Immunology
Abstract
Targeted injury to the biliary epithelium and impaired bile flow are central mechanisms underlying childhood cholangiopathies. In biliary atresia (BA), immune-mediated cholangiocyte injury drives progressive bile duct obstruction, yet epithelial-intrinsic programs regulating injury susceptibility remain incompletely defined. Here, we modeled virus-epithelium interactions using rhesus rotavirus (RRV) infection of human liver-derived cholangiocyte organoids from normal donors (NCO) and infants with BA at diagnosis (BACO-Dx) or transplantation (BACO-Tx). Compared with NCO, BA organoids displayed baseline defects in tight junction architecture and barrier function, with prominent epithelial disruption and apoptosis following RRV exposure. Transcriptomic profiling revealed that while NCO and BACO-Dx mounted predominantly interferon-associated antiviral responses, BACO-Tx exhibited an expanded inflammatory program characterized by enrichment of NF-κB (RELA/NFKB1) regulatory network at baseline and amplified by infection. Inhibition of NF-κB signaling with the hydrogen sulfide donor GYY4137 restored organoid growth, improved tight junction organization, reduced permeability, and attenuated RRV-induced apoptosis. In the murine BA model, GYY4137 improved disease severity, preserved bile duct architecture, and protected epithelial junctional integrity while limiting cholangiocyte apoptosis. These findings identify an epithelial NF-κB-predominant program as a key determinant of intrinsic susceptibility to viral injury in BA and support targeting cholangiocyte NF-κB signaling to suppress disease progression.
Authors
Wenqi Li, Ashley Fonseca-Mejia, Reena Mourya, Pavithra Sudhakara, Pranavkumar Shivakumar, Jorge A. Bezerra
Abstract
Bone metastases are a frequent complication of breast cancer, leading to reduced quality of life and increased morbidity. By intratibially injecting PyMT breast cancer cells in mice, we showed that the presence in the gut microbiome of segmented filamentous bacteria (SFB), a taxon that induces IL-17–producing Th17 cells and TNF-α (TNF)–producing T cells (TNF+ T cells), accelerated intraosseous tumor growth. SFB increased the activity of parathyroid hormone–related protein (PTHrP), a known driver of breast cancer bone metastasis produced by breast cancer cells. SFB promoted the PTHrP-induced expansion of intestinal Th17 cells and TNF+ T cells, their migration to bone marrow (BM) in tumor-bearing bones, and the BM expression of TNF, IL-17, and RANKL, cytokines that promote bone resorption. Demonstrating the functional relevance of IL-17 and TNF, silencing of either IL-17 or TNF blunted the growth of bone lesions in SFB+ mice. Thus, the abundance of SFB in the microbiome of mice and of SFB-like taxa in humans may determine the potency of PTHrP and the rate of growth of bone metastasis in breast cancer. Targeting the gut microbiota may represent a novel therapeutic strategy for breast cancer bone metastasis.
Authors
Nand K. Roy, Subhashis Pal, Hamid Y. Dar, Sanchiti Patil, M. Neale Weitzmann, Roberto Pacifici
Abstract
Castleman disease (CD) is an inflammatory disorder characterized by lymphadenopathy with distinctive histologic features, yet its pathophysiology remains poorly understood. This delays diagnoses and limits treatments, leading to additional morbidity and mortality. We used single- cell and spatial transcriptomics to characterize lymph nodes from unicentric CD (UCD) compared with non-specific inflammatory lymphadenopathies. While hematopoietic cells showed few compositional or transcriptional differences, lymph node stromal cells exhibited marked alterations in UCD, most notably an increased abundance of vascular smooth muscle cells (VSMCs) and broadly increased stromal signaling activity. A generalized linear model distinguished histologically indeterminate lymph nodes resembling UCD from non-specific inflammation most accurately using stromal rather than hematopoietic cell composition. Immunohistochemical staining for the VSMC marker CD146 (Melanoma Cell Adhesion Molecule, MCAM) further discriminated UCD from other causes of lymphadenopathy. Together, these findings identify increased VSMC abundance as a hallmark of UCD and suggest that this stromal signature can be leveraged to improve pathologic diagnosis and patient stratification.
