The Journal of clinical investigation
Alter, C;Henseler, AS;Owenier, C;Hesse, J;Ding, Z;Lautwein, T;Bahr, J;Hayat, S;Kramann, R;Kostenis, E;Scheller, J;Schrader, J;
PMID: 36943408 | DOI: 10.1172/JCI163799
Plasma IL-6 is elevated after myocardial infarction (MI) and is associated with increased morbidity and mortality. Which cardiac cell type preferentially contributes to IL-6 and how its production is regulated is largely unknown. Here, we studied the cellular source and purinergic regulation of IL-6 formation in a murine MI model. IL-6, measured in various cell types in post MI hearts by qPCR, RNAscope and at protein level, was preferentially formed by fibroblasts (CFs). scRNAseq in infarcted mouse and human hearts confirmed this finding. Adenosine stimulated fibroblast IL-6 formation via A2bR in a Gq-dependent manner. CFs highly expressed Adora2b, rapidly degraded extracellular ATP to AMP but lacked CD73. In mice and humans Adora2B was also mainly expressed by fibroblasts (scRNAseq). Global IL-6 formation was assessed in isolated hearts in mice lacking CD73 on T-cells (CD4CD73-/-) a condition known to be associated with adverse cardiac remodeling. The ischemia-induced release of IL-6 was strongly attenuated in CD4CD73-/- mice, suggesting adenosine-mediated modulation. Together this demonstrates that post-MI IL-6 is mainly derived from activated CFs and is controlled by T-cell derived adenosine. Purinergic metabolic cooperation between CFs and T-cells is a novel mechanism with therapeutic potential which modulates IL6 formation by the heart.
Rigoni R, Fontana E, Dobbs K, Marrella V, Taverniti V, Maina V, Facoetti A, D'Amico G, Al-Herz W, Cruz-Munoz ME, Schuetz C, Gennery AR, Garabedian EK, Giliani S, Draper D, Dbaibo G, Geha RS, Meyts I1, Tousseyn T, Neven B, Moshous D, Fischer A, Schulz A, Finocchi A, Kuhns DB, Fink DL, Lionakis MS, Swamydas M, Guglielmetti S, Alejo J, Myles IA, Pittaluga S, Notarangelo LD, Villa A, Cassani B
PMID: 32311393 | DOI: 10.1016/j.jaci.2020.04.005
BACKGROUND:
Severe early-onset erythroderma and gut inflammation, with massive tissue infiltration of oligoclonal activated T cells are the hallmark of Omenn Syndrome (OS).
OBJECTIVE:
The impact of altered gut homeostasis in the cutaneous manifestations of OS remains to be clarified.
METHODS:
We analyzed a cohort of 15 patients with OS and the Rag2R229Q mouse model. Homing phenotype of circulating lymphocytes were analyzed by flow cytometry. Inflammatory cytokines and chemokines were examined in the sera by ELISA and in skin biopsies by immunohistochemistry and in situ RNA hybridization. Experimental colitis was induced in mice by dextran sulfate sodium salt (DSS).
RESULTS:
We show that memory/activated T cells from OS patients and from the Rag2R229Q mouse model of OS abundantly express the skin homing receptors Cutaneous Lymphocyte Associated Antigen (CLA) and CCR4, associated with high levels of CCL17 and CCL22 chemokines. Serum levels of LPS are also elevated. A broad Th1/Th2/Th17 inflammatory signature is detected in the periphery and in the skin. Increased Tlr4 expression in the skin of Rag2R229Q mice is associated with enhanced cutaneous inflammation upon local and systemic administration of LPS. Likewise, boosting colitis in Rag2R229Q mice results in increased frequency of CCR4+ splenic T cells and worsening of skin inflammation, as indicated by epidermal thickening, enhanced epithelial cell activation and dermal infiltration by Th1 effector T cells.
