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1.
Epidemiol Infect ; 152: e87, 2024 May 16.
Article in English | MEDLINE | ID: mdl-38751220

ABSTRACT

It is so far unclear how the COVID-19 winter waves started and what should be done to prevent possible future waves. In this study, we deciphered the dynamic course of a winter wave in 2021 in Saxony, a state in Eastern Germany neighbouring the Czech Republic and Poland. The study was carried out through the integration of multiple virus genomic epidemiology approaches to track transmission chains, identify emerging variants and investigate dynamic changes in transmission clusters. For identified local variants of interest, functional evaluations were performed. Multiple long-lasting community transmission clusters have been identified acting as driving force for the winter wave 2021. Analysis of the dynamic courses of two representative clusters indicated a similar transmission pattern. However, the transmission cluster caused by a locally occurring new Delta variant AY.36.1 showed a distinct transmission pattern, and functional analyses revealed a replication advantage of it. This study indicated that long-lasting community transmission clusters starting since early autumn caused by imported or locally occurring variants all contributed to the development of the 2021 winter wave. The information we achieved might help future pandemic prevention.


Subject(s)
COVID-19 , SARS-CoV-2 , Seasons , COVID-19/epidemiology , COVID-19/transmission , COVID-19/virology , Germany/epidemiology , Humans , SARS-CoV-2/genetics
2.
J Clin Microbiol ; 60(5): e0253321, 2022 05 18.
Article in English | MEDLINE | ID: mdl-35387489

ABSTRACT

Time to results for identification (ID) and antimicrobial susceptibility testing (AST) from blood cultures is an important factor impacting outcome in sepsis. In this study we evaluated a novel device, the FAST™ system from Qvella that concentrates microbial biomass from positive blood culture flasks with the FAST-PBC Prep™ cartridge thereby producing a liquid colony™ (LC), which can be used immediately in standard laboratory downstream applications. We tested 250 positive blood culture bottles collected from January 2021 to May 2021. Results were obtained either with LC or from bacterial overnight cultures using Bruker's MALDI Biotyper™ and bioMérieux's Vitek 2. We compared ID and AST results obtained by both methods and evaluated turnaround times. Two-hundred and fourteen blood cultures could be included in the analysis. In 94% of the cases (n = 201) identification was obtained directly from the LC with concordant results compared to the standard workflow. No discordant results were observed. AST results could be analyzed for 175 samples. Using categorical analysis, concordant agreement was 97.4% of 1,676 AST results for Gram positive bacteria. Agreement for Gram negative bacteria was 98.5% of 980 AST results. Times-to-result were 36.9 h versus 12.8 h for ID and 52.9 h versus 26.8 h for AST in routine workflow vs FASTTM system, respectively. The FASTTM system gives reliable results for ID and AST directly from positive blood cultures and allows for significant time savings in blood culture diagnostics.


Subject(s)
Bacteremia , Blood Culture , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Bacteremia/microbiology , Blood Culture/methods , Gram-Negative Bacteria , Humans , Microbial Sensitivity Tests , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Time Factors
3.
Infection ; 50(6): 1483-1490, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35460495

ABSTRACT

PURPOSE: To quantify the number of SARS-CoV-2 infections in students and teachers in 14 Secondary schools in eastern Saxony, Germany. Seroprevalence of SARS-CoV-2 antibodies in study population. Number of undetected cases. METHODS: Serial seroprevalence study. RESULTS: The role of educational settings in the SARS-CoV-2 Pandemic is still controversial. Seroprevalence increases from 0.8 to 5.9% from October to December when schools remained open and to 12.2% in March/April during a strict lockdown with closed schools. The ratio of undetected to detected cases decreased from 0.76 to 0.44 during the study period. CONCLUSION: During the second and third wave of the pandemic in Germany, students and teachers are not overrepresented in SARS-CoV-2 infections. The percentage of undetected cases is moderate and decreases over time. The risk of contracting SARS-CoV-2 within the household is higher than contracting it in educational settings making school closures rather ineffective in terms of pandemic control measures or individual risk reduction in children and adolescents. TRIAL REGISTRATION: DRKS00022455 (July 23rd, 2020).