Authors
Joshua D. Brandstadter, Samuel Meili, Joseph Zinski, Hung-Wei Cheng, Dorottya Laczko, Michael V. Gonzalez, Subin S. George, Megan S Lim, Adam Bagg, Yves Stanossek, Lucas Onder, Mechthild Lϋtge, Angelina De Martin, Bridget Austin, Melanie Mumau, Katherine S. Forsyth, Vinodh Pillai, Antonio Ferreira, Jon C. Aster, Sunita Nasta, Burkhard Ludewig, David C. Fajgenbaum, Ivan Maillard
Abstract
BACKGROUND. Despite the availability of effective vaccines, pneumococcal disease remains a major global health concern. Pneumococcal conjugate vaccines (PCVs) have progressively increased in valency, a change associated with reduced antibody titers against individual polysaccharide antigens. Whether increasing vaccine valency affects B cell responses through antigenic competition remains incompletely understood. We investigated pneumococcal polysaccharide-specific B cell responses in peripheral blood and vaccine draining lymph nodes following vaccination with PCV13. METHODS. Healthy adults (n = 5) received PCV13. Peripheral blood and lymph node fine needle aspirations (FNA) were collected longitudinally at baseline and after vaccination. Pneumococcal polysaccharide-specific B cell responses, polysaccharide-specific antibody responses and opsonophagocytic activity were analyzed in peripheral blood and draining lymph nodes. RESULTS. Antigen-specific memory B cells in peripheral blood expanded rapidly and peaked 2 weeks after vaccination. In contrast, germinal center formation in lymph nodes was delayed, peaking at 4 weeks. Germinal center B cell responses were dominated by a limited number of polysaccharide specificities, whereas the expansion of memory B cells in peripheral blood was more evenly distributed across specificities. Polysaccharide-specific antibodies followed similar dynamics in plasma and FNA supernatant. CONCLUSION. Adult immune responses to PCV are characterized by robust extrafollicular memory B cell expansion and delayed germinal center responses. The restricted specificity of germinal center B cells provides evidence for antigenic competition during germinal center formation, with potential implications for the design and immunogenicity of multivalent vaccines. TRIAL REGISTRATION. EU CT number 2022-501519-15-00. FUNDING. LUMC PhD Fellowship, ZonMW Vidi and ZonMW Clinical Fellowship.
Authors
David W. de Vos, Marina Johnson, Dennis Hoving, Giovanni E. Loe-Sack-Sioe, Catherina Kienhuis, Els L. van Persijn van Meerten, David Goldblatt, Leo G. Visser, Anna H.E. Roukens, Simon P. Jochems
Abstract
An immunosuppressive, macrophage-rich tumor microenvironment (TME) is a barrier to immunotherapy across many cancers including osteosarcoma, where immunotherapy has largely failed. cGAS-STING agonism has been explored to inflame such tumors, yet the mechanisms of STING-mediated TME remodeling remain poorly understood, especially in sarcomas. Using multi-modal single cell analysis, we show that systemic STING agonism in osteosarcoma triggers a myeloid-predominant inflammatory response and rapid tumor necrosis, followed by a T cell-mediated response, immunologic memory, and long-term cure in some models. Within two hours of treatment, STING agonism induces pro-inflammatory interferon programs in tumor-associated macrophages and monocytes, with additional contributions from endothelial cells. Efficacy persists in the absence of tumor-intrinsic STING or IFNAR, confirming that the therapeutic axis resides within the host TME rather than the tumor cell compartment. While cGAS-STING is frequently repressed in human osteosarcoma models of aggressive disease, a STING activation gene signature predicts survival in newly diagnosed patients, suggesting that this pathway is engaged during tumor progression. Together, these data identify an opportunity to exploit the myeloid compartment of osteosarcoma with STING pathway therapies, charting a path forward for engaging the TME to secure long term cure in an aggressive malignancy still treated with highly toxic chemotherapy.
