Publications by authors named "Katja Klein"

34 Publications

Deep Gene Sequence Cluster Analyses of Multi-Virus-Infected Mucosal Tissue Reveal Enhanced Transmission of Acute HIV-1.

J Virol 2021 01 13;95(3). Epub 2021 Jan 13.

Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada

Exposure of the genital mucosa to a genetically diverse viral swarm from the donor HIV-1 can result in breakthrough and systemic infection by a single transmitted/founder (TF) virus in the recipient. The highly diverse HIV-1 envelope (Env) in this inoculating viral swarm may have a critical role in transmission and subsequent immune response. Thus, chronic (Env) and acute (Env) Env chimeric HIV-1 were tested using multivirus competition assays in human mucosal penile and cervical tissues. Viral competition analysis revealed that Env viruses resided and replicated mainly in the tissue, while Env viruses penetrated the human tissue and established infection of CD4 T cells more efficiently. Analysis of the replication fitness, as tested in peripheral blood mononuclear cells (PBMCs), showed similar replication fitness of Env and Env viruses, which did not correlate with transmission fitness in penile tissue. Further, we observed that chimeric Env viruses with higher replication in genital mucosal tissue (chronic Env viruses) had higher binding affinity to C-type lectins. Data presented herein suggest that the inoculating HIV-1 may be sequestered in the genital mucosal tissue (represented by chronic Env HIV-1) but that a single HIV-1 clone (e.g., acute Env HIV-1) can escape this trapped replication for systemic infection. During heterosexual HIV-1 transmission, a genetic bottleneck occurs in the newly infected individual as the virus passes from the mucosa, leading to systemic infection with a single transmitted HIV-1 clone in the recipient. This bottleneck in the recipient has just been described (K. Klein et al., PLoS Pathog 14:e1006754, https://doi.org/10.1371/journal.ppat.1006754), and the mechanisms involved in this selection process have not been elucidated. However, understanding mucosal restriction is of the utmost importance for understanding dynamics of infections and for designing focused vaccines. Using our human penile and cervical mucosal tissue models for mixed HIV infections, we provide evidence that HIV-1 from acute/early infection, compared to that from chronic infection, can more efficiently traverse the mucosal epithelium and be transmitted to T cells, suggesting higher transmission fitness. This study focused on the role of the HIV-1 envelope in transmission and provides strong evidence that HIV transmission may involve breaking the mucosal lectin trap.
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http://dx.doi.org/10.1128/JVI.01737-20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7925087PMC
January 2021

Neuropilin-1 is a host factor for SARS-CoV-2 infection.

Science 2020 11 20;370(6518):861-865. Epub 2020 Oct 20.

School of Cellular and Molecular Medicine, Faculty of Life Sciences, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, UK.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), uses the viral spike (S) protein for host cell attachment and entry. The host protease furin cleaves the full-length precursor S glycoprotein into two associated polypeptides: S1 and S2. Cleavage of S generates a polybasic Arg-Arg-Ala-Arg carboxyl-terminal sequence on S1, which conforms to a C-end rule (CendR) motif that binds to cell surface neuropilin-1 (NRP1) and NRP2 receptors. We used x-ray crystallography and biochemical approaches to show that the S1 CendR motif directly bound NRP1. Blocking this interaction by RNA interference or selective inhibitors reduced SARS-CoV-2 entry and infectivity in cell culture. NRP1 thus serves as a host factor for SARS-CoV-2 infection and may potentially provide a therapeutic target for COVID-19.
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http://dx.doi.org/10.1126/science.abd3072DOI Listing
November 2020

Investigation of magnetically driven passage of magnetic nanoparticles through eye tissues for magnetic drug targeting.

Nanotechnology 2020 Dec;31(49):495101

Institut für Biomedizinische Technik und Informatik, Technische Universität Ilmenau, Germany.

This paper elucidates the feasibility of magnetic drug targeting to the eye by using magnetic nanoparticles (MNPs) to which pharmaceutical drugs can be linked. Numerical simulations revealed that a magnetic field gradient of 20 T m seems to be promising for dragging magnetic multicore nanoparticles of about 50 nm into the eye. Thus, a targeting magnet system made of superconducting magnets with a magnetic field gradient at the eye of about 20 T m was simulated. For the proof-of-concept tissue experiments presented here the required magnetic field gradient of 20 T m was realized by a permanent magnet array. MNPs with an optimized multicore structure were selected for this application by evaluating their stability against agglomeration of MNPs with different coatings in water for injections, physiological sodium chloride solution and biological media such as artificial tear fluid. From these investigations, starch turned out to be the most promising coating material because of its stability in saline fluids due to its steric stabilization mechanism. To evaluate the passage of MNPs through the sclera and cornea of the eye tissues of domestic pigs (Sus scrofa domesticus), a three-dimensionally printed setup consisting of two chambers (reservoir and target chamber) separated by the eye tissue was developed. With the permanent magnet array emulating the magnetic field gradient of the superconducting setup, experiments on magnetically driven transport of the MNPs from the reservoir chamber into the target chamber via the tissue were performed. The resulting concentration of MNPs in the target chamber was determined by means of quantitative magnetic particle spectroscopy. It was found that none of the tested particles passed the cornea, but starch-coated particles could pass the sclera at a rate of about 5 ng mm within 24 h. These results open the door for future magnetic drug targeting to the eye.
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http://dx.doi.org/10.1088/1361-6528/abb0b4DOI Listing
December 2020

A targeted reactivation of latent HIV-1 using an activator vector in patient samples from acute infection.

EBioMedicine 2020 Sep 9;59:102853. Epub 2020 Jul 9.

Department of Microbiology and Immunology, University of Western Ontario, London, Ontario N6A 5C1, Canada; Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, OH 44106, United States. Electronic address:

Background: During combined anti-retroviral treatment, a latent HIV reservoir persists within resting memory CD4 T cells that initiates viral recrudescence upon treatment interruption. Strategies for HIV-1 cure have largely focused on latency reversing agents (LRAs) capable of reactivating and eliminating this viral reservoir. Previously investigated LRAs have largely failed to achieve a robust latency reversal sufficient for reduction of latent HIV pool or the potential of virus-free remission in the absence of treatment.

