141 research outputs found
T helper cell subsets specific for pseudomonas aeruginosa in healthy individuals and patients with cystic fibrosis
Background: We set out to determine the magnitude of antigen-specific memory T helper cell responses to Pseudomonas aeruginosa in healthy humans and patients with cystic fibrosis.
Methods: Peripheral blood human memory CD4+ T cells were co-cultured with dendritic cells that had been infected with different strains of Pseudomonas aeruginosa. The T helper response was determined by measuring proliferation, immunoassay of cytokine output, and immunostaining of intracellular cytokines.
Results: Healthy individuals and patients with cystic fibrosis had robust antigen-specific memory CD4+ T cell responses to Pseudomonas aeruginosa that not only contained a Th1 and Th17 component but also Th22 cells. In contrast to previous descriptions of human Th22 cells, these Pseudomonal-specific Th22 cells lacked the skin homing markers CCR4 or CCR10, although were CCR6+. Healthy individuals and patients with cystic fibrosis had similar levels of Th22 cells, but the patient group had significantly fewer Th17 cells in peripheral blood.
Conclusions: Th22 cells specific to Pseudomonas aeruginosa are induced in both healthy individuals and patients with cystic fibrosis. Along with Th17 cells, they may play an important role in the pulmonary response to this microbe in patients with cystic fibrosis and other conditions
Ξ³Ξ΄ T lymphocytes from cystic fibrosis patients and healthy donors are high TNF-Ξ± and IFN-Ξ³-producers in response to Pseudomonas aeruginosa
BACKGROUND: Ξ³Ξ΄ T cells have an important immunoregulatory and effector function through cytokine release. They are involved in the responses to Gram-negative bacterium and in protection of lung epithelium integrity. On the other hand, they have been implicated in airway inflammation. METHODS: The aim of the present work was to study intracytoplasmic IL-2, IL-4, IFN-Ξ³ and TNF-Ξ± production by Ξ³Ξ΄ and Ξ±Ξ² T lymphocytes from cystic fibrosis patients and healthy donors in response to Pseudomonas aeruginosa (PA). Flow cytometric detection was performed after peripheral blood mononuclear cells (PBMC) culture with a cytosolic extract from PA and restimulation with phorbol ester plus ionomycine. Proliferative responses, activation markers and receptor usage of Ξ³Ξ΄ T cells were also evaluated. RESULTS: The highest production of cytokine was of TNF-Ξ± and IFN-Ξ³, Ξ³Ξ΄ being better producers than Ξ±Ξ². No differences were found between patients and controls. The VΞ³9Ξ΄2 subset of Ξ³Ξ΄ T cells was preferentially expanded. CD25 and CD45RO expression by the Ξ±Ξ² T subset and PBMC proliferative response to PA were defective in cystic fibrosis lymphocytes. CONCLUSION: Our results support the hypothesis that Ξ³Ξ΄ T lymphocytes play an important role in the immune response to PA and in the chronic inflammatory lung reaction in cystic fibrosis patients. They do not confirm the involvement of a supressed Th1 cytokine response in the pathogenesis of this disease
A Phase Ib dose-escalation study to evaluate safety and tolerability of the addition of the aminopeptidase inhibitor tosedostat (CHR-2797) to paclitaxel in patients with advanced solid tumours
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89517timmer-bonte.pdf (publisher's version ) (Closed access)BACKGROUND: This Phase Ib dose-escalating study investigated safety, maximum tolerated dose (MTD), dose-limiting toxicity (DLT), pharmacokinetics (PK) and clinical antitumour activity of tosedostat (CHR-2797), an orally bioavailable aminopeptidase inhibitor, in combination with paclitaxel. METHODS: A total of 22 patients received paclitaxel (135-175 mg m(-2)) intravenously, administered once every three weeks for up to six cycles, with oral tosedostat (90-240 mg) daily. RESULTS: One DLT (grade 3 dyspnoea) was observed in one patient with tosedostat 180 mg combined with paclitaxel 175 mg m(-2). A high number of paclitaxel infusion reactions was noted during the second administration (59%) and this prompted interruption of tosedostat dosing for 5 days around every second and subsequent paclitaxel infusion. No formal MTD was determined because of the high frequency of paclitaxel infusion reactions that may have been influenced by tosedostat. Most frequently observed drug-related adverse events were alopecia, fatigue (95% each), peripheral sensory neuropathy (59%), paclitaxel hypersensitivity (59%) and rash (55%). One patient died because of eosinophilic myocarditis, possibly related to study medication. There was no PK interaction between tosedostat and paclitaxel. In all, 3 patients had a partial response and 12 patients had stable disease lasting >3 months. CONCLUSION: The combination of tosedostat with paclitaxel was well tolerated except for the high incidence of paclitaxel-related infusion reactions
