Research Article
Abstract
Despite effective antiretroviral therapy, transcriptionally competent HIV-1 reservoirs remain and contribute to persistent immune activation in people living with HIV (PWH). HIV-1–infected macrophages are important mediators of chronic innate immune activation, though the mechanisms remain unclear. We previously reported that nuclear export and cytoplasmic expression of HIV-1 intron-containing RNA (icRNA) activates mitochondrial antiviral signaling (MAVS) protein–mediated type I IFN responses in macrophages. In this study, we demonstrate an essential role of melanoma differentiation–associated protein 5 (MDA5) in sensing HIV-1 icRNA and promoting MAVS-dependent interferon regulatory factor 5 (IRF5) activation in macrophages. Suppression of MDA5 but not retinoic acid–inducible gene I expression nor disruption of the endosomal TLR pathway abrogated HIV-1 icRNA-induced type I IFN responses and IP-10 expression in macrophages. Furthermore, induction of IP-10 in macrophages upon HIV-1 icRNA sensing by MDA5 was dependent on IRF5. Additionally, monocytes and monocyte-derived macrophages (MDMs) from older (>50 years) individuals exhibited constitutively higher levels of IRF5 expression compared with younger (<35 years) individuals, and HIV-1 icRNA-induced IP-10 expression was significantly enhanced in older macrophages, which was attenuated upon ablation of IRF5 expression, suggesting that IRF5 functions as a major mediator of proinflammatory response downstream of MDA5-dependent HIV-1 icRNA sensing, dysregulation of which might contribute to chronic inflammation in older PWH.
Authors
Sita Ramaswamy, Hisashi Akiyama, Jacob Berrigan, Andrés A. Quiñones-Molina, Alex J. Olson, Yunhan Chen, YanMei Liang, Andrew J. Henderson, Archana Asundi, Manish Sagar, Suryaram Gummuluru
Abstract
Influenza-associated bacterial superinfections in the lung lead to increased morbidity and mortality. Nearly all people have preexisting memory to influenza virus, which can protect against subsequent infection in the lung. This study explored the role B cells play in protection against bacterial (Staphylococcus aureus or Klebsiella pneumoniae) superinfection with previous heterotypic influenza memory. B cell deficiency resulted in an increased inflammatory lung environment and lung tissue injury during superinfection. Loss of B cells increased populations of memory CD8+ T cells in the lung, and these CD8+ T cells were transcriptionally and functionally distinct from those of WT mice. Use of antibody-deficient mouse models showed that this phenotype was specifically due to loss of antibody production from B cells. Passive immunization with influenza antibody serum in B cell–deficient mice rescued the CD8+ T cell phenotype. CD8+ T cell depletion and lethal superinfection challenge experiments showed that the cytotoxic memory CD8+ T cells from B cell–deficient mice protect against superinfection bacterial burden and mortality. These findings provide insight into the importance of B cells for regulating immune responses against infection.
Authors
Leigh M. Miller, Alexis M. Duray, Ellyse M. Cipolla, Flavia Rago, Brooke P. Dresden, Kristen L. Parenteau, Abhigya Gupta, John F. Alcorn
Abstract
Lupus nephritis (LN) is a frequent manifestation of systemic lupus erythematosus, and fewer than half of patients achieve complete renal response with standard immunosuppressants. Identifying noninvasive, blood-based immune alterations associated with renal injury could aid therapeutic decisions. Here, we used mass cytometry immunophenotyping of peripheral blood mononuclear cells in 145 patients with biopsy-proven LN and 40 healthy controls to evaluate the heterogeneity of immune activation and identify correlates of renal parameters. Unbiased analysis identified 3 immunologically distinct groups of patients that were associated with different patterns of histopathology, renal cell infiltrates, urine proteomic profiles, and treatment response at 1 year. Patients with enriched circulating granzyme B+ T cells showed more active disease and increased numbers of activated CD8+ T cells in the kidney, yet they had the highest likelihood of treatment response. A second group characterized by a high type I interferon signature had a lower likelihood of response to therapy, while a third group appeared immunologically inactive but with chronic renal injuries. The major immunologic axes of variation could be distilled down to 5 simple cytometric parameters that recapitulate several clinical associations, highlighting the potential for blood immunoprofiling to translate to clinically useful noninvasive metrics to assess immune-mediated disease in LN.