Methods: We utilize a polyvalent virus-like particle (VLP) formulation called Activator Vector (ACT-VEC) to 'shock' provirus into transcriptional activity. Ex vivo co-culture experiments were used to evaluate the efficacy of ACT-VEC in relation to other LRAs in individuals diagnosed and treated during the acute stage of infection. IFN-γ ELISpot, qRT-PCR and Illumina MiSeq were used to evaluate antigenicity, latency reversal, and diversity of induced virus respectively.

Findings: Using samples from HIV patients diagnosed and treated at acute/early infection, we demonstrate that ACT-VEC can reverse latency in HIV infected CD4 T cells to a greater extent than other major recall antigens as stimuli or even mitogens such as PMA/Iono. Furthermore, ACT-VEC activates more latent HIV-1 than clinically tested HDAC inhibitors or protein kinase C agonists.

Interpretation: Taken together, these results show that ACT-VEC can induce HIV reactivation from latently infected CD4 T cells collected from participants on first line combined antiretroviral therapy for at least two years after being diagnosed and treated at acute/early stage of infection. These findings could provide guidance to possible targeted cure strategies and treatments.

Funding: NIH and CIHR.
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http://dx.doi.org/10.1016/j.ebiom.2020.102853DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7502668PMC
September 2020

Fast Access to Amphiphilic Multiblock Architectures by the Anionic Copolymerization of Aziridines and Ethylene Oxide.

J Am Chem Soc 2018 10 8;140(41):13407-13412. Epub 2018 Oct 8.

Max-Planck-Institut für Polymerforschung (MPI-P) , Ackermannweg 10 , 55128 Mainz , Germany.

An ideal system for stimuli-responsive and amphiphilic (block) polymers would be the copolymerization of aziridines with epoxides. However, to date, no copolymerization of these two highly strained three-membered heterocycles had been achieved. Herein, we report the combination of the living oxy- and azaanionic ring-opening polymerization of ethylene oxide (EO) and sulfonamide-activated aziridines. In a single step, well-defined amphiphilic block copolymers are obtained by a one-pot copolymerization. Real-time H NMR spectroscopy revealed the highest difference in reactivity ratios ever reported for an anionic copolymerization (with r = 265 and r = 0.004 for 2-methyl- N-tosylaziridine/EO and r = 151 and r = 0.013 for 2-methyl- N-mesylaziridine/EO), leading to the formation of block copolymers with monomodal and moderate molecular weight distributions ( M/ M mostly ≤1.3). The amphiphilic diblock copolymers were used to stabilize emulsions and to prepare polymeric nanoparticles by miniemulsion polymerization, representing a novel class of nonionic and responsive surfactants. In addition, this unique comonomer reactivity of activated-Az/EO allows fast access to multiblock copolymers, and we prepared the first amphiphilic penta- or tetrablock copolymers containing aziridines in only one or two steps, respectively. These examples render the combination of epoxide and aziridine copolymerizations via a powerful strategy for producing sophisticated macromolecular architectures and nanostructures.
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http://dx.doi.org/10.1021/jacs.8b08054DOI Listing
October 2018

Hydrophilicity Regulates the Stealth Properties of Polyphosphoester-Coated Nanocarriers.

Angew Chem Int Ed Engl 2018 05 14;57(19):5548-5553. Epub 2018 Apr 14.

Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany.

Increasing the plasma half-life is an important goal in the development of drug carriers, and can be effectively achieved through the attachment of polymers, in particular poly(ethylene glycol) (PEG). While the increased plasma half-life has been suggested to be a result of decreased overall protein adsorption on the hydrophilic surface in combination with the adsorption of specific proteins, the molecular reasons for the success of PEG and other hydrophilic polymers are still widely unknown. We prepared polyphosphoester-coated nanocarriers with defined hydrophilicity to control the stealth properties of the polymer shell. We found that the log P value of the copolymer controls the composition of the protein corona and the cell interaction. Upon a significant change in hydrophilicity, the overall amount of blood proteins adsorbed on the nanocarrier remained unchanged, while the protein composition varied. This result underlines the importance of the protein type for the protein corona and cellular uptake.
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http://dx.doi.org/10.1002/anie.201800272DOI Listing
May 2018

A heterogeneous human immunodeficiency virus-like particle (VLP) formulation produced by a novel vector system.

NPJ Vaccines 2018 19;3. Epub 2018 Jan 19.

1Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1 Canada.

First identified as the etiological agent behind Acquired Immunodeficiency Syndrome (AIDS) in the early 1980s, HIV-1 has continued to spread into a global pandemic and major public health concern. Despite the success of antiretroviral therapy at reducing HIV-1 viremia and preventing the dramatic CD4 T-cell collapse, infected individuals remain HIV positive for life. Unfortunately, it is increasingly clear that natural immunity is not, and may never be, protective against this pathogen. Therefore, efficacious vaccine interventions, which can either prevent infection or eradicate the latent viral reservoir and effect cure, are a major medical priority. Here we describe the development of a safe vaccine platform, currently being utilized in on-going prophylactic and therapeutic preclinical studies and consisting of highly heterogeneous virus-like particle formulations that represent the virus diversity within infected individuals. These VLPs contain no 5'LTR, no functional integrase, and have a severely mutated stem loop 1-thereby preventing any potential reverse transcription, integration, and RNA packaging. Furthermore, we demonstrate that these VLPs are morphologically identical to wild-type virus with polyvalent Env in a functional form. Finally, we show that the VLPs are antigenic and capable of generating strong immune recall responses.
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http://dx.doi.org/10.1038/s41541-017-0040-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5775397PMC
January 2018

Higher sequence diversity in the vaginal tract than in blood at early HIV-1 infection.

PLoS Pathog 2018 01 18;14(1):e1006754. Epub 2018 Jan 18.

Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada.