Antibodies Targeted to the Brain with Image-Guided Focused Ultrasound Reduces Amyloid-Ξ² Plaque Load in the TgCRND8 Mouse Model of Alzheimer's Disease
Immunotherapy for Alzheimer's disease (AD) relies on antibodies directed against toxic amyloid-beta peptide (AΞ²), which circulate in the bloodstream and remove AΞ² from the brain [1], [2]. In mouse models of AD, the administration of anti-AΞ² antibodies directly into the brain, in comparison to the bloodstream, was shown to be more efficient at reducing AΞ² plaque pathology [3], [4]. Therefore, delivering anti-AΞ² antibodies to the brain of AD patients may also improve treatment efficiency. Transcranial focused ultrasound (FUS) is known to transiently-enhance the permeability of the blood-brain barrier (BBB) [5], allowing intravenously administered therapeutics to enter the brain [6]β[8]. Our goal was to establish that anti-AΞ² antibodies delivered to the brain using magnetic resonance imaging-guided FUS (MRIgFUS) [9] can reduce plaque pathology. To test this, TgCRND8 mice [10] received intravenous injections of MRI and FUS contrast agents, as well as anti-AΞ² antibody, BAM-10. MRIgFUS was then applied transcranially. Within minutes, the MRI contrast agent entered the brain, and BAM-10 was later found bound to AΞ² plaques in targeted cortical areas. Four days post-treatment, AΞ² pathology was significantly reduced in TgCRND8 mice. In conclusion, this is the first report to demonstrate that MRIgFUS delivery of anti-AΞ² antibodies provides the combined advantages of using a low dose of antibody and rapidly reducing plaque pathology
Optimal free descriptions of many-body theories
Interacting bosons or fermions give rise to some of the most fascinating phases of matter, including high-temperature superconductivity, the fractional quantum Hall effect, quantum spin liquids and Mott insulators. Although these systems are promising for technological applications, they also present conceptual challenges, as they require approaches beyond mean-field and perturbation theory. Here we develop a general framework for identifying the free theory that is closest to a given interacting model in terms of their ground-state correlations. Moreover, we quantify the distance between them using the entanglement spectrum. When this interaction distance is small, the optimal free theory provides an effective description of the low-energy physics of the interacting model. Our construction of the optimal free model is non-perturbative in nature; thus, it offers a theoretical framework for investigating strongly correlated systems
Viral Evolution and Cytotoxic T Cell Restricted Selection in Acute Infant HIV-1 Infection
Antiretroviral therapy-naive HIV-1 infected infants experience poor viral containment and rapid disease progression compared to adults. Viral factors (e.g. transmitted cytotoxic T- lymphocyte (CTL) escape mutations) or infant factors (e.g. reduced CTL functional capacity) may explain this observation. We assessed CTL functionality by analysing selection in CTL-targeted HIV-1 epitopes following perinatal infection. HIV-1 gag, pol and nef sequences were generated from a historical repository of longitudinal specimens from 19 vertically infected infants. Evolutionary rate and selection were estimated for each gene and in CTL-restricted and non-restricted epitopes. Evolutionary rate was higher in nef and gag vs. pol, and lower in infants with non-severe immunosuppression vs. severe immunosuppression across gag and nef. Selection pressure was stronger in infants with non-severe immunosuppression vs. severe immunosuppression across gag. The analysis also showed that infants with non-severe immunosuppression had stronger selection in CTL-restricted vs. non-restricted epitopes in gag and nef. Evidence of stronger CTL selection was absent in infants with severe immunosuppression. These data indicate that infant CTLs can exert selection pressure on gag and nef epitopes in early infection and that stronger selection across CTL epitopes is associated with favourable clinical outcomes. These results have implications for the development of paediatric HIV-1 vaccines
