Dysregulated healing of injured mucosa is a hallmark of many pathological conditions including inflammatory bowel disease. Mucosal injury and chronic inflammation including persistent neutrophil (PMN) infiltration are also associated with alterations in epithelial glycosylation. Previous studies have revealed the inflammation induced glycan sLea on epithelial CD44v6 acts as a ligand for transmigrating PMN. Furthermore, blocking sLea-mediated binding interactions with the mAb GM35 reduced PMN transepithelial migration. Here we report that robust sialylated Lewis glycan expression is induced in colonic mucosa from individuals with ulcerative colitis (UC) and Crohn’s disease (CD) as well as in colonic epithelium of mice with DSS colitis. Targeting of sialylated epithelial Lewis glycans with mAb GM35 reduced disease activity and improved mucosal integrity during DSS induced colitis in mice. Wound healing studies revealed increased epithelial proliferation and migration responses as well as improved mucosal repair following ligation of epithelial sialyl Lewis glycans. Finally, we show GM35-mediated increases in epithelial proliferation and migration are mediated through activation of kinases that signal downstream of CD44v6 (Src, FAK, Akt). These findings suggest that sialylated Lewis glycans on epithelial CD44v6 may represent targets for improved recovery of epithelial barrier function and restitution of mucosal homeostasis following intestinal inflammation or injury
Matthias Kelm, Miguel Quiros, Veronica Azcutia, Kevin Boerner, Richard D. Cummings, Asma Nusrat, Jennifer C. Brazil, Charles A. Parkos
Immune checkpoint blockade immunotherapy delivers promising clinical results in colorectal cancer (CRC). However, only a fraction of cancer patients develop durable responses. The tumor microenvironment (TME) negatively impacts tumor immunity and subsequently clinical outcomes. Therefore, there is a need to identify other checkpoint targets associated with the TME. Early-onset factors secreted by stromal cells as well as tumor cells often help recruit immune cells to the TME, among which are alarmins such as IL-33. The only known receptor for IL-33 is stimulation 2 (ST2). Here we demonstrated that high ST2 expression is associated with poor survival and is correlated with low CD8+ T cell cytotoxicity in CRC patients. ST2 is particularly expressed in tumor-associated macrophages (TAMs). In preclinical models of CRC, we demonstrated that ST2-expressing TAMs (ST2+ TAMs) were recruited into the tumor via CXCR3 expression and exacerbated the immunosuppressive TME; and that combination of ST2 depletion using ST2-KO mice with anti–programmed death 1 treatment resulted in profound growth inhibition of CRC. Finally, using the IL-33trap fusion protein, we suppressed CRC tumor growth and decreased tumor-infiltrating ST2+ TAMs. Together, our findings suggest that ST2 could serve as a potential checkpoint target for CRC immunotherapy.
Kevin Van der Jeught, Yifan Sun, Yuanzhang Fang, Zhuolong Zhou, Hua Jiang, Tao Yu, Jinfeng Yang, Malgorzata M. Kamocka, Ka Man So, Yujing Li, Haniyeh Eyvani, George E. Sandusky, Michael Frieden, Harald Braun, Rudi Beyaert, Xiaoming He, Xinna Zhang, Chi Zhang, Sophie Paczesny, Xiongbin Lu
Loss of melanocytes is the pathological hallmark of vitiligo, a chronic inflammatory skin depigmenting disorder induced by exaggerated immune response, including autoreactive CD8 T cells producing high levels of type-1 cytokines. However, the interplay between this inflammatory response and melanocyte disappearance remains to be fully characterized. Here, we demonstrate that vitiligo skin contains a significant proportion of suprabasal melanocytes, associated with disruption of E-cadherin expression, a major protein involved in melanocyte adhesion. This phenomenon is also observed in lesional psoriatic skin. Importantly, apoptotic melanocytes were mainly observed once cells were detached from the basal layer of the epidermis, suggesting that additional mechanism(s) could be involved in melanocyte loss. The type-1 cytokines IFNg and TNFa induce melanocyte detachment through E-cadherin disruption, and the release of its soluble form, partly due to the matrix metalloproteinase MMP-9. MMP-9, whose levels are increased in vitiligo skin and patients’ sera, is produced by keratinocytes in response to IFNg and TNFa. Inhibition of MMP-9 or the JAK/STAT signaling pathway prevents melanocyte detachment in vitro and in vivo. Therefore, stabilization of melanocytes in the basal layer of the epidermis by preventing E-cadherin disruption appears promising to prevent the depigmentation occurring in vitiligo and during chronic skin inflammation.
