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We introduce measures of quantum coherence as the speed of evolution of a system under decoherence. That is, coherence is the ability to estimate a dephasing channel, quantified by the quantum Fisher information. We extend the analysis to interferometric noise estimation, proving that quantum discord is the minimum sensitivity to local dephasing. A physically motivated set of free operations for discord is proposed. The amount of discord created by strictly incoherent operations is upper-bounded by the initial coherence., 4+2 pages, minor changes, link with previous results clarified

Due to their capacity to skew T cell responses towards Th1 oriented immunity, oligonucleotides containing unmethylated CpG motifs (CpG) have emerged as interesting adjuvants for vaccination. Whereas the signalling pathways in response to CpG mediated TLR9 activation have been extensively documented at the level of the individual cell, little is however known on the precise identity of the innate immune cells that govern T cell priming and polarisation to CpG adjuvanted protein antigens in vivo. In this study, we demonstrate that optimal induction of Th1 oriented immunity to CpG adjuvanted protein vaccines requires the coordinated actions of conventional DCs and of monocytes. Whilst conventional DCs were required for antigen presentation and initial T cell priming, monocytes constitute the main source of the Th1 polarising cytokine IL-12.

Sepsis is one of the leading causes of death around the world. The failure of clinical trials to treat sepsis demonstrates that the molecular mechanisms are multiple and are still insufficiently understood.To clarify the long disputed hierarchical contribution of several central inflammatory mediators (IL-1β, IL-18, caspase [CASP] 7, CASP1, and CASP11) in septic shock and to explore their therapeutic potential.LPS- and tumor necrosis factor (TNF)-induced lethal shock, and cecal ligation and puncture (CLP) were performed in genetically or pharmacologically targeted mice. Body temperature and survival were monitored closely, and plasma was analyzed for several markers of cellular disintegration and inflammation.Interestingly, deficiency of both IL-1β and IL-18 additively prevented LPS-induced mortality. The detrimental role of IL-1β and IL-18 was confirmed in mice subjected to a lethal dose of TNF, or to a lethal CLP procedure. Although their upstream activator, CASP1, and its amplifier, CASP11, are considered potential therapeutic targets because of their crucial involvement in endotoxin-induced toxicity, CASP11- or CASP1/11-deficient mice were not, or hardly, protected against a lethal TNF or CLP challenge. In line with our results obtained in genetically deficient mice, only the combined neutralization of IL-1 and IL-18, using the IL-1 receptor antagonist anakinra and anti-IL-18 antibodies, conferred complete protection against endotoxin-induced lethality.Our data point toward the therapeutic potential of neutralizing IL-1 and IL-18 simultaneously in sepsis, rather than inhibiting the upstream inflammatory caspases.

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants worldwide. Despite decades of research, there is still no registered vaccine available for this major pathogen. We investigated the protective efficacy of a recombinant influenza virus, PR8/NA-F 85–93 , that carries the RSV CD8 + T cell epitope F 85–93 in its neuraminidase stalk. F 85–93 -specific cytotoxic T lymphocytes (CTLs) were induced in mice after a single intranasal immunization with PR8/NA-F 85-93 virus, and these CTLs provided a significant reduction in the lung viral load upon a subsequent challenge with RSV. To avoid influenza-induced morbidity, we treated mice with matrix protein 2 (M2e)-specific monoclonal antibodies before PR8/NA-F 85-93 virus infection. Treatment with anti-M2e antibodies reduced the infiltration of immune cells in the lungs upon PR8/NA-F 85-93 infection, whereas the formation of inducible bronchus-associated lymphoid tissue was not affected. Moreover, this treatment prevented body weight loss yet still permitted the induction of RSV F-specific T cell responses and significantly reduced RSV replication upon challenge. These results demonstrate that it is possible to take advantage of the infection-permissive protection of M2e-specific antibodies against influenza A virus to induce heterologous CD8 + T cell-mediated immunity by an influenza A virus vector expressing the RSV F 85-93 epitope.