CONCLUSIONS:
These results support the existence of an interplay between gut and skin that can sustain skin inflammation in O
The induction of preterm labor in rhesus macaques is determined by the strength of immune response to intrauterine infection
Cappelletti, M;Presicce, P;Feiyang, M;Senthamaraikannan, P;Miller, LA;Pellegrini, M;Sim, MS;Jobe, AH;Divanovic, S;Way, SS;Chougnet, CA;Kallapur, SG;
PMID: 34495952 | DOI: 10.1371/journal.pbio.3001385
Intrauterine infection/inflammation (IUI) is a major contributor to preterm labor (PTL). However, IUI does not invariably cause PTL. We hypothesized that quantitative and qualitative differences in immune response exist in subjects with or without PTL. To define the triggers for PTL, we developed rhesus macaque models of IUI driven by lipopolysaccharide (LPS) or live Escherichia coli. PTL did not occur in LPS challenged rhesus macaques, while E. coli-infected animals frequently delivered preterm. Although LPS and live E. coli both caused immune cell infiltration, E. coli-infected animals showed higher levels of inflammatory mediators, particularly interleukin 6 (IL-6) and prostaglandins, in the chorioamnion-decidua and amniotic fluid (AF). Neutrophil infiltration in the chorio-decidua was a common feature to both LPS and E. coli. However, neutrophilic infiltration and IL6 and PTGS2 expression in the amnion was specifically induced by live E. coli. RNA sequencing (RNA-seq) analysis of fetal membranes revealed that specific pathways involved in augmentation of inflammation including type I interferon (IFN) response, chemotaxis, sumoylation, and iron homeostasis were up-regulated in the E. coli group compared to the LPS group. Our data suggest that the intensity of the host immune response to IUI may determine susceptibility to PTL.
Riedel, JH;Robben, L;Paust, HJ;Zhao, Y;Asada, N;Song, N;Peters, A;Kaffke, A;Borchers, AC;Tiegs, G;Seifert, L;Tomas, NM;Hoxha, E;Wenzel, UO;Huber, TB;Wiech, T;Turner, JE;Krebs, CF;Panzer, U;
PMID: 36355429 | DOI: 10.1172/jci.insight.160251
Glucocorticoids remain a cornerstone of therapeutic regimes for autoimmune and chronic inflammatory diseases, for example, in different forms of crescentic glomerulonephritis because of their rapid anti-inflammatory effects, low cost, and wide availability. Despite their routine use for decades, the underlying cellular mechanisms by which steroids exert their therapeutic effects need to be fully elucidated.Here, we demonstrate that high-dose steroid treatment rapidly reduced the number of proinflammatory CXCR3+ CD4+ T cells in the kidney by combining high-dimensional single-cell and morphological analyses of kidney biopsies from patients with antineutrophil cytoplasmic antibody (ANCA)-associated crescentic glomerulonephritis. Using an experimental model of crescentic glomerulonephritis, we show that the steroid-induced decrease in renal CD4+ T cells is a consequence of reduced T-cell recruitment, which is associated with an ameliorated disease course. Mechanistic in vivo and in vitro studies revealed that steroids act directly on renal tissue cells, such as tubular epithelial cells, but not on T cells, which resulted in an abolished renal expression of CXCL9 and CXCL10, as well as in the prevention of CXCR3+ CD4+ T-cell recruitment to the inflamed kidneys. Thus, we identified the CXCL9/10-CXCR3 axis as a previously unrecognized cellular and molecular target of glucocorticoids providing protection from immune-mediated pathology.
Influence of the microenvironment on modulation of the host response by typhoid toxin
Martin, OCB;Bergonzini, A;Lopez Chiloeches, M;Paparouna, E;Butter, D;Theodorou, SDP;Haykal, MM;Boutet-Robinet, E;Tebaldi, T;Wakeham, A;Rhen, M;Gorgoulis, VG;Mak, T;Pateras, IS;Frisan, T;
PMID: 33826883 | DOI: 10.1016/j.celrep.2021.108931
Bacterial genotoxins cause DNA damage in eukaryotic cells, resulting in activation of the DNA damage response (DDR) in vitro. These toxins are produced by Gram-negative bacteria, enriched in the microbiota of inflammatory bowel disease (IBD) and colorectal cancer (CRC) patients. However, their role in infection remains poorly characterized. We address the role of typhoid toxin in modulation of the host-microbial interaction in health and disease. Infection with a genotoxigenic Salmonella protects mice from intestinal inflammation. We show that the presence of an active genotoxin promotes DNA fragmentation and senescence in vivo, which is uncoupled from an inflammatory response and unexpectedly associated with induction of an anti-inflammatory environment. The anti-inflammatory response is lost when infection occurs in mice with acute colitis. These data highlight a complex context-dependent crosstalk between bacterial-genotoxin-induced DDR and the host immune response, underlining an unexpected role for bacterial genotoxins.
