486 research outputs found

    Update on biomarkers to monitor clinical efficacy response during and post treatment in allergen immunotherapy

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    Allergen immunotherapy (AIT) is an immune modulating treatment for allergic diseases. Although highly effective, some patients do not respond to the treatment. To date there are no surrogate biomarkers that are predictive of the clinical response to AIT. More and more is known about the underlying immunological mechanism involved in AIT. Through modulation of both innate and adaptive immune responses, involving reduced ILC2 and enhanced Treg and Breg induction and functionality, along with induction of IgG4 antibody production which have the capacity to inhibit both allergen-induced basophil responsiveness and CD23-mediated IgE-facilitated allergen presentation, the result is an immune skewing towards a more balanced Type I response. So far, however there is not a clear correlation with the observed immunological changes and predictive correlates of clinical efficacy. The most promising biomarker of successful AIT is IgE-FAB as a reflection of functional IgG4. Cellular responses and cytokine analysis gives a great deal of insight into the mechanisms of AIT but may not represent useful or indeed reliable biomarkers in a clinical setting. There is a need for more research for confirmation and interpretation of the possible association with biomarkers and clinical response to AIT

    Nasal Lipopolysaccharide Challenge and Cytokine Measurement Reflects Innate Mucosal Immune Responsiveness

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    <div><p>Background</p><p><b>P</b>ractical methods of monitoring innate immune mucosal responsiveness are lacking. Lipopolysaccharide (LPS) is a component of the cell wall of Gram negative bacteria and a potent activator of Toll-like receptor (TLR)-4. To measure LPS responsiveness of the nasal mucosa, we administered LPS as a nasal spray and quantified chemokine and cytokine levels in mucosal lining fluid (MLF).</p><p>Methods</p><p>We performed a 5-way cross-over, single blind, placebo-controlled study in 15 healthy non-atopic subjects (n = 14 <i>per protocol</i>). Doses of ultrapure LPS (1, 10, 30 or 100μg/100μl) or placebo were administered by a single nasal spray to each nostril. Using the recently developed method of nasosorption with synthetic adsorptive matrices (SAM), a series of samples were taken. A panel of seven cytokines/chemokines were measured by multiplex immunoassay in MLF. mRNA for intercellular cell adhesion molecule-1 (ICAM-1) was quantified from nasal epithelial curettage samples taken before and after challenge.</p><p>Results</p><p>Topical nasal LPS was well tolerated, causing no symptoms and no visible changes to the nasal mucosa. LPS induced dose-related increases in MLF levels of IL-1β, IL-6, CXCL8 (IL-8) and CCL3 (MIP-1α) (AUC at 0.5 to 10h, compared to placebo, p<0.05 at 30 and 100μg LPS). At 100μg LPS, IL-10, IFN-α and TNF-α were also increased (p<0.05). Dose-related changes in mucosal ICAM-1 mRNA were also seen after challenge, and neutrophils appeared to peak in MLF at 8h. However, 2 subjects with high baseline cytokine levels showed prominent cytokine and chemokine responses to relatively low LPS doses (10μg and 30μg LPS).</p><p>Conclusions</p><p>Topical nasal LPS causes dose-dependent increases in cytokines, chemokines, mRNA and cells. However, responsiveness can show unpredictable variations, possibly because baseline innate tone is affected by environmental factors. We believe that this new technique will have wide application in the study of the innate immune responses of the respiratory mucosa.</p><p>Key Messages</p><p>Ultrapure LPS was used as innate immune stimulus in a human nasal challenge model, with serial sampling of nasal mucosal lining fluid (MLF) by nasosorption using a synthetic absorptive matrix (SAM), and nasal curettage of mucosal cells. A dose response could be demonstrated in terms of levels of IL-1β, IL-6, CXCL8 and CCL3 in MLF, as well as ICAM-1 mRNA in nasal curettage specimens, and levels of neutrophils in nasal lavage. Depending on higher baseline levels of inflammation, there were occasional magnified innate inflammatory responses to LPS.</p><p>Trial Registration</p><p>Clinical Trials.gov <a href="https://clinicaltrials.gov/ct2/show/NCT02284074?term=nasal+lipopolysaccharide&rank=1" target="_blank">NCT02284074</a></p></div

