Publications by authors named "Hortense Slevogt"

77 Publications

Inhibition of the NLRP3/IL-1β axis protects against sepsis-induced cardiomyopathy.

J Cachexia Sarcopenia Muscle 2021 Sep 2. Epub 2021 Sep 2.

Experimental and Clinical Research Center (ECRC), Charité-Universitätsmedizin Berlin, Max Delbrück Center (MDC) for Molecular Medicine in the Helmholtz Association, Berlin, Germany.

Background: Septic cardiomyopathy worsens the prognosis of critically ill patients. Clinical data suggest that interleukin-1β (IL-1β), activated by the NLRP3 inflammasome, compromises cardiac function. Whether or not deleting Nlrp3 would prevent cardiac atrophy and improve diastolic cardiac function in sepsis was unclear. Here, we investigated the role of NLRP3/IL-1β in sepsis-induced cardiomyopathy and cardiac atrophy.

Methods: Male Nlrp3 knockout (KO) and wild-type (WT) mice were exposed to polymicrobial sepsis by caecal ligation and puncture (CLP) surgery (KO, n = 27; WT, n = 33) to induce septic cardiomyopathy. Sham-treated mice served as controls (KO, n = 11; WT, n = 16). Heart weights and morphology, echocardiography and analyses of gene and protein expression were used to evaluate septic cardiomyopathy and cardiac atrophy. IL-1β effects on primary and immortalized cardiomyocytes were investigated by morphological and molecular analyses. IonOptix and real-time deformability cytometry (RT-DC) analysis were used to investigate functional and mechanical effects of IL-1β on cardiomyocytes.

Results: Heart morphology and echocardiography revealed preserved systolic (stroke volume: WT sham vs. WT CLP: 33.1 ± 7.2 μL vs. 24.6 ± 8.7 μL, P < 0.05; KO sham vs. KO CLP: 28.3 ± 8.1 μL vs. 29.9 ± 9.9 μL, n.s.; P < 0.05 vs. WT CLP) and diastolic (peak E wave velocity: WT sham vs. WT CLP: 750 ± 132 vs. 522 ± 200 mm/s, P < 0.001; KO sham vs. KO CLP: 709 ± 152 vs. 639 ± 165 mm/s, n.s.; P < 0.05 vs. WT CLP) cardiac function and attenuated cardiac (heart weight-tibia length ratio: WT CLP vs. WT sham: -26.6%, P < 0.05; KO CLP vs. KO sham: -3.3%, n.s.; P < 0.05 vs. WT CLP) and cardiomyocyte atrophy in KO mice during sepsis. IonOptix measurements showed that IL-1β decreased contractility (cell shortening: IL-1β: -15.4 ± 2.3%, P < 0.001 vs. vehicle, IL-1RA: -6.1 ± 3.3%, P < 0.05 vs. IL-1β) and relaxation of adult rat ventricular cardiomyocytes (time-to-50% relengthening: IL-1β: 2071 ± 225 ms, P < 0.001 vs. vehicle, IL-1RA: 564 ± 247 ms, P < 0.001 vs. IL-1β), which was attenuated by an IL-1 receptor antagonist (IL-1RA). RT-DC analysis indicated that IL-1β reduced cardiomyocyte size (P < 0.001) and deformation (P < 0.05). RNA sequencing showed that genes involved in NF-κB signalling, autophagy and lysosomal protein degradation were enriched in hearts of septic WT but not in septic KO mice. Western blotting and qPCR disclosed that IL-1β activated NF-κB and its target genes, caused atrophy and decreased myosin protein in myocytes, which was accompanied by an increased autophagy gene expression. These effects were attenuated by IL-1RA.

Conclusions: IL-1β causes atrophy, impairs contractility and relaxation and decreases deformation of cardiomyocytes. Because NLRP3/IL-1β pathway inhibition attenuates cardiac atrophy and cardiomyopathy in sepsis, it could be useful to prevent septic cardiomyopathy.
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http://dx.doi.org/10.1002/jcsm.12763DOI Listing
September 2021

Context-dependent regulation of immunoglobulin mutagenesis by p53.

Mol Immunol 2021 Oct 12;138:128-136. Epub 2021 Aug 12.

Department of Cell Biology, Institute of Biochemistry and Biophysics, Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany; Institute of Clinical Molecular Biology, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany. Electronic address:

p53 plays a major role in genome maintenance. In addition to multiple p53 functions in the control of DNA repair, a regulation of DNA damage bypass via translesion synthesis has been implied in vitro. Somatic hypermutation of immunoglobulin genes for affinity maturation of antibody responses is based on aberrant translesion polymerase action and must be subject to stringent control to prevent genetic alterations and lymphomagenesis. When studying the role of p53 in somatic hypermutation in vivo, we found altered translesion polymerase-mediated A:T mutagenesis in mice lacking p53 in all organs, but notably not in mice with B cell-specific p53 inactivation, implying that p53 functions in non-B cells may alter mutagenesis in B cells. During class switch recombination, when p53 prevents formation of chromosomal translocations, we in addition detected a B cell-intrinsic role for p53 in altering G:C and A:T mutagenesis. Thus, p53 regulates translesion polymerase activity and shows differential activity during somatic hypermutation versus class switch recombination in vivo. Finally, p53 inhibition leads to increased somatic hypermutation in human B lymphoma cells. We conclude that loss of p53 function may promote genetic instability via multiple routes during antibody diversification in vivo.
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http://dx.doi.org/10.1016/j.molimm.2021.08.005DOI Listing
October 2021

Bacterial colonization dynamics and antibiotic resistance gene dissemination in the hospital environment after first patient occupancy: a longitudinal metagenetic study.

Microbiome 2021 08 11;9(1):169. Epub 2021 Aug 11.

Jena University Hospital, ZIK Septomics, Host Septomics, Jena, Germany.

Background: Humans spend the bulk of their time in indoor environments. This space is shared with an indoor ecosystem of microorganisms, which are in continuous exchange with the human inhabitants. In the particular case of hospitals, the environmental microorganisms may influence patient recovery and outcome. An understanding of the bacterial community structure in the hospital environment is pivotal for the prevention of hospital-acquired infections and the dissemination of antibiotic resistance genes. In this study, we performed a longitudinal metagenetic approach in a newly opened ward at the Charité Hospital (Berlin) to characterize the dynamics of the bacterial colonization process in the hospital environment after first patient occupancy.