Authors
Alice Horisberger, Alec Griffith, Joshua Keegan, Arnon Arazi, John Pulford, Ekaterina Murzin, Kaitlyn Howard, Brandon Hancock, Andrea Fava, Takanori Sasaki, Tusharkanti Ghosh, Jun Inamo, Rebecca Beuschel, Ye Cao, Katie Preisinger, Maria Gutierrez-Arcelus, Thomas M. Eisenhaure, Joel Guthridge, Paul J. Hoover, Maria Dall’Era, David Wofsy, Diane L. Kamen, Kenneth C. Kalunian, Richard Furie, Michael Belmont, Peter Izmirly, Robert Clancy, David Hildeman, E. Steve Woodle, William Apruzzese, Maureen A. McMahon, Jennifer Grossman, Jennifer L. Barnas, Fernanda Payan-Schober, Mariko Ishimori, Michael Weisman, Matthias Kretzler, Celine C. Berthier, Jeffrey B. Hodgin, Dawit S. Demeke, Chaim Putterman, Accelerating Medicines Partnership Rheumatoid Arthritis and Systemic Lupus Erythematosus (AMP RA/SLE) Network, Michael B. Brenner, Jennifer H. Anolik, Soumya Raychaudhuri, Nir Hacohen, Judith A. James, Anne Davidson, Michelle A. Petri, Jill P. Buyon, Betty Diamond, Fan Zhang, James A. Lederer, Deepak A. Rao
Abstract
Proinflammatory signaling in adipocytes is essential for healthy adipose expansion, remodeling, and tissue integrity. We investigated the effects of targeting inflammation in either adipocytes or mammary gland epithelial cells, in the context of mammary tumor development, by locally expressing the antiinflammatory adenoviral RIDα/β protein complex in a cell type–specific manner. Suppression of adipocyte inflammation (RIDad mice) in a mammary tumor model driven by MMTV-PyMT (PyMT-RIDad mice) led to an elevated number of tumor-associated macrophages and upregulation of immunoregulatory molecules in the mammary fat pad. This was accompanied by metabolic dysfunction and abnormal mammary gland development. Importantly, this phenotype correlated with accelerated mammary tumor onset, enhanced growth, and lung metastasis. Tumors in PyMT-RIDad mice exhibited upregulated CD36 expression, suggesting enhanced fatty acid uptake. Conversely, suppression of inflammation in mammary gland epithelial cells by RIDα/β expression (RIDMMTV mice) decelerated mammary tumor growth without affecting tumor onset or macrophage accumulation. These findings highlight the differential impact on tumor development exerted through the suppression of inflammatory signals in different cell types in the microenvironment. Our results underscore the role of the suppression of adipocyte inflammation leading to a tumor-friendly microenvironment, promoting mammary cancer progression. This study sheds light on the complex interplay between inflammation, specifically driven by the adipocyte, in breast cancer pathogenesis.
Authors
Dae-Seok Kim, Toshiharu Onodera, Jan-Bernd Funcke, Kyounghee Min, Qingzhang Zhu, Qian Lin, Shiuhwei Chen, Chanmin Joung, Min Kim, R. Max Wynn, Joselin Velasco, Charlotte Lee, Megan Virostek, Chao Li, Philipp E. Scherer
Abstract
Functional inactivation of tumor suppressor genes drives cancer initiation, progression, and treatment responses. Most tumor suppressor genes are inactivated through 1 of 2 well-characterized mechanisms: DNA-level mutations, such as point mutations or deletions, and promoter DNA hypermethylation. Here, we report a distinct third mechanism of tumor suppressor inactivation based on alterations to the histone rather than DNA code. We demonstrated that PAX2 is an endometrial tumor suppressor recurrently inactivated by a distinct epigenetic reprogramming event in more than 80% of human endometrial cancers. Integrative transcriptomic, epigenomic, 3D genomic, and machine learning analyses showed that PAX2 transcriptional downregulation is associated with replacement of open/active chromatin features (H3K27ac/H3K4me3) with inaccessible/repressive chromatin features (H3K27me3) in a framework dictated by 3D genome organization. The spread of the repressive H3K27me3 signal resembled a pearl necklace, with its length modulated by cohesin loops, thereby preventing transcriptional dysregulation of neighboring genes. This mechanism, involving the loss of a promoter-proximal superenhancer, was shown to underlie transcriptional silencing of PAX2 in human endometrial cancers. Mouse and human preclinical models established PAX2 as a potent endometrial tumor suppressor. Functionally, PAX2 loss promoted endometrial carcinogenesis by rewiring the transcriptional landscape via global enhancer reprogramming. The discovery that most endometrial cancers originate from a recurring epigenetic alteration carries profound implications for their diagnosis and treatment.
