Safety and biodistribution of sulfated archaeal glycolipid archaeosomes as vaccine adjuvants

Archaeosomes are liposomes comprised of ether lipids derived from various archaea which, as adjuvants, can induce robust, long-lasting humoral and cell-mediated immune responses to entrapped antigens. Traditional total polar lipid (TPL) archaeosome formulations are relatively complex and semi-synthetic archaeosomes involve many synthetic steps to arrive at the final desired glycolipid composition. We have developed a novel archaeosome formulation comprising a sulfated saccharide group covalently linked to the free sn-1 hydroxyl backbone of an archaeal core lipid (sulfated S-lactosylarchaeol, SLA) mixed with uncharged glycolipid (lactosylarchaeol, LA). This new class of adjuvants can be easily synthesized and retains strong immunostimulatory activity for induction of cell-mediated immunity following systemic immunization. Herein, we demonstrate the safety of SLA/LA archaeosomes following intramuscular injection to mice and evaluate the immunogenicity, in vivo distribution and cellular uptake of antigen (ovalbumin) encapsulated into SLA/LA archaeosomes. Overall, we have found that semi-synthetic sulfated glycolipid archaeosomes are a safe and effective novel class of adjuvants capable of inducing strong antigen-specific immune responses in mice and protection against subsequent B16 melanoma tumor challenge. A key step in their mechanism of action appears to be the recruitment of immune cells to the injection site and the subsequent trafficking of antigen to local draining lymph nodes. A better understanding of the safety and mechanism of action of novel adjuvants such as archaeosomes is a key step in their advancement into clinical use

Ranging behaviour of hen harriers breeding in Special Protection Areas in Scotland

Capsule: Breeding female Hen Harriers hunted mostly within 1 km from the nest and males mostly within 2 km. Aims: To quantify temporal and spatial variation in home-range sizes and hunting distances of breeding male and female Hen Harriers. Methods: We radio-tracked ten breeding harriers (five males and five females) in three Special Protection Areas in Scotland between 2002 and 2004. Results: Male Hen Harriers travelled up to 9 km from nests but had a home-range size that averaged only 8 km2 (90% kernel); average home-range size for females was 4.5 km2. Hunting distances did not vary throughout the season. No significant differences were found among study areas, but there was large individual variability. Conclusion: Our results provide information on foraging harriers to support management: actions within 1 km of nesting sites will favour both sexes, and within 2 km will mostly favour males. Our data also suggest overlap between foraging areas of neighbouring birds. Thus, there is the potential for good foraging areas to be utilized by multiple breeding pairs

Temperature-mediated shifts in the foraging behaviour of the Eurasian otter, Lutra lutra L

Environmental variables will influence the behaviour of an animal by changing its state, and a relationship exists between such variables and the animal's behaviour. Aquatic animals are particularly under the influence of the medium in which they forage, and changes in this may have profound effects on the behaviour Recent studies have demonstrated that the metabolic costs of foraging in the Eurasian otter (Lutra lutra) are increased substantially by depressed water temperature. Otters are common around the west coast of Scotland, and yet they are frequently exposed to low water temperatures. This project examined the foraging behaviour of otters at the Taynish peninsula, Mid-Argyll, Scotland, and the effect of low water temperatures on otters and their prey, by observing the behaviour of otters at a range of water temperatures around. A regime of stationary fish trapping was initiated over 15 months to examine seasonal and spatial fluctuations in the abundance of the prey species. While the limitations of this method of assessing prey populations are discussed, it was clear that there were profound differences in the prey composition of the three habitats studied and that these changed seasonally. An examination of the accuracy of faecal analysis as a means of quantifying the diet of otters, was carried out. From this, potentially more accurate methods of assessing diet were suggested. The diet of the otters around the study site, as determined by observations and analysis of the faeces, demonstrated that the otters were selective of their prey at certain times of year, corresponding with those times of high prey abundance, but at times of poor prey abundance such selectivity was reduced. Foraging site use by the otters was examined in the context of temperature mediated fluctuations in prey biomass, as determined from the trapping. While the overall use of the habitats matched that with the highest biomass, temporal variations in this did not correspond with variations in biomass. Potential explanations for this are discussed. Changes in the activity levels and escape responses of some of the otter prey species were examined experimentally, and were found to have a significant positive relationship with water temperature. However, the actual capture times of these species, as determined from direct observations of the otters feeding, did not change with water temperature. This may have been caused by longer search times in colder water, or be due to the fact that otters forage for their prey when it is in the inactive component of its activity cycle. From this it was hypothesised that the otters would change the timing of their foraging in cold water, as it would no longer be dependent on the behaviour of their prey. This was tested by direct observation, and while no relationship was observed at any time of year with the tide, the observed relationship between foraging activity and time of day was altered in the winter. The relationship between the parameters of dive behaviour and water temperature was investigated. There was no strong relationship with any of them, however following recent studies in the literature, it was hypothesised that the metabolic costs of foraging would largely be met after the foraging bout was completed. A mathematical model was constructed to describe the relative amount of on land recovery time needed after a foraging bout at different water temperatures. This predicted that more time would be spent on land in lower water temperatures, and these predictions were upheld by observations from the wild. It was also apparent that the otters made greater use of deeper water during warmer water temperatures. This phenomenon was investigated by cost benefit analysis. Fish trapping revealed that there were better prey in deeper water and the success rate of dives was also higher. Conversely, dive times were longer in deeper water, and the prey, though of better quality were associated with longer handling times. Furthermore the rate of heat loss from the otter pelt was determined experimentally to be greater in deeper water. These data were combined in the form of an optimality model, which confirmed the results of observations that the otter only foraged in deeper water when the temperature of the water was relatively high. In conclusion it was found that the foraging behaviour of the otter was influenced by water temperature in the following ways: 1. The temporal pattern of foraging changes in the winter 2. Post-foraging recovery times on land are increased in colder water temperatures 3. Otters are restricted in their use of depth in colder water These results have demonstrated that the foraging behaviour of the otter cannot simply be viewed in terms of handling costs and prey energetic value, rather the complex influences of environmental variables on the otters physiological state, and the complex relationship this has with its behaviour, must be considered

