25 resultados para immunological

em Deakin Research Online - Australia


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The project was conducted between May 2006 and September 2007, and involved the collection of effluent samples from 45 wastewater treatment plants (WWTPs). The 45 WWTPs included 16 lagoon-based plants and 29 with activated sludge-based processes. Permission was obtained from all the relevant water authorities to collect samples of final effluent at point of discharge to the environment, whether that was to a creek, a river, the ocean, or the land. Samples were collected on two occasions, namely, in August 2006 (winter) and late February–early March 2007 (summer), and subjected to a number of biological and chemical analyses, including toxicity tests, measurement of hormonal (estrogenic) activity using yeast-based bioassays, and measurement of specific hormonal concentrations using enzyme-linked immunosorbent assays (ELISAs). Almost all of the effluents examined showed estrogenic activity: in winter, no activity to 73 ng/l 17β-estradiol equivalents (EEQ); and in summer, no activity to 20 ng/l EEQ. On the whole, the levels of estrogenic activity observed were comparable with the range recently reported in Australia and New Zealand using human estrogen receptor-based assays (“not detected” to ~10 ng/l EEQ). The low/no bioassay response was confirmed by the chemical assessment of estradiol, estrone, and ethinyl estradiol concentrations by ELISA, which returned concentrations of these compounds for the most part below 10 ng/l.

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Inspired by the human immune system, and in particular the negative selection algorithm, we propose a learning mechanism that enables the detection of abnormal activities. Three detectors for detecting abnormal activity are generated using negative selection. Tracks gathered by people’s movements in a room are used for experimentation and results have shown that the classifier is able to discriminate abnormal from normal activities in terms of both trajectory and time spent at a location.

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Inspired by the human immune system, and in particular the negative selection algorithm, we propose a learning mechanism that enables the detection of abnormal activities. Three types of detectors for detecting abnormal activity are developed using negative selection. Tracks gathered by people's movements in a room are used for experimentation and results have shown that the classifier is able to discriminate abnormal from normal activities in terms of both trajectory and time spent at a location.

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Exercise at regular intervals is assumed to have a positive effect on immune functions. Conversely, after spaceflight and under simulated weightlessness (e.g., bed rest), immune functions can be suppressed. We aimed to assess the effects of simulated weightlessness (Second Berlin BedRest Study; BBR2-2) on immunological parameters and to investigate the effect of exercise (resistive exercise with and without vibration) on these changes. Twenty-four physically and mentally healthy male volunteers (20-45 years) performed resistive vibration exercise (n=7), resistance exercise without vibration (n=8) or no exercise (n=9) within 60 days of bed rest. Blood samples were taken 2 days before bed rest, on days 19 and 60 of bed rest. Composition of immune cells was analyzed by flow cytometry. Cytokines and neuroendocrine parameters were analyzed by Luminex technology and ELISA/RIA in plasma. General changes over time were identified by paired t-test, and exercise-dependent effects by pairwise repeated measurements (analysis of variance (ANOVA)). With all subjects pooled, the number of granulocytes, natural killer T cells, hematopoietic stem cells and CD45RA and CD25 co-expressing T cells increased and the number of monocytes decreased significantly during the study; the concentration of eotaxin decreased significantly. Different impacts of exercise were seen for lymphocytes, B cells, especially the IgD(+) subpopulation of B cells and the concentrations of IP-10, RANTES and DHEA-S. We conclude that prolonged bed rest significantly impacts immune cell populations and cytokine concentrations. Exercise was able to specifically influence different immunological parameters. In summary, our data fit the hypothesis of immunoprotection by exercise and may point toward even superior effects by resistive vibration exercise.Cellular & Molecular Immunology advance online publication, 10 November 2014; doi:10.1038/cmi.2014.106.

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 The study demonstrated that peanut allergens were able to adhere and cross a model of the intestinal epithelium. Peanut contact causes a decrease in barrier integrity and mislocalisation of tight junctions. Both allergens are endocytosed by multiple endocytotic mechanisms, which are useful targets for the development of future therapeutics.