Resident alveolar macrophages (rAMs) residing in the bronchoalveolar lumen of the airways play an important role in limiting excessive inflammatory responses in the respiratory tract. High phagocytic activity along with hyporesponsiveness to inflammatory insults and lack of autonomous IFN-β production are crucial assets in this regulatory function. Using a mouse model of asthma, we analyzed the fate of rAMs both during and after allergic bronchial inflammation. Although nearly indistinguishable phenotypically from naïve rAMs, postinflammation rAMs exhibited a strongly reduced basal phagocytic capacity, accompanied by a markedly increased inflammatory reactivity to Toll-like receptors TLR-3 (poly I:C), TLR-4 [lipopolysaccharide (LPS)], and TLR-7 (imiquimod). Importantly, after inflammation, rAMs exhibited a switch from an IFN-β-defective to an IFN-β-competent phenotype, thus indicating the occurrence of a new, inflammatory-released rAM population in the postallergic lung. Analysis of rAM turnover revealed a rapid disappearance of naïve rAMs after the onset of inflammation. This inflammation-induced rAM turnover is critical for the development of the hyperinflammatory rAM phenotype observed after clearance of bronchial inflammation. These data document a novel mechanism of innate imprinting in which noninfectious bronchial inflammation causes alveolar macrophages to acquire a highly modified innate reactivity. The resulting increase in secretion of inflammatory mediators on TLR stimulation implies a role for this phenomenon of innate imprinting in the increased sensitivity of postallergic lungs to inflammatory insults.

Recombinant antigens hold high potential to develop vaccines against lethal intracellular pathogens and cancer. However, they are poorly immunogenic and fail to induce potent cellular immunity. In this paper, we demonstrate that polymeric multilayer capsules (PMLC) strongly increase antigen delivery toward professional antigen-presenting cells in vivo, including dendritic cells (DCs), macrophages, and B cells, thereby enforcing antigen presentation and stimulating T cell proliferation. A thorough analysis of the T cell response demonstrated their capacity to induce IFN-gamma secreting CD4 and CD8 T cells, in addition to follicular T-helper cells, a recently identified CD4 T cell subset supporting antibody responses. On the B cell level, PMLC-mediated antigen delivery promoted the formation of germinal centers, resulting in increased numbers of antibody-secreting plasma cells and elevated antibody titers. The functional relevance of the induced immune responses was validated in murine models of influenza and melanoma. On a mechanistic level, we have demonstrated the capacity of PMLC to activate the NALP3 inflammasome and trigger the release of the potent pro-inflammatory cytokine IL-1beta. Finally, using DC-depleted mice, we have identified DCs as the key mediators of the immunogenic properties of PMLC.

Despite the medical importance of respiratory syncytial virus (RSV) infections, there is no vaccine or therapeutic agent available. Prophylactic administration of palivizumab, a humanized monoclonal RSV fusion (F) protein-specific antibody, can protect high-risk children. Previously, we have demonstrated that RSV can be neutralized by picomolar concentrations of a camelid immunoglobulin single-variable domain that binds the RSV protein F (F-VHHb nanobodies). Here, we investigated the mechanism by which these nanobodies neutralize RSV and tested their antiviral activity in vivo. We demonstrate that bivalent RSV F-specific nanobodies neutralize RSV infection by inhibiting fusion without affecting viral attachment. The ability of RSV F-specific nanobodies to protect against RSV infection was investigated in vivo. Intranasal administration of bivalent RSV F-specific nanobodies protected BALB/c mice from RSV infection, and associated pulmonary inflammation. Moreover, therapeutic treatment with these nanobodies after RSV infection could reduce viral replication and reduced pulmonary inflammation. Thus, nanobodies are promising therapeutic molecules for treatment of RSV.