Methods to quantify avian airspace use in relation to wind energy development

It is likely that there will continue to be a substantial increase in the number of wind turbines as we aim to meet global energy demands through renewable sources. However, these structures can have adverse impacts on airborne wildlife, such as posing a potential collision risk with the turbine structure. A range of methods and technologies have been applied to the collection of bird flight parameters, such as height and speed, to improve the estimation of potential collision compared with traditional visual methods, but these are currently not applied in a consistent and systematic way. To this end, a systematic literature search was conducted to (1) examine the methods and technologies that can be used to provide bird flight data to assess the impact of wind energy developments and (2) provide an updated framework to guide how they might be most usefully applied within the impact assessment process. Four empirical measurement methods were found that improve the estimation of bird flight parameters: radar, telemetry, ornithodolite and LiDAR. These empirical sensor-based tools were typically more often applied in academic peer-reviewed papers than in report-based environmental statements. Where sensor-based tools have been used in the report-based literature, their inconsistent application has resulted in an uncertain regulatory environment for practitioners. Our framework directly incorporates sensor-based methods, together with their limitations and data requirements, from pre-deployment of infrastructure to post-consent monitoring of impacts. This revised approach will help improve the accuracy of estimation of bird flight parameters for ornithological assessment of wind energy. Sensor-based tools may not be the most cost-effective. However, a precedent has been set for wind energy development consent refusal based on ornithological impact assessment, and therefore the cost of collecting accurate and reliable flight data may be balanced favourably against the cost of development consent refusalacceptedVersio

Dissociation by steroids of eosinophilic inflammation from airway hyperresponsiveness in murine airways

Background The link between eosinophils and the development of airway hyperresponsiveness (AHR) in asthma is still controversial. This question was assessed in a murine model of asthma in which we performed a dose ranging study to establish whether the dose of steroid needed to inhibit the eosinophil infiltration correlated with that needed to block AHR. Methods The sensitised BALB/c mice were dosed with vehicle or dexamethasone (0.01–3 mg/kg) 2 hours before and 6 hours after each challenge (once daily for 6 days) and 2 hours before AHR determination by whole-body plethysmography. At 30 minutes after the AHR to aerosolised methacholine the mice were lavaged and differential white cell counts were determined. Challenging with antigen caused a significant increase in eosinophils in the bronchoalveolar lavage (BAL) fluid and lung tissue, and increased AHR. Results Dexamethasone reduced BAL and lung tissue eosinophilia (ED50 values of 0.06 and 0.08 mg/kg, respectively), whereas a higher dose was needed to block AHR (ED50 of 0.32 mg/kg at 3 mg/ml methacholine. Dissociation was observed between the dose of steroid needed to affect AHR in comparison with eosinophilia and suggests that AHR is not a direct consequence of eosinophilia. Conclusion This novel pharmacological approach has revealed a clear dissociation between eosinophilia and AHR by using steroids that are the mainstay of asthma therapy. These data suggest that eosinophilia is not associated with AHR and questions the rationale that many pharmaceutical companies are adopting in developing low-molecular-mass compounds that target eosinophil activation/recruitment for the treatment of asthma