Subject(s)
COVID-19 , SARS-CoV-2 , Adolescent , Child , Humans , Seroepidemiologic Studies , COVID-19/epidemiology , Longitudinal Studies , Communicable Disease Control , Schools
4.
RNA ; 25(7): 869-880, 2019 07.
Article in English | MEDLINE | ID: mdl-31019095

ABSTRACT

Bacterial RNA has emerged as an important activator of innate immune responses by stimulating Toll-like receptors TLR7 and TLR8 in humans. Guanosine 2'-O-methylation at position 18 (Gm18) in bacterial tRNA was shown to antagonize tRNA-induced TLR7/8 activation, suggesting a potential role of Gm18 as an immune escape mechanism. This modification also occurs in eukaryotic tRNA, yet a physiological immune function remained to be tested. We therefore set out to investigate the immune modulatory role of Gm18 in both prokaryotic and eukaryotic microorganisms, Escherichia coli and Saccharomyces cerevisiae, and in human cells. Using RiboMethSeq analysis we show that mutation of trmH in E. coli, trm3 in S. cereviase, and CRISPR/Cas9-induced knockout of TARBP1 in H. sapiens results in loss of Gm18 within tRNA. Lack of Gm18 across the kingdoms resulted in increased immunostimulation of peripheral blood mononuclear cells when activated by tRNA preparations. In E. coli, lack of 2'-O-methyltransferase trmH also enhanced immune stimulatory properties by whole cellular RNA. In contrast, lack of Gm18 in yeasts and human cells did not affect immunostimulation by whole RNA preparations. When using live E. coli bacteria, lack of trmH did not affect overall immune stimulation although we detected a defined TLR8/RNA-dependent gene expression signature upon E. coli infection. Together, these results demonstrate that Gm18 is a global immune inhibitory tRNA modification across the kingdoms and contributes to tRNA recognition by innate immune cells, but as an individual modification has insufficient potency to modulate recognition of the investigated microorganisms.


Subject(s)
Endosomes/metabolism , Eukaryotic Cells/immunology , Guanosine/chemistry , Immunity, Innate/immunology , Prokaryotic Cells/immunology , RNA, Transfer/metabolism , Toll-Like Receptors/metabolism , Eukaryotic Cells/metabolism , Humans , Methylation , Prokaryotic Cells/metabolism , RNA, Transfer/genetics , Toll-Like Receptors/genetics , tRNA Methyltransferases/genetics , tRNA Methyltransferases/metabolism
5.
J Pediatr ; 237: 136-142, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34324882

ABSTRACT

OBJECTIVE: To evaluate the role of childcare facilities in the transmission of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) in a longitudinal study to gain further knowledge of SARS-CoV-2 prevalence, transmission, and spread among preschool children, their parents, and their caregivers. STUDY DESIGN: Children aged 1-6 years, their parents, and their caregivers in 14 childcare facilities in Dresden, Saxony/Germany were invited to participate in the KiTaCoviDD19-study between July 2020 and January 2021. Seroprevalence of SARS-CoV-2 antibodies was assessed up to 4 times during the study period in all participating adults, and demographic characteristics, as well as epidemiologic information on personal SARS-CoV-2 history were obtained. Samples for stool virus shedding of SARS-CoV-2 were analyzed by polymerase chain reaction every 2-4 weeks in all participating children. RESULTS: In total, 318 children, 299 parents and 233 childcare workers were enrolled. By January 2021, 11% of the participating adults were found to be seropositive, whereas the percentage of children shedding SARS-CoV-2 was 6.8%. Overall, we detected 17 children with SARS-CoV-2 virus shedding in 8 different childcare facilities. In 4 facilities, there were a maximum of 3 connected cases in children. Approximately 50% of SARS-CoV-2 infections in the children could not be connected to a secondary case in our study population. CONCLUSIONS: This study does not provide evidence of relevant asymptomatic ("silent") spread of SARS-CoV-2 in childcare facilities in both low- and high-prevalence settings. Our findings add to the evidence that childcare and educational settings do not have a crucial role in driving the SARS-CoV-2 pandemic.


Subject(s)
COVID-19/transmission , Child Day Care Centers/statistics & numerical data , Adult , COVID-19/epidemiology , COVID-19 Testing/methods , Child , Child, Preschool , Feces/virology , Female , Germany/epidemiology , Humans , Infant , Longitudinal Studies , Male , Middle Aged , Pandemics , Parents , Prevalence , Quarantine , Retrospective Studies , SARS-CoV-2 , Virus Shedding
6.
Epidemiol Infect ; 149: e177, 2021 07 30.
Article in English | MEDLINE | ID: mdl-34325753

ABSTRACT

In Germany, Eastern regions had a mild first wave of coronavirus disease 2019 (COVID-19) from March to May 2020, but were badly hit by a second wave later in autumn and winter. It is unknown how the second wave was initiated and developed in Eastern Germany where the number of COVID-19 cases was close to zero in June and July 2020. We used genomic epidemiology to investigate the dynamic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lineage development across the first and second waves in Eastern Germany. With detailed phylogenetic analyses we could show that SARS-CoV-2 lineages prevalent in the first and second waves in Eastern Germany were different, with several new variants including four predominant lineages in the second wave, having been introduced into Eastern Germany between August and October 2020. The results indicate that the major driving force behind the second wave was the introduction of new variants.


