We report that in the presence of signal 1 (NF-κB), the NLRP3 inflammasome was activated by mitochondrial apoptotic signaling that licensed production of interleukin-1β (IL-1β). NLRP3 secondary ...signal activators such as ATP induced mitochondrial dysfunction and apoptosis, resulting in release of oxidized mitochondrial DNA (mtDNA) into the cytosol, where it bound to and activated the NLRP3 inflammasome. The antiapoptotic protein Bcl-2 inversely regulated mitochondrial dysfunction and NLRP3 inflammasome activation. Mitochondrial DNA directly induced NLRP3 inflammasome activation, because macrophages lacking mtDNA had severely attenuated IL-1β production, yet still underwent apoptosis. Both binding of oxidized mtDNA to the NLRP3 inflammasome and IL-1β secretion could be competitively inhibited by the oxidized nucleoside 8-OH-dG. Thus, our data reveal that oxidized mtDNA released during programmed cell death causes activation of the NLRP3 inflammasome. These results provide a missing link between apoptosis and inflammasome activation, via binding of cytosolic oxidized mtDNA to the NLRP3 inflammasome.
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► NLRP3 activators induce apoptosis that activates the inflammasome ► Apoptosis is required for NLRP3 activation ► Oxidized mtDNA that is generated during apoptosis binds to NLRP3 and activates it ► The oxidized nucleoside 8-OH-dG inhibits mtDNA binding to NLRP3
Left untreated, malignant pleural mesothelioma (MPM) is associated with uniformly poor prognosis. Better survival has been reported with surgery-based multimodality therapy, but to date, no trial has ...demonstrated survival benefit of surgery over other therapies. We evaluated whether cancer-directed surgery influenced survival independently from other predictors in a large population-based dataset.
The SEER database was explored from 1973 to 2009 to identify all cases of pathologically-proven MPM. Age, sex, race, year of diagnosis, histology stage, cancer-directed surgery, radiation, and vital status were analyzed. The association between prognostic factors and survival was estimated using Cox regression and propensity matched analysis.
There were 14,228 patients with pathologic diagnosis of MPM. On multivariable analysis, female gender, younger age, early stage, and treatment with surgery were independent predictors of longer survival. In comparison to no treatment, surgery alone was associated with significant improvement in survival adjusted hazard ratio (adj HR) 0.64 (0.61-0.67), but not radiation adj HR 1.15 (1.08-1.23). Surgery and radiation combined had similar survival as surgery alone adj HR 0.69 (0.64-0.76). Results were similar when cases diagnosed between 1973 and 1999 were compared to cases diagnosed between 2000 and 2009.
Despite developments in surgical and radiation techniques, the prognosis for MPM patients has not improved over the past 4 decades. Cancer-directed surgery is independently associated with better survival, suggesting that multimodal surgery-based therapy can benefit these patients. Further research in adjuvant treatment is necessary to improve prognosis in this challenging disease.
This comprehensive meta-analysis was conducted to answer the question as to which procedure, pleurectomy decortication (P/D) or extrapleural pneumonectomy (EPP) is more beneficial to malignant ...pleural mesothelioma patients' outcome.
Original research studies that evaluated long-term outcomes of P/D versus EPP were identified, from January 1990 to January 2014. The combined percent perioperative and 2-year mortality, and median survival were calculated according to both a fixed and a random effect model. The Q statistics and I(2) statistic were used to test for heterogeneity between the studies.
There were 24 distinct data sets, for a total of 1,512 patients treated with P/D, and 1,391 treated with EPP. There was a significantly higher proportion of short-term deaths in the EPP group versus the P/D group (percent mortality meta estimate; 4.5% vs 1.7%; p < 0.05). There was no statistically significant difference in 2-year mortality between the 2 groups, but there was significant heterogeneity.
The reanalysis of the large number of studies comparing P/D to EPP suggests that P/D is associated with a 2 ½-fold lower short-term mortality (perioperatively and within 30 days) than EPP. Pleurectomy decortication should therefore be preferred when technically feasible.