Nesrine Boukhedouni, Christina Martins, Anne-Sophie Darrigade, Claire Drullion, Jérôme Rambert, Christine Barrault, Julien Garnier, Clement Jacquemin, Denis Thiolat, Fabienne Lucchese, Franck Morel, Khaled Ezzedine, Alain TAIEB, François-Xavier Bernard, Julien Seneschal, Katia Boniface
Alveolar macrophages (AM) play a central role in initiation and resolution of lung inflammation, but the integration of these opposing core functions is poorly understood. AM expression of cholesterol-25-hydroxylase (CH25H), the primary biosynthetic enzyme for 25-hydroxycholesterol (25HC), far exceeds that of macrophages in other tissues, but no role for CH25H has been defined in lung biology. As 25HC is an agonist for the anti-inflammatory nuclear receptor, Liver X Receptor (LXR), we speculated that CH25H might regulate inflammatory homeostasis in the lung. Here, we show that, of natural (oxy)sterols, 25HC is uniquely induced in the inflamed lung of mice and humans. Ch25h-/- mice fail to induce 25HC and LXR target genes in the lung after LPS inhalation and exhibit delayed resolution of airway neutrophilia which can be rescued by systemic treatment with either 25HC or synthetic LXR agonists. LXR-null mice also display delayed resolution, suggesting that native oxysterols promote resolution. During resolution, Ch25h is induced in macrophages upon their encounter with apoptotic cells and is required for LXR-dependent prevention of AM lipid overload, induction of Mertk, efferocytic resolution of airway neutrophilia, and induction of TGFb. CH25H/25HC/LXR is thus an inducible metabolic axis that programs AMs for efferocytic resolution of inflammation.
Jennifer H. Madenspacher, Eric D. Morrell, Kymberly M. Gowdy, Jeffrey G. McDonald, Bonne M. Thompson, Ginger W. Muse, Jennifer Martinez, Seddon Y. Thomas, Carmen Mikacenic, Jerry A. Nick, Edward Abraham, Stavros Garantziotis, Renee D. Stapleton, Julie M. Meacham, Mary Jane Thomassen, William J. Janssen, Donald N. Cook, Mark M. Wurfel, Michael B. Fessler
In severe cases of coronavirus disease 2019 (COVID-19), viral pneumonia progresses to respiratory failure. Neutrophil extracellular traps (NETs) are extracellular webs of chromatin, microbicidal proteins, and oxidant enzymes that are released by neutrophils to contain infections. However, when not properly regulated, NETs have potential to propagate inflammation and microvascular thrombosis — including in the lungs of patients with acute respiratory distress syndrome. While elevated levels of blood neutrophils predict worse outcomes in COVID-19, the role of NETs has not been investigated. We now report that sera from patients with COVID-19 (n = 50 patients, n = 84 samples) have elevated levels of cell-free DNA, myeloperoxidase(MPO)-DNA, and citrullinated histone H3 (Cit-H3); the latter two are highly specific markers of NETs. Highlighting the potential clinical relevance of these findings, cell-free DNA strongly correlated with acute phase reactants including C-reactive protein, D-dimer, and lactate dehydrogenase, as well as absolute neutrophil count. MPO-DNA associated with both cell-free DNA and absolute neutrophil count, while Cit-H3 correlated with platelet levels. Importantly, both cell-free DNA and MPO-DNA were higher in hospitalized patients receiving mechanical ventilation as compared with hospitalized patients breathing room air. Finally, sera from individuals with COVID-19 triggered NET release from control neutrophils in vitro. In summary, these data reveal high levels of NETs in many patients with COVID-19, where they may contribute to cytokine release and respiratory failure. Future studies should investigate the predictive power of circulating NETs in longitudinal cohorts, and determine the extent to which NETs may be novel therapeutic targets in severe COVID-19.