Results: The sequencing data showed a site-specific taxonomic succession, which led to stable community structures after only a few weeks. This data was further supported by network analysis and beta-diversity metrics. Furthermore, the fast colonization process was characterized by a significant increase of the bacterial biomass and its alpha-diversity. The compositional dynamics could be linked to the exchange with the patient microbiota. Over a time course of 30 weeks, we did not detect a rise of pathogenic bacteria in the hospital environment, but a significant increase of antibiotic resistance determinants on the hospital floor.

Conclusions: The results presented in this study provide new insights into different aspects of the environmental microbiome in the clinical setting, and will help to adopt infection control strategies in hospitals and health care-related buildings. Video Abstract.
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http://dx.doi.org/10.1186/s40168-021-01109-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8359561PMC
August 2021

Interaction of TLR4 and TLR8 in the Innate Immune Response against Mycobacterium Tuberculosis.

Int J Mol Sci 2021 Feb 4;22(4). Epub 2021 Feb 4.

Department of Internal Medicine III, Division of Infectious Diseases, University Hospital of Ulm, 89081 Ulm, Germany.

The interaction and crosstalk of Toll-like receptors (TLRs) is an established pathway in which the innate immune system recognises and fights pathogens. In a single nucleotide polymorphisms (SNP) analysis of an Indian cohort, we found evidence for both TLR4-399T and TRL8-1A conveying increased susceptibility towards tuberculosis (TB) in an interdependent manner, even though there is no established TLR4 ligand present in (Mtb), which is the causative pathogen of TB. Docking studies revealed that TLR4 and TLR8 can build a heterodimer, allowing interaction with TLR8 ligands. The conformational change of TLR4-399T might impair this interaction. With immunoprecipitation and mass spectrometry, we precipitated TLR4 with TLR8-targeted antibodies, indicating heterodimerisation. Confocal microscopy confirmed a high co-localisation frequency of TLR4 and TLR8 that further increased upon TLR8 stimulation. The heterodimerisation of TLR4 and TLR8 led to an induction of IL12p40, NF-κB, and IRF3. TLR4-399T in interaction with TLR8 induced an increased NF-κB response as compared to TLR4-399C, which was potentially caused by an alteration of subsequent immunological pathways involving type I IFNs. In summary, we present evidence that the heterodimerisation of TLR4 and TLR8 at the endosome is involved in Mtb recognition via TLR8 ligands, such as microbial RNA, which induces a Th1 response. These findings may lead to novel targets for therapeutic interventions and vaccine development regarding TB.
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http://dx.doi.org/10.3390/ijms22041560DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7913854PMC
February 2021

IL-17C contributes to NTHi-induced inflammation and lung damage in experimental COPD and is present in sputum during acute exacerbations.

PLoS One 2021 7;16(1):e0243484. Epub 2021 Jan 7.

Department of Internal Medicine V - Pulmonology, Allergology and Respiratory Critical Care Medicine, Saarland University, Homburg, Germany.

Neutrophilic inflammation results in loss of lung function in chronic obstructive pulmonary disease (COPD). Gram-negative bacteria, such as nontypeable Haemophilus influenzae (NTHi), trigger acute exacerbations of COPD (AECOPD) and contribute to chronic lung inflammation. The pro-inflammatory cytokine interleukin-17C (IL-17C) is expressed by airway epithelial cells and regulates neutrophilic chemotaxis. Here, we explored the function of IL-17C in NTHi- and cigarette smoke (CS)-induced models of COPD. Neutrophilic inflammation and tissue destruction were decreased in lungs of IL-17C-deficient mice (Il-17c-/-) chronically exposed to NTHi. Numbers of pulmonary neutrophils were decreased in Il-17c-/- mice after acute exposure to the combination of NTHi and CS. However, Il-17c-/- mice were not protected from CS-induced lung inflammation. In a preliminary patient study, we show that IL-17C is present in sputum samples obtained during AECOPD and associates with disease severity. Concentrations of IL-17C were significantly increased during advanced COPD (GOLD III/IV) compared to moderate COPD (GOLD I/II). Concentrations of IL-17A and IL-17E did not associate with disease severity. Our data suggest that IL-17C promotes harmful pulmonary inflammation triggered by bacteria in COPD.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0243484PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7790230PMC
April 2021

Metabolic modeling predicts specific gut bacteria as key determinants for Candida albicans colonization levels.

ISME J 2021 05 15;15(5):1257-1270. Epub 2020 Dec 15.

Systems Biology & Bioinformatics Unit, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, 07745, Jena, Germany.

Candida albicans is a leading cause of life-threatening hospital-acquired infections and can lead to Candidemia with sepsis-like symptoms and high mortality rates. We reconstructed a genome-scale C. albicans metabolic model to investigate bacterial-fungal metabolic interactions in the gut as determinants of fungal abundance. We optimized the predictive capacity of our model using wild type and mutant C. albicans growth data and used it for in silico metabolic interaction predictions. Our analysis of more than 900 paired fungal-bacterial metabolic models predicted key gut bacterial species modulating C. albicans colonization levels. Among the studied microbes, Alistipes putredinis was predicted to negatively affect C. albicans levels. We confirmed these findings by metagenomic sequencing of stool samples from 24 human subjects and by fungal growth experiments in bacterial spent media. Furthermore, our pairwise simulations guided us to specific metabolites with promoting or inhibitory effect to the fungus when exposed in defined media under carbon and nitrogen limitation. Our study demonstrates that in silico metabolic prediction can lead to the identification of gut microbiome features that can significantly affect potentially harmful levels of C. albicans.
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http://dx.doi.org/10.1038/s41396-020-00848-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8115155PMC
May 2021

Characterization of the pathoimmunology of necrotizing enterocolitis reveals novel therapeutic opportunities.

Nat Commun 2020 11 13;11(1):5794. Epub 2020 Nov 13.

Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC, Australia.

