Publications by authors named "Davide Lucchesi"

20 Publications

  • Page 1 of 1

Advanced imaging for quantification of abnormalities in the salivary glands of patients with primary Sjögren's syndrome.

Rheumatology (Oxford) 2021 05;60(5):2396-2408

Research and Development, GlaxoSmithKline, Stevenage.

Objectives: To assess non-invasive imaging for detection and quantification of gland structure, inflammation and function in patients with primary Sjogren's syndrome (pSS) using PET-CT with 11C-Methionine (11C-MET; radiolabelled amino acid), and 18F-fluorodeoxyglucose (18F-FDG; glucose uptake marker), to assess protein synthesis and inflammation, respectively; multiparametric MRI evaluated salivary gland structural and physiological changes.

Methods: In this imaging/clinical/histology comparative study (GSK study 203818; NCT02899377) patients with pSS and age- and sex-matched healthy volunteers underwent MRI of the salivary glands and 11C-MET PET-CT. Patients also underwent 18F-FDG PET-CT and labial salivary gland biopsies. Clinical and biomarker assessments were performed. Primary endpoints were semi-quantitative parameters of 11C-MET and 18F-FDG uptake in submandibular and parotid salivary glands and quantitative MRI measures of structure and inflammation. Clinical and minor salivary gland histological parameter correlations were explored.

Results: Twelve patients with pSS and 13 healthy volunteers were included. Lower 11C-MET uptake in parotid, submandibular and lacrimal glands, lower submandibular gland volume, higher MRI fat fraction, and lower pure diffusion in parotid and submandibular glands were observed in patients vs healthy volunteer, consistent with reduced synthetic function. Disease duration correlated positively with fat fraction and negatively with 11C-MET and 18F-FDG uptake, consistent with impaired function, inflammation and fatty replacement over time. Lacrimal gland 11C-MET uptake positively correlated with tear flow in patients, and parotid gland 18F-FDG uptake positively correlated with salivary gland CD20+ B-cell infiltration.

Conclusion: Molecular imaging and MRI may be useful tools to non-invasively assess loss of glandular function, increased glandular inflammation and fat accumulation in pSS.
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http://dx.doi.org/10.1093/rheumatology/keaa624DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8121449PMC
May 2021

The use of digital image analysis in the histological assessment of Sjögren's syndrome salivary glands improves inter-rater agreement and facilitates multicentre data harmonisation.

Clin Exp Rheumatol 2020 Jul-Aug;38 Suppl 126(4):180-188. Epub 2020 Sep 23.

Centre for Experimental Medicine and Rheumatology, William Harvey Research Institute, Queen Mary University of London, UK.

Objectives: To assess whether the use of digital image analysis (DIA) in primary Sjögren's syndrome (pSS) for the calculation of the total area of the salivary gland (SG), focus score (FS) and SG area occupied by the inflammatory infiltrate (area fraction, AF), was able to generate reproducible readings among different raters, reducing disagreement.

Methods: Haematoxylin and Eosin digital slides from pSS and non-specific chronic sialadenitis (NSCS) patients were analysed blindly by 4 independent raters among 3 centres. Using an open-source software (QuPath) raters were asked to provide the total area of the gland i) using a grid-based method and ii) a software-based area-calculation tool, iii) the number of inflammatory foci and iv) the total area of the inflammatory infiltrate. Collected data was used to calculate the inter-rater agreement.

Results: For the calculation of the total SG area, DIA generated higher agreement among raters than grid-based calculation (inter-class correlation coefficient ICC=0.85 vs 0.98). Agreement for calculated total area of the inflammatory infiltrate (ICC=0.94) and for AF (ICC=0.94) was higher than infiltrates count number (ICC=0.54) and FS (ICC=0.56). AF achieved a 30% improvement over the FS at generating consensus among raters when used as a diagnostic cut-off.

Conclusions: A digital approach achieved a far superior inter-rater agreement when calculating the total area compared to a grid-based approach. The calculation of AF proved superior to FS in correctly classifying pSS vs NSCS biopsies. We suggest that digitally calculated AF should be used alongside FS for large multi-centre studies to improve data harmonisation.
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October 2020

One year in review 2020: pathogenesis of primary Sjögren's syndrome.

Clin Exp Rheumatol 2020 Jul-Aug;38 Suppl 126(4):3-9. Epub 2020 Sep 29.

Rheumatology Unit, Department of Clinical and Experimental Rheumatology, University of Pisa, Italy.

