Immunology
Abstract
The NF-κB signaling pathway coordinates inflammation, cell survival, and proliferation, while restraining excessive cell death to maintain immune homeostasis. Truncating mutations in RELA, encoding the NF-κB subunit p65, have been linked to autoinflammation and autoimmunity, but the underlying mechanisms remain incompletely defined. We investigated six patients from five unrelated families carrying previously unreported heterozygous truncating RELA variants. Despite reduced p65 expression, patients exhibited a broad spectrum of inflammatory manifestations alongside elevated baseline and stimulus-induced pro-inflammatory cytokines. Functional analyses in patient-derived cells and mutant RELA knock-in models showed that upstream NF-κB signaling was intact, but induction of inhibitory regulators such as IκBα and A20 was impaired. This defective feedback control shifted immune homeostasis toward amplified inflammatory responses that depended on the residual activity of the remaining functional RELA allele. Single-cell transcriptomics revealed distinct cell type-specific consequences: monocytes displayed constitutive type I interferon and NF-κB activation, B cells retained partial compensatory signaling, whereas T and NK cells exhibited transcriptional signatures of cell death pathways. Patient fibroblasts and mutant RELA knock-in cells further confirmed enhanced TNF-induced inflammatory gene expression and hypersensitivity to apoptosis and necroptosis. These findings establish RELA haploinsufficiency as a cause of systemic immune dysregulation, and link defective NF-κB feedback control to unchecked inflammation and inflammatory cell death.
Authors
Nadja Lucas, Sophia Weidler, Antonia A. Eicher, Baerbel Keller, Özlem Satirer, Adam Desrochers, Timothy J.S. Ramnarine, Mohammad Mokhtari, Sophie Elstner, Timmy Strauss, Simon W. Mages, Arek Kendirli, Oana Cristina Buzoianu, Tobias B. Haack, Lina Igel, Tim Niehues, Sandra von Hardenberg, Maria Fasshauer, Rami Abou Jamra, Hagen Ott, Ulrike Hüffmeier, Catharina Schütz, Marisa Bijwaard, Susan Wagner, Paulina Switala, Sarah Koss, Jurek Schultz, Stefanie Kretschmer, Jasmin Kümmerle-Deschner, Christine Wolf, Johanna Klughammer, Min Ae Lee-Kirsch
Abstract
Authors
Yudai Miyashita, Taisuke Kaiho, Yuriko Yagi, Taichi Nagano, Xin Wu, Yuanqing Yan, Haiying Sun, Carl Atkinson, GR Scott Budinger, Ankit Bharat, Chitaru Kurihara
Abstract
BACKGROUND Acute interstitial nephritis (AIN) is a common cause of acute kidney injury (AKI), but the diagnosis may be missed as kidney biopsies are rarely obtained when acute tubular injury (ATI) is suspected.METHODS The Kidney Precision Medicine Project is a cohort study that obtains kidney biopsies from individuals with AKI, which undergo pathologic and molecular interrogation. We compared ATI and AIN cases among the first 60 AKI participants.RESULTS On clinicopathologic adjudication, 30 patients (50%) had a primary adjudicated diagnosis of ATI, 13 (22%) patients had AIN, 9 (15%) had diabetic nephropathy, and 3 (5%) had other conditions. There were increased interstitial white blood cells and tubulitis (P < 0.05 for both) in AIN compared with ATI. Prior to biopsy, the treating clinician suspected ATI in 83% of the cases with adjudicated ATI, while the treating clinician suspected AIN in 54% of the cases with AIN. Tissue transcriptomic signatures showed enrichment of proinflammatory signaling and increased expression of CXCL9, a chemokine induced by IFN-γ, in myeloid cells of participants with AIN. CXCL9 localized to inflammatory infiltration in spatial transcriptomic data.CONCLUSION Adjudication of kidney biopsies revealed distinct pathologic and molecular profiles between ATI and AIN. Kidney biopsy should be considered more frequently in AKI, as AIN is clinically underrecognized.TRIAL REGISTRATION ClinicalTrials.gov NCT04334707.FUNDING National Institute of Diabetes and Digestive and Kidney Diseases grants U01DK133081, U01DK133091, U01DK133092, U01DK133093, U01DK133095, U01DK133097, U01DK114866, U01DK114908, U01DK133090, U01DK133113, U01DK133766, U01DK133768, U01DK114907, U01DK114920, U01DK114923, U01DK114933, U24DK114886, UH3DK114926, UH3DK114861, UH3DK114915, and UH3DK114937.