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IgE-mediated allergy to chicken egg affects a large number of children and adults worldwide. The current management strategy for egg allergy is strict avoidance, however this is impractical due to the presence of eggs in a range of foods and pharmaceutical products including vaccines. Strict avoidance also poses nutritional disadvantages due to high nutritional value of eggs. Allergen specific immunotherapy is being pursued as a curative treatment, in which an allergic individual is gradually exposed to the allergen to induce tolerance. Use of recombinant proteins for immunotherapy has been beneficial due to the purity of the recombinant proteins compared to natural proteins. In this study, we produced IgE reactive recombinant egg white proteins that can be used for future immunotherapy. Using E. coli as an expression system, we successfully produced recombinant versions of Gal d 1, 2 and 3, that were IgE reactive when tested against a pool of egg allergic patients' sera. The IgE reactivity indicates that these recombinant proteins are capable of eliciting an immune response, thus being potential candidates for immunotherapy. We have, for the first time, attempted to produce recombinant versions of all 4 major egg white allergens in E. coli, and successfully produced 3, with only Gal d 4 showing loss of IgE reactivity in the recombinant version. The results suggest that egg allergy in Australian populations may mainly be due to IgE reactivity to Gal d 3 and 4, while Gal d 1 shows higher IgE reactivity. This is the first report of a collective and comparative immunological analysis of all 4 egg white allergens. The significance of this study is the potential use of the IgE reactive recombinant egg white proteins in immunotherapy to treat egg allergic patients.

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Allergy to hen's (Gallus domesticus) egg white is one of the most common forms of food allergy. Allergy to hen's yolk also exists however, to a lesser extent when compared to egg white allergy. Two minor allergens from the hen's egg yolk known as α-livetin (Gal d 5) and YGP42 (Gal d 6) were discovered recently. In this study, we investigated whether sensitization to egg white is associated with reactivity to egg yolk as well. Sera obtained from 25 patients with allergy to egg white were tested for specific IgE binding for egg yolk proteins through western immunoblotting. 36% of patients were found with true IgE-sensitization against egg yolk proteins. It was found that most of the IgE reactive yolk proteins were fragments of major precursor proteins of hen; vitellogenin-1 (VTG-1), vitellogenin-2 (VTG-2) and apolipoprotein B (Apo B). The egg yolk allergen Gal d 6 is the C-terminal part of VTG-1 and was found to be allergenic in significant percentage of egg white allergy patients. These results highlight the significance of Gal d 6 as an important allergen of egg yolk. Therefore, the secondary aim of this study involved developing a recombinant version of YGP42 in an Escherichia coli expression system. Recombinant Gal d 6 (rGal d6) was expressed as a fusion peptide with a 6 × His tag and purified using metal chelating resin. The inhibition ELISA results showed that rYGP42 was IgE reactive and was able to inhibit IgE binding to crude egg yolk (CEY) by up to 30%. Traditionally, it was thought that allergy to egg yolk occurred independently from sensitization to egg white. This study underlies the importance of concomitant sensitization to egg yolk proteins in patients allergic to egg white. Evidence reported in this study strongly suggests that egg yolk has potentially undiscovered allergens and therefore warrants further investigation. Furthermore, IgE reactive Gal d 6 presented in this study has the potential to be used in diagnosis and immunotherapy to treat egg allergy.