Authors
Elizabeth P. Young, Christine A. Johnson, Alex G. Lee, Douglass Morris II, Georgia M. Edmondson, Alfonso G. Ramirez-Ristori, Jessica Tsui, Marcus R. Breese, Juan Antonio Camara Serrano, Courtney R. Schott, Clare L. Abram, Stanley G. Leung, Leanne C. Sayles, Aafrin M. Pettiwala, Vanessa S. Gutierrez Vera, Clifford A. Lowell, Alexis J. Combes, Troy A. McEachron, E. Alejandro Sweet-Cordero
Abstract
Obesity is a chronic progressive disease strongly linked to numerous comorbidities. This is underpinned by a chronic inflammatory environment and significant immune dysregulation. γδ T cells are unconventional T cells that display innate and adaptive characteristics, the predominant one being their independence of MHC restriction. In humans, γδ T cells represent up to 5% of the peripheral blood T cell compartment and are capable of rapidly producing a range of effector cytokines and driving cytotoxic responses. This is critical for protection from both bacterial and viral infections. We investigated circulating γδ T cell metabolic and functional responses in cohorts of people living with obesity (PWO) and people without obesity. We showed that PWO have reduced Vδ2+ T cell frequencies, and their effector responses are diminished following stimulation. We identified that the CD98-LAMTOR5-mTORC1 metabolic axis was critical for functional responses, and demonstrated significant defects in each component of this axis in PWO. Furthermore, STAT5 the initiator of amino acid metabolism was also decreased in PWO. Finally, we showed restoration of this metabolic axis after bariatric surgery, combined with robust improvements in functional responses. Collectively, our data highlighted that obesity drives a reversible dysregulation of Vδ2+ T cells by disrupting cellular metabolism.
Authors
Ciara L. Flynn, Eimear K. Ryan, Cian Davis, Czara A. Kennedy, Katherine G. Egan, Aimee Brennan, Philip Mc Entee, Kirstan Murphy, Niamh Lynam-Lennon, Linda V. Sinclair, Nicholas Jones, Donal O'Shea, Helen M. Heneghan, Andrew E. Hogan
Abstract
The inflammasome is an innate immune complex responsible for aberrant interleukin-1β (IL-1β) signaling in numerous chronic inflammatory diseases, including gout and Alzheimer’s disease. The inflammasome is composed of several proteins, including the apoptosis-associated speck-like protein containing a caspase activation and recruitment domain (ASC). We developed vaccines targeting various regions of ASC using a Qβ virus-like particle (VLP) platform to assess the efficacy of anti-ASC antibodies for inhibiting inflammasome activity. Using a mouse model of gout, we assessed seven vaccines targeting mouse ASC for their ability to reduce inflammasome activation and neutrophil responses. Three vaccines targeting different regions of the ASC protein (pyrin domain, linker region, and the caspase activation and recruitment domain) successfully targeted ASC, reduced IL-1β, and reduced neutrophil activation. Combining these three vaccines into one cocktail vaccine yielded similar efficacy in the gout model with a favorable safety profile. The combined ASC vaccine also reduced inflammasome levels and pathologically phosphorylated tau in a transgenic mouse model of tauopathy and did not significantly impair host immune responses to bacterial or viral infections. Thus, Qβ-VLP vaccines against ASC can neutralize pathological inflammasome activity across multiple inflammatory disease models.
