Stat3 promotes IL-10 expression in lupus T cells through trans-activation and chromatin remodeling.

The immune-regulatory cytokine IL-10 plays a central role during innate and adaptive immune responses. IL-10 is elevated in the serum and tissues of patients with systemic lupus erythematosus (SLE), an autoimmune disorder characterized by autoantibody production, immune-complex formation, and altered cytokine expression. Because of its B cell-promoting effects, IL-10 may contribute to autoantibody production and tissue damage in SLE. We aimed to determine molecular events governing T cell-derived IL-10 expression in health and disease. We link reduced DNA methylation of the IL10 gene with increased recruitment of Stat family transcription factors. Stat3 and Stat5 recruitment to the IL10 promoter and an intronic enhancer regulate gene expression. Both Stat3 and Stat5 mediate trans-activation and epigenetic remodeling of IL10 through their interaction with the histone acetyltransferase p300. In T cells from SLE patients, activation of Stat3 is increased, resulting in enhanced recruitment to regulatory regions and competitive replacement of Stat5, subsequently promoting IL-10 expression. A complete understanding of the molecular events governing cytokine expression will provide new treatment options in autoimmune disorders, including SLE. The observation that altered activation of Stat3 influences IL-10 expression in T cells from SLE patients offers molecular targets in the search for novel target-directed treatment options.

A T cell gene expression panel for the diagnosis and monitoring of disease activity in patients with systemic lupus erythematosus.

Systemic Lupus Erythematosus (SLE) remains a challenging disease to diagnose and follow, as no reliable biomarkers are known to date. We designed a gene expression panel with 40 genes known to play a role in SLE pathogenesis. We found that the combined expression of these genes in SLE T cells can accurately differentiate SLE from healthy individuals and patients with other autoimmune diseases. The accuracy of the test increased further (83%) when only three out of the initial genes (OAS2, CD70 and IL10) were used. A T cell score, calculated from the combined expression levels of these genes, correlated positively with various SLE activity markers in a cross-sectional cohort and in a few patients that were followed prospectively. These data showcase the usefulness of measuring mRNA levels of key molecules in diagnosing and following patients with SLE.

Spleen tyrosine kinase (Syk) regulates systemic lupus erythematosus (SLE) T cell signaling.

Engagement of the CD3/T cell receptor complex in systemic lupus erythematosus (SLE) T cells involves Syk rather than the zeta-associated protein. Because Syk is being considered as a therapeutic target we asked whether Syk is central to the multiple aberrantly modulated molecules in SLE T cells. Using a gene expression array, we demonstrate that forced expression of Syk in normal T cells reproduces most of the aberrantly expressed molecules whereas silencing of Syk in SLE T cells normalizes the expression of most abnormally expressed molecules. Protein along with gene expression modulation for select molecules was confirmed. Specifically, levels of cytokine IL-21, cell surface receptor CD44, and intracellular molecules PP2A and OAS2 increased following Syk overexpression in normal T cells and decreased after Syk silencing in SLE T cells. Our results demonstrate that levels of Syk affect the expression of a number of enzymes, cytokines and receptors that play a key role in the development of disease pathogenesis in SLE and provide support for therapeutic targeting in SLE patients.

Splicing factor SF2/ASF rescues IL-2 production in T cells from systemic lupus erythematosus patients by activating IL-2 transcription.

T cells from patients with systemic lupus erythematosus (SLE) produce insufficient amounts of the vital cytokine IL-2. We previously showed that SLE T cells express decreased levels of the T-cell receptor-CD3ζ chain and forced expression of CD3ζ into SLE T cells restores IL-2 production. We recently showed that the serine arginine protein splicing factor 2/alternative splicing factor (SF2/ASF) enhances the expression of CD3ζ chain by limiting the production of an unstable splice variant. Here we demonstrate that SF2/ASF levels are decreased in patients with SLE and more so in those with active disease. More importantly, we reveal a function of SF2/ASF, independent of T-cell receptor/CD3 signaling, whereby it is recruited to the IL-2 promoter, increases transcriptional activity, and enhances IL-2 production in SLE T cells. Our results demonstrate that SF2/ASF regulates IL-2 production and that decreased SF2/ASF expression in SLE T cells contributes to deficient IL-2 production.

cAMP-responsive element modulator α (CREMα) contributes to decreased Notch-1 expression in T cells from patients with active systemic lupus erythematosus (SLE).