Necrotizing enterocolitis (NEC) is a severe, currently untreatable intestinal disease that predominantly affects preterm infants and is driven by poorly characterized inflammatory pathways. Here, human and murine NEC intestines exhibit an unexpected predominance of type 3/T17 polarization. In murine NEC, pro-inflammatory type 3 NKp46RORγtTbet innate lymphoid cells (ILC3) are 5-fold increased, whereas ILC1 and protective NKp46RORγt ILC3 are obliterated. Both species exhibit dysregulation of intestinal TLR repertoires, with TLR4 and TLR8 increased, but TLR5-7 and TLR9-12 reduced. Transgenic IL-37 effectively protects mice from intestinal injury and mortality, whilst exogenous IL-37 is only modestly efficacious. Mechanistically, IL-37 favorably modulates immune homeostasis, TLR repertoires and microbial diversity. Moreover, IL-37 and its receptor IL-1R8 are reduced in human NEC epithelia, and IL-37 is lower in blood monocytes from infants with NEC and/or lower birthweight. Our results on NEC pathomechanisms thus implicate type 3 cytokines, TLRs and IL-37 as potential targets for novel NEC therapies.
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http://dx.doi.org/10.1038/s41467-020-19400-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7666196PMC
November 2020

Proteome analysis of bronchoalveolar lavage fluids reveals host and fungal proteins highly expressed during invasive pulmonary aspergillosis in mice and humans.

Virulence 2020 12;11(1):1337-1351

Microbial Immunology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knoell Institute , Jena, Germany.

Invasive pulmonary aspergillosis (IPA) is a severe infection that is difficult to diagnose due to the ubiquitous presence of fungal spores, the underlying diseases of risk patients, and limitations of currently available markers. In this study, we performed a comprehensive liquid chromatography tandem mass spectrometry (LC-MS/MS)-based identification of host and fungal proteins expressed during IPA in mice and humans. The proteomic analysis of bronchoalveolar lavage samples of individual IPA and control cases allowed the description of common host factors that had significantly increased abundance in both infected animals and IPA patients compared to their controls. Although increased levels of these individual host proteins might not be sufficient to distinguish bacterial from fungal infection, a combination of these markers might be beneficial to improve diagnosis. We also identified 16 fungal proteins that were specifically detected during infection and may be valuable candidates for biomarker evaluation.
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http://dx.doi.org/10.1080/21505594.2020.1824960DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7549978PMC
December 2020

A simple sequence-based filtering method for the removal of contaminants in low-biomass 16S rRNA amplicon sequencing approaches.

J Microbiol Methods 2020 Sep 16;178:106060. Epub 2020 Sep 16.

Jena University Hospital, ZIK Septomics, Host Septomics, Albert-Einstein-Str. 10, Jena 07745, Germany. Electronic address:

Controlling for contaminant sequences in microbiome experiments involving low-biomass samples is a highly challenging task which still lacks of standardized protocols. Here we propose a simple sequence-based filtering method for 16S rRNA gene microbial profiling approaches, and validate its efficiency using mock community dilution series and environmental samples collected in a clinical setting.
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http://dx.doi.org/10.1016/j.mimet.2020.106060DOI Listing
September 2020

First molecular detection of Pneumocystis spp. in red foxes (Vulpes vulpeslinnaeus, 1758) and raccoon dogs (Nyctereutes procyonoidesgray, 1834).

Comp Immunol Microbiol Infect Dis 2020 Dec 14;73:101531. Epub 2020 Aug 14.

Division of Tropical Medicine and Infectious Diseases, Department of Medicine, University of Rostock, Germany.

Fungal organisms of the genus Pneumocystis may cause Pneumocystis pneumonia (PCP) in humans, but also domestic and wild mammals. Almost every animal species hosts its own genetically distinct Pneumocystis species, however information is sparse. In this study, 62 red foxes (Vulpes vulpes) and 37 raccoon dogs (Nyctereutes procyonoides) were collected in North-East Germany. The lung tissues of the animals were analysed by a new designed specific pan-Pneumocystis mtLSU rRNA gene PCR and sequencing. With this PCR, detection and discrimination of all known Pneumocystis spp. in a single step should be possible. This first detection of Pneumocystis spp. in 29/62 (46.8%) red foxes and 29/37 (78.4%) raccoon dogs indicated, that they harbour two dissimilar strains, as seen by specific single nucleotide position changes (SNPs). Nevertheless, five samples with contrary SNPs showed a probable inter-species transmission.
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http://dx.doi.org/10.1016/j.cimid.2020.101531DOI Listing
December 2020

Early Bacterial Colonization and Antibiotic Resistance Gene Acquisition in Newborns.

Front Cell Infect Microbiol 2020 10;10:332. Epub 2020 Jul 10.

Host Septomics, ZIK Septomics Research Center, Jena University Hospital, Jena, Germany.

Several studies have recently identified the main factors contributing to the bacterial colonization of newborns and the dynamics of the infant microbiome development. However, most of these studies address large time periods of weeks or months after birth, thereby missing on important aspects of the early microbiome maturation, such as the acquisition of antibiotic resistance determinants during postpartum hospitalization. The pioneer bacterial colonization and the extent of its associated antibiotic resistance gene (ARG) dissemination during this early phase of life are largely unknown. Studies addressing resistant bacteria or ARGs in neonates often focus only on the presence of particular bacteria or genes from a specific group of antibiotics. In the present study, we investigated the gut-, the oral-, and the skin-microbiota of neonates within the first 72 h after birth using 16S rDNA sequencing approaches. In addition, we screened the neonates and their mothers for the presence of 20 different ARGs by directed TaqMan qPCR assays. The taxonomic analysis of the newborn samples revealed an important shift of the microbiota during the first 72 h after birth, showing a clear site-specific colonization pattern in this very early time frame. Moreover, we report a substantial acquisition of ARGs during postpartum hospitalization, with a very high incidence of macrolide resistance determinants and detection across different body sites of the newborns. This study highlights the importance of antibiotic resistance determinant dissemination in neonates during hospitalization, and the need to investigate the implication of the mothers and the hospital environment as potential sources of ARGs.
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http://dx.doi.org/10.3389/fcimb.2020.00332DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7366792PMC
June 2021

Functional surface proteomic profiling reveals the host heat-shock protein A8 as a mediator of Lichtheimia corymbifera recognition by murine alveolar macrophages.

Environ Microbiol 2020 09 21;22(9):3722-3740. Epub 2020 Jul 21.

Jena Microbial Resource Collection, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Jena, Germany.