Subject(s)
COVID-19/epidemiology , Genome, Viral , Pandemics , SARS-CoV-2/genetics , COVID-19/virology , Germany/epidemiology , Humans , Phylogeny , SARS-CoV-2/classification
7.
Int J Mol Sci ; 22(11)2021 Jun 07.
Article in English | MEDLINE | ID: mdl-34200296

ABSTRACT

Recent studies found that expression of NEDD4-2 is reduced in lung tissue from patients with idiopathic pulmonary fibrosis (IPF) and that the conditional deletion of Nedd4-2 in lung epithelial cells causes IPF-like disease in adult mice via multiple defects, including dysregulation of the epithelial Na+ channel (ENaC), TGFß signaling and the biosynthesis of surfactant protein-C proprotein (proSP-C). However, knowledge of the impact of congenital deletion of Nedd4-2 on the lung phenotype remains limited. In this study, we therefore determined the effects of congenital deletion of Nedd4-2 in the lung epithelial cells of neonatal doxycycline-induced triple transgenic Nedd4-2fl/fl/CCSP-rtTA2S-M2/LC1 mice, with a focus on clinical phenotype, survival, lung morphology, inflammation markers in BAL, mucin expression, ENaC function and proSP-C trafficking. We found that the congenital deletion of Nedd4-2 caused a rapidly progressive lung disease in neonatal mice that shares key features with interstitial lung diseases in children (chILD), including hypoxemia, growth failure, sterile pneumonitis, fibrotic lung remodeling and high mortality. The congenital deletion of Nedd4-2 in lung epithelial cells caused increased expression of Muc5b and mucus plugging of distal airways, increased ENaC activity and proSP-C mistrafficking. This model of congenital deletion of Nedd4-2 may support studies of the pathogenesis and preclinical development of therapies for chILD.


Subject(s)
Epithelial Cells/pathology , Lung/pathology , Nedd4 Ubiquitin Protein Ligases/physiology , Pulmonary Alveoli/pathology , Pulmonary Fibrosis/pathology , Animals , Animals, Newborn , Epithelial Cells/metabolism , Female , Inflammation Mediators/metabolism , Lung/immunology , Lung/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Pulmonary Alveoli/immunology , Pulmonary Alveoli/metabolism , Pulmonary Fibrosis/etiology
8.
Eur J Clin Microbiol Infect Dis ; 39(7): 1245-1250, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32026192

ABSTRACT

Syndromic panel-based molecular testing has been suggested to improve and accelerate microbiological diagnosis. We aimed to analyze workflow improvements when using the multiplex Seegene Allplex™ GI-Bacteria(I) assay as a first-line assay for bacterial diarrhea. Technical assay evaluation was done using spiked stool samples and stored patient samples. After implementation of the assay in the routine clinical workflow, an analysis of 5032 clinical samples analyzed by the Seegene assay and 4173 control samples examined by culture in a similar time period 1 year earlier was performed. Sensitivity of the assay was shown to be between 0.4 and 95.9 genome equivalents/PCR. For 159 positive patient samples with a composite reference of culture and/or a molecular assay, the sensitivity of the assay was 100% for Campylobacter, 92% for Salmonella, 89% for Aeromonas, and 83% for Shigella. Sensitivity for C. difficile toxin B detection was 93.9%. The comparison of clinical samples obtained in two 8-month periods showed increased detection rates for Aeromonas (2.90%vs. 0.34%), Campylobacter spp. (2.25% vs. 1.34%), Shigella spp. (0.42% vs. 0.05%) whereas detection of Salmonella was slightly decreased (0.46% vs. 0.67%) when using the Seegene assay. An analysis of the time-to-result showed that the median dropped from 52.7 to 26.4 h when using the molecular panel testing. The Seegene Allplex™ GI-Bacteria(I) assay allows accelerated, reliable detection of major gastrointestinal bacteria roughly within 1 day. Workload is reduced, specifically in a low-prevalence setting.


