Induction of OCT2 contributes to regulate the gene expression program in human neutrophils activated via TLR8

The transcription factors (TFs) that regulate inducible genes in activated neutrophils are not yet completely characterized. Herein, we show that the genomic distribution of the histone modification H3K27Ac, as well as PU.1 and C/EBP beta, two myeloid-lineage-determining TFs (LDTFs), significantly changes in human neutrophils treated with R848, a ligand of Toll-like receptor 8 (TLR8). Interestingly, differentially acetylated and LDTF-marked regions reveal an over-representation of OCT-binding motifs that are selectively bound by OCT2/POU2F2. Analysis of OCT2 genomic distribution in primary neutrophils and of OCT2-depletion in HL-60-differentiated neutrophils proves the requirement for OCT2 in contributing to promote, along with nuclear factor kappa B (NF-kappa B) and activator protein 1 (AP-1), the TLR8-induced gene expression program in neutrophils. Altogether, our data demonstrate that neutrophils, upon activation via TLR8, profoundly reprogram their chromatin status, ultimately displaying cell-specific, prolonged transcriptome changes. Data also show an unexpected role for OCT2 in amplifying the transcriptional response to TLR8-mediated activation

Electrokinetic remediation of metal-polluted marine sediments: experimental investigation for plant design

This paper presents the results of an extensive set of laboratory experiments performed to design a demonstrative electrokinetic plant for extracting heavy metals from marine sediments dredged from the Livorno marine harbour. The investigated sediments displayed a high salinity, a high acid neutralization capacity, a low electrical resistivity (0.5 Ωm), a high alkalinity (pH ≈ 8) and a large fraction of fine particles. The target metals were Cd, Cr, Cu, Ni, Pb and Zn at relatively weak and inhomogeneous concentrations with high non-mobile fractions. After an accurate characterization, several screening and full electrokinetic tests were performed using cells of two different sizes, several conditioning agents (HNO3, HCl, H2SO4, citric acid, oxalic acid, ascorbic acid, EDTA), different applied current intensities and durations. The tests highlighted the need for long treatment times in order to obtain a significant pH reduction, with some appreciable metal removal being attained only after several weeks. The best results were obtained with strong acids used as the conditioning agents, with significant specific effects of each acid, including pronounced resistivity increase (from 0.5 up to 10 Ωm) and a high electroosmotic flow (EOF) with H2SO4, or a reversed EOF (electroendosmosis), and minor resistivity changes with HNO3. The use of the obtained data to design a demonstrative plant is also presented in the paper, with considerations on operating parameters such as energy and reagent consumption, characteristics of plant components and required safety measures. buffer capacity, conditioning agent

Chromatin remodelling and autocrine TNFα are required for optimal interleukin-6 expression in activated human neutrophils

How IL-6 expression is regulated in human neutrophils has remained unclear. Here the authors show, using highly purified neutrophils, that TLR8 or TLR4 signalling activates latent enhancers and cooperates with autocrine TNFα to induce IL-6 transcription

DNA damage contributes to neurotoxic inflammation in Aicardi-Goutières Syndrome astrocytes

Aberrant induction of type I IFN is a hallmark of the inherited encephalopathy Aicardi-Goutières syndrome (AGS), but the mechanisms triggering disease in the human central nervous system (CNS) remain elusive. Here, we generated human models of AGS using genetically modified and patient-derived pluripotent stem cells harboring TREX1 or RNASEH2B loss-of-function alleles. Genome-wide transcriptomic analysis reveals that spontaneous proinflammatory activation in AGS astrocytes initiates signaling cascades impacting multiple CNS cell subsets analyzed at the single-cell level. We identify accumulating DNA damage, with elevated R-loop and micronuclei formation, as a driver of STING- and NLRP3-related inflammatory responses leading to the secretion of neurotoxic mediators. Importantly, pharmacological inhibition of proapoptotic or inflammatory cascades in AGS astrocytes prevents neurotoxicity without apparent impact on their increased type I IFN responses. Together, our work identifies DNA damage as a major driver of neurotoxic inflammation in AGS astrocytes, suggests a role for AGS gene products in R-loop homeostasis, and identifies common denominators of disease that can be targeted to prevent astrocyte-mediated neurotoxicity in AGS

Co-option of Neutrophil Fates by Tissue Environments.