Mucormycosis is an emergent, fatal fungal infection of humans and warm-blooded animals caused by species of the order Mucorales. Immune cells of the innate immune system serve as the first line of defence against inhaled spores. Alveolar macrophages were challenged with the mucoralean fungus Lichtheimia corymbifera and subjected to biotinylation and streptavidin enrichment procedures followed by LC-MS/MS analyses. A total of 28 host proteins enriched for binding to macrophage-L. corymbifera interaction. Among those, the HSP70-family protein Hspa8 was found to be predominantly responsive to living and heat-killed spores of a virulent and an attenuated strain of L. corymbifera. Confocal scanning laser microscopy of infected macrophages revealed colocalization of Hspa8 with phagocytosed spores of L. corymbifera. The amount of detectable Hspa8 was dependent on the multiplicity of infection. Incubation of alveolar macrophages with an anti-Hspa8 antibody prior to infection reduced their capability to phagocytose spores of L. corymbifera. In contrast, anti-Hspa8 antibodies did not abrogate the phagocytosis of Aspergillus fumigatus conidia by macrophages. These results suggest an important contribution of the heat-shock family protein Hspa8 in the recognition of spores of the mucoralean fungus L. corymbifera by host alveolar macrophages and define a potential immunomodulatory therapeutic target.
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http://dx.doi.org/10.1111/1462-2920.15140DOI Listing
September 2020

Unaltered Fungal Burden and Lethality in Human CEACAM1-Transgenic Mice During Dissemination and Systemic Infection.

Front Microbiol 2019 26;10:2703. Epub 2019 Nov 26.

Host Septomics Group, Centre for Innovation Competence (ZIK) Septomics, University Hospital Jena, Jena, Germany.

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1, CD66a) is a receptor for It is crucial for the immune response of intestinal epithelial cells to this opportunistic pathogen. Moreover, CEACAM1 is of importance for the mucosal colonization by different bacterial pathogens. We therefore studied the influence of the human CEACAM1 receptor in human CEACAM1-transgenic mice on the colonization and infection utilizing a colonization/dissemination and a systemic infection mouse model. Our results showed no alterations in the host response between the transgenic mice and the wild-type littermates to the infections. Both mouse strains showed comparable colonization and mycobiota, similar fungal burdens in various organs, and a similar survival in the systemic infection model. Interestingly, some of the mice treated with anti-bacterial antibiotics (to prepare them for colonization oral infection) also showed a strong reduction in endogenous fungi instead of the normally observed increase in fungal numbers. This was independent of the expression of human CEACAM1. In the systemic infection model, the human CEACAM1 expression was differentially regulated in the kidneys and livers of -infected transgenic mice. Notably, in the kidneys, a total loss of the largest human CEACAM1 isoform was observed. However, the overwhelming immune response induced in the systemic infection model likely covered any CEACAM1-specific effects in the transgenic animals. studies using bone marrow-derived neutrophils from both mouse strains also revealed no differences in their reaction to . In conclusion, in contrast to bacterial pathogens interacting with CEACAM1 on different mucosal surfaces, the human CEACAM1-transgenic mice did not reveal a role of human CEACAM1 in the candidiasis models used here. Further studies and different approaches will be needed to reveal a putative role of CEACAM1 in the host response to .
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http://dx.doi.org/10.3389/fmicb.2019.02703DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6889641PMC
November 2019

Controlling intestinal colonization of high-risk haematology patients with ESBL-producing Enterobacteriaceae: a randomized, placebo-controlled, multicentre, Phase II trial (CLEAR).

J Antimicrob Chemother 2019 07;74(7):2065-2074

Department I of Internal Medicine, University Hospital of Cologne, Cologne, Germany.

Objectives: We assessed the efficacy and safety of an oral antimicrobial regimen for short- and long-term intestinal eradication of ESBL-producing Escherichia coli and Klebsiella pneumoniae (ESBL-EC/KP) in immunocompromised patients.

Methods: We performed a randomized (2:1), double-blind multicentre Phase II study in four haematology-oncology departments. Patients colonized with ESBL-EC/KP received a 7 day antimicrobial regimen of oral colistin (2 × 106 IU 4×/day), gentamicin (80 mg 4×/day) and fosfomycin (three administrations of 3 g every 72 h), or placebo. Faecal, throat and urine specimens were collected on day 0, 6 ± 2, 11 ± 2, 28 ± 4 and 42 ± 4 after treatment initiation, and the quantitative burden of ESBL-EC/KP, resistance genes and changes in intestinal microbiota were analysed. Clinicaltrials.gov: NCT01931592.

Results: As the manufacture of colistin powder was suspended worldwide, the study was terminated prematurely. Overall, 29 (18 verum/11 placebo) out of 47 patients were enrolled. The short-term intestinal eradication was marginal at day 6 (verum group 15/18, 83.3% versus placebo 2/11, 18.2%; relative risk 4.58, 95% CI 1.29-16.33; Fisher's exact test P = 0.001) and not evident at later timepoints. Quantitative analysis showed a significant decrease of intestinal ESBL-EC/KP burden on day 6. Sustained intestinal eradication (day 28 + 42) was not achieved (verum, 38.9% versus placebo, 27.3%; P = 0.299). In the verum group, mcr-1 genes were detected in two faecal samples collected after treatment. Microbiome analysis showed a significant decrease in alpha diversity and a shift in beta diversity.

Conclusions: In this prematurely terminated study of a 7 day oral antimicrobial eradication regimen, short-term ESBL-EC/KP suppression was marginal, while an altered intestinal microbiota composition was clearly apparent.
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http://dx.doi.org/10.1093/jac/dkz124DOI Listing
July 2019

A SNP upstream of the cyclic GMP-AMP synthase (cGAS) gene protects from relapse and extra-pulmonary TB and relates to BCG vaccination status in an Indian cohort.

Genes Immun 2020 01 23;21(1):13-26. Epub 2019 May 23.

Institute for Microbiology and Hygiene, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany.