Notch signaling constitutes an evolutionarily conserved pathway that transduces signals between neighboring cells and determines major decisions in cell proliferation, survival, and differentiation. Notch signaling has been shown to play a pivotal role during T cell lineage determination. T lymphocytes from patients with systemic lupus erythematosus (SLE) display a severely altered phenotype with several molecular and functional aberrations, including defective capacities to up-regulate Notch-1 receptor expression upon T cell receptor activation. Here, we demonstrate that basal Notch-1 expression is decreased in T cells from active SLE patients at the mRNA and protein levels in various T cell subpopulations. Notch-1 transcript numbers inversely correlate with disease activity in SLE patients. We provide evidence that both enhanced histone H3 methylation and CpG DNA methylation of the human Notch-1 promoter contribute to decreased Notch-1 expression in SLE T cells. Previous data from our group identified cAMP-responsive element modulator α (CREMα), which is up-regulated in SLE T cells, as a key regulator of epigenetic patterns and gene transcription, e.g. that of IL2 and IL17 genes. In this study, we observed increased CREMα binding to the Notch-1 promoter, which eventually resulted in significantly reduced Notch-1 promoter activity and gene transcription. Notably, decreased Notch-1 levels were associated with elevated IL-17A levels. Our data suggest a role for Notch-1 in SLE immunopathogenesis, and for the first time, we present molecular mechanisms that mediate dysregulated Notch-1 expression in SLE T cells.

Immunodeficiency and autoimmunity: lessons from systemic lupus erythematosus.

Recent evidence suggests that systemic autoimmunity and immunodeficiency are not separate entities, but rather are interconnected processes. Immunodeficiency results from distinct defects of the immune response and primarily presents as infections but also frequently with autoimmune features. Systemic autoimmunity is the combined effect of multiple genetic variations and infectious and immunoregulatory factors that result in dominant autoimmune manifestations, in addition to frequent and opportunistic infections. The overlap in disease manifestations and symptoms suggests that immunodeficiency should be considered in the presence of autoimmunity, and vice versa. In this review, we present the shared or similar aspects of immunodeficiency and autoimmunity using systemic lupus erythematosus as a paradigm and discuss the implications for clinical care.

Keap1 mutations and Nrf2 pathway activation in epithelial ovarian cancer.

Resistance to platinum-based chemotherapy develops in the majority of patients with epithelial ovarian cancer (EOC). Platinum compounds form electrophilic intermediates that mediate DNA cross-linking and induce double-strand DNA breaks. Because the cellular response to electrophilic xenobiotics is partly mediated by Keap1-Nrf2 pathway, we evaluated the presence of Kelch-like ECH-associated protein 1 (Keap1) mutations and NF-E2-related factor 2 (Nrf2) pathway activation in EOC and correlated these with platinum resistance and clinical outcome. Nrf2 immunohistochemistry revealed nuclear localization (a surrogate of pathway activation) in over half of EOC patient specimens examined, with more common occurrence in the clear cell EOC subtype. Quantitative real-time PCR revealed that Nrf2 target genes were upregulated in tumors with nuclear positivity for Nrf2. Microarray analysis also showed upregulation of Nrf2 target genes in clear cell EOCs compared with other EOC subtypes. In addition, Keap1 sequence analysis revealed genetic mutations in 29% of clear cell samples and 8% of nonclear cell tumors. RNAi-mediated knockdown of Keap1 was associated with Nrf2 pathway activation and resistance to carboplatin in vitro. Importantly, patients with evidence of Nrf2 pathway activation had fewer complete clinical responses to platinum-based therapy, were enriched for platinum resistance, and had shorter median overall survival compared with those who did not show evidence of Nrf2 pathway activation. Our findings identify Keap1 mutations in EOC and they suggest a previously unrecognized role for the Keap1-Nrf2 pathway in mediating chemotherapeutic responses in this disease.