Contrary to the T-helper (Th)-2 bias and eosinophil-dominated bronchial inflammation encountered in most asthmatic subjects, other patients may exhibit neutrophil-predominant asthma subphenotypes, along with Th-1 and Th-17 cells. However, the etiology of many neutrophil-dominated asthma subphenotypes remains ill-understood, in part due to a lack of appropriate experimental models. To better understand the distinct immune-pathological features of eosinophilic vs. neutrophilic asthma types, we developed an ovalbumin (OVA)-based mouse model of neutrophil-dominated allergic pulmonary inflammation. Consequently, we probed for particular inflammatory signatures and checkpoints underlying the immune pathology in this new model, as well as in a conventional, eosinophil-dominated asthma model. Briefly, mice were OVA sensitized using either aluminum hydroxide (alum) or complete Freund's adjuvants, followed by OVA aerosol challenge. T-cell, granulocyte, and inflammatory mediator profiles were determined, along with alveolar macrophage genomewide transcriptome profiling. In contrast to the Th-2-dominated phenotype provoked by alum, OVA/ complete Freund's adjuvants adjuvant-based sensitization, followed by allergen challenge, elicited a pulmonary inflammation that was poorly controlled by dexamethasone, and in which Th-1 and Th-17 cells additionally participated. Analysis of the overall pulmonary and alveolar macrophage inflammatory mediator profiles revealed remarkable similarities between both models. Nevertheless, we observed pronounced differences in the IL-12/IFN-γ axis and its control by IL-18 and IL-18 binding protein, but also in macrophage arachidonic acid metabolism and expression of T-cell instructive ligands. These differential signatures, superimposed onto a generic inflammatory signature, denote distinctive inflammatory checkpoints potentially involved in orchestrating neutrophil-dominated asthma.

Mycobacterium bovis bacille Calmette-Guerin (BCG) provides only limited protection against pulmonary tuberculosis. We tested the hypothesis that BCG might have retained immunomodulatory properties from its pathogenic parent that limit its protective immunogenicity. Mutation of the molecules involved in immunomodulation might then improve its vaccine potential. We studied the vaccine potential of BCG mutants deficient in the secreted acid phosphatase, SapM, or in the capping of the immunomodulatory ManLAM cell wall component with α-1,2-oligomannoside. Both systemic and intratracheal challenge of mice with Mycobacterium tuberculosis following vaccination showed that the SapM mutant, compared to the parental BCG vaccine, provided better protection: it led to longer-term survival. Persistence of the SapM-mutated BCG in vivo resembled that of the parental BCG indicating that this mutation will likely not compromise the safety of the BCG vaccine. The SapM mutant BCG vaccine was more effective than the parental vaccine in inducing recruitment and activation of CD11c(+) MHC-II(int) CD40(int) dendritic cells (DCs) to the draining lymph nodes. Thus, SapM acts by inhibiting recruitment of DCs and their activation at the site of vaccination.

Zeb2 (Sip1/Zfhx1b) is a member of the zinc-finger E-box-binding (ZEB) family of transcriptional repressors previously demonstrated to regulate epithelial-to-mesenchymal transition (EMT) processes during embryogenesis and tumor progression. We found high Zeb2 mRNA expression levels in HSCs and hematopoietic progenitor cells (HPCs), and examined Zeb2 function in hematopoiesis through a conditional deletion approach using the Tie2-Cre and Vav-iCre recombination mouse lines. Detailed cellular analysis demonstrated that Zeb2 is dispensable for hematopoietic cluster and HSC formation in the aorta-gonadomesonephros region of the embryo, but is essential for normal HSC/HPC differentiation. In addition, Zeb2-deficient HSCs/HPCs fail to properly colonize the fetal liver and/or bone marrow and show enhanced adhesive properties associated with increased β1 integrin and Cxcr4 expression. Moreover, deletion of Zeb2 resulted in embryonic (Tie2-Cre) and perinatal (Vav-icre) lethality due to severe cephalic hemorrhaging and decreased levels of angiopoietin-1 and, subsequently, improper pericyte coverage of the cephalic vasculature. These results reveal essential roles for Zeb2 in embryonic hematopoiesis and are suggestive of a role for Zeb2 in hematopoietic-related pathologies in the adult. ispartof: Blood vol:117 issue:21 pages:5620-5630 ispartof: location:United States status: published