Classically considered short-lived and purely defensive leukocytes, neutrophils are unique in their fast and moldable response to stimulation. This plastic behavior may underlie variable and even antagonistic functions during inflammation or cancer, yet the full spectrum of neutrophil properties as they enter healthy tissues remains unexplored. Using a new model to track neutrophil fates, we found short but variable lifetimes across multiple tissues. Through analysis of the receptor, transcriptional, and chromatin accessibility landscapes, we identify varying neutrophil states and assign non-canonical functions, including vascular repair and hematopoietic homeostasis. Accordingly, depletion of neutrophils compromised angiogenesis during early age, genotoxic injury, and viral infection, and impaired hematopoietic recovery after irradiation. Neutrophils acquired these properties in target tissues, a process that, in the lungs, occurred in CXCL12-rich areas and relied on CXCR4. Our results reveal that tissues co-opt neutrophils en route for elimination to induce programs that support their physiological demands.This study was supported byIntramural grants from the Severo Ochoa program (IGP-SO), a grant from Fundacio la Marato de TV3 (120/C/2015-20153032), grant SAF2015-65607-R fromMinisterio de Ciencia e Innovacion (MICINN) with co-funding by Fondo Eu-ropeo de Desarrollo Regional (FEDER), RTI2018-095497-B-I00 from MICINN,HR17_00527 from Fundacion La Caixa, and Transatlantic Network of Excel-lence (TNE-18CVD04) from the Leducq Foundation to A.H. I.B. is supportedby fellowship MSCA-IF-EF-748381 and EMBO short-term fellowship 8261.A.R.-P. is supported by a fellowship (BES-2016-076635) and J.A.N.-A. byfellowship SVP-2014-068595 from MICINN. R.O. is supported by ERC startinggrant 759532, Italian Telethon Foundation SR-Tiget grant award F04, ItalianMoH grant GR-201602362156, AIRC MFAG 20247, Cariplo Foundation grant2015-0990, and the EU Infect-ERA 126. C.S. is supported by the SFB 1123,project A07, as well as by the DZHK (German Centre for Cardiovascular Research) and the BMBF (German Ministry of Education and Research) grant81Z0600204. L.G.N. is supported by SIgN core funding from A*STAR. The CNIC is supported by the MICINN and the Pro-CNIC Foundation and is a Severo Ochoa Center of Excellence (MICINN award SEV-2015-0505). G.F.-C. issupported by the Spanish Ministerio de Ciencia e Innovacio ́n (grantPID2019-110895RB-100) and Junta de Comunidades de Castilla-La Mancha(grant SBPLY/19/180501/000211). C.R. received funding from the BoehingerIngelheim Foundation (consortium grant ‘‘Novel and Neglected CardiovascularRisk Factors’’) and German Federal Ministry of Education and Research(BMBF 01EO1503) and is a Fellow of the Gutenberg Research College (GFK)at the Johannes Gutenberg-University MainzS

DC-ATLAS: a systems biology resource to dissect receptor specific signal transduction in dendritic cells

BACKGROUND: The advent of Systems Biology has been accompanied by the blooming of pathway databases. Currently pathways are defined generically with respect to the organ or cell type where a reaction takes place. The cell type specificity of the reactions is the foundation of immunological research, and capturing this specificity is of paramount importance when using pathway-based analyses to decipher complex immunological datasets. Here, we present DC-ATLAS, a novel and versatile resource for the interpretation of high-throughput data generated perturbing the signaling network of dendritic cells (DCs). RESULTS: Pathways are annotated using a novel data model, the Biological Connection Markup Language (BCML), a SBGN-compliant data format developed to store the large amount of information collected. The application of DC-ATLAS to pathway-based analysis of the transcriptional program of DCs stimulated with agonists of the toll-like receptor family allows an integrated description of the flow of information from the cellular sensors to the functional outcome, capturing the temporal series of activation events by grouping sets of reactions that occur at different time points in well-defined functional modules. CONCLUSIONS: The initiative significantly improves our understanding of DC biology and regulatory networks. Developing a systems biology approach for immune system holds the promise of translating knowledge on the immune system into more successful immunotherapy strategies

Heterogeneity of neutrophils

Structured models of ontogenic, phenotypic and functional diversity have been instrumental for a renewed understanding of the biology of immune cells, such as macrophages and lymphoid cells. However, there are no established models that can be used to define the diversity of neutrophils, the most abundant myeloid cells. This lack of an established model is largely due to the uniquely short lives of neutrophils, a consequence of their inability to divide once terminally differentiated, which has been perceived as a roadblock to functional diversity. This perception is rapidly evolving as multiple phenotypic and functional variants of neutrophils have been found, both in homeostatic and disease conditions. In this Opinion article, we present an overview of neutrophil heterogeneity and discuss possible mechanisms of diversification, including genomic regulation. We suggest that neutrophil heterogeneity is an important feature of immune pathophysiology, such that co-option of the mechanisms of diversification by cancer or other disorders contributes to disease progression.The authors are grateful to members of their laboratories for continued enthusiasm and discussions, which are reflected in many parts of this text, and to J. M. Adrover and I. Kwok for the original artwork. The authors apologize to the many colleagues whose contributions could not be discussed in this manuscript. This article is supported by Singapore Immunology Network (A*STAR) core funding to L.G.N. This paper is also supported in part by SAF2015-65607-R and Fondo Europeo de Desarrollo Regional (FEDER) to A.H. The Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC) is supported by the Ministerio de Ciencia, Innovacion y Universidades (MCIU) and the Pro CNIC Foundation and is a Severo Ochoa Center of Excellence (MCIU award SEV-2015-0505). Research in the R.O. laboratory is supported by grants from the European Research Council (ERC Starting Grant #759532, X-TAM), the Italian Telethon Foundation (SR-Tiget grant award F04), the Italian Ministry of Health (GR-2016-02362156), the Associazione Italiana per la Ricerca sul Cancro (AIRC MFAG, #20247), the Cariplo Foundation (2015-0990) and the European Union (Infect-ERA #126).S

Epigenetic regulation of neutrophil development and function

In addition to performing well-defined effector functions, neutrophils are now recognized as versatile and sophisticated cells with critical immunoregulatory roles. These include the release of a variety of proinflammatory or immunosuppressive cytokines, as well as the expression of genes with regulatory functions. Neutrophils share broad transcriptional features with monocytes, in keeping with the close developmental relation between the two cell types. However, neutrophil-specific gene expression patterns conferring cell type-specific responses to bacterial, viral or fungal components have been identified. Accumulating evidence suggest that these differences reflect the peculiar epigenomic and regulatory landscapes of neutrophils and monocytes, in turn controlled by the specific lineage-determining transcription factors shaping their identity. In this review, we will describe current knowledge on how neutrophil identity and function are controlled at the molecular level, focusing on transcriptional and chromatin regulation of neutrophil development and activation in response to inflammatory stimuli