Meta-analyses on pediatric infections and vaccines.

In pediatric infections, meta-analyses have helped clarify several controversial management issues. Unfortunately, many more aspects remain to be elucidated. This is particularly true in the field of UTIs, the most common serious bacterial infections in children, where prospective, well-designed, randomized clinical trials are urgently needed. Regarding vaccines, it is generally acknowledged that, although meta-analyses can provide useful information on their value, people who make decisions and set policies should not rely on that information alone, but rather use it alongside other sources of information. The fact that government policies do not always coincide with conclusions produced by meta-analyses in the field of vaccinations should not be regarded as a failure of the statistical methodology, but rather as a result of the complex societal and financial (cost versus benefit) decisions.

Effectiveness and safety of short vs. long duration of antibiotic therapy for acute bacterial sinusitis: a meta-analysis of randomized trials.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: Treatment guidelines generally support that a 10-14-day antibiotic regimen should be administered to uncomplicated acute bacterial sinusitis patients. However, the level of evidence for such a recommendation is rather weak. Treatment of such duration may have disadvantages compared with a shorter duration but equally effective regimen, including the promotion of bacterial drug resistance, poorest patient compliance, higher toxicity, and a greater overall economic burden. WHAT THIS STUDY ADDS: The findings of this meta-analysis suggest that short-course antibiotic treatment has similar effectiveness to longer-course treatment for patients with acute uncomplicated bacterial sinusitis, when treatment is warranted. However, we should underscore the importance of the clinician's own assessment, so that antimicrobial therapy should not inappropriately be curtailed in a patient not adequately responding to the regimen administered. We sought to evaluate the effectiveness and safety of short-course antibiotic treatment for acute bacterial sinusitis (ABS) compared with longer duration treatment. We performed a meta-analysis of randomized controlled trials (RCTs), identified by searching PubMed and the Cochrane Central Register of Controlled Trials. We included RCTs that compared short-course (up to 7 days) vs. long-course therapy (> or =2 days longer than short-course), with the same antimicrobial agent, in the same daily dosage, for patients with ABS. Twelve RCTs (10 double-blinded) involving adult patients with radiologically confirmed ABS were included. There was no difference in the comparison of short-course (3-7 days) with long-course treatment (6-10 days) regarding clinical success [12 RCTs, 4430 patients, fixed effect model (FEM), odds ratio (OR) 0.95, 95% confidence interval (CI) 0.81, 1.12]; microbiological efficacy; relapses; adverse events (10 RCTs, 4172 patients, random effects model, OR 0.88, 95% CI 0.71, 1.09); or withdrawals due to adverse events. In the sensitivity analysis comparing 5- vs. 10-day regimens, clinical success was similar, although adverse events were fewer with short-course treatment (5 RCTs, 2151 patients, FEM, OR 0.79, 95% CI 0.63, 0.98). Although antibiotics for acute sinusitis should be reserved for select patients with substantial probability of bacterial disease, accurate clinical diagnosis is often difficult to attain. Short-course antibiotic treatment had comparable effectiveness to a longer course of therapy for ABS. Shortened treatment, particularly for patients without severe disease and complicating factors, might lead to fewer adverse events, better patient compliance, lower rates of resistance development and fewer costs.

Therapeutic options for Burkholderia cepacia infections beyond co-trimoxazole: a systematic review of the clinical evidence.

