Inflammation
Abstract
Next-generation sequencing technologies are increasingly used to diagnose genetic disorders, particularly immunological diseases with broad and overlapping immune dysregulation. Cryopyrin-associated periodic syndromes (CAPS) are caused by gain-of-function mutations in NLRP3 and include 3 autoinflammatory diseases spanning a continuum of severity: familial cold autoinflammatory syndrome (FCAS), Muckle-Wells syndrome (MWS), and neonatal-onset multisystem inflammatory disease (NOMID). Linking NLRP3 variants to protein dysfunction and clinical phenotype remains challenging because of genetic modifiers and environmental factors. We report the generation and phenotyping of 5 mouse lines expressing either the common human NLRP3 allele or 1 of 4 CAPS mutations spanning the disease spectrum from FCAS to NOMID. In these lines, the murine Nlrp3 locus is replaced by syntenic integration of the human NLRP3 locus, yielding 1 line with the common allele and 4 lines each carrying a distinct CAPS mutation. Unlike models in which a human mutation is introduced into the mouse protein, these lines recapitulate the spectrum of disease severity observed in humans. These findings support a model in which evaluation of nonsynonymous mutations in mice is optimized when introduced in the context of the human gene. This suggests that species-specific regulation and/or intramolecular epistasis may impact modeling of disease-associated variants.
Authors
John N. Snouwaert, MyTrang Nguyen, Christopher A. Gabel, Ivona Aksentijevich, Jenny P.-Y. Ting, Beverly H. Koller
Abstract
Aberrant neutrophil (PMN) accumulation in the tissue induces chronic vascular diseases. Endothelial cells (ECs) regulate the access of PMNs into the tissue from the blood. However, the mechanisms that prevent PMNs from being activated and accumulating in the tissue, a hallmark of acute lung injury (ALI), remain elusive. We demonstrate that conditional deletion of Erg in ECs spontaneously alters the PMN transcriptome, which is enriched with genes that induce PMN recruitment, adhesion, activation, and 'do not eat me' signals due to impaired synthesis of the deubiquitinase, A20. Decreased A20 levels, in turn, activated the transcription factor NFκB and the secretion of MIP2α (human homolog of IL8) in ECs. EC-secreted MIP2α/IL8 engaged the CXCR2 cascade on PMNs, leading to their activation and inflammatory injury. These findings were recapitulated in the lungs and blood of PMNs from patients dying of ALI. Overexpression of the A20 gene in EC or pharmacological inhibition of CXCR2 on PMNs in iEC-Erg–/– mice rescued EC control of PMNs and tissue homeostasis, and enhanced mouse survival after pneumonia. Thus, the EC-Erg-A20 axis regulates PMN accumulation and hyperactivation in the lungs by inhibiting EC-mediated IL-8 activation of PMN-CXCR2, thereby providing a potential target for neutrophilic inflammatory vascular diseases.
Authors
Vigneshwaran Vellingiri, Vijay Avin Balaji Ragunathrao, Jagdish Chandra Joshi, Md Zahid Akhter, Mumtaz Anwar, Somenath Banerjee, Sayanti Datta, Viktor Pinneker, Steven M. Dudek, Yoshikazu Tsukasaki, Sandra Pinho, Dolly Mehta
Abstract
Immune checkpoint inhibitors (ICIs) can cause immune-related adverse events (irAEs), with acute interstitial nephritis (ICI-AIN) being the most common irAE. While the exact mechanism remains unclear, upregulation of interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) pathways has been implicated. This study used a humanized chimeric PD-1/PD-L1 mouse model to assess renal effects of ICIs, alone or combined with pro-inflammatory cytokines, and to test if selective TNF-α blockade could prevent ICI-AIN. Mice were randomly divided into four experimental groups: Control, ICI-Only, ICI-Cytokines (ICI-Cyt), and ICI-Block (ICI-TNF-α blockade). Renal function and cytokine profiles were assessed, while kidney tissue was analyzed using microscopy and single-cell RNA sequencing. Histology revealed increased renal infiltration of CD4⁺/CD8⁺ T cells in ICI-treated groups and decreased TNF-α expression following TNF-α blockade. Additionally, kidney tissue ELISA demonstrated reduced IFN-γ levels following TNF-α blockade. Plasma IL-6, MCP-1, and TNF-α were lower in ICI-Block mice. Single-cell RNA sequencing revealed shifts in immune cell populations and genes of interest including: Bcl2a1, Icos, Il18r1, Ccr2, and Jaml. This humanized model replicates ICI-AIN key features, revealing a synergistic role of ICIs and pro-inflammatory cytokines. TNF-α blockade demonstrated protective effects, supporting its potential role in mitigating the risk of ICI-AIN.