    A short-term mouse model that reproduces the immunopathological features of rhinovirus-induced exacerbation of COPD

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    © 2015 The Author(s). Viral exacerbations of chronic obstructive pulmonary disease (COPD), commonly caused by rhinovirus (RV) infections, are poorly controlled by current therapies. This is due to a lack of understanding of the underlying immunopathological mechanisms. Human studies have identified a number of key immune responses that are associated with RV-induced exacerbations including neutrophilic inflammation, expression of inflammatory cytokines and deficiencies in innate anti-viral interferon. Animal models of COPD exacerbation are required to determine the contribution of these responses to disease pathogenesis. We aimed to develop a short-term mouse model that reproduced the hallmark features of RV-induced exacerbation of COPD. Evaluation of complex protocols involving multiple dose elastase and lipopolysaccharide (LPS) administration combined with RV1B infection showed suppression rather than enhancement of inflammatory parameters compared with control mice infected with RV1B alone. Therefore, these approaches did not accurately model the enhanced inflammation associated with RV infection in patients with COPD compared with healthy subjects. In contrast, a single elastase treatment followed by RV infection led to heightened airway neutrophilic and lymphocytic inflammation, increased expression of tumour necrosis factor (TNF)-α, C-X-C motif chemokine 10 (CXCL10)/IP-10 (interferon γ-induced protein 10) and CCL5 [chemokine (C-C motif) ligand 5]/RANTES (regulated on activation, normal T-cell expressed and secreted), mucus hypersecretion and preliminary evidence for increased airway hyper-responsiveness compared with mice treated with elastase or RV infection alone. In summary, we have developed a new mouse model of RV-induced COPD exacerbation that mimics many of the inflammatory features of human disease. This model, in conjunction with human models of disease, will provide an essential tool for studying disease mechanisms and allow testing of novel therapies with potential to be translated into clinical practice

    Identification of novel macrolides with antibacterial, anti-inflammatory and type I and III IFN-augmenting activity in airway epithelium

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    BACKGROUND: Exacerbations of asthma and COPD are triggered by rhinoviruses. Uncontrolled inflammatory pathways, pathogenic bacterial burden and impaired antiviral immunity are thought to be important factors in disease severity and duration. Macrolides including azithromycin are often used to treat the above diseases, but exhibit variable levels of efficacy. Inhaled corticosteroids are also readily used in treatment, but may lack specificity. Ideally, new treatment alternatives should suppress unwanted inflammation, but spare beneficial antiviral immunity. METHODS: In the present study, we screened 225 novel macrolides and tested them for enhanced antiviral activity against rhinovirus, as well as anti-inflammatory activity and activity against Gram-positive and Gram-negative bacteria. Primary bronchial epithelial cells were grown from 10 asthmatic individuals and the effects of macrolides on rhinovirus replication were also examined. Another 30 structurally similar macrolides were also examined. RESULTS: The oleandomycin derivative Mac5, compared with azithromycin, showed superior induction (up to 5-fold, EC50 = 5-11 μM) of rhinovirus-induced type I IFNβ, type III IFNλ1 and type III IFNλ2/3 mRNA and the IFN-stimulated genes viperin and MxA, yet had no effect on IL-6 and IL-8 mRNA. Mac5 also suppressed rhinovirus replication at 48 h, proving antiviral activity. Mac5 showed antibacterial activity against Gram-positive Streptococcus pneumoniae; however, it did not have any antibacterial properties compared with azithromycin when used against Gram-negative Escherichia coli (as a model organism) and also the respiratory pathogens Pseudomonas aeruginosa and non-typeable Haemophilus influenzae. Further non-toxic Mac5 derivatives were identified with various anti-inflammatory, antiviral and antibacterial activities. CONCLUSIONS: The data support the idea that macrolides have antiviral properties through a mechanism that is yet to be ascertained. We also provide evidence that macrolides can be developed with anti-inflammatory, antibacterial and antiviral activity and show surprising versatility depending on the clinical need

