Research Article
Abstract
Coinhibitory receptors function as central modulators of the immune response to resolve T effector activation and/or to sustain immune homeostasis. Here, using humanized SCID mice, we found that neuropilin–2 (NRP2) is inducible on late effector and exhausted subsets of human CD4+ T cells and that it is coexpressed with established coinhibitory molecules including PD-1, CTLA4, TIGIT, LAG3, and TIM3. In murine models, we also found that NRP2 is expressed on effector memory CD4+ T cells with an exhausted phenotype and that it functions as a key coinhibitory molecule. Knockout (KO) of NRP2 resulted in hyperactive CD4+ T cell responses and enhanced inflammation in delayed-type hypersensitivity and transplantation models. After cardiac transplantation, allograft rejection and graft failure were accelerated in global as well as CD4+ T cell–specific KO recipients, and enhanced alloimmunity was dependent on NRP2 expression on CD4+ T effectors but not on CD4+Foxp3+ Tregs. Also, KO Tregs were found to be as efficient as WT cells in the suppression of effector responses in vitro and in vivo. These collective findings identify NRP2 as a potentially novel coinhibitory receptor and demonstrate that its expression on CD4+ T effector cells is of great functional importance in immunity.
Authors
Johannes Wedel, Nora Kochupurakkal, Sek Won Kong, Sayantan Bose, Ji-Won Lee, Madeline Maslyar, Bayan Alsairafi, Kayla MacLeod, Kaifeng Liu, Hengcheng Zhang, Masaki Komatsu, Hironao Nakayama, Diane R. Bielenberg, David M. Briscoe
Abstract
Chagas disease, caused by Trypanosoma cruzi, is endemic to Latin America and is characterized by chronic inflammation of cardiac tissues due to parasite persistence. Hypoxia within infected tissues may trigger the stabilization of HIF-1 and be linked to ATP release. Extracellular ATP exhibits microbicidal effects but is scavenged by CD39 and CD73 ectonucleotidases, which ultimately generate adenosine (ADO), a potent immunosuppressor. Here, we comprehensively study the importance of HIF-1 stabilization and the CD39/CD73/ADO axis, on CD4+ T cells with the cytotoxic phenotype, in facilitating the persistence of T. cruzi. Myocardial infection induces prominent areas of hypoxia, which is concomitant with HIF-1α stabilization in T cells and linked to early expansion of CD39+CD73+CD4+ T cell infiltrating population. Functional assays further demonstrate that HIF-1 stabilization and CD73 activity are associated with impaired CD4+ T cell cytotoxic potential. RNA-Seq analysis reveals that HIF-1 and purinergic signaling pathways are overrepresented in cardiac tissues of patients with end-stage Chagas disease. The findings highlight a major effect of purinergic signaling on CD4+ T cells with potential cytotoxic capacity in the setting of T. cruzi infection and have translational implications for therapy.
Authors
Gastón Bergero, Yanina L. Mazzocco, Sebastian Del Rosso, Ruining Liu, Zoé M. Cejas Gallardo, Simon C. Robson, Martin Rottenberg, Maria P. Aoki
Abstract
Sustaining the strong rhythmic interactions between cellular adaptations and environmental cues has been posited as essential for preserving the physiological and behavioral alignment of an organism to the proper phase of the daily light/dark (LD) cycle. Here, we demonstrate that mitochondria and synaptic input organization of suprachiasmatic (SCN) vasoactive intestinal peptide–expressing (VIP-expressing) neurons showed circadian rhythmicity. Perturbed mitochondrial dynamics achieved by conditional ablation of the fusogenic protein mitofusin 2 (Mfn2) in VIP neurons caused disrupted circadian oscillation in mitochondria and synapses in SCN VIP neurons, leading to desynchronization of entrainment to the LD cycle in Mfn2-deficient mice that resulted in an advanced phase angle of their locomotor activity onset, alterations in core body temperature, and sleep-wake amount and architecture. Our data provide direct evidence of circadian SCN clock machinery dependence on high-performance, Mfn2-regulated mitochondrial dynamics in VIP neurons for maintaining the coherence in daily biological rhythms of the mammalian organism.