Infection withSalmonella entericaserovar Typhimurium is a complex disease in which the host-bacterium interactions are strongly influenced by genetic factors of the host. We demonstrate that SPRET/Ei, an inbred mouse strain derived fromMus spretus, is resistant toS.Typhimurium infections. The kinetics of bacterial proliferation, as well as histological examinations of tissue sections, suggest that SPRET/Ei mice can control bacterial multiplication and spreading despite significant attenuation of the cytokine response. The resistance of SPRET/Ei mice toS.Typhimurium infection is associated with increased leukocyte counts in the circulation and enhanced neutrophil influx into the peritoneum during the course of infection. A critical role of neutrophils was confirmed by neutrophil depletion: neutropenic SPRET/Ei mice were sensitive to infection withS.Typhimurium and showed much higher bacterial loads. To identify genes that modulate the natural resistance of SPRET/Ei mice toS.Typhimurium infection, we performed a genome-wide study using an interspecific backcross between C3H/HeN and SPRET/Ei mice. The results of this analysis demonstrate that at least two loci, located on chromosomes 6 and 11, affect survival following lethal infection withS.Typhimurium. These two loci contain several interesting candidate genes which may have important implications for the search for genetic factors controllingSalmonellainfections in humans and for our understanding of complex host-pathogen interactions in general.

Asthma is a type-I allergic airway disease characterized by Th(2) cells and IgE. Episodes of bronchial inflammation, eosinophilic in nature and promoting bronchoconstriction, may become chronic and lead to persistent respiratory symptoms and irreversible structural airway changes. Representative mostly of mild to moderate asthma, this clinical definition fails to account for the atypical and often more severe phenotype found in a considerable proportion of asthmatics who have increased neutrophil cell counts in the airways as a distinguishing trait. Neutrophilic inflammation is a hallmark of another type of allergic airway pathology, hypersensitivity pneumonitis. Considered as an immune counterpart of asthma, hypersensitivity pneumonitis is a prototypical type-III allergic inflammatory reaction involving the alveoli and lung interstitium, steered by Th(1) cells and IgG and, in its chronic form, accompanied by fibrosis. Although pathologically very different and commonly approached as separate disorders, as discussed in this review, clinical studies as well as data from animal models reveal undeniable parallels between both airway diseases. Danger signaling elicited by the allergenic agent or by accompanying microbial patterns emerges as critical in enabling immune sensitization and in determining the type of sensitization and ensuing allergic disease. On this basis, we propose that asthma allergens cause severe noneosinophilic asthma because of sensitization in the presence of hypersensitivity pneumonitis-promoting danger signaling.

Background NBPF1 (Neuroblastoma Breakpoint Family, member 1) was originally identified in a neuroblastoma patient on the basis of its disruption by a chromosomal translocation t(1;17)(p36.2;q11.2). Considering this genetic defect and the frequent genomic alterations of the NBPF1 locus in several cancer types, we hypothesized that NBPF1 is a tumor suppressor. Decreased expression of NBPF1 in neuroblastoma cell lines with loss of 1p36 heterozygosity and the marked decrease of anchorage-independent clonal growth of DLD1 colorectal carcinoma cells with induced NBPF1 expression further suggest that NBPF1 functions as tumor suppressor. However, little is known about the mechanisms involved. Methods Expression of NBPF was analyzed in human skin and human cervix by immunohistochemistry. The effects of NBPF1 on the cell cycle were evaluated by flow cytometry. We investigated by real-time quantitative RT-PCR the expression profile of a panel of genes important in cell cycle regulation. Protein levels of CDKN1A-encoded p21CIP1/WAF1 were determined by western blotting and the importance of p53 was shown by immunofluorescence and by a loss-of-function approach. LC-MS/MS analysis was used to investigate the proteome of DLD1 colon cancer cells with induced NBPF1 expression. Possible biological interactions between the differentially regulated proteins were investigated with the Ingenuity Pathway Analysis tool. Results We show that NBPF is expressed in the non-proliferative suprabasal layers of squamous stratified epithelia of human skin and cervix. Forced expression of NBPF1 in HEK293T cells resulted in a G1 cell cycle arrest that was accompanied by upregulation of the cyclin-dependent kinase inhibitor p21CIP1/WAF1 in a p53-dependent manner. Additionally, forced expression of NBPF1 in two p53-mutant neuroblastoma cell lines also resulted in a G1 cell cycle arrest and CDKN1A upregulation. However, CDKN1A upregulation by NBPF1 was not observed in the DLD1 cells, which demonstrates that NBPF1 exerts cell-specific effects. In addition, proteome analysis of NBPF1-overexpressing DLD1 cells identified 32 differentially expressed proteins, of which several are implicated in carcinogenesis. Conclusions We demonstrated that NBPF1 exerts different tumor suppressive effects, depending on the cell line analyzed, and provide new clues into the molecular mechanism of the enigmatic NBPF proteins. Electronic supplementary material The online version of this article (doi:10.1186/s12885-015-1408-5) contains supplementary material, which is available to authorized users.