In the majority of cases, human immunodeficiency virus type 1 (HIV-1) infection is transmitted through sexual intercourse. A single founder virus in the blood of the newly infected donor emerges from a genetic bottleneck, while in rarer instances multiple viruses are responsible for systemic infection. We sought to characterize the sequence diversity at early infection, between two distinct anatomical sites; the female reproductive tract vs. systemic compartment. We recruited 72 women from Uganda and Zimbabwe within seven months of HIV-1 infection. Using next generation deep sequencing, we analyzed the total genetic diversity within the C2-V3-C3 envelope region of HIV-1 isolated from the female genital tract at early infection and compared this to the diversity of HIV-1 in plasma. We then compared intra-patient viral diversity in matched cervical and blood samples with three or seven months post infection. Genetic analysis of the C2-V3-C3 region of HIV-1 env revealed that early HIV-1 isolates within blood displayed a more homogeneous genotype (mean 1.67 clones, range 1-5 clones) than clones in the female genital tract (mean 5.7 clones, range 3-10 clones) (p<0.0001). The higher env diversity observed within the genital tract compared to plasma was independent of HIV-1 subtype (A, C and D). Our analysis of early mucosal infections in women revealed high HIV-1 diversity in the vaginal tract but few transmitted clones in the blood. These novel in vivo finding suggest a possible mucosal sieve effect, leading to the establishment of a homogenous systemic infection.
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http://dx.doi.org/10.1371/journal.ppat.1006754DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5773221PMC
January 2018

Eradication of HIV-1 latent reservoirs through therapeutic vaccination.

AIDS Res Ther 2017 Sep 12;14(1):45. Epub 2017 Sep 12.

Department of Microbiology and Immunology, University of Western Ontario, London, ON, N6A 5C1, Canada.

Despite the significant success of combination anti-retroviral therapy to reduce HIV viremia and save lives, HIV-1 infection remains a lifelong infection that must be appropriately managed. Advances in the understanding of the HIV infection process and insights from vaccine development in other biomedical fields such as cancer, imaging, and genetic engineering have fueled rapid advancements in HIV cure research. In the last few years, several studies have focused on the development of "Kick and Kill" therapies to reverse HIV latency and kick start viral translational activity. This has been done with the aim that concomitant anti-retroviral treatment and the elicited immune responses will prevent de novo infections while eradicating productively infected cells. In this review, we describe our perspective on HIV cure and the new approaches we are undertaking to eradicate the established pro-viral reservoir.
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http://dx.doi.org/10.1186/s12981-017-0177-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5594457PMC
September 2017

An in vitro Model to Mimic Selection of Replication-Competent HIV-1 Intersubtype Recombination in Dual or Superinfected Patients.

J Mol Biol 2017 07 1;429(14):2246-2264. Epub 2017 May 1.

Department of Molecular Biology and Microbiology, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; Department of Microbiology and Immunology, Western University, London, Ontario N6A 5C1, Canada. Electronic address:

The low frequency of HIV-1 recombinants within entire viral populations in both individual patients and culture-based infection models impedes investigation of the underlying factors contributing to either the occurrence of recombinants or the survival of recombinants once they are formed. So far, most of the related studies have no consideration of recombinants' functionality. Here, we established a functional recombinant production (FRP) system to produce pure and functional HIV-1 intersubtype Env recombinants and utilized 454 pyrosequencing to investigate the distribution of over 4000 functional and non-functional recombination breakpoints from either the FRP system or dual infection cultures. The results revealed that most of the breakpoints converged in gp41 (62%) and C1 (25.3%) domains of gp120, which has strong correlation with the similarity between the two recombining sequences. Yet, the breakpoints also appeared in C2 (5.2%) and C5 (4.6%) domains not correlated with the recombining sequence similarity. Interestingly, none of the intersubtype gp120 recombinants recombined between C1 and gp41 regions either from the FRP system or from the dual infection culture, and very few from the HIV epidemic were functional. The present study suggests that the selection of functional Env recombinants is one of the reasons for the predominance of C1 and gp41 Env recombinants in the HIV epidemic, and it provides an in vitro model to mimic the selection of replication-competent HIV-1 intersubtype recombination in dual or superinfected patients.
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http://dx.doi.org/10.1016/j.jmb.2017.04.016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6202033PMC
July 2017

First Phase I human clinical trial of a killed whole-HIV-1 vaccine: demonstration of its safety and enhancement of anti-HIV antibody responses.

Retrovirology 2016 Nov 28;13(1):82. Epub 2016 Nov 28.

Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, The University of Western Ontario, 1400 Western Road, London, ON, N6G 2V4, Canada.

Background: Vaccination with inactivated (killed) whole-virus particles has been used to prevent a wide range of viral diseases. However, for an HIV vaccine this approach has been largely negated due to inherent safety concerns, despite the ability of killed whole-virus vaccines to generate a strong, predominantly antibody-mediated immune response in vivo. HIV-1 Clade B NL4-3 was genetically modified by deleting the nef and vpu genes and substituting the coding sequence for the Env signal peptide with that of honeybee melittin signal peptide to produce a less virulent and more replication efficient virus. This genetically modified virus (gmHIV-1) was inactivated and formulated as a killed whole-HIV vaccine, and then used for a Phase I human clinical trial (Trial Registration: Clinical Trials NCT01546818). The gmHIV-1 was propagated in the A3.01 human T cell line followed by virus purification and inactivation with aldrithiol-2 and γ-irradiation. Thirty-three HIV-1 positive volunteers receiving cART were recruited for this observer-blinded, placebo-controlled Phase I human clinical trial to assess the safety and immunogenicity.

Results: Genetically modified and killed whole-HIV-1 vaccine, SAV001, was well tolerated with no serious adverse events. HIV-1-specific PCR showed neither evidence of vaccine virus replication in the vaccine virus-infected human T lymphocytes in vitro nor in the participating volunteers receiving SAV001 vaccine. Furthermore, SAV001 with adjuvant significantly increased the pre-existing antibody response to HIV-1 proteins. Antibodies in the plasma of vaccinees were also found to recognize HIV-1 envelope protein on the surface of infected cells as well as showing an enhancement of broadly neutralizing antibodies inhibiting tier I and II of HIV-1 B, D, and A subtypes.