Authors
Subhransu S. Sahoo, Susmita G. Ramanand, Ileana C. Cuevas, Yunpeng Gao, Sora Lee, Ahmed Abbas, Xunzhi Zhang, Ashwani Kumar, Prasad Koduru, Sambit Roy, Russell R. Broaddus, Victoria L. Bae-Jump, Andrew B. Gladden, Jayanthi Lea, Elena Lucas, Chao Xing, Akio Kobayashi, Ram S. Mani, Diego H. Castrillon
Abstract
Anxiety disorders pose a substantial threat to global mental health, with chronic stress identified as a major etiologic factor. Over the past few decades, extensive studies have revealed that chronic stress induces anxiety states through a distributed neuronal network of interconnected brain structures. However, the precise circuit mechanisms underlying the transition from chronic stress to anxiety remain incompletely understood. Employing the chronic social defeat stress (CSDS) paradigm in mice, we uncovered a critical role of the parasubthalamic nucleus (PSTh) in both the induction and expression of anxiety-like behavior. The anxiogenic effect was mediated by an excitatory trisynaptic circuitry involving the lateral parabrachial nucleus (LPB), PSTh, and bed nucleus of the stria terminalis (BNST). Furthermore, CSDS downregulated Kv4.3 channels in glutamatergic neurons of the PSTh. Reexpression of these channels dampened neuronal overexcitability and alleviated anxiety-like behavior in stressed animals. In parallel with the well-known anxiety network centered on the amygdala, here we identify a noncanonical LPB-PSTh-BNST pathway in the transformation of stress into anxiety. These findings suggest that the PSTh may serve as a potential therapeutic target for anxiety-related disorders.
Authors
Na Liu, Jun Wang, Huan Wang, Bin Gao, Zheng Lin, Tian-Le Xu, Shumin Duan, Han Xu
Abstract
Tumor gene alterations can serve as predictive biomarkers for therapy response. The nucleotide excision repair (NER) helicase ERCC2 carries heterozygous missense mutations in approximately 10% of bladder tumors, and these may predict sensitivity to cisplatin treatment. To explore the clinical actionability of ERCC2 mutations, we assembled a multinational cohort of 2,012 individuals with bladder cancer and applied the highly quantitative CRISPR-Select assay to functionally profile recurrent ERCC2 mutations. We also developed a single-allele editing version of CRISPR-Select to assess heterozygous missense variants in their native context. From the cohort, 506 ERCC2 mutations were identified, with 93% being heterozygous missense variants. CRISPR-Select pinpointed deleterious, cisplatin-sensitizing mutations, particularly within the conserved helicase domains. Importantly, single-allele editing revealed that heterozygous helicase-domain mutations markedly increased cisplatin sensitivity. Integration with clinical data confirmed that these mutations were associated with improved response to platinum-based neoadjuvant chemotherapy. Comparison with computational algorithms showed substantial discrepancies, highlighting the importance of precision functional assays for interpreting mutation effects in clinically relevant contexts. Our results demonstrate that CRISPR-Select provides a robust platform to advance biomarker-driven therapy in bladder cancer and supports its potential integration into precision oncology workflows.
Authors
Judit Börcsök, Diyavarshini Gopaul, Daphne Devesa-Serrano, Clémence Mooser, Nicolas Jonsson, Matteo Cagiada, Dag R. Stormoen, Maya N. Ataya, Brendan J. Guercio, Hristos Z. Kaimakliotis, Gopa Iyer, Kresten Lindorff-Larsen, Lars Dyrskjøt, Kent W. Mouw, Zoltan Szallasi, Claus S. Sørensen
Abstract
Platelet hyperreactivity increases the risk of cardiovascular thrombosis in diabetes and failure of antiplatelet drug therapies. Elevated basal and agonist-induced calcium flux is a fundamental cause of platelet hyperreactivity in diabetes; however, the mechanisms responsible for this remain largely unknown. Using a high-sensitivity, unbiased proteomic platform, we consistently detected over 2,400 intracellular proteins and identified proteins that were differentially released by platelets in type 2 diabetes. We identified that SEC61 translocon subunit β (SEC61B) was increased in platelets from humans and mice with hyperglycemia and in megakaryocytes from mice with hyperglycemia. SEC61 is known to act as an endoplasmic reticulum (ER) calcium leak channel in nucleated cells. Using HEK293 cells, we showed that SEC61B overexpression increased calcium flux into the cytosol and decreased protein synthesis. Concordantly, platelets in hyperglycemic mice mobilized more calcium and had decreased protein synthesis. Platelets in both humans and mice with hyperglycemia had increased ER stress. ER stress induced the expression of platelet SEC61B and increased cytosolic calcium. Inhibition of SEC61 with anisomycin decreased platelet calcium flux and inhibited platelet aggregation in vitro and in vivo. These studies demonstrate the existence of a mechanism whereby ER stress–induced upregulation of platelet SEC61B leads to increased cytosolic calcium, potentially contributing to platelet hyperreactivity in diabetes.