The pathogenesis of primary Sjögren's syndrome (pSS) remains poorly understood. However, important efforts have been made during the last few months. In this review, following the others of this series we will summarise the most recent literature on pSS pathogenesis focusing in particular on new insights into pSS animal models, genetics and epigenetics, innate and adaptive immune system abnormalities and tertiary lymphoid structures. Hopefully, novel insights into pSS pathogenesis will pave the way to new therapeutic approaches to the disease improving patients' management and prognosis.
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October 2020

Unique expansion of IL-21+ Tfh and Tph cells under control of ICOS identifies Sjögren's syndrome with ectopic germinal centres and MALT lymphoma.

Ann Rheum Dis 2020 12 22;79(12):1588-1599. Epub 2020 Sep 22.

Centre for Experimental Medicine and Rheumatology, William Harvey Research Institute, London, England, UK

Objectives: To explore the relevance of T-follicular-helper (Tfh) and pathogenic peripheral-helper T-cells (Tph) in promoting ectopic lymphoid structures (ELS) and B-cell mucosa-associated lymphoid tissue (MALT) lymphomas (MALT-L) in Sjögren's syndrome (SS) patients.

Methods: Salivary gland (SG) biopsies with matched peripheral blood were collected from four centres across the European Union. Transcriptomic (microarray and quantitative PCR) analysis, FACS T-cell immunophenotyping with intracellular cytokine detection, multicolor immune-fluorescence microscopy and hybridisation were performed to characterise lesional and circulating Tfh and Tph-cells. SG-organ cultures were used to investigate functionally the blockade of T-cell costimulatory pathways on key proinflammatory cytokine production.

Results: Transcriptomic analysis in SG identified Tfh-signature, interleukin-21 (IL-21) and the inducible T-cell co-stimulator (ICOS) costimulatory pathway as the most upregulated genes in ELS+SS patients, with parotid MALT-L displaying a 400-folds increase in IL-21 mRNA. Peripheral CD4CXC-motif chemokine receptor 5 (CXCR5)programmed cell death protein 1 (PD1)ICOS Tfh-like cells were significantly expanded in ELS+SS patients, were the main producers of IL-21, and closely correlated with circulating IgG and reduced complement C4. In the SG, lesional CD4CD45ROICOSPD1 cells selectively infiltrated ELS+ tissues and were aberrantly expanded in parotid MALT-L. In ELS+SG and MALT-L parotids, conventional CXCR5CD4PD1ICOSFoxp3 Tfh-cells and a uniquely expanded population of CXCR5CD4PD1ICOSFoxp3 Tph-cells displayed frequent IL-21/interferon-γ double-production but poor IL-17 expression. Finally, ICOS blockade in SG-organ cultures significantly reduced the production of IL-21 and inflammatory cytokines IL-6, IL-8 and tumour necrosis factor-α (TNF-α).

Conclusions: Overall, these findings highlight Tfh and Tph-cells, IL-21 and the ICOS costimulatory pathway as key pathogenic players in SS immunopathology and exploitable therapeutic targets in SS.
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http://dx.doi.org/10.1136/annrheumdis-2020-217646DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7677495PMC
December 2020

Impaired Interleukin-27-Mediated Control of CD4+ T Cell Function Impact on Ectopic Lymphoid Structure Formation in Patients With Sjögren's Syndrome.

Arthritis Rheumatol 2020 09 21;72(9):1559-1570. Epub 2020 Jul 21.

Queen Mary University of London, London, UK.

Objective: Ectopic lymphoid structures (ELS) develop at sites of infection, autoimmunity, and cancer. In patients with Sjögren's syndrome (SS), ELS support autoreactive B cell activation and lymphomagenesis. Interleukin-27 (IL-27) is a key regulator of adaptive immunity and limits Th17 cell-driven pathology. We undertook this study to elucidate the role of IL-27 in ELS formation and function in autoimmunity using a murine model of sialadenitis and in patients with SS.

Methods: ELS formation was induced in wild-type and Il27ra mice via salivary gland (SG) cannulation of a replication-deficient adenovirus in the presence or absence of IL-17A neutralization. In SG biopsy samples, IL-27-producing cells were identified by multicolor immunofluorescence microscopy. Lesional and circulating IL-27 levels were determined by gene expression and enzyme-linked immunosorbent assay. The in vitro effect of IL-27 on T cells was assessed using fluorescence-activated cell sorting and cytokine release.