Oral immunization with pBsVP6-transgenic alfalfa protects mice against rotavirus infection

AbstractA critical factor in edible plant-derived vaccine development is adequate expression of the exogenous antigens in transgenic plants. We synthesized a codon-optimized gene (sVP6) encoding the VP6 protein of human group A rotavirus and inserted it into the alfalfa genome using agrobacterium-mediated transformation. As much as 0.28% of the total soluble protein of the pBsVP6-transgenic alfalfa was sVP6. Female BALB/c mice were gavaged weekly with 10 mg of transgenic alfalfa extract containing 24 μg of sVP6 protein and 10 μg of CpG-rich oligodeoxynucleotides as mucosal adjuvant. Immunized mice developed high titers of anti-VP6 serum IgG and mucosal IgA. Offspring of immunized dams developed less severe diarrhea after challenge with simian rotavirus SA-11, indicating that antibodies generated in the dams provided passive heterotypic protection to the pups. These results suggest that oral immunization with pBsVP6-transgenic alfalfa provides a potential means of protecting children and young animals from severe acute rotavirus-induced diarrhea

Comparison of immune responses in parenteral FaeG DNA primed pigs boosted orally with F4 protein or reimmunized with the DNA vaccine

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Environmentally sustainable grasshopper control in an ecologically protected habitat

viii, 98 leaves : ill., maps ; 29 cm.Scientific literature indicates potential for using plant extracts to control arthropod pests thereby decreasing the amount of synthetic chemicals introduced into the ecosystem. The research presented below tested several control candidates in a field settig to determine if selected oils can be used to control grasshopper infestations. Two field studies tested the effects of five plant extract oils on grasshopper pests in southern Alberta: Rosmarinus officinalis, Cedrus deodorata, Melaleuca alternifolia, Eucalyptus globulus, and Azadirachta indica. Grasshopper abundance increased in the first study in all plots and decreased in the second study in all plots. A third study was conducted in a greenhouse where grasshoppers were treated with two concentrations of cedarwood and rosemary oil and were monitored for eight days for mortality and behavioural effects. A non-target study was conducted in order to determine if control candidates would negatively affect other beneficial arthropods. Cedarwood, neem oil and carbaryl bait were tested on the mortality of Carabidae and Phalangiidae using pitfall trap sampling

Evaluation of recombinant adenovirus vectors and adjuvanted protein as a heterologous prime-boost strategy using HER2 as a model antigen.

Induction of strong antigen-specific cell-mediated and humoral responses are critical to developing a successful therapeutic vaccine. Herein, using HER2 as a model antigen, we aim to evaluate a therapeutic vaccine protocol that elicits anti-tumor antibody and cytotoxic T cells to HER2/neu antigen. Replication-competent (ΔPS AdV) and non-replicating recombinant adenoviral vectors (AdV) expressing a rat HER2/neu (ErbB2) oncogene, were generated and compared for four different doses and over four time points for their ability to induce antigen-specific T and B cell responses in mice. Although ΔPS AdV:Her2 vector was shown to induce more durable antigen-specific CD8⁺ T cell responses, overall, the AdV:Her2 vector induced broader T and B cell responses. Hence the AdV:Her2 vector was used to evaluate a heterologous prime-boost vaccination regimen using rat HER2 protein encapsulated in archaeosomes composed of a semi-synthetic glycolipid (sulfated S-lactosylarchaeol, SLA; and lactosylarchaeol, LA) (SLA/LA:HER2enc) or admixed with archaeosomes composed of SLA alone (SLA:HER2adm). We first tested AdV:Her2 using a prime-boost approach with SLA/LA:HER2enc, and thereafter evaluated a sub-optimal AdV:Her2 dose in a heterologous prime-boost approach with SLA:HER2adm. A single administration of AdV:Her2 alone induced strong cell-mediated immune responses, whereas SLA/LA:HER2enc alone induced strong antigen-specific IgG titers. In mice primed with a suboptimal dose of AdV:Her2, strong CD8⁺ T-cell responses were observed after a single dose which were not further augmented by protein boost. AdV:Her2 induced CD4⁺ specific T-cell responses were augmented by SLA:HER2adm. Homologous vaccination using SLA:HER2adm induced strong antigen-specific antibody responses. However, the overall magnitude of the responses was similar with three doses of SLA:HER2adm or Ad:HER2 prime followed by two doses of SLA:HER2adm. We demonstrate that AdV:Her2 is capable of inducing strong antigen-specific CD8⁺ T cell responses, even at a low dose, and that these responses can be broadened to include antigen-specific antibody responses by boosting with SLA adjuvanted proteins without compromising CD8 T cell responses elicited by AdV priming