Authors
Jennifer A. Schaub, Rajasree Menon, Ricardo Melo Ferreira, Elizabeth Kiernan, Insa M. Schmidt, Christine P. Limonte, Soumya Yennapureddy, Ying-Hua Cheng, Leal Herlitz, Avi Z. Rosenberg, Joel M. Henderson, Kelly D. Smith, Jeffrey B. Hodgin, Edgar Otto, Gilbert W. Moeckel, Lloyd G. Cantley, Suman Setty, Ulysses G.J. Balis, Dawit Demeke, Agnes B. Fogo, Andrew S. Bomback, Vivette D. D’Agati, Isaac E. Stillman, Jose R. Torrealba, Allen R. Hendricks, Erika Bracamonte, Vanessa Moreno, Pavan Bhatraju, Amy K. Mottl, Frank C. Brosius, Bijin Thajudeen, Steven G. Coca, Paul M. Palevsky, Parmjeet S. Randhawa, Raghavan Murugan, Laura Barisoni, Charles E. Alpers, Steven Menez, F. Perry Wilson, Dennis G. Moledina, Michael T. Eadon, Matthias Kretzler, Jonathan Himmelfarb, Chirag R. Parikh, the Kidney Precision Medicine Project
Abstract
Obstructive nephropathy is a significant and preventable contributor to chronic kidney disease, yet no disease-modifying anti-fibrotic agents are currently available.We hypothesized that interferon regulatory factor 5 (IRF5) functions as a macrophage transcriptional regulator that directly transactivates matrix metalloproteinase 9 (MMP9) to initiate early extracellular matrix (ECM) remodeling. Analysis of 30 human obstructive nephropathy biopsy specimens demonstrated that IRF5+CD68+ macrophage density increased progressively with fibrosis severity and correlated significantly with α-smooth muscle actin (α-SMA) positive areas. In the murine unilateral ureteral obstruction (UUO) model, both global and myeloid-specific Irf5 deletion significantly attenuated collagen deposition, immune cell infiltration, and fibrotic gene expression compared with wild-type controls. Cleavage under targets and tagmentation (CUT&Tag) analysis demonstrated that IRF5 directly binds the Mmp9 enhancer region and increases chromatin accessibility. Consequently, myeloid-specific Irf5 knockout significantly reduced Mmp9 mRNA and MMP9 protein levels. Pharmacological inhibition using the IRF5 inhibitor N5-1 mitigated established fibrosis, down-regulated α-SMA and MMP9 expression, and reduced CD68+ macrophage infiltration. These findings identify the IRF5-MMP9 axis as a therapeutically targetable pathway driving macrophage-mediated ECM expansion and provide pre-clinical evidence supporting IRF5 inhibition as a potential treatment strategy for patients with obstructive nephropathy.
Authors
Jia Wei, Gengyu Du, Zixia Li, Min Yang, Ting Chen, Zihao Xu, Zhen Yuan, Yidan Zheng, Xiang Yan
Abstract
Natural killer (NK) cells undergo stepwise differentiation from multipotent progenitors within secondary lymphoid tissues. Despite the central importance of the tissue microenvironment in their development, little is known about cell-cell interactions that regulate human NK cell trafficking and maturation. Here, we identify the chemokine receptor CXCR4 and its ligand CXCL12 as regulators of stromal-NK cell interactions required for NK cell maturation. We demonstrate that CXCR4 is expressed throughout human NK cell development in peripheral blood and tonsil, and CXCL12 is enriched in stromal niches containing developing NK cells. Pharmacologic blockade or genetic disruption of CXCR4 resulted in diminished adhesion to integrin ligands, and high-resolution imaging demonstrated crosstalk between CXCR4 and integrins, providing a mechanistic basis for chemokine-dependent modulation of adhesion. Further, CXCR4 blockade resulted in altered contact-dependent motility on stromal cells and integrin ligands, with decreased stable stromal engagement and increased cell speed. Consistent with a requirement for these interactions, treatment with the CXCR4 antagonist plerixafor (AMD3100) impaired NK cell generation from CD34+ precursors. Analysis of NK cells from WHIM syndrome patients with CXCR4 gain-of-function mutations treated with plerixafor revealed similar defects in migration and adhesion, supporting the in-vivo relevance of CXCR4-dependent regulation of NK cell adhesion and motility.