Burkholderia cepacia complex (BCC) is an important group of pathogens affecting patients with cystic fibrosis and chronic granulomatous disease as well as immunocompromised and hospitalised patients. Therapeutic options are limited owing to high levels of resistance of the organism, either intrinsic or acquired, to many antimicrobial agents. Co-trimoxazole (trimethoprim/sulfamethoxazole) has been a drug of choice. However, in some cases it cannot be administered because of allergic or hypersensitivity reactions, intolerance or resistance. We systematically searched for relevant publications including clinical data in PubMed and Scopus. The search identified 48 relevant case reports (57 cases) and 8 cohort studies or trials. Nineteen (33.3%) of 57 patients included in the case reports received ceftazidime-based regimens, 14 (73.7%) of whom were cured. Meropenem was administered in seven patients (12.3%), one (14.3%) of whom improved and five (71.4%) were cured. Seven (12.3%) of 57 cases were treated with penicillins, four of which were piperacillin (all had a favourable outcome). Based on the data reported in the eight relevant cohort studies or trials identified, favourable outcomes were observed in 68.4% (26/38) to 100% (16/16) of cases treated with ceftazidime and 66.7% (6/9) of cases treated with meropenem. Also, 9/12 (75%) of patients receiving penicillins improved. Thus, Ceftazidime, meropenem and penicillins, mainly piperacillin, either alone or in combination with other antimicrobial agents, may be considered as alternative options for BCC infections, according to the in vitro antimicrobial susceptibility patterns and clinical results. However, the available clinical data are not sufficient and further clinical experience is required to clarify the appropriateness of these antibiotics for BCC infections.

Optimal duration of the antimicrobial treatment of ventilator-acquired pneumonia.

The optimal duration of antimicrobial treatment of patients with ventilator-associated pneumonia is a major concern for clinicians. We looked for the evidence that a short course of therapy (< or =10 days) is as effective as a traditional long-course therapy (14-21 days). Unfortunately, only one trial (PneumA trial) has focused directly on this question. To further evaluate this issue, we identified trials in which the duration of anti-infective treatment was used as the outcome. Such trials, by providing data on mortality, length of intensive care unit stay and recurrence, may allow for estimating the association between duration of therapy and the aforementioned outcomes. Nine such trials were identified; all reported a decrease in the total length of antibiotic administration (statistically significant in seven) with the application of the intervention studied. Short, as opposed to long, courses of antibiotics did not adversely affect mortality, length of intensive care unit stay or recurrence rates. In conclusion, the available evidence seems to support the use of short-course antimicrobial treatments (< or =10 days) for patients with ventilator-acquired pneumonia not caused by nonfermenting Gram-negative bacilli.

Potential of old-generation antibiotics to address current need for new antibiotics.

Despite the constantly increasing need for new antimicrobial agents, antibiotic drug discovery and development seem to have greatly decelerated in recent years. Presented with the significant problem of advancing antimicrobial resistance, the global scientific community has attempted to find alternative solutions; one of the most promising ones is the evaluation and use of old antibiotic compounds. Due to the low-level use of many of the old antibiotic compounds, these have remained active against a large number of currently prevalent bacterial isolates. Thus, clinicians are beginning to re-evaluate their use in various patient populations and infections, despite the fact that they were previously thought to be less effective and/or more toxic than newer agents. A number of old antibiotic compounds, such as polymyxins, fosfomycin, fusidic acid, cotrimoxazole, aminoglycosides and chloramphenicol, are re-emerging as valuable alternatives for the treatment of difficult-to-treat infections. The availability of novel genetic and molecular modification methods provides hope that the toxicity and efficacy drawbacks presented by some of these agents can be surpassed in the future.

Short- versus long-course antibacterial therapy for community-acquired pneumonia : a meta-analysis.

BACKGROUND: The evidence for traditionally recommended 7- to 14-day duration of antibacterial therapy for community-acquired pneumonia (CAP) is not well established. OBJECTIVES: We endeavoured to assess the effectiveness and safety of shorter than traditionally recommended antibacterial therapy for CAP. METHODS: We performed a meta-analysis of randomized controlled trials (RCTs) comparing short- (< or = 7 days) versus long- (> or = 2 days difference) course therapy for CAP with the same antibacterial regimens, in the same daily dosages. RESULTS: Five RCTs involving adults (including outpatients and inpatients who did not require intensive care) and two RCTs involving children (aged 2-59 months, residing in developing countries) were included. All RCTs were double-blind and assessed patients with CAP of mild to moderate severity. No differences were found between short- (adults 3-7 days; children 3 days) and long- (adults 7-10 days; children 5 days) course regimens (adults - amoxicillin, cefuroxime, ceftriaxone, telithromycin and gemifloxacin; children - amoxicillin) regarding clinical success at end-of-therapy (six RCTs; 5107 patients [1095 adults, 4012 children]; fixed-effect model [FEM]; odds ratio [OR] = 0.89; 95% CI 0.74, 1.07), clinical success at late follow-up, microbiological success, relapses, mortality (seven RCTs; 5438 patients; FEM; OR = 0.57; 95% CI 0.23, 1.43), adverse events (five RCTs; 3214 patients; FEM; OR = 0. 90; 95% CI 0.72, 1.13) or withdrawals as a result of adverse events. No differences were found in subset analyses of adults or children, and of patients treated with no more than 5-day short-course regimens versus at least 7-day long-course regimens. CONCLUSION: No difference was found in the effectiveness and safety of short- versus long-course antimicrobial treatment of adult and paediatric patients with CAP of mild to moderate severity.