Conclusion: The killed whole-HIV vaccine, SAV001, is safe and triggers anti-HIV immune responses. It remains to be determined through an appropriate trial whether this immune response prevents HIV infection.
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http://dx.doi.org/10.1186/s12977-016-0317-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5126836PMC
November 2016

Protein source and choice of anticoagulant decisively affect nanoparticle protein corona and cellular uptake.

Nanoscale 2016 Mar;8(10):5526-36

Max Planck Institute of Polymer Research, Ackermannweg 10, 55128 Mainz, Germany. and Dermatology Clinic, University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany.

Protein adsorption on nanoparticles has been a focus of the field of nanocarrier research in the past few years and more and more papers are dealing with increasingly detailed lists of proteins adsorbed to a plethora of nanocarriers. While there is an urgent need to understand the influence of this protein corona on nanocarriers' interactions with cells the strong impact of the protein source on corona formation and the consequence for interaction with different cell types are factors that are regularly neglected, but should be taken into account for a meaningful analysis. In this study, the importance of the choice of protein source used for in vitro protein corona analysis is concisely investigated. Major and decisive differences in cellular uptake of a polystyrene nanoparticle incubated in fetal bovine serum, human serum, human citrate and heparin plasma are reported. Furthermore, the protein compositions are determined for coronas formed in the respective incubation media. A strong influence of heparin, which is used as an anticoagulant for plasma generation, on cell interaction is demonstrated. While heparin enhances the uptake into macrophages, it prevents internalization into HeLa cells. Taken together we can give the recommendation that human plasma anticoagulated with citrate seems to give the most relevant results for in vitro studies of nanoparticle uptake.
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http://dx.doi.org/10.1039/c5nr08196cDOI Listing
March 2016

Evaluation of mucosal adjuvants and immunization routes for the induction of systemic and mucosal humoral immune responses in macaques.

Hum Vaccin Immunother 2015 ;11(12):2913-22

b Mucosal Infection & Immunity Group; Section of Virology; Imperial College London; St. Mary's Campus ; London , UK.

Delivering vaccine antigens to mucosal surfaces is potentially very attractive, especially as protection from mucosal infections may be mediated by local immune responses. However, to date mucosal immunization has had limited successes, with issues of both safety and poor immunogenicity. One approach to improve immunogenicity is to develop adjuvants that are effective and safe at mucosal surfaces. Differences in immune responses between mice and men have overstated the value of some experimental adjuvants which have subsequently performed poorly in the clinic. Due to their closer similarity, non-human primates can provide a more accurate picture of adjuvant performance. In this study we immunised rhesus macaques (Macaca mulatta) using a unique matrix experimental design that maximised the number of adjuvants screened while reducing the animal usage. Macaques were immunised by the intranasal, sublingual and intrarectal routes with the model protein antigens keyhole limpet haemocyanin (KLH), β-galactosidase (β-Gal) and ovalbumin (OVA) in combination with the experimental adjuvants Poly(I:C), Pam3CSK4, chitosan, Thymic Stromal Lymphopoietin (TSLP), MPLA and R848 (Resiquimod). Of the routes used, only intranasal immunization with KLH and R848 induced a detectable antibody response. When compared to intramuscular immunization, intranasal administration gave slightly lower levels of antigen specific antibody in the plasma, but enhanced local responses. Following intranasal delivery of R848, we observed a mildly inflammatory response, but no difference to the control. From this we conclude that R848 is able to boost antibody responses to mucosally delivered antigen, without causing excess local inflammation.
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http://dx.doi.org/10.1080/21645515.2015.1070998DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5054781PMC
September 2016

Glutathione Responsive Hyaluronic Acid Nanocapsules Obtained by Bioorthogonal Interfacial "Click" Reaction.

Biomacromolecules 2016 Jan 16;17(1):148-53. Epub 2015 Dec 16.

Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.

Azide-functionalized hyaluronic acid and disulfide dialkyne have been used for "click" reaction polymerization at the miniemulsion droplets interface leading to glutathione responsive nanocapsules (NCs). Inverse miniemulsion polymerization was chosen, due to its excellent performance properties, for example, tuning of size and size distribution, shell thickness/density, and high pay loading efficiency. The obtained size, size distribution, and encapsulation efficiency were checked via fluorescent spectroscopy, and the tripeptide glutathione was used to release an encapsulated fluorescent dye after cleavage of the nanocapsules shell. To show the glutathione-mediated intracellular cleavage of disulfide-containing NC shells, CellTracker was encapsulated into the nanocapsules. The cellular uptake in dendritic cells and the cleavage of the nanocapsules in the cells were studied using confocal laser scanning microscopy. Because of the mild reaction conditions used during the interfacial polymerization and the excellent cleavage properties, we believe that the synthesis of glutathione responsive hyaluronic acid NCs reported herein are of high interest for the encapsulation and release of sensitive compounds at high yields.
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http://dx.doi.org/10.1021/acs.biomac.5b01279DOI Listing
January 2016

Discrete partitioning of HIV-1 Env forms revealed by viral capture.

Retrovirology 2015 Sep 24;12:81. Epub 2015 Sep 24.

Mucosal Infection and Immunity Group, Section of Infectious Diseases, Imperial College London, St Mary's Campus, London, W2 1PG, UK.

Background: The structure of HIV-1 envelope glycoprotein (Env) is flexible and heterogeneous on whole virions. Although functional Env complexes are thought to require trimerization of cleaved gp41/gp120 heterodimers, variable processing can result in the potential incorporation of non-functional uncleaved proteins (gp160), non-trimeric arrangements of gp41/gp120 heterodimers, and gp120 depleted gp41 stumps. The potential distribution of functional and non-functional Env forms across replication-competent viral populations may have important implications for neutralizing and non-neutralizing antibody functions. This study applied an immuno-bead viral capture assay (VCA) to interrogate the potential distribution (heterologous vs homologous) of functional and non-functional forms of virion associated Env.

Results: The VCA revealed a significant association between depletion of infectious virions and virion Env incorporation, but not between infectivity and p24-gag. Three distinct subpopulations of virions were identified within pools of genetically homogenous viral particles. Critically, a significant subpopulation of infectious virions were exclusively captured by neutralizing antibodies (nAbs) indicative of a homologous distribution of functional trimeric Env forms. A second infectious subpopulation bound both neutralizing and non-neutralizing antibodies (nnAbs) representative of a heterologous distribution of Env forms, while a third non-infectious subpopulation was predominantly bound by nnAbs recognizing gp41 stumps.