The use of DNA and viral vector-based vaccines for the induction of cellular immune responses is increasingly gaining interest. However, concerns have been raised regarding the safety of these immunization strategies. Due to the lack of their genome integration, mRNA-based vaccines have emerged as a promising alternative. In this study, we evaluated the potency of antigen-encoding mRNA complexed with the cationic lipid 1,2-dioleoyl-3-trimethylammonium- propane/1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOTAP/DOPE) as a novel vaccination approach. We demonstrate that subcutaneous immunization of mice with mRNA encoding the HIV-1 antigen Gag complexed with DOTAP/DOPE elicits antigen-specific, functional T cell responses resulting in specific killing of Gag peptide-pulsed cells and the induction of humoral responses. In addition, we show that DOTAP/DOPE complexed antigen-encoding mRNA displays immune-activating properties characterized by secretion of type I interferon (IFN) and the recruitment of proinflammatory monocytes to the draining lymph nodes. Finally, we demonstrate that type I IFN inhibit the expression of DOTAP/DOPE complexed antigen-encoding mRNA and the subsequent induction of antigen-specific immune responses. These results are of high relevance as they will stimulate the design and development of improved mRNA-based vaccination approaches. Received 3 April 2012; accepted 23 August 2012; advance online publication 25 September 2012. doi:10.1038/mt.2012.202

Influenza is a global health concern. Licensed influenza vaccines induce strain-specific virus-neutralizing antibodies but hamper the induction of possibly cross-protective T-cell responses upon subsequent infection. 1 In this study, we compared protection induced by a vaccine based on the conserved extracellular domain of matrix 2 protein (M2e) with that of a conventional whole inactivated virus (WIV) vaccine using single as well as consecutive homo- and heterosubtypic challenges. Both vaccines protected against a primary homologous (with respect to hemagglutinin and neuraminidase in WIV) challenge. Functional T-cell responses were induced after primary challenge of M2e-immune mice but were absent in WIV-vaccinated mice. M2e-immune mice displayed limited inducible bronchus-associated lymphoid tissue, which was absent in WIV-immune animals. Importantly, M2e- but not WIV-immune mice were protected from a primary as well as a secondary, severe heterosubtypic challenge, including challenge with pandemic H1N1 2009 virus. Our findings advocate the use of infection-permissive influenza vaccines, such as those based on M2e, in immunologically naive individuals. The combined immune response induced by M2e-vaccine and by clinically controlled influenza virus replication results in strong and broad protection against pandemic influenza. We conclude that the challenge of the M2e-immune host induces strong and broadly reactive immunity against influenza virus infection. Fil: Schotsaert, M.. Flanders Interuniversity Institute For Biotechnology; Bélgica. University of Ghent; Bélgica Fil: Ysenbaert, T.. Flanders Interuniversity Institute For Biotechnology; Bélgica. University of Ghent; Bélgica Fil: Neyt, K.. Flanders Interuniversity Institute For Biotechnology; Bélgica. University of Ghent; Bélgica Fil: Ibañez, Lorena Itatí. Flanders Interuniversity Institute For Biotechnology; Bélgica. University of Ghent; Bélgica. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Bogaert, P.. University of Ghent; Bélgica. Flanders Interuniversity Institute For Biotechnology; Bélgica Fil: Schepens, B.. Flanders Interuniversity Institute For Biotechnology; Bélgica. University of Ghent; Bélgica Fil: Lambrecht, B. N.. University of Ghent; Bélgica. Flanders Interuniversity Institute For Biotechnology; Bélgica Fil: Fiers, W.. University of Ghent; Bélgica. Flanders Interuniversity Institute For Biotechnology; Bélgica Fil: Saelens, X.. Flanders Interuniversity Institute For Biotechnology; Bélgica. University of Ghent; Bélgica