The genetic and environmental basis of atopic diseases.

The prevalence of atopic diseases has increased abruptly in recent years in most Westernized societies, making the question why this happened the topic of a heated debate. The best paradigm available to date to explain this steep rise, the 'hygiene hypothesis', supports that it is the excess 'cleanliness' of our environments that has led to the decline in the number of infectious stimuli that are necessary for the proper development of our immune system. Recent findings support that it is the combined effect that not only pathogenic, but also non-pathogenic microorganisms, and even their structural components,can exert on the immune system that deters from the development of atopic responses. Adding to these results are intriguing new findings on the effect different gene polymorphisms can have on an individual's predisposition to allergic diseases. The most important linkages produced, to date, include those among the genes for IL-4, IL-13, HLA-DRB, TNF, LTA,FCER1B, IL-4RA, ADAM33, TCR alpha/delta, PHF11, GPRA, TIM, p40, CD14, DPP10, T-bet, GATA-3, and FOXP3 and allergic disorders. The two parallel research efforts, epidemiologic and genetic, are only recently starting to converge,producing fascinating results on the effect particular gene-environment interactions might have in the development of atopy.The most important lesson learned through this tremendous research effort is that not only a small number but thousands and millions of separate risk factors act in concordance in the production of the allergic phenotype.

Fluoroquinolones compared with beta-lactam antibiotics for the treatment of acute bacterial sinusitis: a meta-analysis of randomized controlled trials.

BACKGROUND: The presumed superiority of newer fluoroquinolones for the treatment of acute bacterial sinusitis is based on laboratory data but has not yet been established on clinical grounds. METHODS: We performed a meta-analysis of randomized controlled trials comparing the effectiveness and safety of fluoroquinolones and beta-lactams in acute bacterial sinusitis. RESULTS: We identified 8 randomized controlled trials investigating the newer "respiratory" fluoroquinolones moxifloxacin, levofloxacin and gatifloxacin. In the primary effectiveness analysis involving 2133 intention-to-treat patients from 5 randomized controlled trials, the extent of clinical cure and improvement did not differ between fluoroquinolones and beta-lactams (odds ratio [OR] 1.09, 95% confidence interval [CI] 0.85-1.39) at the test-of-cure assessment, which varied from 10 to 31 days after the start of treatment. Fluoroquinolones were associated with an increased chance of clinical success among the clinically evaluable patients in all of the randomized controlled trials (OR 1.29, 95% CI 1.03-1.63) and in 4 blinded randomized controlled trials (OR 1.45, 95% CI 1.05-2.00). There was no statistically significant difference between fluoroquinolones and amoxicillin-clavulanate (OR 1.24, 95% CI 0.93-1.65). Eradication or presumed eradication of the pathogens isolated before treatment was more likely with fluoroquinolone treatment than with beta-lactam treatment (OR 2.11, 95% CI 1.09-4.08). In the primary safety analysis, adverse events did not differ between treatments (OR 1.17, 95% CI 0.86-1.59). However, more adverse events occurred with fluoroquinolone use than with beta-lactam use in 2 blinded randomized controlled trials. The associations described here were generally consistent when we included 3 additional studies involving other fluoroquinolones (ciprofloxacin and sparfloxacin) in the analysis. INTERPRETATION: In the treatment of acute bacterial sinusitis, newer fluoroquinolones conferred no benefit over beta-lactam antibiotics. The use of fluoroquinolones as first-line therapy cannot be endorsed.