Adaptive immunity to Mycobacterium tuberculosis controls progressive bacterial growth and disease but does not eradicate infection. Among CD4+ T cells in the lungs of M. tuberculosis-infected mice, ...we observed that few produced IFN-γ without ex vivo restimulation. Therefore, we hypothesized that one mechanism whereby M. tuberculosis avoids elimination is by limiting activation of CD4+ effector T cells at the site of infection in the lungs. To test this hypothesis, we adoptively transferred Th1-polarized CD4+ effector T cells specific for M. tuberculosis Ag85B peptide 25 (P25TCRTh1 cells), which trafficked to the lungs of infected mice and exhibited antigen-dependent IFN-γ production. During the early phase of infection, ∼10% of P25TCRTh1 cells produced IFN-γ in vivo; this declined to <1% as infection progressed to chronic phase. Bacterial downregulation of fbpB (encoding Ag85B) contributed to the decrease in effector T cell activation in the lungs, as a strain of M. tuberculosis engineered to express fbpB in the chronic phase stimulated P25TCRTh1 effector cells at higher frequencies in vivo, and this resulted in CD4+ T cell-dependent reduction of lung bacterial burdens and prolonged survival of mice. Administration of synthetic peptide 25 alone also increased activation of endogenous antigen-specific effector cells and reduced the bacterial burden in the lungs without apparent host toxicity. These results indicate that CD4+ effector T cells are activated at suboptimal frequencies in tuberculosis, and that increasing effector T cell activation in the lungs by providing one or more epitope peptides may be a successful strategy for TB therapy.
β-glucans are recognized by the innate immune system. This recognition plays important roles in host defense and presents specific opportunities for clinical modulation of the host immune response. ...Neutrophils, macrophages, and dendritic cells among others express several receptors capable of recognizing β-glucan in its various forms. This review explores what is currently known about β-glucan recognition and how this recognition stimulates immune responses. Special emphasis is placed on Dectin-1, as we know the most about how this key β-glucan receptor translates recognition into intracellular signaling, stimulates cellular responses, and participates in orchestrating the adaptive immune response.
To address the frequency of identifying nonsolid nodules, diagnosing lung cancer manifesting as such nodules, and the long-term outcome after treatment in a prospective cohort, the International ...Early Lung Cancer Action Program.
A total of 57,496 participants underwent baseline and subsequent annual repeat computed tomographic (CT) screenings according to an institutional review board, HIPAA-compliant protocol. Informed consent was obtained. The frequency of participants with nonsolid nodules, the course of the nodule at follow-up, and the resulting diagnoses of lung cancer, treatment, and outcome are given separately for baseline and annual repeat rounds of screening. The χ(2) statistic was used to compare percentages.
A nonsolid nodule was identified in 2392 (4.2%) of 57,496 baseline screenings, and pathologic pursuit led to the diagnosis of 73 cases of adenocarcinoma. A new nonsolid nodule was identified in 485 (0.7%) of 64,677 annual repeat screenings, and 11 had a diagnosis of stage I adenocarcinoma; none were in nodules 15 mm or larger in diameter. Nonsolid nodules resolved or decreased more frequently in annual repeat than in baseline rounds (322 66% of 485 vs 628 26% of 2392, P < .0001). Treatment of the cases of lung cancer was with lobectomy in 55, bilobectomy in two, sublobar resection in 26, and radiation therapy in one. Median time to treatment was 19 months (interquartile range IQR, 6-41 months). A solid component had developed in 22 cases prior to treatment (median transition time from nonsolid to part-solid, 25 months). The lung cancer-survival rate was 100% with median follow-up since diagnosis of 78 months (IQR, 45-122 months).
Nonsolid nodules of any size can be safely followed with CT at 12-month intervals to assess transition to part-solid. Surgery was 100% curative in all cases, regardless of the time to treatment.
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