Tuberculosis (TB) caused by Mycobacterium tuberculosis (M.tb) is a major health care threat worldwide causing over a million deaths annually. Host-pathogen interaction is complex, and a strong genetic contribution to disease susceptibility has been proposed. We have investigated single-nucleotide polymorphisms (SNPs) within cGAS/STING in Indian TB patients and healthy cohorts from India and Germany by Lightcycler®480 genotyping technique. The cGAS/STING pathway is an essential defense pathway within the cytosol after M.tb is internalized and mycobacterial DNA is released inducing the production of type I IFNs. We found that the rs311686 SNP upstream of cGAS provides protection from getting TB overall and is differently distributed in pulmonary TB patients compared with extra-pulmonary and particularly relapse cases. This SNP furthermore differs in distribution when comparing individuals with respect to BCG vaccination status. Taken together, our results show that the presence of the rs311686 SNP influences the course of TB significantly. However, structural conformation changes were found only for the cGAS rs610913 SNP. These findings underscore the importance of M.tb DNA recognition for TB pathogenesis and may eventually help in risk stratification of individuals. This may ultimately help in prevention of disease and aid in developing new vaccination and treatment strategies.
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http://dx.doi.org/10.1038/s41435-019-0080-1DOI Listing
January 2020

Raman spectroscopy reveals LPS-induced changes of biomolecular composition in monocytic THP-1 cells in a label-free manner.

Integr Biol (Camb) 2019 May 13. Epub 2019 May 13.

Leibniz Institute of Photonic Technology, Jena, Germany.

The human innate immune system is able to recognize pathogen-associated molecular patterns like lipopolysaccharides (LPS) leading to the activation of signal cascades and the release of different cytokines. Activation of the immune cells can be assessed in different ways which are either indirect (ELISA of cytokine release), require staining protocols (flow cytometry) or lysis of the cells (mRNA analysis). Here, Raman spectroscopy as a non-destructive spectroscopic method is presented to enable direct and label-free monitoring of changes in cellular metabolism, biomolecular composition as well as morphology. Exemplarily, the potential of Raman spectroscopy is presented for the characterization of LPS-stimulation of monocytic THP-1 cells over a time course of 16 h. The cell culture stimulation model is characterized using gene transcription and expression of the two cytokines TNFα and IL-1β. After 1 h, 3 h, 8 h and 16 h specific Raman spectroscopic fingerprints are generated which encode cell activation pattern after TLR4 stimulation. Most prevalent changes in the spectra occur after 8 h, but slight differences are already detectable after 1 h. Spatially highly resolved Raman scans are used to generate false-color Raman images which provide spatial information of the biochemical state of the cells and changes over time. One of the most significant observed differences is an increase in Raman signal from DNA/RNA content in LPS-stimulated cells when compared to unstimulated cells. The systematic assignment of Raman spectroscopic profiles of LPS-activated cells to cellular activation assessed by cytokine gene transcription and expression opens new ways for label-free and direct immunological studies of specific pathogen recognizing receptors and their downstream signaling pathways.
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http://dx.doi.org/10.1093/intbio/zyz009DOI Listing
May 2019

The composition of the pulmonary microbiota in sarcoidosis - an observational study.

Respir Res 2019 Feb 28;20(1):46. Epub 2019 Feb 28.

Department of Internal Medicine V - Pulmonology, Allergology, Critical Care Medicine, Saarland University Hospital, Homburg, Germany.

Background: Sarcoidosis is a systemic disease of unknown etiology. The disease mechanisms are largely speculative and may include the role microbial patterns that initiate and drive an underlying immune process. The aim of this study was to characterize the microbiota of the lung of patients with sarcoidosis and compare its composition and diversity with the results from patients with other interstitial lung disease (ILD) and historic healthy controls.

Methods: Patients (sarcoidosis, n = 31; interstitial lung disease, n = 19) were recruited within the PULMOHOM study, a prospective cohort study to characterize inflammatory processes in pulmonary diseases. Bronchoscopy of the middle lobe or the lingula was performed and the recovered fluid was immediately sent for analysis of the pulmonary microbiota by 16sRNA gene sequencing. Subsequent bioinformatic analysis was performed to compare the groups.

Results: There were no significant differences between patients with sarcoidosis or other ILDs with regard to microbiome composition and diversity. In addition, the abundance of the genera Atopobium, Fusobacterium, Mycobacterium or Propionibacterium were not different between the two groups. There were no gross differences to historical healthy controls.

Conclusion: The analysis of the pulmonary microbiota based on 16sRNA gene sequencing did not show a significant dysbiosis in patients with sarcoidosis as compared to other ILD patients. These data do not exclude a microbiological component in the pathogenesis of sarcoidosis.
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http://dx.doi.org/10.1186/s12931-019-1013-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6396534PMC
February 2019

Acute Airway Infection of Chronically Smoke-Exposed Mice Increases Mechanisms of Emphysema Development: A Pilot Study.

Eur J Microbiol Immunol (Bp) 2018 Dec 11;8(4):128-134. Epub 2018 Dec 11.

Septomics Research Center, Jena University Hospital, Jena, Germany.

In chronic obstructive pulmonary disease (COPD), acute exacerbations and emphysema development are characteristics for disease pathology. COPD is complicated by infectious exacerbations with acute worsening of respiratory symptoms with as one of the most frequent pathogens. Although cigarette smoke (CS) is the primary risk factor, additional molecular mechanisms for emphysema development induced by bacterial infections are incompletely understood. We investigated the impact of on emphysema development in CS exposed mice and asked whether an additional infection would induce a solubilization of pro-apoptotic and pro-inflammatory endothelial monocyte-activating-protein-2 (EMAPII) to exert its activities in the pulmonary microvas-culature and other parts of the lungs not exposed directly to CS. Mice were exposed to smoke (6 or 9 months) and/or infected with Lungs, bronchoalveolar lavage fluid (BALF), and plasma were analyzed. CS exposure reduced ciliated area, caused rarefaction of the lungs, and induced apoptosis. EMAPII was increased independent of prior smoke exposure in BALF of infected mice. Importantly, acute infection increased release of matrixmetalloproteases-9 and -12, which are involved in emphysema development and comprise a mechanism of EMAPII release. Our data suggest that acute infection represents an independent risk factor for emphysema development in smoke-exposed mice.
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http://dx.doi.org/10.1556/1886.2018.00019DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6348706PMC
December 2018

Comparison of sample preparation techniques and data analysis for the LC-MS/MS-based identification of proteins in human follicular fluid.

Am J Reprod Immunol 2018 08 25;80(2):e12994. Epub 2018 Jun 25.

Host Septomics Research Group, Jena University Hospital, Jena, Germany.