Yu Zuo, Srilakshmi Yalavarthi, Hui Shi, Kelsey Gockman, Melanie Zuo, Jacqueline A. Madison, Christopher N. Blair, Andrew Weber, Betsy J. Barnes, Mikala Egeblad, Robert J. Woods, Yogendra Kanthi, Jason S. Knight
Background: Prehospital plasma improves survival in severely injured trauma patients at risk for hemorrhagic shock and transported by air ambulance. We hypothesized that prehospital plasma would be associated with a reduction in immune imbalance and endothelial damage. Methods: We collected blood samples from 405 trauma patients enrolled in the Prehospital Air MedicalPlasma (PAMPer) trial upon hospital admission (0 hours) and 24 hours post admission across 6 U.S. sites(9 level-one trauma centers) with air medical transport services. We assayed samples for 21 inflammatory mediators and 7 markers of endothelial damage. We performed hierarchical clustering analysis (HCA) on principal components of these biomarkers of the immune response and endothelial injury. Regression analysis was used to control for known differences across study arms near the time of randomization and to assess any association with prehospital plasma administration. Results: HCA based on inflammatory mediator and endothelial damage marker concentrations distinguished two patient clusters, each with different injury patterns and outcomes. Patients in cluster A had greater injury severity and incidence of blunt trauma, traumatic brain injury, and mortality. Cluster A patients that received prehospital plasma as compared to standard care fluid resuscitation showed improved 30-day survival. Prehospital plasma did not improve survival in cluster B patients. In an adjusted analysis of themost seriously injured patients (ISS>30), plasma was associated with a an increase in circulating levels of adiponectin, IL-1β, IL-17A, IL-23, and IL-17E upon admission. One day following admission, prehospital plasmas was associated with a reduction in syndecan-1, TM, VEGF, IL-6, IP-10, MCP-1, and TNF-α, and an increase in IL-33, IL-21, IL-23, and IL-17E. Conclusion: This is the first human study to suggest that prehospital plasma may ameliorate the endotheliopathy of trauma and modulate an imbalance between pro-inflammatory (e.g. IL-6, TNF-α, and MCP-1) and protective (e.g. IL-33 and IL-17E) mediators. These effects of early plasma administration may contribute to improved survival in severely injured patients. Trial Registration: ClinicalTrials.gov NCT01818427 Funding: National Institutes of Health T32; U.S. Army Medical Research and Materiel Command W81XWH-12-2-0023; National Institutes of Health R35; National Institutes of Health 1R35GM119526-01; the Office of the Assistant Secretary of Defense for Health Affairs, through the Defense Medical Research and Development Program W81XWH-18-2-0051 and W81XWH-15-PRORP-OCRCA. Opinions, interpretations, conclusions and recommendations are those of the authors and not necessarily endorsed by the Department of Defense.
Danielle S. Gruen, Joshua B. Brown, Francis X. Guyette, Yoram Vodovotz, Par I. Johansson, Jakob Stensballe, Derek A. Barclay, Jinling Yin, Brian J. Daley, Richard S. Miller, Brian G. Harbrecht, Jeffrey A. Claridge, Herb A. Phelan, Matthew D. Neal, Brian Zuckerbraun, Timothy R. Billiar, Jason L. Sperry
Septic cardiomyopathy is a life-threatening organ dysfunction caused by sepsis. Ribonuclease 1 (RNase 1) belongs to a group of host-defense peptides that specifically cleave extracellular RNA (eRNA). The activity of RNase1 is inhibited by ribonuclease-inhibitor 1 (RNH1). The role of RNase 1 in septic cardiomyopathy and associated cardiac apoptosis, however, is completely unknown. Here, we showed that sepsis resulted in a significant increase in RNH1 and eRNA serum levels compared to those of healthy subjects (p < 0.05). Treatment with RNase 1 resulted in a significant decrease of apoptosis, induced by the intrinsic pathway, and TNF expression in murine cardiomyocytes exposed to either necrotic cardiomyocytes or serum of septic patients for 16 h (p < 0.05). Furthermore, treatment of septic mice with RNase 1 resulted in a reduction in cardiac apoptosis, TNF expression and septic cardiomyopathy (p < 0.05). These data demonstrate that eRNA plays a crucial role in the pathophysiology of the organ (cardiac) dysfunction in sepsis and RNase and RNH1 may be new therapeutic targets/strategies to reduce the cardiac injury and dysfunction caused by sepsis.
Elisabeth Zechendorf, Caroline E O'Riordan, Lara Stiehler, Natalie Wischmeyer, Fausto Chiazza, Debora Collotta, Bernd Denecke, Sabrina Ernst, Gerhard Müller-Newen, Sina M. Coldewey, Bianka Wissuwa, Massimo Collino, Tim-Philipp Simon, Tobias Schuerholz, Christian Stoppe, Gernot Marx, Christoph Thiemermann, Lukas Martin
Systemic juvenile idiopathic arthritis (sJIA) begins with fever, rash, and high-grade systemic inflammation but commonly progresses to a persistent afebrile arthritis. The basis for this transition is unknown. To evaluate a role for lymphocyte polarization, we characterized T cells from patients with acute and chronic sJIA using flow cytometry, mass cytometry, and RNA sequencing. Acute and chronic sJIA each featured an expanded population of activated Tregs uncommon in healthy controls or in children with nonsystemic JIA. In acute sJIA, Tregs expressed IL-17A and a gene expression signature reflecting Th17 polarization. In chronic sJIA, the Th17 transcriptional signature was identified in T effector cells (Teffs), although expression of IL-17A at the protein level remained rare. Th17 polarization was abrogated in patients responding to IL-1 blockade. These findings identify evolving Th17 polarization in sJIA that begins in Tregs and progresses to Teffs, likely reflecting the impact of the cytokine milieu and consistent with a biphasic model of disease pathogenesis. The results support T cells as a potential treatment target in sJIA.