Application of Equilibrium Models of Solution Hybridization to Microarray Design and Analysis
Background: The probe percent bound value, calculated using multi-state equilibrium models of solution hybridization, is shown to be useful in understanding the hybridization behavior of microarray probes having 50 nucleotides, with and without mismatches. These longer oligonucleotides are in widespread use on microarrays, but there are few controlled studies of their interactions with mismatched targets compared to 25-mer based platforms. Principal Findings: 50-mer oligonucleotides with centrally placed single, double and triple mismatches were spotted on an array. Over a range of target concentrations it was possible to discriminate binding to perfect matches and mismatches, and the type of mismatch could be predicted accurately in the concentration midrange (100 pM to 200 pM) using solution hybridization modeling methods. These results have implications for microarray design, optimization and analysis methods. Conclusions: Our results highlight the importance of incorporating biophysical factors in both the design and the analysis of microarrays. Use of the probe ββpercent boundβ β value predicted by equilibrium models of hybridization is confirmed to be important for predicting and interpreting the behavior of long oligonucleotide arrays, as has been shown for shor
Sex matters during adolescence: Testosterone-related cortical thickness maturation differs between boys and girls
Age-related changes in cortical thickness have been observed during adolescence, including thinning in frontal and parietal cortices, and thickening in the lateral temporal lobes. Studies have shown sex differences in hormone-related brain maturation when boys and girls are age-matched, however, because girls mature 1-2 years earlier than boys, these sex differences could be confounded by pubertal maturation. To address puberty effects directly, this study assessed sex differences in testosterone-related cortical maturation by studying 85 boys and girls in a narrow age range and matched on sexual maturity. We expected that testosterone-by-sex interactions on cortical thickness would be observed in brain regions known from the animal literature to be high in androgen receptors. We found sex differences in associations between circulating testosterone and thickness in left inferior parietal lobule, middle temporal gyrus, calcarine sulcus, and right lingual gyrus, all regions known to be high in androgen receptors. Visual areas increased with testosterone in boys, but decreased in girls. All other regions were more impacted by testosterone levels in girls than boys. The regional pattern of sex-by-testosterone interactions may have implications for understanding sex differences in behavior and adolescent-onset neuropsychiatric disorders. Β© 2012 Bramen et al
Identification, Expression and Target Gene Analyses of MicroRNAs in Spodoptera litura
MicroRNAs (miRNAs) are small RNAs widely present in animals and plants and involved in post-transcriptional regulation of gene transcripts. In this study we identified and validated 58 miRNAs from an EST dataset of Spodoptera litura based on the computational and experimental analysis of sequence conservation and secondary structure of miRNA by comparing the miRNA sequences in the miRbase. RT-PCR was conducted to examine the expression of these miRNAs and stem-loop RT-PCR assay was performed to examine expression of 11 mature miRNAs (out of the 58 putative miRNA) that showed significant changes in different tissues and stages of the insect development. One hundred twenty eight possible target genes against the 11 miRNAs were predicted by using computational methods. Binding of one miRNA (sli-miR-928b) with the three possible target mRNAs was confirmed by Southern blotting, implying its possible function in regulation of the target genes
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