The proteomic analysis of complex body fluids by liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis requires the selection of suitable sample preparation techniques and optimal parameter settings in data analysis software packages to obtain reliable results. Proteomic analysis of follicular fluid, as a representative of a complex body fluid similar to serum or plasma, is difficult as it contains a vast amount of high abundant proteins and a variety of proteins with different concentrations. However, the accessibility of this complex body fluid for LC-MS/MS analysis is an opportunity to gain insights into the status, the composition of fertility-relevant proteins including immunological factors or for the discovery of new diagnostic and prognostic markers for, for example, the treatment of infertility. In this study, we compared different sample preparation methods (FASP, eFASP and in-solution digestion) and three different data analysis software packages (Proteome Discoverer with SEQUEST, Mascot and MaxQuant with Andromeda) combined with semi- and full-tryptic databank search options to obtain a maximum coverage of the follicular fluid proteome. We found that the most comprehensive proteome coverage is achieved by the eFASP sample preparation method using SDS in the initial denaturing step and the SEQUEST-based semi-tryptic data analysis. In conclusion, we have developed a fractionation-free methodical workflow for in depth LC-MS/MS-based analysis for the standardized investigation of human follicle fluid as an important representative of a complex body fluid. Taken together, we were able to identify a total of 1392 proteins in follicular fluid.
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http://dx.doi.org/10.1111/aji.12994DOI Listing
August 2018

The Interaction of Human Pathogenic Fungi With C-Type Lectin Receptors.

Front Immunol 2018 4;9:1261. Epub 2018 Jun 4.

Septomics Research Center, Jena University Hospital, Jena, Germany.

Fungi, usually present as commensals, are a major cause of opportunistic infections in immunocompromised patients. Such infections, if not diagnosed or treated properly, can prove fatal. However, in most cases healthy individuals are able to avert the fungal attacks by mounting proper antifungal immune responses. Among the pattern recognition receptors (PRRs), C-type lectin receptors (CLRs) are the major players in antifungal immunity. CLRs can recognize carbohydrate ligands, such as β-glucans and mannans, which are mainly found on fungal cell surfaces. They induce proinflammatory immune reactions, including phagocytosis, oxidative burst, cytokine, and chemokine production from innate effector cells, as well as activation of adaptive immunity Th17 responses. CLRs such as Dectin-1, Dectin-2, Mincle, mannose receptor (MR), and DC-SIGN can recognize many disease-causing fungi and also collaborate with each other as well as other PRRs in mounting a fungi-specific immune response. Mutations in these receptors affect the host response and have been linked to a higher risk in contracting fungal infections. This review focuses on how CLRs on various immune cells orchestrate the antifungal response and on the contribution of single nucleotide polymorphisms in these receptors toward the risk of developing such infections.
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http://dx.doi.org/10.3389/fimmu.2018.01261DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5994417PMC
August 2019

AmpliSeq Screening of Genes Encoding the C-Type Lectin Receptors and Their Signaling Components Reveals a Common Variant in Associated with Pulmonary Tuberculosis in an Indian Population.

Front Immunol 2018 20;9:242. Epub 2018 Feb 20.

ZIK Septomics, Jena University Hospital, Jena, Germany.

Tuberculosis (TB) is a multifactorial disease governed by bacterial, host and environmental factors. On the host side, growing evidence shows the crucial role that genetic variants play in the susceptibility to (Mtb) infection. Such polymorphisms have been described in genes encoding for different cytokines and pattern recognition receptors (PRR), including numerous Toll-like receptors (TLRs). In recent years, several members of the C-type lectin receptors (CTLRs) have been identified as key PRRs in TB pathogenesis. Nevertheless, studies to date have only addressed particular genetic polymorphisms in these receptors or their related pathways in relation with TB. In the present study, we screened the main CTLR gene clusters as well as CTLR pathway-related genes for genetic variation associated with pulmonary tuberculosis (PTB). This case-control study comprised 144 newly diagnosed pulmonary TB patients and 181 healthy controls recruited at the Bhagwan Mahavir Medical Research Center (BMMRC), Hyderabad, India. A two-stage study was employed in which an explorative AmpliSeq-based screening was followed by a validation phase using iPLEX MassARRAY. Our results revealed one SNP (rs3774275) in significantly associated with PTB in our population (joint analysis  = 0.0028). Furthermore, serum levels of MASP1 were significantly elevated in TB patients when compared to healthy controls. Moreover, in the present study we could observe an impact of increased MASP1 levels on the lectin pathway complement activity . In conclusion, our results demonstrate a significant association of polymorphism rs3774275 and MASP1 serum levels with the development of pulmonary TB. The present work contributes to our understanding of host-Mtb interaction and reinforces the critical significance of mannose-binding lectin and the lectin-complement pathway in Mtb pathogenesis. Moreover, it proposes a polymorphism as a potential genetic marker for TB resistance.
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http://dx.doi.org/10.3389/fimmu.2018.00242DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5826192PMC
March 2019

Digital Image Analyses on Whole-Lung Slides in Mouse Models of Acute Pneumonia.

Am J Respir Cell Mol Biol 2018 04;58(4):440-448

1 Department of Veterinary Pathology, Freie Universität Berlin, Berlin, Germany.

Descriptive histopathology of mouse models of pneumonia is essential in assessing the outcome of infections, molecular manipulations, or therapies in the context of whole lungs. Quantitative comparisons between experimental groups, however, have been limited to laborious stereology or ill-defined scoring systems that depend on the subjectivity of a more or less experienced observer. Here, we introduce self-learning digital image analyses that allow us to transform optical information from whole mouse lung sections into statistically testable data. A pattern-recognition-based software and a nuclear count algorithm were adopted to quantify user-defined pathologies from whole slide scans of lungs infected with Streptococcus pneumoniae or influenza A virus compared with PBS-challenged lungs. The readout parameters "relative area affected" and "nuclear counts per area" are proposed as relevant criteria for the quantification of lesions from hematoxylin and eosin-stained sections, also allowing for the generation of a heat map of, for example, immune cell infiltrates with anatomical assignments across entire lung sections. Moreover, when combined with immunohistochemical labeling of marker proteins, both approaches are useful for the identification and counting of, for example, immune cell populations, as validated here by direct comparisons with flow cytometry data. The solutions can easily and flexibly be adjusted to specificities of different models or pathogens. Automated digital analyses of whole mouse lung sections may set a new standard for the user-defined, high-throughput comparative quantification of histological and immunohistochemical images. Still, our algorithms established here are only a start, and need to be tested in additional studies and other applications in the future.
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http://dx.doi.org/10.1165/rcmb.2017-0337MADOI Listing
April 2018

Differential regulation of the transcriptomic and secretomic landscape of sensor and effector functions of human airway epithelial cells.