Authors
Jonathan Hulse, Zachary Villaseñor, Samuel Kress, Kathryn Sánchez, Julianne Peabody, Kimberly A. Morrissey, Alan McNolty, Benjamin Lantz, Laura Gonzalez Bosc, Judy L. Cannon, Seth Daly, Bryce Chackerian, Kiran Bhaskar
Abstract
Hemophagocytic Lymphohistiocytosis (HLH) is a hyperinflammatory syndrome with multiple contributors, often including an infectious trigger. The Macrophage Activation Syndrome (MAS) subtype is linked to marked IL-18 excess, cytotoxic T-lymphocyte (CTL) activation, and natural killer (NK) cell abnormalities. We asked how excess IL-18 shapes NK and CTL responses to viral challenge. Mice with chronic IL-18 overproduction (Il18tg), showed baseline NK-cytopenia and CTL activation resembling MAS-susceptible patients. NK transcriptomes reflected IL-18/IFNg-axis activation and cell cycle upregulation. LCMV infection of Il18tg mice causes HLH/MAS without affecting viral control, but is not a significant NK challenge. Early after infection with NK-dependent mousepox, Il18tg NKs failed to activate appropriately, but CTLs quickly hyperactivated and mousepox control remained intact. Mousepox-infected Il18tg mice then developed signs of HLH/MAS including hepatosplenic necrosis. Their viral control was impaired, possibly because they failed to expand mousepox-specific CTLs. Il18bpKO mice, despite more normal resting lymphocytes, succumbed similarly to viremic HLH/MAS. Transfer of pre-activated NKs into Il18tg mice partially rescued virus-specific CTL responses, viral control, and survival. Thus, excess IL-18 contributes to HLH/MAS via disparate effects on CTL and NK cells, demonstrating a novel, context-specific NK immunodeficiency and highlighting how subtle host-pathogen interactions can affect the mechanisms and treatment rationale of life-threatening HLH/MAS.
Authors
Jemy A. Varghese, Leonardo Huang, Stephen D. Carro, Emily E. Landy, Anastasia Frank-Kamenetskii, Hannah Klinghoffer, Jeremy A. Morrissette, Vinh Dang, Laurence C. Eisenlohr, Scott W. Canna
Abstract
Glioblastoma (GBM) is a lethal brain tumor with a 95% five-year mortality rate, and remains a major unmet clinical need. An innovative approach to target GBM is administration of chimeric antigen receptor (CAR) T cells. In this study we identified B7-H3 as a favorable target antigen for CAR T cell therapy of GBM and developed a B7-H3 targeting CAR T cell. This CAR demonstrates robust, antigen-specific cytolysis and cytokine production, low tonic signaling, and preservation of a stem/naïve cell phenotype. Using orthotopic xenograft models of GBM we show that a single intravenous administration of this B7-H3 targeted CAR confers tumor control, and long-term survival. We identified upregulation of T cell inhibitory ligands PD-L1 and PD-L2 as a mechanism of resistance, and modified our B7-H3 targeting CAR vector to include a secreted a PD-1 blocking scFv. We further demonstrate that concomitant PD-1 blockade by the secreted PD-1 blocking scFv augments the antitumor capabilities of B7-H3-targeting CAR T cells through increased intratumoral infiltration by the CAR T cells and improved effector function. These data demonstrate B7-H3 targeting CAR T cells with concomitant PD-1 blockade is a safe and efficient method for improving the antitumor capacity of CAR T cells for GBM.
Authors
Jonathan F. Khan, Parwiz Abrahimi, Winson Cai, Lauren Dong, Kenny Kwok-Hei Yu, Svena Verma, Yacine Marouf, Sadna Budhu, Tara Pal Chaudhuri, Valeria Estrada Navarro, Mamadou A. Bah, Kelsey Hopland, Yanhong Yang, Terence J. Purdon, Ileana C. Miranda, Viviane Tabar, Jedd D. Wolchok, Taha Merghoub, Renier J. Brentjens
Abstract
Authors
Rocio J. Jimenez-Valdes, Quoc Vo, Alison Morris, Chad Steele, Seyed Mehdi Nouraie, Jonathan K. Alder, Kambez H. Benam
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