Conclusions: The observation that a distinct and significant subpopulation of infectious virions is exclusively captured by neutralizing antibodies has important implications for understanding antibody binding and neutralization, as well as other antibody effector functions.
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http://dx.doi.org/10.1186/s12977-015-0207-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4581120PMC
September 2015

Human Non-neutralizing HIV-1 Envelope Monoclonal Antibodies Limit the Number of Founder Viruses during SHIV Mucosal Infection in Rhesus Macaques.

PLoS Pathog 2015 Aug 3;11(8):e1005042. Epub 2015 Aug 3.

Duke Human Vaccine Institute, Duke School of Medicine, Durham, North Carolina, United States of America.

HIV-1 mucosal transmission begins with virus or virus-infected cells moving through mucus across mucosal epithelium to infect CD4+ T cells. Although broadly neutralizing antibodies (bnAbs) are the type of HIV-1 antibodies that are most likely protective, they are not induced with current vaccine candidates. In contrast, antibodies that do not neutralize primary HIV-1 strains in the TZM-bl infection assay are readily induced by current vaccine candidates and have also been implicated as secondary correlates of decreased HIV-1 risk in the RV144 vaccine efficacy trial. Here, we have studied the capacity of anti-Env monoclonal antibodies (mAbs) against either the immunodominant region of gp41 (7B2 IgG1), the first constant region of gp120 (A32 IgG1), or the third variable loop (V3) of gp120 (CH22 IgG1) to modulate in vivo rectal mucosal transmission of a high-dose simian-human immunodeficiency virus (SHIV-BaL) in rhesus macaques. 7B2 IgG1 or A32 IgG1, each containing mutations to enhance Fc function, was administered passively to rhesus macaques but afforded no protection against productive clinical infection while the positive control antibody CH22 IgG1 prevented infection in 4 of 6 animals. Enumeration of transmitted/founder (T/F) viruses revealed that passive infusion of each of the three antibodies significantly reduced the number of T/F genomes. Thus, some antibodies that bind HIV-1 Env but fail to neutralize virus in traditional neutralization assays may limit the number of T/F viruses involved in transmission without leading to enhancement of viral infection. For one of these mAbs, gp41 mAb 7B2, we provide the first co-crystal structure in complex with a common cyclical loop motif demonstrated to be critical for infection by other retroviruses.
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http://dx.doi.org/10.1371/journal.ppat.1005042DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4523205PMC
August 2015

Effects of core strength training using stable versus unstable surfaces on physical fitness in adolescents: a randomized controlled trial.

BMC Sports Sci Med Rehabil 2014 15;6(1):40. Epub 2014 Dec 15.

Division of Training and Movement Sciences, Research Focus Cognition Sciences, University of Potsdam, Am Neuen Palais 10, Building 12, 14469 Potsdam, Germany.

Background: It has been demonstrated that core strength training is an effective means to enhance trunk muscle strength (TMS) and proxies of physical fitness in youth. Of note, cross-sectional studies revealed that the inclusion of unstable elements in core strengthening exercises produced increases in trunk muscle activity and thus provide potential extra training stimuli for performance enhancement. Thus, utilizing unstable surfaces during core strength training may even produce larger performance gains. However, the effects of core strength training using unstable surfaces are unresolved in youth. This randomized controlled study specifically investigated the effects of core strength training performed on stable surfaces (CSTS) compared to unstable surfaces (CSTU) on physical fitness in school-aged children.

Methods: Twenty-seven (14 girls, 13 boys) healthy subjects (mean age: 14 ± 1 years, age range: 13-15 years) were randomly assigned to a CSTS (n = 13) or a CSTU (n = 14) group. Both training programs lasted 6 weeks (2 sessions/week) and included frontal, dorsal, and lateral core exercises. During CSTU, these exercises were conducted on unstable surfaces (e.g., TOGU© DYNAIR CUSSIONS, THERA-BAND© STABILITY TRAINER).

Results: Significant main effects of Time (pre vs. post) were observed for the TMS tests (8-22%, f = 0.47-0.76), the jumping sideways test (4-5%, f = 1.07), and the Y balance test (2-3%, f = 0.46-0.49). Trends towards significance were found for the standing long jump test (1-3%, f = 0.39) and the stand-and-reach test (0-2%, f = 0.39). We could not detect any significant main effects of Group. Significant Time x Group interactions were detected for the stand-and-reach test in favour of the CSTU group (2%, f = 0.54).

Conclusions: Core strength training resulted in significant increases in proxies of physical fitness in adolescents. However, CSTU as compared to CSTS had only limited additional effects (i.e., stand-and-reach test). Consequently, if the goal of training is to enhance physical fitness, then CSTU has limited advantages over CSTS.

Trial Registration: ClinicalTrials.gov Identifier: NCT02290457 Registered 13 November 2014.
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http://dx.doi.org/10.1186/2052-1847-6-40DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4290805PMC
January 2015

Characterization of a plant-produced recombinant human secretory IgA with broad neutralizing activity against HIV.

MAbs 2014 ;6(6):1585-97

a The Hotung Molecular Immunology Group; Institute for Infection & Immunity; St George's ; University of London ; London , UK.

Recombinant Secretory IgA (SIgA) complexes have the potential to improve antibody-based passive immunotherapeutic approaches to combat many mucosal pathogens. In this report, we describe the expression, purification and characterization of a human SIgA format of the broadly neutralizing anti-HIV monoclonal antibody (mAb) 2G12, using both transgenic tobacco plants and transient expression in Nicotiana benthamiana as expression hosts (P2G12 SIgA). The resulting heterodecameric complexes accumulated in intracellular compartments in leaf tissue, including the vacuole. SIgA complexes could not be detected in the apoplast. Maximum yields of antibody were 15.2 μg/g leaf fresh mass (LFM) in transgenic tobacco and 25 μg/g LFM after transient expression, and assembly of SIgA complexes was superior in transgenic tobacco. Protein L purified antibody specifically bound HIV gp140 and neutralised tier 2 and tier 3 HIV isolates. Glycoanalysis revealed predominantly high mannose structures present on most N-glycosylation sites, with limited evidence for complex glycosylation or processing to paucimannosidic forms. O-glycan structures were not identified. Functionally, P2G12 SIgA, but not IgG, effectively aggregated HIV virions. Binding of P2G12 SIgA was observed to CD209 / DC-SIGN, but not to CD89 / FcalphaR on a monocyte cell line. Furthermore, P2G12 SIgA demonstrated enhanced stability in mucosal secretions in comparison to P2G12 IgG mAb.
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http://dx.doi.org/10.4161/mabs.36336DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4622858PMC
September 2015

Aggregate complexes of HIV-1 induced by multimeric antibodies.