Authors
Shira E. Eisman, Francesca E. Grossberg, Batya S. Koenigsberg, David H. McDermott, Frédérique van den Haak, Luis A. Pedroza, Everardo Hegewisch-Solloa, Philip M. Murphy, Emily M. Mace
Abstract
Type 2 (T2) immune cells dominate the airways of mild-moderate asthma (MMA) patients with a more complex Type 1 (T1)-T2 mixed immune response evident in treatment-refractory severe asthma (SA). We hypothesized that comparing the transcriptomes of the airway epithelium of SA and MMA patients would reveal molecular signatures associated with more severe disease in the context of a complex immune response. Using our novel interpretable machine learning tool, SLIDE, meaningful latent factors (context-specific gene co-expression networks) were revealed that distinguished SA from MMA. Unexpectedly, an aberrant high expression of normally host-protective, membrane-tethered and IFN-inducible mucins, MUC1 and MUC4, was identified in SA. Gene networks in the significant latent factors discriminating SA from MMA corresponded to enrichment of a keratinization program in SA airways. Keratinization was marked by increased expression of the stress keratin KRT16, signifying squamous metaplasia suggesting adaptive reprogramming of the airway epithelium in response to chronic stress. These mucins and KRT16 were inversely associated with lung function in two separate asthma cohorts. Imaging of endobronchial biopsies revealed significantly higher KRT16 protein expression in SA compared to MMA that strongly correlated with MUC1 protein expression. Our study identifies dysregulated host-protective and maladaptive repair responses in SA distinguishing from MMA.
Authors
Sagar L. Kale, Augusta M. Vincent, Mark A. Ross, Isha Mehta, Michael J. Calderon, Richard P. Ramonell, Himanshu Setya, Jessica C. McCreary-Partyka, Huijuan Yuan, Stephanie A. Christenson, Prescott G. Woodruff, Mario Castro, Kaharu Sumino, Nizar N. Jarjour, Loren C. Denlinger, Benjamin Gaston, Eugene R. Bleecker, Deborah A. Meyers, Wendy C. Moore, Elliot Israel, Bruce D. Levy, David Mauger, Serpil Erzurum, Anthony Newbrough, Taylor J. Nee, Prabir Ray, Claudette M. St. Croix, Sally E. Wenzel, Jishnu Das, Anuradha Ray, Marc C. Gauthier
Abstract
Polycystic kidney disease (PKD) arises from mutations in cilia-associated genes, such as PKD1 and PKD2, expressed in renal epithelial cells, leading to progressive kidney dysfunction and end-stage kidney disease (ESKD). PKD patients exhibit significant heterogeneity in disease progression, largely due to genetic and environmental modifiers. Like patients, mouse models of PKD also exhibit significant heterogeneity with regards to the gene mutated, age of disease onset, and rate of disease progression. To elucidate the cellular and molecular consequences of these variables, we constructed an integrated single-cell RNA sequencing atlas across mouse models of PKD, mapping changes in cell type composition, gene expression, and intercellular signaling networks across the whole atlas and within individual models. Across models, single cell RNA sequencing (scRNAseq) data revealed increased Spp1 (osteopontin) expression and signaling from PKD-enriched clusters. Global deletion of Spp1 in Pkd1RC/RC mice resulted in a modest reduction in cyst severity and improved kidney function. From these studies, we created a freely available, searchable website (https://bmblx.bmi.osumc.edu/scPKD/) that can be used to identify cross- and intra-model changes in gene expression, guiding researchers to new therapeutic targets for treating PKD.