Subject(s)
Bacteria/isolation & purification , Bacterial Typing Techniques/methods , Diarrhea/diagnosis , Molecular Diagnostic Techniques/methods , Bacteria/classification , Bacteria/genetics , Bacterial Typing Techniques/standards , Diagnostic Tests, Routine , Diarrhea/microbiology , Feces/microbiology , Humans , Molecular Diagnostic Techniques/standards , Multiplex Polymerase Chain Reaction , Sensitivity and Specificity , Time Factors , Workflow
9.
Gastroenterology ; 154(8): 2237-2251.e16, 2018 06.
Article in English | MEDLINE | ID: mdl-29535029

ABSTRACT

BACKGROUND & AIMS: Hepatitis C virus (HCV) infections most often result in chronic outcomes, although the virus constantly produces replication intermediates, in particular double-stranded RNA (dsRNA), representing potent inducers of innate immunity. We aimed to characterize the fate of HCV dsRNA in hepatocyte cultures to identify mechanisms contributing to viral persistence in presence of an active innate immune response. METHODS: We analyzed hepatocyte-based culture models for HCV for induction of innate immunity, secretion of virus positive- or negative-strand RNA, and viral replication using different quantification methods and microscopy techniques. Expression of pattern recognition receptors was reconstituted in hepatoma cells by lentiviral transduction. RESULTS: HCV-infected cells secrete substantial amounts of virus positive- and negative-strand RNAs in extracellular vesicles (EVs), toward the apical and basolateral domain of hepatocytes. Secretion of negative-strand RNA was independent from virus production, and viral RNA secreted in EVs contained higher relative amounts of negative-strands, indicating that mostly virus dsRNA is released. A substantial part of viral replication complexes and dsRNA was found in the endosomal compartment and multivesicular bodies, indicating that secretion of HCV replication intermediates is mediated by the exosomal pathway. Block of vesicle release in HCV-positive cells increased intracellular dsRNA levels and increased activation of toll-like receptor 3, inhibiting HCV replication. CONCLUSIONS: Using hepatocyte-based culture models for HCV, we found a portion of HCV dsRNA intermediates to be released from infected cells in EVs, which reduces activation of toll-like receptor 3. This represents a novel mechanism how HCV evades host immune responses, potentially contributing to viral persistence.


Subject(s)
Hepacivirus/physiology , Hepatitis C, Chronic/immunology , Hepatocytes/metabolism , Immunity, Innate , Toll-Like Receptor 3/immunology , Cell Line , Extracellular Vesicles/immunology , Extracellular Vesicles/metabolism , Hepatitis C, Chronic/blood , Hepatitis C, Chronic/virology , Hepatocytes/immunology , Host-Pathogen Interactions/immunology , Humans , Interferons/immunology , Interferons/metabolism , Primary Cell Culture , RNA, Double-Stranded/immunology , RNA, Double-Stranded/isolation & purification , RNA, Double-Stranded/metabolism , RNA, Viral/immunology , RNA, Viral/isolation & purification , RNA, Viral/metabolism , Signal Transduction/immunology , Toll-Like Receptor 3/metabolism , Virus Replication/immunology
10.
RNA ; 23(9): 1344-1351, 2017 09.
Article in English | MEDLINE | ID: mdl-28576825

ABSTRACT

Bacterial RNA serves an important function as activator of the innate immune system. In humans bacterial RNA is sensed by the endosomal receptors TLR7 and TLR8. Differences in the posttranscriptional modification profile of prokaryotic when compared with eukaryotic RNA allow innate immune cells to discriminate between "host" and "foreign" RNA. Ribose 2'-O-methylation is of particular importance and has been reported to antagonize TLR7/8 activation. Yet, the exact sequence context in which 2'-O-methylation has to occur to mediate its inhibitory activity remains largely undefined. On the basis of a naturally occurring 2'-O-methylated RNA sequence, we performed a systematic permutation of the methylated nucleotide as well as adjacent bases and hereby identify two minimal trinucleotide motifs within a 9-mer oligoribonucleotide that are necessary and sufficient to antagonize TLR7 and TLR8 activation, respectively. Given the growing interest in the development of inhibitors of nucleic acid-sensing TLRs for therapeutic purposes, these results will facilitate the rational design of such antagonists in the future.


Subject(s)
Nucleotide Motifs , RNA/genetics , RNA/metabolism , Toll-Like Receptor 7/antagonists & inhibitors , Toll-Like Receptor 8/antagonists & inhibitors , Cytidine , Humans , Inhibitory Concentration 50 , Leukocytes, Mononuclear , Methylation , Mutation , Nucleotides/chemistry , Nucleotides/metabolism , RNA/chemistry , RNA, Bacterial/chemistry , RNA, Bacterial/genetics , RNA, Bacterial/metabolism , RNA, Transfer/chemistry , RNA, Transfer/genetics , RNA, Transfer/metabolism , Toll-Like Receptor 7/metabolism , Toll-Like Receptor 8/metabolism
11.
BMC Microbiol ; 19(1): 42, 2019 02 18.
Article in English | MEDLINE | ID: mdl-30777006