Results: In experimental sialadenitis, Il27ra mice had larger and more hyperactive ELS (focus score; P < 0.001), increased autoimmunity, and an expanded Th17 response (P < 0.001), compared to wild-type mice. IL-17 blockade in Il27ra mice suppressed the aberrant ELS response (B and T cell reduction against control; P < 0.01). SS patients displayed increased circulating IL-27 levels (P < 0.01), and in SG biopsy samples, IL-27 was expressed by DC-LAMP+ dendritic cells in association with CD3+ T cells. Remarkably, in SS T cells (but not in T cells from patients with rheumatoid arthritis or healthy controls), IL-27-mediated suppression of IL-17 secretion was severely impaired and associated with an aberrant interferon-γ release upon IL-27 stimulation.

Conclusion: Our data indicate that the physiologic ability of IL-27 to limit the magnitude and function of ELS through control of Th17 cell expansion is severely impaired in SS patients, highlighting a defective immunoregulatory checkpoint in this condition.
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http://dx.doi.org/10.1002/art.41289DOI Listing
September 2020

Serum Copeptin levels in the emergency department predict major clinical outcomes in adult trauma patients.

BMC Emerg Med 2020 02 24;20(1):14. Epub 2020 Feb 24.

Department of Emergency Medicine Azienda USL-IRCCS di Reggio Emilia, via Amendola 2, 42122, Reggio Emilia, Italy.

Background: Early prognostication in trauma patients is challenging, but particularly important. We wanted to explore the ability of copeptin, the C-terminal fragment of arginine vasopressin, to identify major trauma, defined as Injury Severity Score (ISS) > 15, in a heterogeneous cohort of trauma patients and to compare its performances with lactate. We also evaluated copeptin performance in predicting other clinical outcomes: mortality, hospital admission, blood transfusion, emergency surgery, and Intensive Care Unit (ICU) admission.

Methods: This single center, pragmatic, prospective observational study was conducted at Arcispedale Santa Maria Nuova, a level II trauma center in Reggio Emilia, Italy. Copeptin determination was obtained on Emergency Department (ED) arrival, together with venous lactate. Different outcomes were measured including ISS, Revised Trauma Score (RTS), hospital and ICU admission, blood transfusion, emergency surgery, and mortality.

Results: One hundred and twenty five adult trauma patients admitted to the ED between June 2017 and March 2018. Copeptin showed a good ability to identify patients with ISS > 15 (AUC 0.819). Similar good performances were recorded also in predicting other outcomes. Copeptin was significantly superior to lactate in identifying patients with ISS > 15 (P 0.0015), and in predicting hospital admission (P 0.0002) and blood transfusion (P 0.016). Comparable results were observed in a subgroup of patients with RTS 7.84.

Conclusions: In a heterogeneous group of trauma patients, a single copeptin determination at the time of ED admission proved to be an accurate biomarker, statistically superior to lactate for the identification of major trauma, hospital admission, and blood transfusion, while no statistical difference was observed for ICU admission and emergency surgery. These results, if confirmed, may support a role for copeptin during early management of trauma patients.
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http://dx.doi.org/10.1186/s12873-020-00310-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7041089PMC
February 2020

Interleukin-36 family dysregulation drives joint inflammation and therapy response in psoriatic arthritis.

Rheumatology (Oxford) 2020 04;59(4):828-838

Centre for Experimental Medicine & Rheumatology, William Harvey Research Institute and Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK.

Objectives: IL-36 agonists are pro-inflammatory cytokines involved in the pathogenesis of psoriasis. However, their role in the pathogenesis of arthritis and treatment response to DMARDs in PsA remains uncertain. Therefore, we investigated the IL-36 axis in the synovium of early, treatment-naïve PsA, and for comparison RA patients, pre- and post-DMARDs therapy.

Methods: Synovial tissues were collected by US-guided biopsy from patients with early, treatment-naïve PsA and RA at baseline and 6 months after DMARDs therapy. IL-36 family members were investigated in synovium by RNA sequencing and immunohistochemistry, and expression levels correlated with DMARDs treatment response ex vivo. Additionally, DMARDs effects on IL-36 were investigated in vitro in fibroblast-like synoviocytes.