There was an error in affiliations 1, 3, and 4 for authors Jonathan Maelfait, Kenny Roose, Pieter Bogaert, Mozes Sze, Xavier Saelens, Isabelle Carpentier, Geert van Loo, and Rudi Beyaert. Affiliation 1 should be: Unit of Molecular Signal Transduction in Inflammation, Department for Molecular Biomedical Research, VIB, Ghent, Belgium. Affiliation 3 should be: Unit of Molecular Virology, Department for Molecular Biomedical Research, VIB, Ghent, Belgium. Affiliation 4 should be: Cell Culture and Sorting Core Facility, Department for Molecular Biomedical Research, VIB, Ghent, Belgium.

The innate immune response provides the first line of defense against viruses and other pathogens by responding to specific microbial molecules. Influenza A virus (IAV) produces double-stranded RNA as an intermediate during the replication life cycle, which activates the intracellular pathogen recognition receptor RIG-I and induces the production of proinflammatory cytokines and antiviral interferon. Understanding the mechanisms that regulate innate immune responses to IAV and other viruses is of key importance to develop novel therapeutic strategies. Here we used myeloid cell specific A20 knockout mice to examine the role of the ubiquitin-editing protein A20 in the response of myeloid cells to IAV infection. A20 deficient macrophages were hyperresponsive to double stranded RNA and IAV infection, as illustrated by enhanced NF-κB and IRF3 activation, concomitant with increased production of proinflammatory cytokines, chemokines and type I interferon. In vivo this was associated with an increased number of alveolar macrophages and neutrophils in the lungs of IAV infected mice. Surprisingly, myeloid cell specific A20 knockout mice are protected against lethal IAV infection. These results challenge the general belief that an excessive host proinflammatory response is associated with IAV-induced lethality, and suggest that under certain conditions inhibition of A20 might be of interest in the management of IAV infections., Author Summary Influenza virus or flu epidemics represent a recurrent threat to the public health, especially for individuals which are part of a high-risk group such as children, elderly or immune-compromised people. Sporadic pandemic flu outbreaks, such as the Spanish flu of 1918, may cause high grades of mortality among healthy persons. A better understanding of how the immune system deals with these pathogens is of key importance. The protein A20 is an important negative regulator of both innate and adaptive immune responses. We show that the specific deletion of A20 in myeloid cells, such as macrophages and neutrophils, improves the resistance against otherwise lethal influenza infections. This protective effect is mediated by an enhanced innate immune response following respiratory challenge with influenza virus. Although exaggerated pulmonary immune responses are believed to be the primary cause of often life threatening influenza virus induced pneumonia, we demonstrate that boosting the innate immune response by selectively targeting the functionality of A20 in myeloid cells is beneficial for the host survival. This finding provides us with a novel valuable approach for treating influenza and potentially other respiratory viral infections.

The synthetic utility of N-alkylidene-(2,3-dibromo-2-methylpropyl)amines and N-(2,3-dibromo-2-methylpropylidene)benzylamines was demonstrated by the unexpected synthesis of 3-methoxy-3-methylazetidines upon treatment with sodium borohydride in methanol under reflux through a rare aziridine to azetidine rearrangement. These findings stand in contrast to the known reactivity of the closely related N-alkylidene-(2,3-dibromopropyl)amines, which are easily converted into 2-(bromomethyl)aziridines under the same reaction conditions. A thorough insight into the reaction mechanism was provided by both experimental study and theoretical rationalization.