ABSTRACT

BACKGROUND: Postoperative complications are of great relevance in daily clinical practice, and the gut microbiome might play an important role by preventing pathogens from crossing the intestinal barrier. The two aims of this prospective clinical pilot study were: (1) to examine changes in the gut microbiome following pancreatic surgery, and (2) to correlate these changes with the postoperative course of the patient. RESULTS: In total, 116 stool samples of 32 patients undergoing pancreatic surgery were analysed by 16S-rRNA gene next-generation sequencing. One sample per patient was collected preoperatively in order to determine the baseline gut microbiome without exposure to surgical stress and/or antibiotic use. At least two further samples were obtained within the first 10 days following the surgical procedure to observe longitudinal changes in the gut microbiome. Whenever complications occurred, further samples were examined. Based on the structure of the gut microbiome, the samples could be allocated into three different microbial communities (A, B and C). Community B showed an increase in Akkermansia, Enterobacteriaceae and Bacteroidales as well as a decrease in Lachnospiraceae, Prevotella and Bacteroides. Patients showing a microbial composition resembling community B at least once during the observation period were found to have a significantly higher risk for developing postoperative complications (B vs. A, odds ratio = 4.96, p < 0.01**; B vs. C, odds ratio = 2.89, p = 0.019*). CONCLUSIONS: The structure of the gut microbiome is associated with the development of postoperative complications.


Subject(s)
Bacteria/classification , Gastrointestinal Microbiome , Pancreatic Diseases/surgery , Postoperative Complications/microbiology , Aged , Bacteria/isolation & purification , Feces/microbiology , High-Throughput Nucleotide Sequencing , Humans , Middle Aged , Odds Ratio , Phylogeny , Pilot Projects , Prospective Studies , RNA, Ribosomal, 16S/genetics , Risk Factors
12.
J Immunol ; 195(2): 411-8, 2015 Jul 15.
Article in English | MEDLINE | ID: mdl-26138638

ABSTRACT

Although DNA of bacterial and viral origin, as well as viral RNA, have been intensively studied as triggers of innate immune responses, the stimulatory properties of bacterial RNA and its role during infections have just begun to be deciphered. Bacterial RNA is a strong inducer of type I IFN and NF-κB-dependent cytokines, and it also can activate the Nlrp3 inflammasome. In this review, we focus on the receptors and signaling pathways involved in innate immune activation by bacterial RNA and analyze the physiological relevance of bacterial RNA recognition during infections. Furthermore, we present the concept that RNA modifications can impair RNA-dependent immune activation. RNA modifications differ between eukaryotes and prokaryotes; thus, they can serve to define the innate pattern that is recognized. In this regard, we discuss the role of ribose 2'-O-methylation as a potential immune-escape mechanism.


Subject(s)
Dendritic Cells/immunology , Immunity, Innate , Inflammasomes/immunology , Monocytes/immunology , RNA, Bacterial/immunology , Ribose/immunology , Bacteria/immunology , Carrier Proteins/genetics , Carrier Proteins/immunology , Dendritic Cells/microbiology , Gene Expression Regulation , Host-Pathogen Interactions , Humans , Inflammasomes/genetics , Interferon-alpha/genetics , Interferon-alpha/immunology , Interferon-beta/genetics , Interferon-beta/immunology , Methylation , Monocytes/microbiology , NLR Family, Pyrin Domain-Containing 3 Protein , RNA, Bacterial/genetics , RNA, Bacterial/metabolism , Ribose/metabolism , Signal Transduction , Toll-Like Receptors/genetics , Toll-Like Receptors/immunology
13.
J Immunol ; 195(3): 1092-9, 2015 Aug 01.
Article in English | MEDLINE | ID: mdl-26101323

ABSTRACT

Microbial nucleic acids constitute an important group of pathogen-associated molecular patterns (PAMPs) that efficiently trigger innate immune activation. In mice, TLR13 has recently been identified to sense a highly conserved region within bacterial 23S rRNA. However, TLR13 is not expressed in humans, and the identity of its human homolog remains elusive. Moreover, the contribution of bacterial RNA to the induction of innate immune responses against entire bacteria is still insufficiently defined. In the current study, we show that human monocytes respond to bacterial RNA with secretion of IL-6, TNF, and IFN-ß, which is critically dependent on lysosomal maturation. Using small interfering RNA and overexpression, we unambiguously identify TLR8 as receptor for bacterial RNA in primary human monocyte-derived macrophages. We further demonstrate that the sequence motif sensed by TLR8 is clearly distinct from that recognized by TLR13. Moreover, TLR8-dependent detection of bacterial RNA was critical for triggering monocyte activation in response to infection with Streptococcus pyogenes. Bacterial RNA within streptococci was also a dominant stimulus for murine immune cells, highlighting the physiological relevance of RNA sensing in defense of infections.