Results: PsA synovium displayed a reduced expression of IL-36 antagonists, while IL-36 agonists were comparable between PsA and RA. Additionally, neutrophil-related molecules, which drive a higher activation of the IL-36 pathway, were upregulated in PsA compared with RA. At baseline, the synovial expression of IL-36α was significantly higher in PsA non-responders to DMARDs treatment, with the differential expression being sustained at 6 months post-treatment. In vitro, primary PsA-derived fibroblasts were more responsive to IL-36 stimulation compared with RA and, importantly, DMARDs treatment increased IL-36 expression in PsA fibroblasts.

Conclusion: The impaired balance between IL-36 agonists-antagonists described herein for the first time in PsA synovium and the decreased sensitivity to DMARDs in vitro may explain the apparent lower efficacy of DMARDs in PsA compared with RA. Exogenous replacement of IL-36 antagonists may be a novel promising therapeutic target for PsA patients.
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http://dx.doi.org/10.1093/rheumatology/kez358DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7188345PMC
April 2020

CXCL13 as biomarker for histological involvement in Sjögren's syndrome.

Rheumatology (Oxford) 2020 01;59(1):165-170

Rheumatology Research Group, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK.

Objectives: SS is an autoimmune condition characterized by systemic B-cell activation, autoantibody production and ectopic germinal centres' formation within the salivary gland (SG). The extent of SG infiltrate has been proposed as a biomarker of disease severity. Plasma levels of CXCL13 correlate with germinal centres' activity in animal models and disease severity in SS, suggesting its potential use as a surrogate serum marker to monitor local B-cell activation. The aim of this study was to evaluate the potential role of CXCL13 as a biomarker of SG pathology in two independent SS cohorts.

Methods: 109 patients with SS were recruited at Sapienza University of Rome (Italy) (n = 60), or at Queen Elizabeth Hospital in Birmingham and Barts Health NHS Trust in London (n = 49). Both sera and matched minor SG biopsy were available. Sicca (n = 57) and healthy subjects' (n = 19) sera were used as control.

Results: CXCL13 serum level was higher in SS patients compared with controls. Correlations between its serum levels and a series of histomorphological parameters, including size of the aggregates and the presence germinal centres', were observed.

Conclusion: Our data foster the use of CXCL13 to monitor the extent of local pathology in SS and its validation in longitudinal clinical studies.
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http://dx.doi.org/10.1093/rheumatology/kez255DOI Listing
January 2020

NK cell recruitment in salivary glands provides early viral control but is dispensable for tertiary lymphoid structure formation.

J Leukoc Biol 2019 03 21;105(3):589-602. Epub 2018 Dec 21.

Unit of Clinical and Experimental Immunology, Humanitas Clinical and Research Center, Via Alessandro Manzoni 113, I-20089, Rozzano, Italy.

Salivary glands (SGs) represent a permissive site for several sialotropic viruses whose persistence is linked to the development of autoimmunity. Natural Killer (NK) cells play a key role in viral clearance but their involvement in viral infection control and in tertiary lymphoid structures (TLS) development within SGs is unknown. By using an inducible model of TLS in the SGs of wild-type C57BL/6 mice, induced by the local delivery of a replication-defective adenovirus (AdV), we demonstrated that circulating NK cells are rapidly recruited to SGs and highly enrich the early inflammatory infiltrate prior to TLS development. NK cells migrating to SGs in response to AdV infection up-regulate NKp46, undergo proliferation, acquire cytotoxic potential, produce Granzyme-B and IFN-γ, and reduce viral load in the acute phase of the infection. Nonetheless, the selective depletion of both circulating and infiltrating NK cells in AdV-infected mice neither affect the development and frequency of TLS nor the onset of autoimmunity. These data demonstrate that, upon local viral delivery of AdV, peripheral NK cells homing to SGs can exert an early control of the viral infection but are dispensable for the formation of TLS and breach of immunologic tolerance.
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http://dx.doi.org/10.1002/JLB.5A1117-462RRDOI Listing
March 2019

A clinical and histopathological analysis of the anti-centromere antibody positive subset of primary Sjögren's syndrome.

Clin Exp Rheumatol 2018 May-Jun;36 Suppl 112(3):145-149. Epub 2018 Aug 14.

Centre for Experimental Medicine and Rheumatology, William Harvey Research Institute, Queen Mary University of London, UK.