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Many herbal medicines are widely used as immuno-modulators in Asian countries. Ganoderma lucidum (Lingzhi) is one of the most commonly used herbs in Asia and preclinical studies have established that the polysaccharide fractions of G. lucidum have potent immuno-modulating effects. However, clinical evidence for this is scanty. The present open-labeled study aimed to evaluate the effects of G. lucidum polysaccharides on selected immune functions in patients with advanced colorectal cancer. Forty-seven patients were enrolled and treated with oral G. lucidum at 5.4 g/day for 12 weeks. Selected immune parameters were monitored using various immunological methods throughout the study. In 41 assessable cancer patients, treatment with G. lucidum tended to increase mitogenic reactivity to phytohemagglutinin, counts of CD3, CD4, CD8 and CD56 lymphocytes, plasma concentrations of interleukin (IL)-2, IL-6 and interferon (IFN)-γ, and NK activity, whereas plasma concentrations of IL-1 and tumor necrosis factor (TNF)-α were decreased. For all of these parameters, no statistical significance was observed when a comparison was conducted between baseline and those values after a 12-week treatment with G. lucidum. The changes of IL-1 were correlated with those for IL-6, IFN-γ, CD3, CD4, CD8 and NK activity (p < 0.05) and IL-2 changes were correlated with those for IL-6, CD8 and NK activity. The results indicate that G. lucidum may have potential immuno-modulating effect in patients with advanced colorectal cancer. Further studies are needed to explore the benefits and safety of G. lucidum in cancer patients.

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Human telomerase reverse transcriptase (hTERT) underlies cancer cell immortalization, and the expression of hTERT is regulated strictly at the gene transcription. Here, we report that transcription factor Ets2 is required for hTERT gene expression and breast cancer cell proliferation. Silencing Ets2 induces a decrease of hTERT gene expression and increase in human breast cancer cell death. Reconstitution with recombinant hTERT rescues the apoptosis induced by Ets2 depression. In vitro and in vivo analyses show that Ets2 binds to the EtsA and EtsB DNA motifs on the hTERT gene promoter. Mutation of either Ets2 binding site reduces the hTERT promoter transcriptional activity. Moreover, Ets2 forms a complex with c-Myc as demonstrated by co-immunoprecipitation and glutathione S-transferase pulldown assays. Immunological depletion of Ets2, or mutation of the EtsA DNA motif, disables c-Myc binding to the E-box, whereas removal of c-Myc or mutation of the E-box also compromises Ets2 binding to EtsA. Thus, hTERT gene expression is maintained by a mechanism involving Ets2 interactions with the c-Myc transcription factor and the hTERT gene promoter, a protein-DNA complex critical for hTERT gene expression and breast cancer cell proliferation.

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The function of the immune system of an animal is to provide defence against infection, in order to maximize fitness. Understanding this and, particularly, how limiting resources are traded off between costly immune responses and other physiological demands, is central to properly understanding life-history traits and their evolution. Here, we propose that functional (rather than immunological) measures of immune responses should be used when investigating this. We further suggest that optimal immune responses are context specific, rather than generic; that is, a maximum immune response is not necessarily optimal. The nature of an optimal immune response will depend on the specific circumstances and infection status of the animal. Identifying and understanding such optimality requires that the effects of different immune strategies on fitness be considered.

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1. Immunological imprinting by maternally derived antibodies has been proposed to have both positive and negative consequences for offspring immunity in early and adult life. However, few studies of maternal effects on immunity have followed individuals past the juvenile stages.

2. Using laboratory Japanese quail, we developed a novel method of directly manipulating yolk antibodies of neonates, and then followed individuals through a series of immune challenges until they were of reproductive age.

3. Our method of directly injecting purified antibodies into the yolk sac of newly hatched chicks successfully elevated the plasma titres of specific anti-KLH IgY in neonates. This allows us to test whether differences in neonatal anti-KLH IgY affect immunity at the juvenile and adult stages of life.

4. We found little evidence for an effect of maternal antibodies on juvenile stage immune response, in contrast to results from previous studies. Adult immune response depended largely on the magnitude of the juvenile immune response regardless of the identity of the antigen in the juvenile immune challenge, and did not depend on neonatal IgY titres. Our results are consistent with a priming effect of early immune experience on adult stage immune responsiveness, but we found no evidence of carryover effects of yolk-derived antibodies on adult immunity.

5. This study employs new methodology for investigation of maternal antibodies and presents results suggesting that further studies of maternal effects on immunity will require careful consideration of the numerous ways maternally derived yolk components can impact the different types of immune response.