Subject(s)
RNA, Bacterial/immunology , RNA, Ribosomal, 23S/immunology , Streptococcus pyogenes/genetics , Toll-Like Receptor 8/immunology , Toll-Like Receptors/immunology , Animals , Cell Line , Humans , Interferon-beta/metabolism , Interleukin-6/metabolism , Macrophages/immunology , Methylation , Mice , Mice, Inbred C57BL , Mice, Knockout , Monocytes/immunology , RNA Interference , RNA, Bacterial/genetics , RNA, Ribosomal, 23S/genetics , RNA, Small Interfering , Streptococcus pyogenes/immunology , Toll-Like Receptor 8/biosynthesis , Toll-Like Receptor 8/genetics , Toll-Like Receptors/metabolism , Tumor Necrosis Factor-alpha/metabolism
14.
J Immunol ; 195(11): 5421-31, 2015 Dec 01.
Article in English | MEDLINE | ID: mdl-26519528

ABSTRACT

Histone deacetylase (HDAC) inhibitors (HDACi) are clinically approved anticancer drugs that have important immune-modulatory properties. We report the surprising finding that HDACi promote LPS-induced IL-1ß processing and secretion in human and murine dendritic cells and murine macrophages. HDACi/LPS-induced IL-1ß maturation and secretion kinetics differed completely from those observed upon inflammasome activation. Moreover, this pathway of IL-1ß secretion was dependent on caspase-8 but was independent of the inflammasome components NACHT, LRR, and PYD domains-containing protein 3, apoptosis-associated speck-like protein containing a carboxyl-terminal caspase-recruitment domain, and caspase-1. Genetic studies excluded HDAC6 and HDAC10 as relevant HDAC targets in this pathway, whereas pharmacological inhibitor studies implicated the involvement of HDAC11. Treatment of mice with HDACi in a dextran sodium sulfate-induced colitis model resulted in a strong increase in intestinal IL-1ß, confirming that this pathway is also operative in vivo. Thus, in addition to the conventional inflammasome-dependent IL-1ß cleavage pathway, dendritic cells and macrophages are capable of generating, secreting, and processing bioactive IL-1ß by a novel, caspase-8-dependent mechanism. Given the widespread interest in the therapeutic targeting of IL-1ß, as well as the use of HDACi for anti-inflammatory applications, these findings have substantial clinical implications.


Subject(s)
Caspase 8/immunology , Dendritic Cells/immunology , Histone Deacetylase Inhibitors/pharmacology , Interleukin-1beta/metabolism , Macrophages/immunology , Animals , Bone Marrow Cells , Carrier Proteins , Caspase 1/genetics , Caspase 1/immunology , Caspase Inhibitors/pharmacology , Caspases/genetics , Caspases, Initiator , Cells, Cultured , Colitis/chemically induced , Dextran Sulfate , Histone Deacetylases/immunology , Inflammasomes/immunology , Lipopolysaccharides , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , NLR Family, Pyrin Domain-Containing 3 Protein
15.
Mediators Inflamm ; 2017: 5047403, 2017.
Article in English | MEDLINE | ID: mdl-29445257

ABSTRACT

A genuine microbiota resides in the lungs which emanates from the colonization by the oropharyngeal microbiota. Changes in the oropharyngeal microbiota might be the source of dysbiosis observed in the lower airways in patients suffering from asthma or cystic fibrosis (CF). To examine this hypothesis, we compared the throat microbiota from healthy children (n = 62) and that from children with asthma (n = 27) and CF (n = 57) aged 6 to 12 years using 16S rRNA amplicon sequencing. Our results show high levels of similarities between healthy controls and children with asthma and CF revealing the existence of a core microbiome represented by Prevotella, Streptococcus, Neisseria, Veillonella, and Haemophilus. However, in CF, the global diversity, the bacterial load, and abundances of 53 OTUs were significantly reduced, whereas abundances of 6 OTUs representing opportunistic pathogens such as Pseudomonas, Staphylococcus, and Streptococcus were increased compared to those in healthy controls controls and asthmatics. Our data reveal a core microbiome in the throat of healthy children that persists in asthma and CF indicating shared host regulation favoring growth of commensals. Furthermore, we provide evidence for dysbiosis with a decrease in diversity and biomass associated with the presence of known pathogens consistent with impaired host defense in children with CF.