Objectives: ACA-positive/primary Sjögren's syndrome (pSS) represents a distinct overlapping entity with intermediate features in between limited systemic sclerosis (lSSc) and pSS. Few data are available on their general risk for lymphoproliferative complications, specifically regarding adverse predictors at the level of minor salivary gland (MSG) histology. The objectives of this work are: a) to characterise, through a detailed immunohistochemistry study, the organisation of the lymphomonocitic infiltrates in ACA-positive/pSS patient vs. ACA-negative/pSS patients focusing on the presence of GC-like structures in minor salivary gland biopsies; b) to compare the frequency of traditional clinical and serological risk factors for lymphoma between the two subgroups.

Methods: We analysed 28 MSG samples from ACA-positive/pSS patients and 43 consecutive MSGs from ACA-negative/pSS, using sequential IHC staining for CD3, CD20 and CD21 in order to define the T/B cell segregation within the periductal infiltrates and presence of ectopic GC-like on the detection of GC-like structures. Clinical and serological data of all the patients were retrieved and analysed.

Results: Ectopic lymphoid structures (ELS) with GC-like structures were observed in 7 out of 28 ACA-positive/pSS patients (25%) and in 13 out of 43 ACA-negative/pSS patients (30.2%). Similarly, no statistical significant difference was found between the two groups as far as the classical pSS risk factors for lymphoproliferative complications was concerned (i.e. salivary gland enlargement, purpura, low C4, leukocytopenia, clonal gammopathy). Finally, the 3 cases of non-Hodgkin's lymphoma observed were equally distributed between the two subsets.

Conclusions: Overall, this study indicates that ACA-positive/and ACA-negative pSS patients apparently present a similar risk for lymphoproliferative complications as suggested indirectly by the analogies between the two groups observed at the histopathology level.
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November 2018

Current views on the pathogenesis of Sjögren's syndrome.

Curr Opin Rheumatol 2018 03;30(2):215-221

Centre for Experimental Medicine and Rheumatology, William Harvey Research Institute, Queen Mary University of London, London, UK.

Purpose Of Review: The purpose of this review is to provide an insight into the pathophysiological mechanisms involved in the pathogenesis of primary Sjögren's Syndrome (pSS), highlighting recent findings with potential therapeutic repercussions.

Recent Findings: In the last 2 years, epigenetic analyses provided new insights into pSS pathogenesis. Characterization of DNA methylation patterns, chromatin structures and microRNA confirmed the importance of aberrant interferon and B-cell responses in the development of the disease. The formation of ectopic B-cell follicles with germinal centers is now a well recognized pathogenic mechanism within salivary glands of pSS. In the context of ectopic germinal centers reaction, T/B-cell interactions, that is regarding T-helper 17 and T-follicular helper cells, and their respective counterparts, T-regulatory and T-follicular regulatory cells, appear particularly relevant in pSS pathogenesis as their imbalance is associated with a dysregulation of B-cell dynamics and the production of autoantibodies.

Summary: Advances in the understanding of pSS pathogenesis have paved the way for clinical trials with novel biologic agents targeting immune pathways regulating T/B-cell interactions and downstream B-cell activation. Reverse translation from these studies provides invaluable novel information of the mechanisms sustaining autoimmunity and chronic inflammation in pSS.
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http://dx.doi.org/10.1097/BOR.0000000000000473DOI Listing
March 2018

IL-22 regulates lymphoid chemokine production and assembly of tertiary lymphoid organs.

Proc Natl Acad Sci U S A 2015 Sep 18;112(35):11024-9. Epub 2015 Aug 18.

Rheumatology Research Group, Centre for Translational Inflammation Research, School of Immunity and Infection, College of Medical and Dental Sciences, University of Birmingham, B15 2TT, United Kingdom; University of Birmingham Research Laboratories, Queen Elizabeth Hospital, Birmingham, B15 2WD, United Kingdom;

The series of events leading to tertiary lymphoid organ (TLO) formation in mucosal organs following tissue damage remain unclear. Using a virus-induced model of autoantibody formation in the salivary glands of adult mice, we demonstrate that IL-22 provides a mechanistic link between mucosal infection, B-cell recruitment, and humoral autoimmunity. IL-22 receptor engagement is necessary and sufficient to promote differential expression of chemokine (C-X-C motif) ligand 12 and chemokine (C-X-C motif) ligand 13 in epithelial and fibroblastic stromal cells that, in turn, is pivotal for B-cell recruitment and organization of the TLOs. Accordingly, genetic and therapeutic blockade of IL-22 impairs and reverses TLO formation and autoantibody production. Our work highlights a critical role for IL-22 in TLO-induced pathology and provides a rationale for the use of IL-22-blocking agents in B-cell-mediated autoimmune conditions.
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http://dx.doi.org/10.1073/pnas.1503315112DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4568258PMC
September 2015

EBV and other viruses as triggers of tertiary lymphoid structures in primary Sjögren's syndrome.

