Significance
Hemagglutinin (HA) is the major influenza virus surface protein and a prime antigen candidate for vaccine development using recombinant subunit approaches. Adjuvants often are used to ...enhance the immunogenicity of recombinant proteins. Here, we show that a next-generation vaccine adjuvant system that seamlessly sequesters and presents antigens on the surface of immunogenic liposomes improves the functional immunogenicity of HA in mice and ferrets. The potential for antigen dose sparing and multivalent presentation is demonstrated using this approach.
Recombinant influenza virus vaccines based on hemagglutinin (HA) hold the potential to accelerate production timelines and improve efficacy relative to traditional egg-based platforms. Here, we assess a vaccine adjuvant system comprised of immunogenic liposomes that spontaneously convert soluble antigens into a particle format, displayed on the bilayer surface. When trimeric H3 HA was presented on liposomes, antigen delivery to macrophages was improved in vitro, and strong functional antibody responses were induced following intramuscular immunization of mice. Protection was conferred against challenge with a heterologous strain of H3N2 virus, and naive mice were also protected following passive serum transfer. When admixed with the particle-forming liposomes, immunization reduced viral infection severity at vaccine doses as low as 2 ng HA, highlighting dose-sparing potential. In ferrets, immunization induced neutralizing antibodies that reduced the upper respiratory viral load upon challenge with a more modern, heterologous H3N2 viral strain. To demonstrate the flexibility and modular nature of the liposome system, 10 recombinant surface antigens representing distinct influenza virus strains were bound simultaneously to generate a highly multivalent protein particle that with 5 ng individual antigen dosing induced antibodies in mice that specifically recognized the constituent immunogens and conferred protection against heterologous H5N1 influenza virus challenge. Taken together, these results show that stable presentation of recombinant HA on immunogenic liposome surfaces in an arrayed fashion enhances functional immune responses and warrants further attention for the development of broadly protective influenza virus vaccines.
Influenza viruses cause seasonal epidemics and represent a pandemic risk. With current vaccine methods struggling to protect populations against emerging strains, there is a demand for a ...next-generation flu vaccine capable of providing broad protection. Recombinant biotechnology, combined with nanomedicine techniques, could address this demand by increasing immunogenicity and directing immune responses toward conserved antigenic targets on the virus. Various nanoparticle candidates have been tested for use in vaccines, including virus-like particles, protein and carbohydrate nanoconstructs, antigen-carrying lipid particles, and synthetic and inorganic particles modified for antigen presentation. These methods have yielded some promising results, including protection in animal models against antigenically distinct influenza strains, production of antibodies with broad reactivity, and activation of potent T cell responses. Based on the evidence of current research, it is feasible that the next generation of influenza vaccines will combine recombinant antigens with nanoparticle carriers.
Intranasal vaccination offers the potential advantage of needle-free prevention of respiratory pathogens such as influenza viruses with induction of mucosal immune responses. Optimal design of ...adjuvants and antigen delivery vehicles for intranasal delivery has not yet been well established. Here, we report that an adjuvant-containing nanoliposome antigen display system that converts soluble influenza hemagglutinin antigens into nanoparticles is effective for intranasal immunization. Intranasal delivery of nanoliposomes in mice delivers the particles to resident immune cells in the respiratory tract, inducing a mucosal response in the respiratory system as evidenced by nasal and lung localized IgA antibody production, while also producing systemic IgG antibodies. Intranasal vaccination with nanoliposome particles decorated with nanogram doses of hemagglutinin protected mice from homologous and heterologous H3N2 and H1N1 influenza virus challenge.
A self-assembling influenza virus vaccine platform that seamlessly converts soluble antigens into nanoparticles is demonstrated with various H1N1 and H3N2 influenza antigens to protect mice against influenza virus challenge following intranasal vaccination. Mucosal immune responses following liposome delivery to lung antigen-presenting cells are demonstrated.
We present in this article the development of a photon-counting, energy-discriminating modular detector based on a pixelated CdZnTe sensor coupled pixel-by-pixel to a novel Digital Pixel Sensor (DPS) ...readout. The detector is designed for munitions inspection, breast X-ray CT and SPECT/MRI. The current DPS design can also be used to read out other solid-state sensors. The prototype detector is 5.5
mm×5.5
mm in size, and consists of 19×19 pixels on a 250
μm pitch. The DPS is designed in a 0.35
μm process, and every pixel includes a preamplifier, a leakage-current subtraction circuit, an auto-zeroed programmable-gain stage, five comparators, a variable-delay reset circuit and five 16
bit counters. The module is expected to operate at high X-ray fluence exceeding 80
MHz/mm
2, and to improve resolution and contrast in images, while significantly enhancing their signal-to-noise ratio, and assist in identifying material composition via dual-energy imaging. The detector design, fabrication and anticipated performance are discussed.
