16,789 research outputs found
Investigation of particulate HIV-1 Env vaccine candidates using Zera® and SpyTag/SpyCatcher technologies
Get PDFThe HIV-1 envelope glycoprotein (Env) is the primary focus of prophylactic HIV vaccine development. However, the unusually low density of Env spikes on the virion (≈14 spikes/virion) is unfavourable for eliciting high titre, long-lasting antibody responses. It is possible that increasing the Env spike density of particulate vaccine candidates generated by protein body formation or via the display of Env on nanoparticles could improve the induction of long-lasting neutralising antibodies (NAbs). For this thesis, two different nanoparticle approaches were therefore investigated. The HIV-1 Env sequence used for both approaches was derived from the superinfecting subtype C CAP256 virus. This was truncated to remove the transmembrane domain, and engineered to contain a flexible linker (FL) in place of the furin cleavage site and an I559P mutation to generate soluble, stable and cleavageindependent gp140 proteins. The first approach investigated the impact of genetically fusing a 27 kDa proline-cysteine-rich domain of the ɣ-zein maize seed storage protein - Zera® - to either the N- or C-terminus of CAP256 gp140. Fusion of Zera® to a protein of interest can promote the self-assembly of large protein bodies (PBs) containing the protein of interest, thereby improving yields of the recombinant protein and enabling easy isolation using gradient ultracentrifugation. The purification of Zera-induced Env PBs from infiltrated Nicotiana benthamiana plants was not optimal. Consequently, the generation of Zera®-induced gp140 protein bodies was evaluated in a mammalian expression system. Stable HEK293 cell lines expressing Zera®-gp140 or gp140-Zera® were generated. A mixture of small PB-like structures was observed in cells expressing gp140-Zera®. However, no PB-like structures were seen in cells expressing Zera®-gp140. The immunogenicity of Zera®-gp140 and gp140-Zera® was evaluated by in rabbits. Binding and Tier 1A neutralising serum titres were higher for gp140-Zera® than for Zera®-gp140. Neither gp140-Zera® nor Zera®-gp140-specific sera neutralised a Tier 1B pseudovirus or the autologous Tier 2 CAP256SU pseudovirus, suggesting that Zera® might have compromised the structure of the Zera®-tagged gp140 proteins. The second approach investigated the two-component SpyCatcher/SpyTag technology. The stable HEK293 cell line expressing CAP256 gp140-SpyTag (gp140-ST) was generated, and trimers were purified to homogeneity using gel filtration. SpyCatcher (SC)-AP205 VLPs were produced in E. coli and purified by ultracentrifugation. The gp140-ST trimers and the SCAP205 VLPs were mixed in varying molar ratios to generate VLPs displaying the glycoprotein (AP205-gp140-ST particles). SDS-PAGE, dynamic light scattering and negative stain electron microscopy indicated that gp140-ST was successfully bound to the VLPs, although not all potential binding sites were occupied. The immunogenicity of the coupled VLPs was evaluated in a pilot study in rabbits. One group was injected four times with coupled VLPs. The second group was primed with DNA vaccines expressing Env and a mosaic Gag, followed by modified vaccinia Ankara expressing the same antigens and then boosted twice with coupled VLPs. Encouragingly, gp140-ST displayed on SC-AP205 VLPs was an effective boost to heterologously primed rabbits, leading to induction of autologous Tier 2 neutralising antibodies in 2/5 rabbits. These results demonstrate that careful selection of a geometrically-suitable nanoparticle scaffold to achieve a high-density display of HIV-1 envelope trimers is an important consideration and that this could improve the effect of nanoparticle-displayed gp140
Image_2_Characterization and Immunogenicity of HIV Envelope gp140 Zera® Tagged Antigens.tiff
No full textHIV-1 envelope glycoprotein (Env) remains the most relevant target for the elicitation of functional antibodies to HIV by vaccination. However, soluble Env antigens often do not elicit the desired immune responses. Delivering subunit antigens on particulate nanoparticles is an established approach to improve their immunogenicity. In this study the sequence encoding Zera®, a proline-rich domain derived from the γ-zein storage protein, was fused to either the C- or N-terminus of the superinfecting HIV-1 CAP256 gp140 envelope: Zera® generally induces the formation of protein bodies (PBs), which can significantly improve both the immunogenicity and yields of the partner protein. The expression of gp140-Zera® and Zera®-gp140 (N- and C-terminal fusions respectively) in mammalian cells was confirmed by western blot analysis and immunostaining. However, isopycnic ultracentrifugation showed that neither gp140-Zera® nor Zera®-gp140 accumulated in characteristic electron-dense PBs. gp140-Zera® elicited higher binding antibody titers in rabbits to autologous gp140 and V1V2 scaffold than Zera®-gp140. Rabbit anti-gp140-Zera® sera also had significantly higher Tier 1A neutralizing antibody titers than anti-Zera®-gp140 sera. Neither gp140-Zera® nor Zera®-gp140-specific sera neutralized Tier 1B or autologous Tier 2 viruses. These results showed that HIV-1 gp140 tagged with Zera® at either the N- or C-termini elicited high titers of gp140 and V1V2 binding antibodies, and low levels of Tier 1 neutralizing antibodies in rabbits.</p
Image_1_Characterization and Immunogenicity of HIV Envelope gp140 Zera® Tagged Antigens.tiff