Expert Rev Clin Immunol 2014 Apr 25;10(4):445-55. Epub 2014 Feb 25.

Centre for Experimental Medicine & Rheumatology, William Harvey Research Institute, Barts and The London School of Medicine & Dentistry, Queen Mary University of London, London, UK.

Sjögren's syndrome (SS) is an autoimmune disease that targets salivary (SG) and lachrymal glands, leading to exocrine dysfunction. Several viruses have been associated with SS, although the role of persistent viral infections in triggering and/or perpetuating the disease is still a matter of controversy. Together with exocrine dysfunction, SS is characterised by the production of autoantibodies and the presence of lymphomonocytic periductal aggregates in the SG, which in 30/40% of the patients display features of tertiary lymphoid structures (TLS) supporting an ectopic germinal centre response. Here we first review i) the relevance of TLS in SS and ii) the evidence in support of a role for viruses in SS insurgence and/or persistence; next, iii) we review recent data which links viral infection with TLS formation in the SG and suggests that viral-host interactions within TLS favour breach of tolerance and development of autoimmunity in SS.
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http://dx.doi.org/10.1586/1744666X.2014.892417DOI Listing
April 2014

Transcriptomic profiling of the development of the inflammatory response in human monocytes in vitro.

PLoS One 2014 3;9(2):e87680. Epub 2014 Feb 3.

Institute of Biomedical Technologies, National Research Council, Pisa/Segrate, Italy ; Institute of Protein Biochemistry, National Research Council, Naples, Italy.

Monocytes/macrophages are key players in all phases of physiological and pathological inflammation. To understanding the regulation of macrophage functional differentiation during inflammation, we designed an in vitro model that recapitulates the different phases of the reaction (recruitment, initiation, development, and resolution), based on human primary blood monocytes exposed to sequential changes in microenvironmental conditions. All reaction phases were profiled by transcriptomic microarray analysis. Distinct clusters of genes were identified that are differentially regulated through the different phases of inflammation. The gene sets defined by GSEA analysis revealed that the inflammatory phase was enriched in inflammatory pathways, while the resolution phase comprised pathways related to metabolism and gene rearrangement. By comparing gene clusters differentially expressed in monocytes vs. M1 and vs. M2 macrophages extracted from an in-house created meta-database, it was shown that cells in the model resemble M1 during the inflammatory phase and M2 during resolution. The validation of inflammatory and transcriptional factors by qPCR and ELISA confirmed the transcriptomic profiles in the different phases of inflammation. The accurate description of the development of the human inflammatory reaction provided by this in vitro kinetic model can help in identifying regulatory mechanisms in physiological conditions and during pathological derangements.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0087680PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3912012PMC
December 2014

The role of viruses in autoreactive B cell activation within tertiary lymphoid structures in autoimmune diseases.

J Leukoc Biol 2013 Dec 28;94(6):1191-9. Epub 2013 Jun 28.

1.William Harvey Research Institute, Barts and The London School of Medicine & Dentistry, Queen Mary University of London, John Vane Science Centre, Charterhouse Square, London EC1M 6BQ, UK.

TLS, characterized by the formation of ectopic B/T cell follicles with FDCs supporting an ectopic GC response, have been described in the target organs of several autoimmune diseases, including MS, RA, SS, and autoimmune thyroiditis. These structures represent functional niches, whereby autoreactive B cells undergo in situ affinity maturation and differentiation to autoantibody-producing cells, thus contributing to the progression and persistence of autoimmunity. Increasing evidence demonstrates that TLS can also develop in the context of cancer, as well as chronic infections. In this review, we collect recent evidences that highlights the relationship between persistent viral infection and the development of ectopic lymphoid structures in animal models and patients. Furthermore, we shall discuss the concept that whereas in physiological conditions, inducible TLS are critical for viral clearance and the establishment of protective immunity, but in the context of susceptible individuals, persistent viral infections may contribute, directly or indirectly, to the development of breach of tolerance against self-antigens and the development of autoimmunity through the formation of TLS.
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http://dx.doi.org/10.1189/jlb.0413240DOI Listing
December 2013

Inducible tertiary lymphoid structures, autoimmunity, and exocrine dysfunction in a novel model of salivary gland inflammation in C57BL/6 mice.