Authors
Milan Stoiljkovic, Jae Eun Song, Hee-kyung Hong, Heiko Endle, Luis Varela, Jonatas Catarino, Xiao-Bing Gao, Zong-Wu Liu, Peter Sotonyi, Sabrina Diano, Jonathan Cedernaes, Joseph T. Bass, Tamas L. Horvath
Abstract
In preclinical mouse models of triple-negative breast cancer (TNBC), we show that a combination of chemotherapy with cisplatin (CDDP) and eribulin (Eri) was additive from an immunological point of view and was accompanied by the induction of an intratumoral immune and inflammatory response favored by the immunogenic cell death induced by CDDP, as well as by the vascular and tumor stromal remodeling induced by each chemotherapy. Unexpectedly, despite the favorable immune context created by this immunomodulatory chemotherapy combination, our models remained refractory to the addition of anti–PD-L1 immunotherapy. These surprising observations led us to discover that CDDP chemotherapy was simultaneously responsible for the production of TGF-β by several populations of cells present in tumors, which favored the emergence of different subpopulations of immune cells and cancer-associated fibroblasts characterized by immunosuppressive properties. Accordingly, co-treatment with anti–TGF-β restored the immunological synergy between this immunogenic doublet of chemotherapy and anti–PD-L1 in a CD8-dependent manner. Translational studies revealed the unfavorable prognostic effect of the TGF-β pathway on the immune response in human TNBC, as well as the ability of CDDP to induce this cytokine also in human TNBC cell lines, thus highlighting the clinical relevance of targeting TGF-β in the context of human TNBC treated with chemoimmunotherapy.
Authors
Laura Kalfeist, Fanny Ledys, Stacy Petit, Cyriane Poirrier, Samia Kada Mohammed, Loïck Galland, Valentin Derangère, Alis Ilie, David Rageot, Romain Aucagne, Pierre-Simon Bellaye, Caroline Truntzer, Marion Thibaudin, Mickaël Rialland, François Ghiringhelli, Emeric Limagne, Sylvain Ladoire
Abstract
Bardet-Biedl syndrome (BBS), a ciliopathy characterized by obesity, hyperphagia, and learning deficits, arises from mutations in Bbs genes. Exacerbated symptoms occur with mutations in genes encoding the BBSome, a complex regulating primary cilia function. We investigated the mechanisms underlying BBS-induced obesity using a Bbs5-knockout (Bbs5–/–) mouse model. Bbs5–/– mice were characterized by hyperphagia, learning deficits, glucose/insulin intolerance, and disrupted metabolic hormones, phenocopying human BBS. White adipose tissue in these mice had a unique immunophenotype, with increased proinflammatory macrophages and dysfunctional Tregs, suggesting a mechanism for adiposity distinct from those of typical obesity models. Additionally, Bbs5–/– mice exhibited pancreatic islet hyperplasia but failed to normalize blood glucose, suggesting defective insulin action. Hypothalamic transcriptomics revealed dysregulation of endocrine signaling pathways, with functional analyses confirming defects in insulin, leptin, and cholecystokinin (CCK) signaling, while glucagon-like peptide-1 receptor (GLP-1R) responsiveness was preserved. Notably, treatment with a GLP-1RA effectively alleviated hyperphagia and body weight gain, improved glucose tolerance, and regulated circulating metabolic hormones in Bbs5–/– mice. This study suggests that Bbs5–/– mice represent a valuable translational model of BBS for understanding pathogenesis and developing better treatments. Our findings highlight the therapeutic potential of GLP-1RAs for managing BBS-associated metabolic dysregulation, indicating that further investigation for clinical application is warranted.