No full textHIV-1 envelope glycoprotein (Env) remains the most relevant target for the elicitation of functional antibodies to HIV by vaccination. However, soluble Env antigens often do not elicit the desired immune responses. Delivering subunit antigens on particulate nanoparticles is an established approach to improve their immunogenicity. In this study the sequence encoding Zera®, a proline-rich domain derived from the γ-zein storage protein, was fused to either the C- or N-terminus of the superinfecting HIV-1 CAP256 gp140 envelope: Zera® generally induces the formation of protein bodies (PBs), which can significantly improve both the immunogenicity and yields of the partner protein. The expression of gp140-Zera® and Zera®-gp140 (N- and C-terminal fusions respectively) in mammalian cells was confirmed by western blot analysis and immunostaining. However, isopycnic ultracentrifugation showed that neither gp140-Zera® nor Zera®-gp140 accumulated in characteristic electron-dense PBs. gp140-Zera® elicited higher binding antibody titers in rabbits to autologous gp140 and V1V2 scaffold than Zera®-gp140. Rabbit anti-gp140-Zera® sera also had significantly higher Tier 1A neutralizing antibody titers than anti-Zera®-gp140 sera. Neither gp140-Zera® nor Zera®-gp140-specific sera neutralized Tier 1B or autologous Tier 2 viruses. These results showed that HIV-1 gp140 tagged with Zera® at either the N- or C-termini elicited high titers of gp140 and V1V2 binding antibodies, and low levels of Tier 1 neutralizing antibodies in rabbits.</p
An Article About Albertus C. Van Raalte, Author Unknown, Except for Parts Taken from an Article by Anna C. Post
Get PDFAn article about Albertus C. Van Raalte, author unknown, except for parts taken from an article by Anna C. Post. The author knew first generation persons in the Holland settlement and therefore, the article has some value.https://digitalcommons.hope.edu/vrp_1890s/1012/thumbnail.jp
Isoconversional kinetics of thermal oxidation of mesoporous silicon
No full textMesoporous silicon (pSi) has several interesting features that makes it suitable for various biomedical applications. In particular, the large surface area make it very sensitive to environment changes. Among other approaches, thermal oxidation is an effective way to passivate its surface. Herein, we present experimental and analytical results concerning kinetics of thermal oxidation reaction of pSi. The experiments were conducted on pSi powders produced from silicon wafer by anodization and converted to particles by sonication. Oxidation experiments were carried out at different heating rates. Structure and morphology of the samples have been investigated by XRD and SEM before and after thermal oxidation. The model-free kinetics proposed by Ozawa–Flynn–Wall (OFW) was used to determine the Arrhenius relationship for the pSi thermal oxidation. The obtained apparent activation energy by OFW was confirmed by Starink method. At low temperature, the oxidation of surface dangling bonds obeys the Avrami–Erofeev mechanism. At high temperature, oxidation is followed by classical bulk oxidation according to diffusion mechanism controlled by the diffusion of oxygen through the silicon dioxide layer on the surface of the pSi. The reaction mechanism was checked by the model fitting kinetics, which confirmed the reaction is a kind of sequential two-stage process, Avrami–Erofeev and 3D diffusion. Finally, differential thermal analysis suggests that the second oxidation step is also possibly affected by phase transformation of the silicon dioxide
Richardson, Barbauld, and the construction of an early modern fan club
No full textMPhilMuch has been written about the life and long works of the eighteenth century epistolary novelist, Samuel Richardson, but the prospect of his position as the first celebrity novelist – responsible for courting his own fame as well as initiating his own fan club – has largely been ignored. The body of manuscripts housed at the National Art Library in the Victoria and Albert Museum in London provides the modern scholar with evidence of the skeletal beginnings of an early fan club. This thesis aims to show how these manuscripts were turned into a saleable commodity by the publisher and entrepreneur Richard Phillips, while under the guiding hand of another, slightly later, literary celebrity, Anna Laetitia Barbauld. In order to restore Richardson’s reputation amongst a new nineteenth century audience, Barbauld was required to construct her own idea of him as an eighteenth century celebrity author, and in doing so the insecurities of a self-professed, apparently diffident man, are revealed. Barbauld’s capacious, but heavily edited selection of letters is analyzed in this thesis, providing ample evidence that Richardson’s correspondents were more than just eager letter writers. By using Barbauld’s biography of Richardson this thesis aims to show how she manipulates the genre of life writing in her construction of him.
This thesis offers an alternative reading of how the Richardson manuscripts are viewed, redefining them as not simply a collection of letters, but as a collective entity, deliberately selected and archived as evidence of an early modern fan club, and its celebrity managing director
Selection of work by Anna Gerber
Get PDFVarious journals and magazines Anna Gerber has contributed to. Anna Gerber is a graphic designer and writer based in London.
She is the author and designer of All Messed Up: Unpredictable Graphics (Laurence King, 2004) and co-editor and co-designer
of Influences: A Lexicon of Contemporary Graphic Design (Die Gestalten Verlag, 2006) with Anja Lutz. She writes regularily for magazines such as Print, Eye, Creative Review, Varoom and Idea Magazine and her work has also been published in shift!, dot dot dot and +rosebud.
She teaches at the London College of Communication on the BA Graphic Design and MA Design Writing Criticism programmes. She has also held workshops and lectures across the U.K. (including Tate Modern and the V&A Museum), as well as in India, the U.S., Australia and Malaysia.
Anna Gerber is currently engaged in research and developing projects relating to sustainability and how it applies to graphic
design as well as exploring contemporary graphic design in India
Author and Lecturer Anna Bird Stewart will Speak at the University of Dayton
Get PDFNews release announcing the visitation and speech of author and lecturer Anna Bird Stewart to the University of Dayton
Operatori del processo edilizio
Get PDFLemma che descrive i diversi attori del processo edilizio, con particolare attenzione al processo edilizio pubblico - ISBN:ISSN 2284-00IX - visibile su: Wikitecnica.com/author/giovenale-anna-mari
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