Three members of the IAP family (X-linked inhibitor of apoptosis (XIAP), cellular inhibitor of apoptosis proteins-1/-2 (cIAP1 and cIAP2)) are potent suppressors of apoptosis. Recent studies have shown that cIAP1 and cIAP2, unlike XIAP, are not direct caspase inhibitors, but block apoptosis by functioning as E3 ligases for effector caspases and receptor-interacting protein 1 (RIP1). cIAP-mediated polyubiquitination of RIP1 allows it to bind to the pro-survival kinase transforming growth factor-β-activated kinase 1 (TAK1) which prevents it from activating caspase-8-dependent death, a process reverted by the de-ubiquitinase CYLD. RIP1 is also a regulator of necrosis, a caspase-independent type of cell death. Here, we show that cells depleted of the IAPs by treatment with the IAP antagonist BV6 are greatly sensitized to tumor necrosis factor (TNF)-induced necrosis, but not to necrotic death induced by anti-Fas, poly(I:C) oxidative stress. Specific targeting of the IAPs by RNAi revealed that repression of cIAP1 is responsible for the sensitization. Similarly, lowering TAK1 levels or inhibiting its kinase activity sensitized cells to TNF-induced necrosis, whereas repressing CYLD had the opposite effect. We show that this sensitization to death is accompanied by enhanced RIP1 kinase activity, increased recruitment of RIP1 to Fas-associated via death domain and RIP3 (which allows necrosome formation), and elevated RIP1 kinase-dependent accumulation of reactive oxygen species (ROS). In conclusion, our data indicate that cIAP1 and TAK1 protect cells from TNF-induced necrosis by preventing RIP1/RIP3-dependent ROS production.

Because of their large surface area, the lungs appear an attractive route for noninvasive vaccine delivery, harboring the potential to induce local mucosal immune responses in addition to systemic immunity. To evoke adaptive immunity, Ags require the addition of adjuvants that not only enhance the strength of the immune response but also determine the type of response elicited. In this study, we evaluate the adjuvant characteristics of polyelectrolyte microcapsules (PEMs) consisting of the biopolymers dextran-sulfate and poly-l-arginine. PEMs form an entirely new class of microcapsules that are generated by the sequential adsorption of oppositely charged polymers (polyelectrolytes) onto a sacrificial colloidal template, which is subsequently dissolved leaving a hollow microcapsule surrounded by a thin shell. Following intratracheal instillation, PEMs were not only efficiently taken up by APCs but also enhanced their activation status. Pulmonary adaptive immune responses were characterized by the induction of a strongly Th17-polarized response. When compared with a mixture of soluble Ag with empty microcapsules, Ag encapsulation significantly enhanced the strength of this local mucosal response. Given their unique property to selectively generate Th17-polarized immune responses, PEMs may become of significant interest in the development of effective vaccines against fungal and bacterial species.

Molecular markers, especially surface markers associated with type II, cytokine-dependent, alternatively activated macrophages (aaMF), remain scarce. Besides the earlier documented markers, macrophage mannose receptor and arginase 1, we demonstrated recently that murine aaMF are characterized by increased expression of found in inflammatory zone 1 (FIZZ1) and the secretory lectin Ym. We now document that expression of the two members of the mouse macrophage galactose-type C-type lectin gene family (mMGL1 and mMGL2) is induced in diverse populations of aaMF, including peritoneal macrophages elicited during infection with the protozoan Trypanosoma brucei brucei or the Helminth Taenia crassiceps and alveolar macrophages elicited in a mouse model of allergic asthma. In addition, we demonstrate that in vitro, interleukin-4 (IL-4) and IL-13 up-regulate mMGL1 and mMGL2 expression and that in vivo, induction of mMGL1 and mMGL2 is dependent on IL-4 receptor signaling. Moreover, we show that expression of MGL on human monocytes is also up-regulated by IL-4. Hence, macrophage galactose-type C-type lectins represent novel surface markers for murine and human aaMF.