In the budding yeast Saccharomyces cerevisiae, a cell cycle checkpoint coordinates mitosis with bud formation. Perturbations that transiently depolarize the actin cytoskeleton cause delays in bud ...formation, and a ‘morphogenesis checkpoint’ detects the actin perturbation and imposes a G2 delay through inhibition of the cyclin‐dependent kinase, Cdc28p. The tyrosine kinase Swe1p, homologous to wee1 in fission yeast, is required for the checkpoint‐mediated G2 delay. In this report, we show that Swe1p stability is regulated both during the normal cell cycle and in response to the checkpoint. Swe1p is stable during G1 and accumulates to a peak at the end of S phase or in early G2, when it becomes unstable and is degraded rapidly. Destabilization of Swe1p in G2 and M phase depends on the activity of Cdc28p in complexes with B‐type cyclins. Several different perturbations of actin organization all prevent Swe1p degradation, leading to the persistence or further accumulation of Swe1p, and cell cycle delay in G2.
Mitochondrial DNA deletions and point mutations accumulate in an age-dependent manner in mammals. The mitochondrial genome in aging humans often displays a 4977-bp deletion flanked by short direct ...repeats. Additionally, direct repeats flank two-thirds of the reported mitochondrial DNA deletions. The mechanism by which these deletions arise is unknown, but direct-repeat-mediated deletions involving polymerase slippage, homologous recombination, and nonhomologous end joining have been proposed. We have developed a genetic reporter to measure the rate at which direct-repeat-mediated deletions arise in the mitochondrial genome of Saccharomyces cerevisiae. Here we analyze the effect of repeat size and heterology between repeats on the rate of deletions. We find that the dependence on homology for repeat-mediated deletions is linear down to 33 bp. Heterology between repeats does not affect the deletion rate substantially. Analysis of recombination products suggests that the deletions are produced by at least two different pathways, one that generates only deletions and one that appears to generate both deletions and reciprocal products of recombination. We discuss how this reporter may be used to identify the proteins in yeast that have an impact on the generation of direct-repeat-mediated deletions.
Summary
In this longitudinal case–control study, acute fracture was associated with low serum testosterone, which was transient in 43 % of men. While assessment of gonadal status is part of the ...assessment of bone fragility, measurement of testosterone in the early period after fracture may overestimate the prevalence of androgen deficiency.
Introduction
Measurement of circulating testosterone is recommended in the evaluation of bone fragility in men. Since acute illness can transiently decrease circulating testosterone, we quantified the association of acute fracture and serum testosterone levels.
Methods
A case–control study was conducted involving 240 men with a radiologically confirmed minimal trauma fracture presenting to a tertiary referral hospital and 89 age-matched men without a history of minimal trauma fracture serving as controls. Follow-up testosterone levels 6 months after baseline were available for 98 cases and 27 controls. Results were expressed as the median and interquartile (IQR) range.
Results
Compared to controls, cases had lower total testosterone TT, 7.2 (3.5, 10.8) vs 13.6 (10.9, 17.1) nmol/L,
p
< 0.001. The 143 cases treated as inpatients had lower testosterone levels than the 97 cases treated as outpatients TT 4.7 (2.3, 8.1) vs 10.3 (7.5, 12.7) nmol/L,
p
< 0.001. Group differences in calculated free testosterone (cFT) were comparable to the group differences in TT. At follow-up, in 98 cases, median TT increased from 6.5 nmol/L (3.2, 8.5) to 9.6 nmol/L (6.9, 12.0)
p
< 0.0001, and SHBG remained unchanged. Of cases with low testosterone, 43 % with TT <10 nmol/L and/or cFT <230 pmol/L at presentation were reclassified as androgen sufficient at follow-up. TT was unchanged in the controls.
Conclusions
Low testosterone levels in men presenting with an acute fracture may, at least in part, be due to an acute, fracture-associated, stress response. To avoid over diagnosis, evaluation for testosterone deficiency should be deferred until recovery from the acute event.
In this Letter, we describe a search for lepton flavor violation (LFV) in the bottomonium system. We search for leptonic decays Upsilon(nS)-->mutau (n=1, 2, and 3) using the data collected with the ...CLEO III detector. We identify the tau lepton using its leptonic decay nu_{tau}nuover _{e}e and utilize multidimensional likelihood fitting with probability density function shapes measured from independent data samples. We report our estimates of 95% C.L. upper limits on LFV branching fractions of Upsilon mesons. We interpret our results in terms of the exclusion plot for the energy scale of a hypothetical new interaction versus its effective LFV coupling in the framework of effective field theory.
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