Rapid endotheliitis and vascular damage characterize SARS-CoV-2 infection in a human lung-on-chip model
Thacker, VV;Sharma, K;Dhar, N;Mancini, GF;Sordet-Dessimoz, J;McKinney, JD;
PMID: 33908688 | DOI: 10.15252/embr.202152744
Severe cases of SARS-CoV-2 infection are characterized by hypercoagulopathies and systemic endotheliitis of the lung microvasculature. The dynamics of vascular damage, and whether it is a direct consequence of endothelial infection or an indirect consequence of an immune cell-mediated cytokine storm remain unknown. Using a vascularized lung-on-chip model, we find that infection of alveolar epithelial cells leads to limited apical release of virions, consistent with reports of monoculture infection. However, viral RNA and proteins are rapidly detected in underlying endothelial cells, which are themselves refractory to apical infection in monocultures. Although endothelial infection is unproductive, it leads to the formation of cell clusters with low CD31 expression, a progressive loss of barrier integrity and a pro-coagulatory microenvironment. Viral RNA persists in individual cells generating an inflammatory response, which is transient in epithelial cells but persistent in endothelial cells and typified by IL-6 secretion even in the absence of immune cells. Inhibition of IL-6 signalling with tocilizumab reduces but does not prevent loss of barrier integrity. SARS-CoV-2-mediated endothelial cell damage thus occurs independently of cytokine storm.
March-Riera, S;Wilson, AA;Bhatia, SN;Muhlberger, E;
| DOI: 10.1016/j.stemcr.2022.08.003
Liver damage and an exacerbated inflammatory response are hallmarks of Ebola virus (EBOV) infection. Little is known about the intrinsic response to infection in human hepatocytes and their contribution to inflammation. Here, we present an induced pluripotent stem cell (iPSC)-derived hepatocyte-like cell (HLC) platform to define the hepato-intrinsic response to EBOV infection. We used this platform to show robust EBOV infection, with characteristic ultrastructural changes and evidence for viral replication. Transcriptomics analysis revealed a delayed response with minimal early transcriptomic changes, followed by a general downregulation of hepatic function and upregulation of interferon signaling, providing a potential mechanism by which hepatocytes participate in disease severity and liver damage. Using RNA-fluorescence in situ hybridization (FISH), we showed that IFNB1 and CXCL10 were mainly expressed in non-infected bystander cells. We did not observe an inflammatory signature during infection. In conclusion, iPSC-HLCs are an immune competent platform to study responses to EBOV infection.
Doke, T;Abedini, A;Aldridge, DL;Yang, YW;Park, J;Hernandez, CM;Balzer, MS;Shrestra, R;Coppock, G;Rico, JMI;Han, SY;Kim, J;Xin, S;Piliponsky, AM;Angelozzi, M;Lefebvre, V;Siracusa, MC;Hunter, CA;Susztak, K;
PMID: 35552540 | DOI: 10.1038/s41590-022-01200-7
Inflammation is an important component of fibrosis but immune processes that orchestrate kidney fibrosis are not well understood. Here we apply single-cell sequencing to a mouse model of kidney fibrosis. We identify a subset of kidney tubule cells with a profibrotic-inflammatory phenotype characterized by the expression of cytokines and chemokines associated with immune cell recruitment. Receptor-ligand interaction analysis and experimental validation indicate that CXCL1 secreted by profibrotic tubules recruits CXCR2+ basophils. In mice, these basophils are an important source of interleukin-6 and recruitment of the TH17 subset of helper T cells. Genetic deletion or antibody-based depletion of basophils results in reduced renal fibrosis. Human kidney single-cell, bulk gene expression and immunostaining validate a function for basophils in patients with kidney fibrosis. Collectively, these studies identify basophils as contributors to the development of renal fibrosis and suggest that targeting these cells might be a useful clinical strategy to manage chronic kidney disease.
Barnett, KC;Xie, Y;Asakura, T;Song, D;Liang, K;Taft-Benz, SA;Guo, H;Yang, S;Okuda, K;Gilmore, RC;Loome, JF;Oguin Iii, TH;Sempowski, GD;Randell, SH;Heise, MT;Lei, YL;Boucher, RC;Ting, JP;
PMID: 36563691 | DOI: 10.1016/j.chom.2022.12.005
Elevated levels of cytokines IL-1β and IL-6 are associated with severe COVID-19. Investigating the underlying mechanisms, we find that while primary human airway epithelia (HAE) have functional inflammasomes and support SARS-CoV-2 replication, they are not the source of IL-1β released upon infection. In leukocytes, the SARS-CoV-2 E protein upregulates inflammasome gene transcription via TLR2 to prime, but not activate, inflammasomes. SARS-CoV-2-infected HAE supply a second signal, which includes genomic and mitochondrial DNA, to stimulate leukocyte IL-1β release. Nuclease treatment, STING, and caspase-1 inhibition but not NLRP3 inhibition blocked leukocyte IL-1β release. After release, IL-1β stimulates IL-6 secretion from HAE. Therefore, infection alone does not increase IL-1β secretion by either cell type. Rather, bi-directional interactions between the SARS-CoV-2-infected epithelium and immune bystanders stimulates both IL-1β and IL-6, creating a pro-inflammatory cytokine circuit. Consistent with these observations, patient autopsy lungs show elevated myeloid inflammasome gene signatures in severe COVID-19.