TNF receptor 1 signaling induces NF-κB activation and necroptosis in L929 cells. We previously reported that cellular inhibitor of apoptosis protein-mediated receptor-interacting protein 1 (RIP1) ubiquitination acts as a cytoprotective mechanism, whereas knockdown of cylindromatosis, a RIP1-deubiquitinating enzyme, protects against tumor necrosis factor (TNF)-induced necroptosis. We report here that RIP1 is a crucial mediator of canonical NF-κB activation in L929 cells, therefore questioning the relative cytoprotective contribution of RIP1 ubiquitination versus canonical NF-κB activation. We found that attenuated NF-κB activation has no impact on TNF-induced necroptosis. However, we identified A20 and linear ubiquitin chain assembly complex as negative regulators of necroptosis. Unexpectedly, and in contrast to RIP3, we also found that knockdown of RIP1 did not block TNF cytotoxicity. Cell death typing revealed that RIP1-depleted cells switch from necroptotic to apoptotic death, indicating that RIP1 can also suppress apoptosis in L929 cells. Inversely, we observed that Fas-associated protein via a death domain, cellular FLICE inhibitory protein and caspase-8, which are all involved in the initiation of apoptosis, counteract necroptosis induction. Finally, we also report RIP1-independent but RIP3-mediated necroptosis in the context of TNF signaling in particular conditions.

In parallel with the Th1/Th2 dichotomy, macrophages are capable of developing into functionally and molecularly distinct subpopulations, due to differences in, for example cytokine environment and pathological conditions. While the best-studied, classically activated macrophage is induced by type I stimuli such as IFN-γ, a type II cytokine environment antagonizes the classical activation of macrophages and is capable of alternatively activating macrophages. However, molecular markers associated with these type II cytokine-dependent, alternatively activated macrophages remain scarce. Besides the earlier documented markers macrophage mannose receptor and arginase 1, we recently demonstrated that murine alternatively activated macrophages are characterized by increased expression of FIZZ1 and Ym. We now report that expression of the two members of the mouse macrophage galactose-type C-type lectin gene family, termed mMGL1 and mMGL2, is induced in diverse populations of alternatively activated macrophages, including peritoneal macrophages elicited during infection with the protozoan Trypanosoma brucei or the Helminth Taenia crassiceps, and alveolar macrophages elicited in a mouse model of allergic asthma. We also demonstrate that, in vitro, interleukin-4 and interleukin-13 upregulate mMGL1 and mMGL2 expression and that, in vivo, induction of mMGL1 and mMGL2 is dependent on interleukin-4 receptor signalling. Moreover, we show that regulation of MGL expression is similar in human monocytes and monocyte-derived macrophages. Hence, macrophage galactose-type C-type lectins represent novel markers for both murine and human alternatively activated macrophages; thus, paving the way for further characterization of the phenotype of macrophages occurring in Th2 conditions.

Anthracycline antibiotics are inducers of an immunogenic form of apoptosis that has immunostimulatory properties because of the release of damage-associated molecular patterns. To study the mechanisms used by the innate immune system to sense this immunogenic form of cell death, we established an in vivo model of cell death induced by intraperitoneal injection of doxorubicin, a prototype of anthracyclines. The acute sterile inflammation in this model is characterized by rapid influx of neutrophils and increased levels of IL-6 and monocyte chemotactic protein-1. We demonstrate that acute inflammation induced by doxorubicin is associated with apoptosis of monocytes/macrophages and that it is specific for doxorubicin, an immunogenic chemotherapeutic. Further, the inflammatory response is significantly reduced in mice deficient in myeloid differentiation primary response gene 88 (MyD88), TLR-2 or TLR-9. Importantly, a TLR-9 antagonist reduces the recruitment of neutrophils induced by doxorubicin. By contrast, the acute inflammatory response is not affected in TRIF(Lps2) mutant mice and in TLR-3, TLR-4 and caspase-1 knockout mice, which shows that the inflammasome does not have a major role in doxorubicin-induced acute inflammation. Our findings provide important new insights into how the innate immune system senses immunogenic apoptotic cells and clearly demonstrate that the TLR-2/TLR-9-MyD88 signaling pathways have a central role in initiating the acute inflammatory response to this immunogenic form of apoptosis.

Sepsis is one of the leading causes of death around the world. The failure of clinical trials to treat sepsis demonstrates that the molecular mechanisms are multiple and still insufficiently understood. The objective is to clarify the long disputed hierarchical contribution of several central inflammatory mediators, namely IL-1β, IL-18, CASP7, CASP1 and CASP11, in septic shock, and to explore their therapeutic potential.