Subject(s)
Asthma/microbiology , Cystic Fibrosis/microbiology , Microbiota , Oropharynx/microbiology , Anti-Bacterial Agents/therapeutic use , Biomass , Child , Female , Humans , Male
16.
J Clin Microbiol ; 54(9): 2321-9, 2016 09.
Article in English | MEDLINE | ID: mdl-27358466

ABSTRACT

Vancomycin-resistant enterococci (VRE) are an important cause of health care-associated infections, resulting in significant mortality and a significant economic burden in hospitals. Active surveillance for at-risk populations contributes to the prevention of infections with VRE. The availability of a combination of automation and molecular detection procedures for rapid screening would be beneficial. Here, we report on the development of a laboratory-developed PCR for detection of VRE which runs on the fully automated Becton Dickinson (BD) Max platform, which combines DNA extraction, PCR setup, and real-time PCR amplification. We evaluated two protocols: one using a liquid master mix and the other employing commercially ordered dry-down reagents. The BD Max VRE PCR was evaluated in two rounds with 86 and 61 rectal elution swab (eSwab) samples, and the results were compared to the culture results. The sensitivities of the different PCR formats were 84 to 100% for vanA and 83.7 to 100% for vanB; specificities were 96.8 to 100% for vanA and 81.8 to 97% for vanB The use of dry-down reagents and the ExK DNA-2 kit for extraction showed that the samples were less inhibited (3.3%) than they were by the use of the liquid master mix (14.8%). Adoption of a cutoff threshold cycle of 35 for discrimination of vanB-positive samples allowed an increase of specificity to 87.9%. The performance of the BD Max VRE assay equaled that of the BD GeneOhm VanR assay, which was run in parallel. The use of dry-down reagents simplifies the assay and omits any need to handle liquid PCR reagents.


Subject(s)
Automation, Laboratory/methods , Gram-Positive Bacterial Infections/diagnosis , Real-Time Polymerase Chain Reaction/methods , Specimen Handling/methods , Vancomycin-Resistant Enterococci/isolation & purification , Bacterial Proteins/genetics , Carbon-Oxygen Ligases/genetics , Gram-Positive Bacterial Infections/microbiology , Humans , Retrospective Studies , Sensitivity and Specificity
17.
RNA ; 20(9): 1351-5, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25051971

ABSTRACT

RNA can function as a pathogen-associated molecular pattern (PAMP) whose recognition by the innate immune system alerts the body to an impending microbial infection. The recognition of tRNA as either self or nonself RNA by TLR7 depends on its modification patterns. In particular, it is known that the presence of a ribose methylated guanosine at position 18, which is overrepresented in self-RNA, antagonizes an immune response. Here, we report that recognition extends to the next downstream nucleotide and the effectively recognized molecular detail is actually a methylated dinucleotide. The most efficient nucleobases combination of this motif includes two purines, while pyrimidines diminish the effect of ribose methylation. The constraints of this motif stay intact when transposed to other parts of the tRNA. The results argue against a fixed orientation of the tRNA during interaction with TLR7 and, rather, suggest a processive type of inspection.


Subject(s)
RNA, Transfer/metabolism , Toll-Like Receptor 7/metabolism , Base Sequence , Binding Sites/genetics , Cells, Cultured , Humans , Models, Molecular , Molecular Sequence Data , Nucleic Acid Conformation , Protein Binding , RNA, Transfer/chemistry , Substrate Specificity/genetics
18.
J Immunol ; 193(3): 1475-84, 2014 Aug 01.
Article in English | MEDLINE | ID: mdl-24965772

ABSTRACT

Airway epithelial cells mount a tolerogenic microenvironment that reduces the proinflammatory potential of respiratory dendritic cells (DCs). We recently demonstrated that tracheal epithelial cells continuously secrete soluble mediators that affect the reactivity of local innate immune cells. Using transcriptional profiling, we now observed that conditioning of DCs by tracheal epithelial cells regulated 98 genes under homeostatic conditions. Among the most upregulated genes were Ms4a8a and Ym1, marker genes of alternatively activated myeloid cells. Ex vivo analysis of respiratory DCs from nonchallenged mice confirmed a phenotype of alternative activation. Bioinformatic analysis showed an overrepresentation of hormone-nuclear receptors within the regulated genes, among which was the glucocorticoid receptor. In line with a role for glucocorticoids, pharmacological blockade as well as genetic manipulation of the glucocorticoid receptor within DCs inhibited Ms4a8a and Ym1 expression as well as MHC class II and CD86 regulation upon epithelial cell conditioning. Within epithelial cell-conditioned medium, low amounts of glucocorticoids were present. Further analysis showed that airway epithelial cells did not produce glucocorticoids de novo, yet were able to reactivate inactive dehydrocorticosterone enzymatically. The results show that airway epithelial cells regulate local immune responses, and this modulation involves local production of glucocorticoids and induction of an alternative activation phenotype in DCs.