Authors
Arashdeep Singh, Naila Haq, Mingxin Yang, Shelby Luckey, Samira Mansouri, Martha Campbell-Thompson, Lei Jin, Sofia Christou-Savina, Guillaume de Lartigue
Abstract
In the kidney, cells of thick ascending limb of the loop of Henle (TAL) are resistant to ischemic injury, despite high energy demands. This adaptive metabolic response is not fully understood even though the integrity of TAL cells is essential for recovery from acute kidney injury (AKI). TAL cells uniquely express uromodulin, the most abundant protein secreted in healthy urine. Here, we demonstrate that alternative splicing generates a conserved intracellular isoform of uromodulin, which contributes to metabolic adaptation of TAL cells. This splice variant was induced by oxidative stress and was upregulated by AKI that is associated with recovery, but not by severe AKI and chronic kidney disease (CKD). This intracellular variant was targeted to the mitochondria, increased NAD+ and ATP levels, and protected TAL cells from hypoxic injury. Augmentation of this variant using antisense oligonucleotides after severe AKI improved the course of injury. These findings underscore an important role of condition-specific alternative splicing in adaptive energy metabolism to hypoxic stress. Enhancing this protective splice variant in TAL cells could become a therapeutic intervention for AKI.
Authors
Azuma Nanamatsu, George J. Rhodes, Kaice A. LaFavers, Radmila Micanovic, Virginie Lazar, Shehnaz Khan, Daria Barwinska, Shinichi Makino, Amy Zollman, Ying-Hua Cheng, Emma H. Doud, Amber L. Mosley, Matthew J. Repass, Malgorzata M. Kamocka, Aravind Baride, Carrie L. Phillips, Katherine J. Kelly, Michael T. Eadon, Jonathan Himmelfarb, Matthias Kretzler, Robert L. Bacallao, Pierre C. Dagher, Takashi Hato, Tarek M. El-Achkar
Abstract
Patients with systemic lupus erythematosus (SLE) are photosensitive, developing skin inflammation with even ambient ultraviolet radiation (UVR), and this cutaneous photosensitivity can be associated with UVR-induced flares of systemic disease, which can involve increased autoantibodies and further end-organ injury. Mechanistic insight into the link between the skin responses and autoimmunity is limited. Signals from skin are transmitted directly to the immune system via lymphatic vessels, and here we show evidence for potentiation of UVR-induced lymphatic flow dysfunction in SLE patients and murine models. Improving lymphatic flow by manual lymphatic drainage (MLD) or with a transgenic model with increased lymphatic vessels reduces both cutaneous inflammation and lymph node B and T cell responses, and long-term MLD reduces splenomegaly and titers of a number of autoantibodies. Mechanistically, improved flow restrains B cell responses in part by stimulating a lymph node fibroblastic reticular cell-monocyte axis. Our results point to lymphatic modulation of lymph node stromal function as a link between photosensitive skin responses and autoimmunity and as a therapeutic target in lupus, provide insight into mechanisms by which the skin state regulates draining lymph node function, and suggest the possibility of MLD as an accessible and cost-effective adjunct to add to ongoing medical therapies for lupus and related diseases.
Authors
Mir J. Howlader, William G. Ambler, Madhavi Latha S. Chalasani, Aahna Rathod, Ethan S. Seltzer, Ji Hyun Sim, Jinyeon Shin, Noa Schwartz, William D. Shipman III, Dragos C. Dasoveanu, Camila B. Carballo, Ecem Sevim, Salma Siddique, Yurii Chinenov, Scott A. Rodeo, Doruk Erkan, Raghu P. Kataru, Babak J. Mehrara, Theresa T. Lu
Abstract
Diffuse midline gliomas (DMGs) are lethal brain tumors characterized by p53-inactivating mutations and oncohistone H3.3K27M mutations that rewire the cellular response to genotoxic stress. We used RCAS/tv-a retroviruses and Cre recombinase to inactivate p53 and induce native H3.3K27M mutations in a lineage- and spatially directed manner. We generated primary mouse tumors that recapitulated human DMG. Disrupting ataxia-telangiectasia mutated (ATM) kinase enhanced the efficacy of radiation therapy (RT) in murine and patient-derived DMG models and increased survival. Microscopy-based in situ sequencing was used to spatially resolve transcriptional profiles in more than 750,000 single cells with or without ATM disruption and RT, revealing altered immune-neoplastic and endothelial cell interactions after treatment. An allelic series of primary murine DMG models with different p53 mutations confirmed that transactivation-independent p53 activity was a key mediator of radiosensitivity after ATM disruption. We generated primary DMG mouse models and performed deep profiling that revealed mechanisms of response to ATM disruption and RT that can be utilized as a therapeutic strategy.
