes with vlsE during experimental mouse infections. Previous data had indicated that sera from North A...

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Genetic Variation at the vlsE Locus of Borrelia burgdorferi within Ticks and Mice over the Course of a Single Transmission Cycle

The Lyme disease spirochete, Borrelia burgdorferi, causes a persistent infection in the vertebrate host even though infected animals mount an active immune response against the spirochete. One strategy used by the spirochete to evade vertebrate host immunity is to vary the struct...

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Analysis of Borrelia burgdorferi vlsE Gene Expression and Recombination in the Tick Vector

Expression and recombination of the antigenic variation vlsE gene of the Lyme disease spirochete Borrelia burgdorferi were analyzed in the tick vector. To assess vlsE expression, Ixodes scapularis nymphs infected with the B. burgdorferi strain B31 were fed on mice for 48 or 96 h ...

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Cryptic and Exposed Invariable Regions of VlsE, the Variable Surface Antigen of Borrelia burgdorferi sl

Borrelia burgdorferi, the Lyme disease spirochete, possesses a surface protein, VlsE, which undergoes antigenic variation. VlsE contains two invariable domains and a variable one that includes six variable and six invariable regions (IRs). Five of the IRs are conserved among stra...

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Conservation and Heterogeneity of vlsE among Human and Tick Isolates of Borrelia burgdorferi

The vls (variable major protein [VMP]-like sequence) locus of Borrelia burgdorferi encodes an antigenic variation system that closely resembles the VMP system of relapsing fever borreliae. To determine whether vls sequences are present consistently in low-passage, infectious isol...

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Kinetics and In Vivo Induction of Genetic Variation of vlsE in Borrelia burgdorferi

The Lyme disease agent, Borrelia burgdorferi, is able to persistently infect humans and animals for months or years in the presence of an active immune response. It is not known how the organisms survive immune attack in the mammalian host. vlsE, a gene localized near one end of ...

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The N- and C-Terminal Regions of Rotavirus NSP5 Are the Critical Determinants for the Formation of Viroplasm-Like Structures Independent of NSP2

Molecular events and the interdependence of the two rotavirus nonstructural proteins, NSP5 and NSP2, in producing viroplasm-like structures (VLS) were previously evaluated by using transient cellular coexpression of the genes for the two proteins, and VLS domains as well as the N...

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Prevention of immunotoxin-mediated vascular leak syndrome in rats with retention of antitumor activity.

Immunotoxins are hybrid molecules composed of a cell-surface binding domain and a protein toxin moiety that together target specific cell populations for elimination. These agents represent a promising approach for the treatment of many human diseases, most notably cancer. Howeve...

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Avaliação do vôo tecnológico XVT02 do Veículo Lançador de Satélites VLS-1 por meio de decisão em grupo

Resumo: No lançamento dos primeiros protótipos do Veículo Lançador de Satélites (VLS-1), diferentes falhas impediram o cumprimento da missão. Em 2005, foi decidido realizar novos ensaios em vôo, denominados tecnológicos, com propósito de testar os sistemas do veículo. O objetivo ...

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Temporal Analysis of the Antigenic Composition of Borrelia burgdorferi during Infection in Rabbit Skin

The numbers of host-adapted Borrelia burgdorferi (HAB) organisms in rabbit skin were assessed by real-time PCR over the first 3 weeks of infection. Maximal numbers were found at day 11, while spirochete numbers decreased by more than 30-fold by day 21. The antigenic composition o...

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Human Immunodeficiency Virus-Specific CD8+ T-Cell Responses Do Not Predict Viral Growth and Clearance Rates during Structured Intermittent Antiretroviral Therapy

There is a continuing search for better ways to use existing drugs against human immunodeficiency virus (HIV). One idea is to use short therapy interruptions to “autovaccinate” HIV-infected patients. A group of 13 chronically HIV-infected patients enrolled in a trial of such so-c...

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Antigenic and genetic heterogeneity of Borrelia burgdorferi populations transmitted by ticks

The genome of Borrelia burgdorferi encodes a large number of lipoproteins, many of which are expressed only at certain stages of the spirochete's life cycle. In the current study we describe the B. burgdorferi population structure with respect to the production of two lipopro...

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C-Terminal Invariable Domain of VlsE Is Immunodominant but Its Antigenicity Is Scarcely Conserved among Strains of Lyme Disease Spirochetes

VlsE, the variable surface antigen of Borrelia burgdorferi, contains two invariable domains located at the amino and carboxyl terminal ends, respectively, and a central variable domain. In this study, both immunogenicity and antigenic conservation of the C-terminal invariable dom...

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Significant Improvement of the Recombinant Borrelia-Specific Immunoglobulin G Immunoblot Test by Addition of VlsE and a DbpA Homologue Derived from Borrelia garinii for Diagnosis of Early Neuroborreliosis

We investigated whether the recombinant Borrelia Western blot test previously described (B. Wilske, C. Habermann, V. Fingerle, B. Hillenbrand, S. Jauris-Heipke, G. Lehnert, I. Pradel, D. Rössler, and U. Schulte-Spechtel, Med. Microbiol. Immunol. 188:139-144, 1999) can be improved...

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C-Terminal Invariable Domain of VlsE May Not Serve as Target for Protective Immune Response against Borrelia burgdorferi

VlsE, the variable surface antigen of the Lyme disease spirochete, Borrelia burgdorferi, contains two invariable domains, at the amino and carboxyl termini, respectively, which collectively account for approximately one-half of the entire molecule's length and remain unchanged du...

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Three-dimensional viscous flow simulations over the VLS using overset grids

The present work is inserted into an effort to develop a Chimera flow simulation code capable of handling general launch vehicle configurations. The paper is primarily concerned with presenting results of laminar and turbulent viscous simulations of flows over the first Brazilian...

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