Subject(s)
Cellular Microenvironment/immunology , Dendritic Cells/immunology , Dendritic Cells/metabolism , Receptors, Glucocorticoid/genetics , Respiratory Mucosa/immunology , Respiratory Mucosa/metabolism , Signal Transduction/immunology , Animals , Bronchi/cytology , Bronchi/immunology , Bronchi/metabolism , Cellular Microenvironment/genetics , Cytokines/metabolism , Cytokines/physiology , Dendritic Cells/cytology , Female , Immunophenotyping , Inflammation/genetics , Inflammation/immunology , Inflammation/prevention & control , Mice , Mice, Inbred C57BL , Mice, Transgenic , Primary Cell Culture , Random Allocation , Receptor Cross-Talk/immunology , Receptors, Glucocorticoid/biosynthesis , Receptors, Glucocorticoid/deficiency , Respiratory Mucosa/cytology , Signal Transduction/genetics , Thymic Stromal Lymphopoietin
19.
J Allergy Clin Immunol ; 136(1): 177-188.e11, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25630941

ABSTRACT

BACKGROUND: Rhinovirus infections are the dominant cause of asthma exacerbations, and deficient virus induction of IFN-α/ß/λ in asthmatic patients is important in asthma exacerbation pathogenesis. Mechanisms causing this interferon deficiency in asthmatic patients are unknown. OBJECTIVE: We sought to investigate the expression of suppressor of cytokine signaling (SOCS) 1 in tissues from asthmatic patients and its possible role in impaired virus-induced interferon induction in these patients. METHODS: We assessed SOCS1 mRNA and protein levels in vitro, bronchial biopsy specimens, and mice. The role of SOCS1 was inferred by proof-of-concept studies using overexpression with reporter genes and SOCS1-deficient mice. A nuclear role of SOCS1 was shown by using bronchial biopsy staining, overexpression of mutant SOCS1 constructs, and confocal microscopy. SOCS1 levels were also correlated with asthma-related clinical outcomes. RESULTS: We report induction of SOCS1 in bronchial epithelial cells (BECs) by asthma exacerbation-related cytokines and by rhinovirus infection in vitro. We found that SOCS1 was increased in vivo in bronchial epithelium and related to asthma severity. SOCS1 expression was also increased in primary BECs from asthmatic patients ex vivo and was related to interferon deficiency and increased viral replication. In primary human epithelium, mouse lung macrophages, and SOCS1-deficient mice, SOCS1 suppressed rhinovirus induction of interferons. Suppression of virus-induced interferon levels was dependent on SOCS1 nuclear translocation but independent of proteasomal degradation of transcription factors. Nuclear SOCS1 levels were also increased in BECs from asthmatic patients. CONCLUSION: We describe a novel mechanism explaining interferon deficiency in asthmatic patients through a novel nuclear function of SOCS1 and identify SOCS1 as an important therapeutic target for asthma exacerbations.


Subject(s)
Asthma/immunology , Cell Nucleus/metabolism , Picornaviridae Infections/immunology , Respiratory Mucosa/immunology , Rhinovirus/physiology , Suppressor of Cytokine Signaling Proteins/metabolism , Adolescent , Adult , Animals , Asthma/complications , Asthma/virology , Cells, Cultured , Child , Child, Preschool , Female , Humans , Immunity, Innate/genetics , Interferon-gamma/genetics , Interferon-gamma/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Middle Aged , Mutation/genetics , Picornaviridae Infections/complications , Picornaviridae Infections/virology , Protein Transport , Respiratory Mucosa/virology , Suppressor of Cytokine Signaling 1 Protein , Suppressor of Cytokine Signaling Proteins/genetics , Up-Regulation/genetics , Virus Replication , Young Adult
20.
J Clin Microbiol ; 53(11): 3630-2, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26292311

ABSTRACT

We evaluated the performance of the BD Max StaphSR assay for the direct detection of Staphylococcus aureus from blood culture medium. In a two-center trial, 155 blood cultures from the BD Bactec FX system and 212 from the bioMérieux BacT/Alert system were tested; 170 bottles yielded S. aureus, and all were identified correctly by the BD Max StaphSR assay. The assay required approximately 2.5 h, thus allowing rapid identification of blood cultures flagged positive.


Subject(s)
Bacteremia/diagnosis , Methicillin-Resistant Staphylococcus aureus/genetics , Reagent Kits, Diagnostic , Staphylococcal Infections/diagnosis , Bacteremia/microbiology , Bacterial Proteins/genetics , Bacteriological Techniques/methods , Humans , Methicillin-Resistant Staphylococcus aureus/classification , Micrococcal Nuclease/genetics , Penicillin-Binding Proteins/genetics , Real-Time Polymerase Chain Reaction , Sensitivity and Specificity , Staphylococcal Infections/microbiology
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