    Accreting Black Holes

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    This chapter provides a general overview of the theory and observations of black holes in the Universe and on their interpretation. We briefly review the black hole classes, accretion disk models, spectral state classification, the AGN classification, and the leading techniques for measuring black hole spins. We also introduce quasi-periodic oscillations, the shadow of black holes, and the observations and the theoretical models of jets.Comment: 41 pages, 18 figures. To appear in "Tutorial Guide to X-ray and Gamma-ray Astronomy: Data Reduction and Analysis" (Ed. C. Bambi, Springer Singapore, 2020). v3: fixed some typos and updated some parts. arXiv admin note: substantial text overlap with arXiv:1711.1025

    Neuroblastoma Cell Death is Induced by Inorganic Arsenic Trioxide (As2O3) and Inhibited by a Normal Human Bone Marrow Cell-Derived Factor

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    Three phenotypically distinct cell types are present in human neuroblastomas (NB) and NB cell lines: I-type stem cells, N-type neuroblastic precursors, and S-type Schwannian/melanoblastic precursors. The stimulation of human N-type neuroblastoma cell proliferation by normal human bone marrow monocytic cell conditioned medium (BMCM) has been demonstrated in vitro, a finding consistent with the high frequency of bone marrow (BM) metastases in patients with advanced NB. Inorganic arsenic trioxide (As2O3), already clinically approved for the treatment of several hematological malignancies, is currently under investigation for NB. Recent studies show that As2O3 induces apoptosis in NB cells. We examined the impact of BMCM on growth and survival of As2O3-treated NB cell lines, to evaluate the response of cultured NB cell variants to regulatory agents. We studied the effect of BMCM on survival and clonogenic growth of eleven As2O3-treated NB cell lines grown in sparsely seeded, non-adherent, semi-solid cultures. As2O3 had a strong inhibitory effect on survival of all tested NB cell lines. BMCM augmented cell growth and survival and reversed the inhibitory action of As2O3 in all tested cell lines, but most strongly in N-type cells. While As2O3 effectively reduced survival of all tested NB cell lines, BMCM effectively impacted its inhibitory action. Better understanding of micro-environmental regulators affecting human NB tumor cell growth and survival may be seminal to the development of therapeutic strategies and clinically effective agents for this condition

    In Search of Cellular Immunophenotypes in the Blood of Children with Autism

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    Autism is a neurodevelopmental disorder characterized by impairments in social behavior, communication difficulties and the occurrence of repetitive or stereotyped behaviors. There has been substantial evidence for dysregulation of the immune system in autism.We evaluated differences in the number and phenotype of circulating blood cells in young children with autism (n = 70) compared with age-matched controls (n = 35). Children with a confirmed diagnosis of autism (4-6 years of age) were further subdivided into low (IQ<68, n = 35) or high functioning (IQ ≥ 68, n = 35) groups. Age- and gender-matched typically developing children constituted the control group. Six hundred and forty four primary and secondary variables, including cell counts and the abundance of cell surface antigens, were assessed using microvolume laser scanning cytometry.There were multiple differences in immune cell populations between the autism and control groups. The absolute number of B cells per volume of blood was over 20% higher for children with autism and the absolute number of NK cells was about 40% higher. Neither of these variables showed significant difference between the low and high functioning autism groups. While the absolute number of T cells was not different across groups, a number of cellular activation markers, including HLA-DR and CD26 on T cells, and CD38 on B cells, were significantly higher in the autism group compared to controls.These results support previous findings that immune dysfunction may occur in some children with autism. Further evaluation of the nature of the dysfunction and how it may play a role in the etiology of autism or in facets of autism neuropathology and/or behavior are needed
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