Authors
Victor D. Cuenca Narvaez, Coraima Nava Chavez, Omar Al Refai, Johanna E. J. Jacobs, Luis E. Gutierrez, Song Zhang, Xiaoyan Li, Jacob B. Hirdler, Michael F. Romero, Joerg Herrmann, Xiaogang Li, Haidong Dong, Alfonso Eirin, Sandra M. Herrmann
Abstract
This study provides a comprehensive evaluation of the cutaneous adipose tissue (CAT) transcriptome in psoriasis patients and investigates the effects of IL-17 blockade on CAT inflammation through a randomized placebo-controlled trial using secukinumab (ObePso-S study, NCT03055494). RNA sequencing analysis of CAT biopsies from 82 psoriasis patients revealed 2132 differentially expressed transcripts compared to healthy controls. Notably, significant gene dysregulation was observed in both lesional skin (LS)- and non-lesional (NL)-CAT, including activation of IL-17-driven pathways, antimicrobial peptide-related, and neutrophil degranulation signatures. Stratification by obesity demonstrated that obese psoriatic CAT exhibited more than 2-fold higher number of differentially expressed genes than non-obese counterparts, suggesting a synergistic interaction between psoriasis and obesity in driving CAT inflammation. Treatment with secukinumab markedly improved inflammatory signatures in psoriatic CAT, with greater improvements observed in obese patients. These findings reveal a pronounced and partially dependent on IL-17-dependent inflammatory phenotype in psoriatic CAT, challenge the conventional concept of psoriasis as a solely superficial skin disease, and highlight CAT as an important contributor to systemic inflammation in psoriasis.
Authors
Naomi Shishido-Takahashi, Sandra Garcet, Inna Cueto, Hong Beom Hur, Elisa F. Muscianisi, Jennifer Steadman, Andrew Blauvelt, James G. Krueger
Abstract
Synthetic prostaglandin analogues, such as latanoprost, are first-line treatments to reduce intraocular pressure (IOP) in the management of glaucoma, treating millions of patients daily. Glaucoma is a leading cause of blindness, characterized by progressive optic neuropathy, with elevated IOP being the sole modifiable risk factor. Despite this importance, the underlying latanoprost mechanism of action is still not well defined, being associated with both acute and long term activities, and a growing list of ocular side effects. Prostaglandins are eicosanoid lipid mediators. Yet, there has not been a comprehensive assessment of small lipid mediators in glaucomatous eyes. Here we performed a lipidomic screen of aqueous humour sampled from glaucoma patients and healthy control eyes. The resulting signature was surprisingly focused on significantly elevated levels of arachidonic acid (AA) and its derivative, the ant-inflammatory and cytoprotective mediator, lipoxin A4 (LXA4) in glaucoma eyes. Subsequent experiments reveal that this response is drug-induced, due to latanoprost actions on trabecular meshwork cells, rather than a consequence of elevated IOP. We demonstrate that increased LXA4 inhibits pro-inflammatory cues and promotes TGF-β production in the anterior chamber. In concert, an autocrine prostaglandin circuit mediates canonical rapid IOP-lowering. This work reveals parallel mechanisms underlying acute and long-term latanoprost activities during glaucoma treatment.
Authors
David J. Mathew, Shubham Maurya, Julian Ho, Izhar Livne-Bar, Darren Chan, Jenny Wanyu Zhang, Yvonne M. Buys, Marisa Sit, Graham Trope, Donna M. Peters, John G. Flanagan, Karsten Gronert, Jeremy M. Sivak
Abstract
Sepsis, a systemic inflammatory response to infection, remains a leading cause of mortality in intensive care units, with sepsis-induced immunosuppression being a critical pathophysiological process. In this study, we investigated the role of histone deacetylase 1 (HDAC1) in sepsis-induced CD8+ T cell exhaustion, a key driver of immunosuppression. Clinical analyses of patients with sepsis revealed that reduced peripheral blood lymphocyte levels, particularly CD8+ T cell depletion, strongly correlated with worsened outcomes. In a murine sepsis model, single-cell RNA-Seq revealed a significant decrease in the proportion of CD8+ T cells and an increase in the proportion of exhausted CD8+ T cells in mouse lungs. Adoptive transfer of CD8+ T cells effectively reduced sepsis mortality by preserving organ function. We further demonstrated that HDAC1 expression was significantly upregulated in CD8+ T cells from patients with sepsis. In vitro studies showed that HDAC1 inhibition preserved CD8+ T cell function by maintaining T cell activity and reducing the expression of inhibitory molecules such as PD-1. Pharmacological inhibition of HDAC1 reduced mortality and reversed CD8+ T cell exhaustion by restoring the balance between activator protein-1 (AP-1) and nuclear factor of activated T cells (NFAT). Additionally, we found that HDAC1 directly interacted with NFAT1, promoting its nuclear translocation and further enhancing the expression of inhibitory molecules. Our findings highlight HDAC1 as a potential therapeutic target for sepsis-induced immunosuppression. By elucidating the molecular mechanisms underlying HDAC1-mediated immunosuppression, we have provided potential strategies for developing immunomodulatory therapies for the treatment of sepsis.