Mucosal Immunol 2018 05 3;11(3):627-642. Epub 2018 Jan 3.

Septomics Research Centre, Jena University Hospital, Jena, Germany.

Protein secretion upon TLR, TNFR1, and IFNGR ligation in the human airways is considered to be central for the orchestration of pulmonary inflammatory and immune responses. In this study, we compared the gene expression and protein secretion profiles in response to specific stimulation of all expressed TLRs and in further comparison to TNFR1 and IFNGR in primary human airway epithelial cells. In addition to 22 cytokines, we observed the receptor-induced regulation of 571 genes and 1,012 secreted proteins. Further analysis revealed high similarities between the transcriptional TLR sensor and TNFR1 effector responses. However, secretome to transcriptome comparisons showed a broad receptor stimulation-dependent release of proteins that were not transcriptionally regulated. Many of these proteins are annotated to exosomes with associations to, for example, antigen presentation and wound-healing, or were identified as secretable proteins related to immune responses. Thus, we show a hitherto unrecognized scope of receptor-induced responses in airway epithelium, involving several additional functions for the immune response, exosomal communication and tissue homeostasis.
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http://dx.doi.org/10.1038/mi.2017.100DOI Listing
May 2018

Combination of Classifiers Identifies Fungal-Specific Activation of Lysosome Genes in Human Monocytes.

Front Microbiol 2017 29;8:2366. Epub 2017 Nov 29.

Network Modeling, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Jena, Germany.

Blood stream infections can be caused by several pathogens such as viruses, fungi and bacteria and can cause severe clinical complications including sepsis. Delivery of appropriate and quick treatment is mandatory. However, it requires a rapid identification of the invading pathogen. The current gold standard for pathogen identification relies on blood cultures and these methods require a long time to gain the needed diagnosis. The use of experiments attempts to identify pathogen specific immune responses but these often lead to heterogeneous biomarkers due to the high variability in methods and materials used. Using gene expression profiles for machine learning is a developing approach to discriminate between types of infection, but also shows a high degree of inconsistency. To produce consistent gene signatures, capable of discriminating fungal from bacterial infection, we have employed Support Vector Machines (SVMs) based on Mixed Integer Linear Programming (MILP). Combining classifiers by joint optimization constraining them to the same set of discriminating features increased the consistency of our biomarker list independently of leukocyte-type or experimental setup. Our gene signature showed an enrichment of genes of the lysosome pathway which was not uncovered by the use of independent classifiers. Moreover, our results suggest that the lysosome genes are specifically induced in monocytes. Real time qPCR of the identified lysosome-related genes confirmed the distinct gene expression increase in monocytes during fungal infections. Concluding, our combined classifier approach presented increased consistency and was able to "unmask" signaling pathways of less-present immune cells in the used datasets.
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http://dx.doi.org/10.3389/fmicb.2017.02366DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5712586PMC
November 2017

Kallikrein Cleaves C3 and Activates Complement.

J Innate Immun 2018 14;10(2):94-105. Epub 2017 Dec 14.

Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany.

The human plasma contact system is an immune surveillance system activated by the negatively charged surfaces of bacteria and fungi and includes the kallikrein-kinin, the coagulation, and the fibrinolytic systems. Previous work shows that the contact system also activates complement, and that plasma enzymes like kallikrein, plasmin, thrombin, and FXII are involved in the activation process. Here, we show for the first time that kallikrein cleaves the central complement component C3 directly to yield active components C3b and C3a. The cleavage site within C3 is identical to that recognized by the C3 convertase. Also, kallikrein-generated C3b forms C3 convertases, which trigger the C3 amplification loop. Since kallikrein also cleaves factor B to yield Bb and Ba, kallikrein alone can trigger complement activation. Kallikrein-generated C3 convertases are inhibited by factor H; thus, the kallikrein activation pathway merges with the amplification loop of the alternative pathway. Taken together, these data suggest that activation of the contact system locally enhances complement activation on cell surfaces. The human pathogenic microbe Candida albicans activates the contact system in normal human serum. However, C. albicans immediately recruits factor H to the surface, thereby evading the alternative and likely kallikrein-mediated complement pathways.
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http://dx.doi.org/10.1159/000484257DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6757171PMC
September 2019

Spectrum of pathogen- and model-specific histopathologies in mouse models of acute pneumonia.

PLoS One 2017 20;12(11):e0188251. Epub 2017 Nov 20.

Department of Veterinary Pathology, Freie Universität Berlin, Berlin, Germany.

Pneumonia may be caused by a wide range of pathogens and is considered the most common infectious cause of death in humans. Murine acute lung infection models mirror human pathologies in many aspects and contribute to our understanding of the disease and the development of novel treatment strategies. Despite progress in other fields of tissue imaging, histopathology remains the most conclusive and practical read out tool for the descriptive and semiquantitative evaluation of mouse pneumonia and therapeutic interventions. Here, we systematically describe and compare the distinctive histopathological features of established models of acute pneumonia in mice induced by Streptococcus (S.) pneumoniae, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Legionella pneumophila, Escherichia coli, Middle East respiratory syndrome (MERS) coronavirus, influenza A virus (IAV) and superinfection of IAV-incuced pneumonia with S. pneumoniae. Systematic comparisons of the models revealed striking differences in the distribution of lesions, the characteristics of pneumonia induced, principal inflammatory cell types, lesions in adjacent tissues, and the detectability of the pathogens in histological sections. We therefore identified core criteria for each model suitable for practical semiquantitative scoring systems that take into account the pathogen- and model-specific patterns of pneumonia. Other critical factors that affect experimental pathologies are discussed, including infectious dose, time kinetics, and the genetic background of the mouse strain. The substantial differences between the model-specific pathologies underscore the necessity of pathogen- and model-adapted criteria for the comparative quantification of experimental outcomes. These criteria also allow for the standardized validation and comparison of treatment strategies in preclinical models.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0188251PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5695780PMC
December 2017

The sirtuin 1/2 inhibitor tenovin-1 induces a nonlinear apoptosis-inducing factor-dependent cell death in a p53 null Ewing's sarcoma cell line.

Invest New Drugs 2018 06 18;36(3):396-406. Epub 2017 Nov 18.