Retrovirology 2014 Oct 2;11:78. Epub 2014 Oct 2.

Mucosal Infection & Immunity Group, Section of Infectious Diseases, Imperial College London, St Mary's Campus, London, W2 1PG, UK.

Background: 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.

Results: 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.

Conclusions: 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.
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http://dx.doi.org/10.1186/s12977-014-0078-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4193994PMC
October 2014

Enhanced immunogenicity of an HIV-1 DNA vaccine delivered with electroporation via combined intramuscular and intradermal routes.

J Virol 2014 Jun 9;88(12):6959-69. Epub 2014 Apr 9.

Mucosal Infection & Immunity Group, Section of Infectious Diseases, Imperial College London, St Mary's Campus, London, United Kingdom

Unlabelled: It is accepted that an effective prophylactic HIV-1 vaccine is likely to have the greatest impact on viral transmission rates. As previous reports have implicated DNA-priming, protein boost regimens to be efficient activators of humoral responses, we sought to optimize this regimen to further augment vaccine immunogenicity. Here we evaluated single versus concurrent intradermal (i.d.) and intramuscular (i.m.) vaccinations as a DNA-priming strategy for their abilities to elicit humoral and cellular responses against a model HIV-1 vaccine antigen, CN54-gp140. To further augment vaccine-elicited T and B cell responses, we enhanced cellular transfection with electroporation and then boosted the DNA-primed responses with homologous protein delivered subcutaneously (s.c.), intranasally (i.n.), i.m., or transcutaneously (t.c.). In mice, the concurrent priming regimen resulted in significantly elevated gamma interferon T cell responses and high-avidity antigen-specific IgG B cell responses, a hallmark of B cell maturation. Protein boosting of the concurrent DNA strategy further enhanced IgG concentrations but had little impact on T cell reactivity. Interestingly protein boosting by the subcutaneous route increased antibody avidity to a greater extent than protein boosting by either the i.m., i.n., or t.c. route, suggesting that this route may be preferential for driving B cell maturation. Using an alternative and larger animal model, the rabbit, we found the concurrent DNA-priming strategy followed by s.c. protein boosting to again be capable of eliciting high-avidity humoral responses and to also be able to neutralize HIV-1 pseudoviruses from diverse clades (clades A, B, and C). Taken together, we show that concurrent multiple-route DNA vaccinations induce strong cellular immunity, in addition to potent and high-avidity humoral immune responses.

Importance: The route of vaccination has profound effects on prevailing immune responses. Due to the insufficient immunogenicity and protection of current DNA delivery strategies, we evaluated concurrent DNA delivery via simultaneous administration of plasmid DNA by the i.m. and i.d. routes. The rationale behind this study was to provide clear evidence of the utility of concurrent vaccinations for an upcoming human clinical trial. Furthermore, this work will guide future preclinical studies by evaluating the use of model antigens and plasmids for prime-boost strategies. This paper will be of interest not only to virologists and vaccinologists working in the HIV field but also to researchers working in other viral vaccine settings and, critically, to the wider field of vaccine delivery.
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http://dx.doi.org/10.1128/JVI.00183-14DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4054344PMC
June 2014

Polymeric penetration enhancers promote humoral immune responses to mucosal vaccines.

J Control Release 2014 Jun 20;183:43-50. Epub 2014 Mar 20.

Imperial College London, Department of Infectious Diseases, Division of Medicine, Norfolk Place, London W2 1PG, UK. Electronic address:

Protective mucosal immune responses are thought best induced by trans-mucosal vaccination, providing greater potential to generate potent local immune responses than conventional parenteral vaccination. However, poor trans-mucosal permeability of large macromolecular antigens limits bioavailability to local inductive immune cells. This study explores the utility of polymeric penetration enhancers to promote trans-mucosal bioavailability of insulin, as a biomarker of mucosal absorption, and two vaccine candidates: recombinant HIV-1 envelope glycoprotein (CN54gp140) and tetanus toxoid (TT). Responses to vaccinating antigens were assessed by measurement of serum and the vaginal humoral responses. Polyethyleneimine (PEI), Dimethyl-β-cyclodextrin (DM-β-CD) and Chitosan enhanced the bioavailability of insulin following intranasal (IN), sublingual (SL), intravaginal (I.Vag) and intrarectal (IR) administration. The same penetration enhancers also increased antigen-specific IgG and IgA antibody responses to the model vaccine antigens in serum and vaginal secretions following IN and SL application. Co-delivery of both antigens with PEI or Chitosan showed the highest increase in systemic IgG and IgA responses following IN or SL administration. However the highest IgA titres in vaginal secretions were achieved after IN immunisations with PEI and Chitosan. None of the penetration enhancers were able to increase antibody responses to gp140 after I.Vag immunisations, while in contrast PEI and Chitosan were able to induce TT-specific systemic IgG levels following I.Vag administration. In summary, we present supporting data that suggest appropriate co-formulation of vaccine antigens with excipients known to influence mucosal barrier functions can increase the bioavailability of mucosally applied antigens promoting the induction of mucosal and systemic antibody responses.
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http://dx.doi.org/10.1016/j.jconrel.2014.03.018DOI Listing
June 2014

A "prime-pull" vaccine strategy has a modest effect on local and systemic antibody responses to HIV gp140 in mice.

PLoS One 2013 19;8(11):e80559. Epub 2013 Nov 19.