Authors
Yvonne X. Kong, Rajan Rehan, Cesar L. Moreno, Søren Madsen, Yunwei Zhang, Huiwen Zhao, Miao Qi, Callum B. Houlahan, Siân P. Cartland, Declan Robertshaw, Vincent Trang, Frederick Jun Liang Ong, Michael Liu, Edward Cheng, Imala Alwis, Alexander Dupuy, Michelle Cielesh, Kristen C. Cooke, Meg Potter, Jacqueline Stöckli, Grant Morahan, Maggie L. Kalev-Zylinska, Matthew T. Rondina, Sol Schulman, Jean Y. H. Yang, G. Gregory Neely, Simone M. Schoenwaelder, Shaun P. Jackson, David E. James, Mary M. Kavurma, Samantha L. Hocking, Stephen M. Twigg, James C. Weaver, Mark Larance, Freda H. Passam
Abstract
Platelets play a dual role in hemostasis and inflammation-associated thrombosis and hemorrhage. Although the mechanisms linking inflammation to platelet dysfunction remain poorly understood, our previous work demonstrated that TNF-α alters mitochondrial mass, platelet activation, and autophagy-related pathways in megakaryocytes. Here, we hypothesized that TNF-α impairs platelet function by disrupting autophagy, a process critical for mitochondrial health and cellular metabolism. Using human and murine models of TNF-α–driven diseases, including myeloproliferative neoplasms and rheumatoid arthritis, we found that TNF-α downregulates syntaxin 17 (STX17), a key mediator of autophagosome-lysosome fusion. This disruption inhibited autophagy, leading to the accumulation of dysfunctional mitochondria and reduced mitochondrial respiration. These metabolic alterations compromised platelet-driven clot contraction, a process linked to thrombotic and hemorrhagic complications. Our findings reveal a mechanism by which TNF-α disrupts hemostasis through autophagy inhibition, highlighting TNF-α as a critical regulator of platelet metabolism and function. This study provides potentially new insights into inflammation-associated pathologies and suggests autophagy-targeting strategies as potential therapeutic avenues to restore hemostatic balance.
Authors
Guadalupe Rojas-Sanchez, Jorge Calzada-Martinez, Brandon McMahon, Aaron C. Petrey, Gabriela Dveksler, Gerardo P. Espino-Solis, Orlando Esparza, Giovanny Hernandez, Dennis Le, Eric P. Wartchow, Ken Jones, Lucas H. Ting, Catherine Jankowski, Marguerite R. Kelher, Marilyn Manco-Johnson, Marie L. Feser, Kevin D. Deane, Travis Nemkov, Angelo D’Alessandro, Andrew Thorburn, Paola Maycotte, José A. López, Pavel Davizon-Castillo
Abstract
Psoriatic arthritis (PsA) is a multifaceted, chronic inflammatory disease affecting the skin, joints, and entheses, and it is a major comorbidity of psoriasis. Most patients with PsA present with psoriasis before articular involvement; however, the molecular and cellular mechanisms underlying the link between cutaneous psoriasis and PsA are poorly understood. Here, we found that epidermis-specific SPRY1-deficient mice spontaneously developed PsA-like inflammation involving both the skin and joints. Excessive CXCL10 was secreted by SPRY1-deficient epidermal keratinocytes through enhanced activation of JAK1/2/STAT1 signaling, and CXCL10 blockade attenuated PsA-like inflammation. Of note, CXCL10 was found to bind to CD14, but not CXCR3, to promote the TNF-α production of periarticular CD14hi macrophages via PI3K/AKT and NF-κB signaling pathways. Collectively, this study reveals that SPRY1 deficiency in the epidermis is sufficient to drive both skin and joint inflammation, and it identifies keratinocyte-derived CXCL10 and periarticular CD14hi macrophages as critical links in the skin-joint crosstalk leading to PsA. This keratinocyte SPRY1/CXCL10/periarticular CD14hi macrophage/TNF-α axis provides valuable insights into the mechanisms underlying the transition from psoriasis to PsA and suggests potential therapeutic targets for preventing this progression.
Authors
Fan Xu, Ying-Zhe Cui, Xing-Yu Yang, Yu-Xin Zheng, Xi-Bei Chen, Hao Zhou, Zhao-Yuan Wang, Yuan Zhou, Yi Lu, Ying-Ying Li, Li-Ran Ye, Ni-Chang Fu, Si-Qi Chen, Xue-Yan Chen, Min Zheng, Yong Yang, Xiao-Yong Man
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ISSN: 0021-9738 (print), 1558-8238 (online)