Department of Pediatric Hematology and Oncology, Children's Clinic, Jena University Hospital, Jena, Germany.

The sirtuin 1/2 inhibitor tenovin-1 activates p53 and may have potential in the management of cancer. Here, we investigated the responsiveness of Ewing's sarcoma cells to tenovin-1. We examined its effects in two Ewing's sarcoma cell lines with different p53 status, i.e. in p53 wild-type and p53 null cells. Effects were assessed by flow cytometric analyses of cell death, mitochondrial membrane depolarization and reactive oxygen species (ROS) generation, by caspase 3/7 activity measurement, by mRNA expression profiling and by immunoblotting. Tenovin-1 elicited caspase-mediated cell death in p53 wild-type cells, but caspase-independent cell death in p53 null cells. Remarkably, it induced a nonlinear concentration response in the latter: low concentrations of tenovin-1 were much more effective than were higher concentrations. Tenovin-1's effects in p53 null cells involved gene expression changes of Bcl-2 family members, mitochondrial membrane depolarization, nuclear translocation of apoptosis-inducing factor, ROS formation and DNA damage; all these effects followed a bell-shaped pattern. In conclusion, our results provide new insights into tenovin-1's mode of action by demonstrating that it can induce different pathways of cell death.
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http://dx.doi.org/10.1007/s10637-017-0541-1DOI Listing
June 2018

Fungal biomarker discovery by integration of classifiers.

BMC Genomics 2017 08 10;18(1):601. Epub 2017 Aug 10.

Network Modelling, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Beutenbergstraße 11a, Jena, Germany.

Background: The human immune system is responsible for protecting the host from infection. However, in immunocompromised individuals the risk of infection increases substantially with possible drastic consequences. In extreme, systemic infection can lead to sepsis which is responsible for innumerous deaths worldwide. Amongst its causes are infections by bacteria and fungi. To increase survival, it is mandatory to identify the type of infection rapidly. Discriminating between fungal and bacterial pathogens is key to determine if antifungals or antibiotics should be administered, respectively. For this, in situ experiments have been performed to determine regulation mechanisms of the human immune system to identify biomarkers. However, these studies led to heterogeneous results either due different laboratory settings, pathogen strains, cell types and tissues, as well as the time of sample extraction, to name a few.

Methods: To generate a gene signature capable of discriminating between fungal and bacterial infected samples, we employed Mixed Integer Linear Programming (MILP) based classifiers on several datasets comprised of the above mentioned pathogens.

Results: When combining the classifiers by a joint optimization we could increase the consistency of the biomarker gene list independently of the experimental setup. An increase in pairwise overlap (the number of genes that overlap in each cross-validation) of 43% was obtained by this approach when compared to that of single classifiers. The refined gene list was composed of 19 genes and ranked according to consistency in expression (up- or down-regulated) and most of them were linked either directly or indirectly to the ERK-MAPK signalling pathway, which has been shown to play a key role in the immune response to infection. Testing of the identified 12 genes on an unseen dataset yielded an average accuracy of 83%.

Conclusions: In conclusion, our method allowed the combination of independent classifiers and increased consistency and reliability of the generated gene signatures.
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http://dx.doi.org/10.1186/s12864-017-4006-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5553868PMC
August 2017

IL-37 Causes Excessive Inflammation and Tissue Damage in Murine Pneumococcal Pneumonia.

J Innate Immun 2017 10;9(4):403-418. Epub 2017 Jun 10.

Septomics Research Center, Jena University Hospital, Jena, Germany.

Streptococcus pneumoniae infections can lead to severe complications with excessive immune activation and tissue damage. Interleukin-37 (IL-37) has gained importance as a suppressor of innate and acquired immunity, and its effects have been therapeutic as they prevent tissue damage in autoimmune and inflammatory diseases. By using RAW macrophages, stably transfected with human IL-37, we showed a 70% decrease in the cytokine levels of IL-6, TNF-α, and IL-1β, and a 2.2-fold reduction of the intracellular killing capacity of internalized pneumococci in response to pneumococcal infection. In a murine model of infection with S. pneumoniae, using mice transgenic for human IL-37b (IL-37tg), we observed an initial decrease in cytokine expression of IL-6, TNF-α, and IL-1β in the lungs, followed by a late-phase enhancement of pneumococcal burden and subsequent increase of proinflammatory cytokine levels. Additionally, a marked increase in recruitment of alveolar macrophages and neutrophils was noted, while TRAIL mRNA was reduced 3-fold in lungs of IL-37tg mice, resulting in necrotizing pneumonia with augmented death of infiltrating neutrophils, enhanced bacteremic spread, and increased mortality. In conclusion, we have identified that IL-37 modulates several core components of a successful inflammatory response to pneumococcal pneumonia, which lead to increased inflammation, tissue damage, and mortality.
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http://dx.doi.org/10.1159/000469661DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6738772PMC
June 2018

Global analysis of glycoproteins identifies markers of endotoxin tolerant monocytes and GPR84 as a modulator of TNFα expression.

Sci Rep 2017 04 12;7(1):838. Epub 2017 Apr 12.

Septomics Research Center, Jena University Hospital, Jena, Germany.

Exposure of human monocytes to lipopolysaccharide (LPS) induces a temporary insensitivity to subsequent LPS challenges, a cellular state called endotoxin tolerance. In this study, we investigated the LPS-induced global glycoprotein expression changes of tolerant human monocytes and THP-1 cells to identify markers and glycoprotein targets capable to modulate the immunosuppressive state. Using hydrazide chemistry and LC-MS/MS analysis, we analyzed glycoprotein expression changes during a 48 h LPS time course. The cellular snapshots at different time points identified 1491 glycoproteins expressed by monocytes and THP-1 cells. Label-free quantitative analysis revealed transient or long-lasting LPS-induced expression changes of secreted or membrane-anchored glycoproteins derived from intracellular membrane coated organelles or from the plasma membrane. Monocytes and THP-1 cells demonstrated marked differences in glycoproteins differentially expressed in the tolerant state. Among the shared differentially expressed glycoproteins G protein-coupled receptor 84 (GPR84) was identified as being capable of modulating pro-inflammatory TNFα mRNA expression in the tolerant cell state when activated with its ligand Decanoic acid.
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http://dx.doi.org/10.1038/s41598-017-00828-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5429802PMC
April 2017
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