J Immunol 2012 Oct 31;189(7):3767-76. Epub 2012 Aug 31.

Centre for Experimental Medicine and Rheumatology, William Harvey Research Institute, Queen Mary University of London, London EC1M 6BQ, United Kingdom.

Salivary glands in patients with Sjögren's syndrome (SS) develop ectopic lymphoid structures (ELS) characterized by B/T cell compartmentalization, the formation of high endothelial venules, follicular dendritic cell networks, functional B cell activation with expression of activation-induced cytidine deaminase, as well as local differentiation of autoreactive plasma cells. The mechanisms that trigger ELS formation, autoimmunity, and exocrine dysfunction in SS are largely unknown. In this article, we present a novel model of inducible ectopic lymphoid tissue formation, breach of humoral self-tolerance, and salivary hypofunction after delivery of a replication-deficient adenovirus-5 in submandibular glands of C57BL/6 mice through retrograde excretory duct cannulation. In this model, inflammation rapidly and consistently evolves from diffuse infiltration toward the development of SS-like periductal lymphoid aggregates within 2 wk from AdV delivery. These infiltrates progressively acquire ELS features and support functional GL7(+)/activation-induced cytidine deaminase(+) germinal centers. Formation of ELS is preceded by ectopic expression of lymphoid chemokines CXCL13, CCL19, and lymphotoxin-β, and is associated with development of anti-nuclear Abs in up to 75% of mice. Finally, reduction in salivary flow was observed over 3 wk post-AdV infection, consistent with exocrine gland dysfunction as a consequence of the inflammatory response. This novel model has the potential to unravel the cellular and molecular mechanisms that regulate ELS formation and their role in exocrine dysfunction and autoimmunity in SS.
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http://dx.doi.org/10.4049/jimmunol.1201216DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3448973PMC
October 2012

Galectin-3 binds Neisseria meningitidis and increases interaction with phagocytic cells.

Cell Microbiol 2012 Nov 12;14(11):1657-75. Epub 2012 Aug 12.

Centre for Molecular Microbiology and Infection, Department of Microbiology, Imperial College London, London, UK.

Galectin-3 is expressed and secreted by immune cells and has been implicated in multiple aspects of the inflammatory response. It is a glycan binding protein which can exert its functions within cells or exogenously by binding cell surface ligands, acting as a molecular bridge or activating signalling pathways. In addition, this lectin has been shown to bind to microorganisms. In this study we investigated the interaction between galectin-3 and Neisseria meningitidis, an important extracellular human pathogen, which is a leading cause of septicaemia and meningitis. Immunohistochemical analysis indicated that galectin-3 is expressed during meningococcal disease and colocalizes with bacterial colonies in infected tissues from patients. We show that galectin-3 binds to N. meningitidis and we demonstrate that this interaction requiresfull-length, intact lipopolysaccharide molecules. We found that neither exogenous nor endogenous galectin-3 contributes to phagocytosis of N. meningitidis; instead exogenous galectin-3 increases adhesion to monocytes and macrophages but not epithelial cells. Finally we used galectin-3 deficient (Gal-3(-/-) ) mice to evaluate the contribution of galectin-3 to meningococcal bacteraemia. We found that Gal-3(-/-) mice had significantly lower levels of bacteraemia compared with wild-type mice after challenge with live bacteria, indicating that galectin-3 confers an advantage to N. meningitidis during systemic infection.
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http://dx.doi.org/10.1111/j.1462-5822.2012.01838.xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3749814PMC
November 2012

IL-37: a new anti-inflammatory cytokine of the IL-1 family.

Eur Cytokine Netw 2011 Sep;22(3):127-47

Laboratory of Innate Immunity and Cytokines, Institute of Biomedical Technologies, National Research Council, I-56124 Pisa, Italy.