Lauren A. Henderson, Kacie J. Hoyt, Pui Y. Lee, Deepak A. Rao, A. Helena Jonsson, Jennifer P. Nguyen, Kayleigh Rutherford, Amélie M. Julé, Louis-Marie Charbonnier, Siobhan Case, Margaret H. Chang, Ezra M. Cohen, Fatma Dedeoglu, Robert C. Fuhlbrigge, Olha Halyabar, Melissa M. Hazen, Erin Janssen, Susan Kim, Jeffrey Lo, Mindy S. Lo, Esra Meidan, Mary Beth F. Son, Robert P. Sundel, Matthew L. Stoll, Chad Nusbaum, James A. Lederer, Talal A. Chatila, Peter A. Nigrovic
Neutrophil extracellular traps (NETs) promote inflammation and atherosclerosis progression. NETs are increased in diabetes and impair the resolution of inflammation during wound healing. Atherosclerosis resolution, a process resembling wound healing, is also impaired in diabetes. Thus, we hypothesized that NETs impede atherosclerosis resolution in diabetes by increasing plaque inflammation. Indeed, transcriptomic profiling of plaque macrophages from NET positive and negative areas in low-density lipoprotein receptor-deficient (Ldlr-/-) mice revealed inflammasome and glycolysis pathway upregulation, indicating a heightened inflammatory phenotype. We found that NETs decline during atherosclerosis resolution, which was induced by reducing hyperlipidemia in non-diabetic mice, but they persist in diabetes, exacerbating macrophage inflammation and impairing resolution. In diabetic mice deoxyribonuclease 1 (DNase1) treatment reduced plaque NETs content and macrophage inflammation, promoting atherosclerosis resolution after lipid-lowering. Given that humans with diabetes also exhibit impaired atherosclerosis resolution with lipid-lowering, these data suggest that NETs contribute to the increased cardiovascular disease risk in this population and are a potential therapeutic target.
Tatjana Josefs, Tessa J. Barrett, Emily J. Brown, Alexandra Quezada, Xiaoyun Wu, Maud Voisin, Jaume Amengual, Edward A. Fisher
C5a is a potent inflammatory mediator, which binds C5aR1 and C5aR2. Although pathogenic roles of C5a/C5aR1 axis in inflammatory disorders are well-documented, the roles for C5a/C5aR2 axis in inflammatory disorders and underlying mechanisms remain unclear. Here, we show that C5a/C5aR2 axis contributes to renal inflammation and tissue damage in a mouse model of acute pyelonephritis. Compared with WT littermates, C5ar2-/- mice had significantly reduced renal inflammation, tubular damage and renal bacterial load following bladder inoculation with uropathogenic E coli. The decrease in inflammatory responses in the kidney of C5ar2-/- mice was correlated with reduced intrarenal levels of high mobility group box 1 protein (HMGB1), NLRP3 inflammasome components, cleaved caspase-1 and IL-1β. In vitro, C5a stimulation of macrophages from C5ar1-/- mice (lacking C5aR1 but expressing C5aR2) led to significant upregulation of HMGB1 release, NLRP3/caspase-1 inflammasome activation and IL-1β secretion. Furthermore, blockade of HMGB1 significantly reduced C5a-mediated upregulation of NLRP3/caspase-1 inflammasome activation and IL-1β secretion in the macrophages, implying a HMGB1-dependent upregulation of NLRP3/caspase-1 inflammasome activation in macrophages. Our findings demonstrate a pathogenic role for C5a/C5aR2 axis in renal injury following renal infection and suggest that C5a/C5aR2 axis contributes to renal inflammation and tissue damage through up-regulation of HMGB1 and NLRP3/caspase-1 inflammasome.
Ting Zhang, Kun-yi Wu, Ning Ma, Lin-ling Wei, Malgorzata A. Garstka, Wuding Zhou, Ke Li
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