Mucosal Infection & Immunity Group, Section of Infectious Diseases, Imperial College London, London, United Kingdom.

One potential strategy for the prevention of HIV infection is to induce virus specific mucosal antibody that can act as an immune barrier to prevent transmission. The mucosal application of chemokines after immunisation, termed "prime-pull", has been shown to recruit T cells to mucosal sites. We wished to determine whether this strategy could be used to increase B cells and antibody in the vaginal mucosa following immunisation with an HIV antigen. BALB/c mice were immunised intranasally with trimeric gp140 prior to vaginal application of the chemokine CCL28 or the synthetic TLR4 ligand MPLA, without antigen six days later. There was no increase in vaginal IgA, IgG or B cells following the application of CCL28, however vaginal application of MPLA led to a significant boost in antigen specific vaginal IgA. Follow up studies to investigate the effect of the timing of the "pull" stimulation demonstrated that when given 14 days after the initial immunisation MPLA significantly increased systemic antibody responses. We speculate that this may be due to residual inflammation prior to re-immunisation. Overall we conclude that in contrast to the previously observed effect on T cells, the use of "prime-pull" has only a modest effect on B cells and antibody.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0080559PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3834027PMC
August 2014

Characterization of VRC01, a potent and broadly neutralizing anti-HIV mAb, produced in transiently and stably transformed tobacco.

Plant Biotechnol J 2014 Apr 21;12(3):300-11. Epub 2013 Nov 21.

Molecular Immunology Unit, Infection and Immunity Research Centre, St. George's University of London, London, UK.

The proposed clinical trial in Africa of VRC01, a potent broadly neutralizing antibody (bNAb) capable of neutralizing 91% of known HIV-1 isolates, raises concerns about testing a treatment which will be too expensive to be accessible by the most important target population, the poor in under-developed regions such as sub-Saharan Africa. Here, we report the expression of VRC01 in plants as an economic alternative to conventional mammalian-cell-based production platforms. The heavy and light chain genes of VRC01 were cloned onto a single vector, pTRAk.2, which was transformed into Nicotiana benthamiana or Nicotiana tabacum using transient and stable expression production systems respectively. VRC01 has been successfully expressed transiently in plants with expression level of approximately 80 mg antibody/kg; stable transgenic lines expressing up to 100 mg antibody/kg were also obtained. Plant-produced VRC01 from both systems showed a largely homogeneous N-glycosylation profile with a single dominant glycoform. The binding kinetics to gp120 IIIB (approximately 1 nM), neutralization of HIV-1 BaL or a panel of 10 VRC01-sensitive HIV-1 Env pseudoviruses of VRC01 produced in transient and stable plants were also consistent with VRC01 from HEK cells.
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http://dx.doi.org/10.1111/pbi.12137DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4112721PMC
April 2014

Neutralizing IgG at the portal of infection mediates protection against vaginal simian/human immunodeficiency virus challenge.

J Virol 2013 Nov 21;87(21):11604-16. Epub 2013 Aug 21.

Mucosal Infection & Immunity Group, Section of Infectious Diseases, Imperial College London, St. Mary's Campus, London, United Kingdom.

Neutralizing antibodies may have critical importance in immunity against human immunodeficiency virus type 1 (HIV-1) infection. However, the amount of protective antibody needed at mucosal surfaces has not been fully established. Here, we evaluated systemic and mucosal pharmacokinetics (PK) and pharmacodynamics (PD) of 2F5 IgG and 2F5 Fab fragments with respect to protection against vaginal challenge with simian-human immunodeficiency virus-BaL in macaques. Antibody assessment demonstrated that 2F5 IgG was more potent than polymeric forms (IgM and IgA) across a range of cellular and tissue models. Vaginal challenge studies demonstrated a dose-dependent protection for 2F5 IgG and no protection with 2F5 Fab despite higher vaginal Fab levels at the time of challenge. Animals receiving 50 or 25 mg/kg of body weight 2F5 IgG were completely protected, while 3/5 animals receiving 5 mg/kg were protected. In the control animals, infection was established by a minimum of 1 to 4 transmitted/founder (T/F) variants, similar to natural human infection by this mucosal route; in the two infected animals that had received 5 mg 2F5 IgG, infection was established by a single T/F variant. Serum levels of 2F5 IgG were more predictive of sterilizing protection than measured vaginal levels. Fc-mediated antiviral activity did not appear to influence infection of primary target cells in cervical explants. However, PK studies highlighted the importance of the Fc portion in tissue biodistribution. Data presented in this study may be important in modeling serum levels of neutralizing antibodies that need to be achieved by either vaccination or passive infusion to prevent mucosal acquisition of HIV-1 infection in humans.
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http://dx.doi.org/10.1128/JVI.01361-13DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3807318PMC
November 2013

Pulmonary delivery of DNA vaccine constructs using deacylated PEI elicits immune responses and protects against viral challenge infection.

J Control Release 2013 Sep 14;170(3):452-9. Epub 2013 Jun 14.

Imperial College London, Department of Infectious Diseases, Division of Medicine, Norfolk Place, London W2 1PG, UK.

Vaccination through mucosal surfaces has been shown to elicit antiviral immune responses against a number of mucosal pathogens. Here we demonstrate that both mucosal and systemic immune responses can be elicited against a model HIV-1 CN54gp140 antigen when cation-complexed plasmid DNA vaccines are applied topically to the murine pulmonary mucosa as an immune priming strategy. Furthermore, using an influenza challenge model we show that a plasmid DNA vaccine complexed to a less toxic form of PEI called dPEI (a nearly fully hydrolysed linear PEI with 11% additional free protonatable nitrogen atoms) can provide significant protection against a respiratory challenge infection in mice. Furthermore, we show that dPEI polyplexes have the potential to transfect not only mucosal epithelium, but also to enter deeper into tissues through the modulation of tight junction integrity. Taken together, these results demonstrate that less toxic forms of PEI can be effective delivery vehicles for plasmid DNAs to elicit cellular and humoral protective responses in vivo. Moreover, our observations suggest that these less toxic derivatives of PEI could be utilised for topical plasmid DNA vaccine delivery to human mucosal tissue surfaces, and that this application may permit dissemination of the immune responses through the linked mucosal network thus providing protective immunity at distal portals of pathogen entry.
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http://dx.doi.org/10.1016/j.jconrel.2013.06.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3767111PMC
September 2013

Evaluation of TLR agonists as potential mucosal adjuvants for HIV gp140 and tetanus toxoid in mice.