The IL-1 family of cytokines encompasses eleven proteins that each share a similar β-barrel structure and bind to Ig-like receptors. Some of the IL-1-like cytokines have been well characterised, and play key roles in the development and regulation of inflammation. Indeed, IL-1α (IL-1F1), IL-1β (IL-1F2), and IL-18 (IL-1F4) are well-known inflammatory cytokines active in the initiation of the inflammatory reaction and in driving Th1 and Th17 inflammatory responses. In contrast, IL-1 receptor antagonist (IL-1Ra, IL-1F3) and the receptor antagonist binding to IL-1Rrp2 (IL-36Ra, IL-1F5) reduce inflammation by blocking the binding of the agonist receptor ligands. In the case of IL-37 (IL-1F7), of which five different splice variants have been described, less is known of its function, and identification of the components of a heterodimeric receptor complex remains unclear. Some studies suggest that IL-37 binds to the α chain of the IL-18 receptor in a non-competitive fashion, and this may explain some of the disparate biological effects that have been reported for mice deficient in the IL-18R. The biological properties of IL-37 are mainly those of down-regulating inflammation, as assessed in models where human IL-37 is expressed in mice. In this review, an overview of the role of IL-37 in the regulation of inflammation is presented. The finding that IL-37 also locates to the nucleus, as do IL-1α and IL-33, for receptor-independent organ/tissue-specific regulation of inflammation is also reviewed.
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http://dx.doi.org/10.1684/ecn.2011.0288DOI Listing
September 2011

Problems and challenges in the development and validation of human cell-based assays to determine nanoparticle-induced immunomodulatory effects.

Part Fibre Toxicol 2011 Feb 9;8(1). Epub 2011 Feb 9.

Department of Molecular Biology, University of Salzburg, 5020 Salzburg, Austria.

Background: With the increasing use of nanomaterials, the need for methods and assays to examine their immunosafety is becoming urgent, in particular for nanomaterials that are deliberately administered to human subjects (as in the case of nanomedicines). To obtain reliable results, standardised in vitro immunotoxicological tests should be used to determine the effects of engineered nanoparticles on human immune responses. However, before assays can be standardised, it is important that suitable methods are established and validated.

Results: In a collaborative work between European laboratories, existing immunological and toxicological in vitro assays were tested and compared for their suitability to test effects of nanoparticles on immune responses. The prototypical nanoparticles used were metal (oxide) particles, either custom-generated by wet synthesis or commercially available as powders. Several problems and challenges were encountered during assay validation, ranging from particle agglomeration in biological media and optical interference with assay systems, to chemical immunotoxicity of solvents and contamination with endotoxin.

Conclusion: The problems that were encountered in the immunological assay systems used in this study, such as chemical or endotoxin contamination and optical interference caused by the dense material, significantly affected the data obtained. These problems have to be solved to enable the development of reliable assays for the assessment of nano-immunosafety.
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http://dx.doi.org/10.1186/1743-8977-8-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3045340PMC
February 2011

PLGA nanoparticles surface decorated with the sialic acid, N-acetylneuraminic acid.

Biomaterials 2010 Apr 4;31(12):3395-403. Epub 2010 Feb 4.

Department of Pharmaceutical Sciences, University of Modena and RE, Modena, Italy.

There is a broad interest in the development of nanoparticles (NPs) carrying on their surface carbohydrates such as sialic acids. It is known that these carbohydrates influence the biological and physical properties of biopharmaceutical proteins and living cells. Macromolecular compounds containing these carbohydrates showed an anti-recognition effect, exert an antiviral effect and also are able to be recognized by the cell surface of some kind of cancer cells. Thus, in the present research we performed two different approaches in order to obtain polymeric (poly(D,L-lactide-co-glycolide), PLGA) NPs surface decorated with the sialic acid N-acetylneuraminic acid (Neu5Ac). The first strategy that has been followed is based on the derivatization of the polyester PLGA with the thioderivative of Neu5Ac, starting material for the preparation of the NPs; the second is based on the synthesis of compounds potentially able to insert their lipophilic moiety into the underivatized PLGA NPs during their preparation, and to display their hydrophilic moiety (Neu5Ac) on their surface. The first approach allowed the obtainment of NPs surface decorated with Neu5Ac, as evidenced by ESCA spectroscopy and interaction with the lectin Wheat Germ Agglutinin. Moreover, a formulation of these NPs suitable for in vitro assays showed that they are phagocytosed by human monocytes with an apparently different mechanism with respect of those made of underivatized PLGA. The second strategy led to NPs in which their surface appears to be very different with respect to the NPs obtained following the first strategy, with the carboxylic groups of Neu5Ac markedly shielded. Thus, the new Neu5Ac-modified PLGA polyester represent a useful starting material for the preparation of NPs surface decorated with this sialic acid.
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http://dx.doi.org/10.1016/j.biomaterials.2010.01.049DOI Listing
April 2010
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