Authors
Avani Mangoli, Vennesa Valentine, Spencer M. Maingi, Sophie R. Wu, Harrison Q. Liu, Michael Aksu, Vaibhav Jain, Bronwen E. Foreman, Joshua A. Regal, Loren B. Weidenhammer, Connor E. Stewart, Maria E. Guerra Garcia, Emily Hocke, Karen Abramson, Tal Falick Michaeli, Nerissa T. Williams, Lixia Luo, Megan Romero, Katherine Deland, Samantha Gadd, Eita Uchida, Laura Attardi, Kouki Abe, Rintaro Hashizume, David M. Ashley, Oren J. Becher, David G. Kirsch, Simon G. Gregory, Zachary J. Reitman
Abstract
The presence of B cells is essential for the formation of CD8+ T cell memory after infection and vaccination. In this study, we investigated whether B cells influence the programming of naive CD8+ T cells prior to their involvement in an immune response. RNA sequencing indicated that B cells are necessary for sustaining the FOXO1-controlled transcriptional program, which is critical for homeostasis of these T cells. Without an appropriate B cell repertoire, mouse naive CD8+ T cells exhibit a terminal, effector-skewed phenotype, which significantly impacts their response to vaccination. A similar effector-skewed phenotype with reduced FOXO1 expression was observed in naive CD8+ T cells from human patients undergoing B cell–depleting therapies. Furthermore, we show that patients without B cells have a defect in generating long-lived CD8+ T cell memory following COVID vaccination. In summary, we demonstrate that B cells promote the quiescence of naive CD8+ T cells, poising them to become memory cells upon vaccination.
Authors
Cameron Manes, Miguel Guerrero Moreno, Jennifer Cimons, Marc A. D’Antonio, Tonya M. Brunetti, Michael G. Harbell, Sean Selva, Christopher Mizenko, Tyler L. Borko, Erika L. Lasda, Jay R. Hesselberth, Elena W.Y. Hsieh, Michael R. Verneris, Amanda L. Piquet, Laurent Gapin, Ross M. Kedl, Jared Klarquist
Abstract
Autosomal dominant optic atrophy (ADOA), the most prevalent hereditary optic neuropathy, leads to retinal ganglion cell (RGC) degeneration and vision loss. ADOA is primarily caused by mutations in the optic atrophy type 1 (OPA1) gene, which encodes a conserved GTPase important for mitochondrial inner membrane dynamics. To date, the disease mechanism remains unclear, and no therapies are available. We generated a mouse model carrying the pathogenic Opa1R290Q/+ allele that recapitulated key features of human ADOA, including mitochondrial defects, age-related RGC loss, optic nerve degeneration, and reduced RGC functions. We identified sterile alpha and TIR motif containing 1 (SARM1), a neurodegeneration switch, as a key driver of RGC degeneration in these mice. Sarm1 KO nearly completely suppressed all the degeneration phenotypes without reversing mitochondrial fragmentation. Additionally, we show that a portion of SARM1 localized within the mitochondrial intermembrane space. These findings indicated that SARM1 was activated downstream of mitochondrial dysfunction in ADOA, highlighting it as a promising therapeutic target.
Authors
Chen Ding, Papa S. Ndiaye, Sydney R. Campbell, Michelle Y. Fry, Jincheng Gong, Sophia R. Wienbar, Whitney Gibbs, Philippe Morquette, Luke H. Chao, Michael Tri H. Do, Thomas L. Schwarz
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ISSN: 0021-9738 (print), 1558-8238 (online)