PLoS One 2012 13;7(12):e50529. Epub 2012 Dec 13.

Clinical Sciences, St. George's University of London, London, United Kingdom.

In the present study we investigate the impact of a range of TLR ligands and chitosan as potential adjuvants for different routes of mucosal immunisation (sublingual (SL), intranasal (IN), intravaginal (IVag) and a parenteral route (subcutaneous (SC)) in the murine model. We assess their ability to enhance antibody responses to HIV-1 CN54gp140 (gp140) and Tetanus toxoid (TT) in systemic and vaginal compartments. A number of trends were observed by route of administration. For non-adjuvanted antigen, SC>SL>IN immunisation with respect to systemic IgG responses, where endpoint titres were greater for TT than for gp140. In general, co-administration with adjuvants increased specific IgG responses where IN = SC>SL, while in the vaginal compartment IN>SL>SC for specific IgA. In contrast, for systemic and mucosal IgA responses to antigen alone SL>IN = SC. A number of adjuvants increased specific systemic IgA responses where in general IN>SL>SC immunisation, while for mucosal responses IN = SL>SC. In contrast, direct intravaginal immunisation failed to induce any detectable systemic or mucosal responses to gp140 even in the presence of adjuvant. However, significant systemic IgG responses to TT were induced by intravaginal immunisation with or without adjuvant, and detectable mucosal responses IgG and IgA were observed when TT was administered with FSL-1 or Poly I∶C. Interestingly some TLRs displayed differential activity dependent upon the route of administration. MPLA (TLR4) suppressed systemic responses to SL immunisation while enhancing responses to IN or SC immunisation. CpG B enhanced SL and IN responses, while having little or no impact on SC immunisation. These data demonstrate important route, antigen and adjuvant effects that need to be considered in the design of mucosal vaccine strategies.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0050529PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3521731PMC
June 2013

Rational design of HIV vaccines and microbicides: report of the EUROPRISE network annual conference 2010.

J Transl Med 2011 Apr 12;9:40. Epub 2011 Apr 12.

Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Nobels väg, Stockholm, 171 77, Sweden.

Novel, exciting intervention strategies to prevent infection with HIV have been tested in the past year, and the field is rapidly evolving. EUROPRISE is a network of excellence sponsored by the European Commission and concerned with a wide range of activities including integrated developmental research on HIV vaccines and microbicides from discovery to early clinical trials. A central and timely theme of the network is the development of the unique concept of co-usage of vaccines and microbicides. This review, prepared by the PhD students of the network captures much of the research ongoing between the partners. The network is in its 5th year and involves over 50 institutions from 13 European countries together with 3 industrial partners; GSK, Novartis and Sanofi-Pasteur. EUROPRISE is involved in 31 separate world-wide trials of Vaccines and Microbicides including 6 in African countries (Tanzania, Mozambique, South Africa, Kenya, Malawi, Rwanda), and is directly supporting clinical trials including MABGEL, a gp140-hsp70 conjugate trial and HIVIS, vaccine trials in Europe and Africa.
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http://dx.doi.org/10.1186/1479-5876-9-40DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3086860PMC
April 2011

Rational design of HIV vaccine and microbicides: report of the EUROPRISE annual conference.

J Transl Med 2010 Jul 26;8:72. Epub 2010 Jul 26.

Karolinska Institute, Stockholm, Sweden.

EUROPRISE is a Network of Excellence sponsored from 2007 to 2011 by the European Commission within the 6th Framework Program. The Network encompasses a wide portfolio of activities ranging from an integrated research program in the field of HIV vaccines and microbicides to training, dissemination and advocacy. The research program covers the whole pipeline of vaccine and microbicide development from discovery to early clinical trials. The Network is composed of 58 partners representing more than 65 institutions from 13 European countries; it also includes three major pharmaceutical companies (GlaxoSmithKline, Novartis and Sanofi-Pasteur) involved in HIV microbicide and vaccine research. The Network displays a dedicated and informative web page: http://www.europrise.org. Finally, a distinguishing trait of EUROPRISE is its PhD School of students from across Europe, a unique example in the world of science aimed at spreading excellence through training. EUROPRISE held its second annual conference in Budapest in November, 2009. The conference had 143 participants and their presentations covered aspects of vaccine and microbicide research, development and discovery. Since training is a major task of the Network, the students of the EUROPRISE PhD program summarized certain presentations and their view of the conference in this paper.
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http://dx.doi.org/10.1186/1479-5876-8-72DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2922088PMC
July 2010

A Novel Type of Vesicles Based on Ionic and π-π Interactions.

Macromol Rapid Commun 2010 Jan 24;31(1):75-80. Epub 2009 Sep 24.

Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany; Current address: Interdisciplinary Center for Molecular Materials and Department of Chemistry and Pharmacy, Friedrich-Alexander-University Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.

Electrostatic self-assembly can be used to form supramolecular vesicles in aqueous solution. Vesicles consist of cationic G8 poly(amidoamine) dendrimers and the trivalent sulfonate dye Ar27. No classical amphiphiles are present but the interplay of electrostatics, π-π interaction and geometric factors influences the structure formation. Labeled guest molecules, both small molecules and peptides, can be included inside these vesicles and vesicles imaged by fluorescence techniques. The structure was studied by dynamic and static light scattering, small-angle neutron scattering, confocal laser scanning microscopy, and fluorescence correlation spectroscopy. The study indicates the prospect of constructing functional nanoobjects by the self-assembly of charged molecules in aqueous solution.
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http://dx.doi.org/10.1002/marc.200900386DOI Listing
January 2010

Facile route to supramolecular structures: self-assembly of dendrimers and naphthalene dicarboxylic acids.

Chemistry 2008 ;14(23):6866-9

Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz, Germany.

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http://dx.doi.org/10.1002/chem.200800650DOI Listing
October 2008