Authors
Liu Di, Jiang-bo Fan, Rui Wang, You Li, Wan-da Bi, Si-yuan Huang, Heng-hai Nie, Xi-feng Feng, Hua-cai Zhang, Juan Du, Xiao-fei Huang, An-yong Yu, Zhe Xu, Fei Xia, Jian-xin Jiang, Shuang-shuang Dai, Xiang Xu, Zhen Wang, Ling Zeng
Abstract
Authors
Sebastian Kämpf, Marjan Hematianlarki, Leon Altmann, Jessica M. Bright, Alyssa M. A. Toda, Zohreh Mirzapoor, Valentin Zollner, Anja Werner, Johanna Bulang, Barbara Radovani, Miriam Wöhner, William Avery, Mark J. Karbarz, Pamela B. Conley, Greg P. Coffey, Falk Nimmerjahn
Abstract
Adeno-associated viruses (AAVs) have been used in gene therapy, especially for inherited retinal diseases. Despite their effectiveness in gene transduction, immune responses to the AAV capsid and transgene products have been reported, which can compromise both the efficacy and safety of AAV-mediated therapies. The eye is regarded as an immune-privileged organ where immune activity is constitutively suppressed. Here, we highlight that immunomonitoring in an ocular gene transfer reveals variable immune responses, whatever the species (human clinical trial, non-human primates, mice), the site of injection, the cassette, and the dose. We further explored factors contributing to this variability, investigating the potential correlation among immune parameters in a controlled experimental setting. In a syngeneic murine model after a subretinal injection of AAV, our results highlight an inter-individual variability of immune parameters, emphasizing the importance of considering inherent variability among individuals while designing personalized therapies.
Authors
Duohao REN, Gaelle A. CHAUVEAU, Julie VENDOMELE, Emilie CABON, Audrey PINEIRO, Catherine VIGNAL-CLERMONT, Hanadi SALIBA, Giuseppe RONZITTI, Anne GALY, Deniz DALKARA, Juliette PULMAN, Divya AIL, Sylvain FISSON
Abstract
Epigenetic modifications play a crucial role in the pathogenesis of inflammatory bowel disease (IBD) by mediating gene-environment interactions. We previously showed that UHRF1, a central regulator of DNA methylation, contributes to cancer progression; however, its function in IBD remains poorly understood. Here, we revealed that UHRF1 was frequently reduced in inflamed tissues of patients with IBD and that its deficiency exacerbated intestinal epithelial cell (IEC) damage. Through a multilevel approach incorporating human cell models and an intestinal epithelial-specific Uhrf1-KO mouse model, we established UHRF1 as a key mitigator of IBD progression. Mechanistically, UHRF1 bound to the NPY1R promoter, promoted its methylation, and led to transcriptional suppression. The NPY1R upregulation resulting from UHRF1 deficiency attenuated cAMP/PKA/CREB signaling in IECs, thereby enhancing NF-κB activation and subsequent proinflammatory responses, which compromised intestinal epithelial barrier integrity. Furthermore, we identified miR-141 as a negative regulator of NPY1R, highlighting its potential as a therapeutic agent. Collectively, our results identified the UHRF1/NPY1R regulatory axis as a critical epigenetic mechanism in intestinal inflammation and underscored its dual promise for IBD diagnostics and therapy.
Authors
Yanan Han, Lina Sun, Yanxing Liu, Xiaohui Zhang, Hao Liu, Haohao Zhang, Xiaoxia Ren, Fenfan Wang, Huafeng Fan, Jie Chen, Dan Liu, Daiming Fan, Yuanyuan Lu, Xue Bai, Ying Fang, Kaichun Wu, Xiaodi Zhao
Abstract
Authors
Alessandra Ciullo, Xaviar M. Jones, Hiroaki Komuro, Liang Li, Anh Nguyen, Eduardo Marbán, Ahmed Gamal-Eldin Ibrahim
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