Authors
Sarah J. Miller, Hua Zhong, Weidong Wu, Audrey M. Cordova, Morgan E. Yashchenko, Alex Yashchenko, Zhang Li, Daniyal J. Jafree, Chelsea N. Zimmerman, Christa I. DeVette, Vicki Do, Maya E. Hignite, Yohan Park, Fariha Nusrat, Bibi Maryam, Sizhao Lu, Xiaoyan Li, Jenny R. Gipson, Xiaogang Li, David A. Long, Mary C.M. Weiser-Evans, Bradley K. Yoder, Benjamin D. Cowley, Jr., Katharina Hopp, Jason R. Stubbs, Qin Ma, Anjun Ma, Kurt A. Zimmerman
Abstract
Schistosomiasis is a common cause of pulmonary hypertension (PH) worldwide. It is known that adaptive immunity and specifically CD4 T cells are necessary for experimental disease pathogenesis. The lectin complement system is activated in those infected with schistosomiasis. We tested the hypothesis that lectin complement promotes Th2 CD4 T cell activation, leading to PH in a schistosomiasis exposure model. Wildtype and transgenic mice lacking mannose binding lectin (MBL), and bone marrow chimeras, were experimentally exposed to Schistosoma mansoni eggs. PH severity was assessed by hemodynamics and vascular remodeling, and CD4 T cell density and phenotype was assessed by flow cytometry. Wildtype recipients of MBL knockout bone marrow (BM) were protected from Schistosoma-induced PH. The protection from PH was associated with fewer Th2 CD4 T cells. In wildtype mice exposed to Schistosoma, CD4 T cells expression of MBL increased. MBL-deficient CD4 T cells had a suppressed Th2 phenotype when exposed to Schistosoma antigens. Mice with deficiency of C4, which functions downstream of MBL in the lectin complement pathway, were not protected from Schistosoma-PH. Mice lacking MBL were not protected from PH caused by hypoxia exposure. MBL in CD4 T cells promotes Schistosoma-induced PH.
Authors
Claudia Mickael, Dara C. Fonseca Balladares, Rahul Kumar, Michael H. Lee, Kevin Nolan, Linda Sanders, Katie J. Tuscan, Ramraj Prasad, Pilar Londono, Fernanda P. Oliveira, Kennedi B. Pyper, Ari B. Molofsky, Rubin M. Tuder, Kurt R. Stenmark, Brian B. Graham
Abstract
The precise mechanisms underlying the pathogenesis of idiopathic inflammatory myopathy (IIM) remain undefined. However, there has been increasing recognition that tissue-resident memory cells (TRMs) play an important role in the pathogenesis of systemic autoimmune disease. In IIM, TRM-associated transcriptional signatures have been reported, but on a very limited basis. By using multimodal single-cell RNA sequencing analysis in our established murine model of histidyl-tRNA synthetase (HRS)-induced myositis, we identified a prominent population of CD4+ TRMs in inflamed skeletal muscle. Muscle CD4+ TRMs exhibited high expression of genes encoding Cd69, Cxcr6, Runx3, and Prdm1, alongside low expression of Klf2, Ccr7, Sell, S1pr1, and Tcf7 — a profile that is generally consistent with previous reports of TRM gene signature and that we validate through comparison to transcriptomic profiles of human muscle tissue. Detailed pathway analysis in our model indicates that muscle CD4+ TRMs contribute to innate immune regulatory pathways enriched for TNF and IFN-γ signaling. Furthermore, analysis of TCR clonotype distribution and CDR3 sequence similarity revealed pronounced clonal expansion of CD4+ TRMs relative to other T-cell subsets — a pattern that remained stable from 2 to 6 weeks post-immunization. Collectively, these results suggest a potential role for CD4+ TRMs in the pathogenesis of autoimmune myositis.
Authors
Decheng Li, Daniel P. Reay, Iago Pinal-Fernandez, Maria Casal-Dominguez, Andrew L. Mammen, Sarah L. Gaffen, Timothy B. Oriss, Dana P. Ascherman
Abstract
Neonatal sepsis is a predominant cause of neonatal mortality and long-term morbidity which severely effects preterm and low birth weight newborns. Antibiotic resistance and long-term developmental issues associated with neonatal sepsis necessitates finding new and improved treatment options. Interleukin-27 (IL-27) has diverse influences on the immune response, is elevated during the neonatal period compared to adulthood, and continues to rise further during infection. Elevated levels of IL-27 early in life predispose the host to impaired control of the pathogen burden and increased mortality. This study explored the therapeutic potential of IL-27p28 antibody administration to improve treatment outcomes during murine neonatal sepsis. Sepsis was induced by subcutaneous inoculation of K1-encapsulated Escherichia coli and the neonatal pups were rescued with IL-27p28 monoclonal antibody. Pups that received prophylactic antibody prior to the infection demonstrated superior bacterial clearance and significant weight gain compared to controls during infection. The combination of subclinical dose of gentamicin and IL-27p28 antibody administered 2h post-infection, significantly improved bacterial clearance, glucose homeostasis, with reduced serum levels of IL-6 and TNF-α, vital organ damage and significantly improved the survival rate of infected pups compared to gentamicin alone. These findings suggest that IL-27p28 antagonization represents a promising therapeutic tool for treatment of neonatal sepsis.
Authors
Madhavi Annamanedi, Jessica M. Povroznik, Samantha Arevalo-Marcano, Cory M. Robinson
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