Research Article
Abstract
The role of CARD9 in the pathogenesis of various chronic fungal infections has been established; however, the precise mechanisms underlying the pathobiology of these infections remain unclear. We investigated the specific cellular mechanisms by which CARD9 deficiency contributes to the pathogenesis of chronic fungal infections. Using single-cell RNA-seq, we analyzed the immune cell profiles in skin lesions from both murine and human samples. We focused on macrophage differentiation and signaling pathways influenced by CARD9 deficiency. We found that CARD9 deficiency promoted the differentiation of high levels of triggering receptor expressed on myeloid cells 2 (TREM2hi) monocyte–derived macrophages after fungal stimulation, impairing their antifungal functions and inducing exhaustion-like Th1 cells. Mechanistically, NF-κB pathway activation was restricted in CARD9-deficient macrophages, leading to enhanced CREB activation, which, in turn, exerted a positive regulatory effect on Trem2 expression by activating C/EBPβ. Notably, targeting TREM2 enhanced the antifungal immune response in vivo and in vitro, thereby alleviating the severity of CARD9-deficient subcutaneous dematiaceous fungal infection. Our findings highlight the important role of CARD9 in regulating cutaneous antifungal immunity and identify potential targets for immunotherapy in chronic dematiaceous fungal infections.
Authors
Lu Zhang, Zhichun Tang, Yi Zhang, Wenjie Liu, Haitao Jiang, Li Yu, Kexin Lei, Yubo Ma, Yang-Xin Fu, Ruoyu Li, Wenyan Wang, Fan Bai, Xiaowen Wang
Abstract
Older individuals with somatic TP53 mutations manifest clonal hematopoiesis (CH) and are at high risk of developing myeloid neoplasms. However, the underlying mechanisms are not fully understood. Here, we show that inflammatory stress confers a competitive advantage to p53 mutant hematopoietic stem and progenitor cells (HSPCs) by activating the NLRP1 inflammasome and increasing the secretion of pro-inflammatory cytokines such as IL-1β, inhibiting WT HSPC fitness in a paracrine fashion. During aging, mutant p53 dysregulates pre-mRNA splicing in HSPCs, leading to enhanced NF-κB activation and increased secretion of IL-1β and IL-6, thereby generating a chronic inflammatory bone marrow microenvironment. Furthermore, blocking IL-1β with IL-1β neutralizing antibody or inhibiting IL-1β secretion using gasdermin D inhibitor decreases the fitness of p53 mutant HSPCs. Thus, our findings uncover an important role for mutant p53 in regulating inflammatory signaling in CH and suggest that curbing inflammation may prevent the progression of TP53-mutant CH to myeloid neoplasms.
Authors
Sisi Chen, Sergio Barajas, Sasidhar Vemula, Yuxia Yang, Ed Simpson, Hongyu Gao, Rudong Li, Farzaneh Behzadnia, Sarah C. Nabinger, David A. Schmitz, Hongxia Chen, Wenjie Cai, Shiyu Xiao, Ruyue Luo, Mohammed Abdullahel Amin, Maegan L. Capitano, James P. Ropa, Aidan Fahey, Shuyi Zhou, Tiffany M. Mays, Magdalena Sotelo, Hao Pan, Sophie K. Hu, Sophia Veranga, Moiez Ali, Maria Shumilina, Reuben Kapur, Kehan Ren, Yuzhi Jia, Huiping Liu, Irum Khan, Yasmin Abaza, Jessica K. Altman, Elizabeth A. Eklund, Lucy A. Godley, Christine R. Zhang, Peng Ji, Seth L. Masters, Ben A. Croker, H. Scott Boswell, George E. Sandusky, Zhonghua Gao, Lindsey D. Mayo, Sharon A. Savage, Stephanie Halene, Yali Dou, Leonidas C. Platanias, Madina Sukhanova, Yunlong Liu, Omar Abdel-Wahab, Yan Liu
Abstract
Programmed cell death 1 ligand 1–targeted (PD-L1–targeted) immune checkpoint inhibitors are revolutionizing cancer therapy. However, strategies to induce endogenous PD-L1 degradation represent an emerging therapeutic paradigm. Here, we identified proanthocyanidins (PC) as a potent inducer of PD-L1 degradation through an endoplasmic reticulum–associated degradation (ERAD) mechanism. Mechanistically, PC exerted dual effects: First, it targeted and stabilized LKB1 to activate AMPK in tumor cells, subsequently inducing the phosphorylation of PD-L1 at Ser195 — a disruption that in turn impaired glycosylation of PD-L1 and promoted its retention in the ER. Second, PC directly bound to the E3 ubiquitin ligase SYVN1 to increase its protein stability, which strengthened PD-L1–SYVN1 binding, thereby accelerating K48-linked ubiquitination and proteasomal degradation of ER-retained PD-L1. This cascade culminated in the activation of CD8+ T cell–dominated antitumor immune responses, accompanied by suppression of myeloid-derived suppressor cells and regulatory T cells. In preclinical models of lung and colorectal cancer, PC exhibited synergistic antitumor efficacy when combined with anti–cytotoxic T lymphocyte antigen 4 (anti–CTLA-4) antibodies. Notably, PC also potently inhibited the progression of azoxymethane/dextran sodium sulfate–induced orthotopic colorectal cancer in mice. Collectively, our findings unveil an antitumor mechanism of PC, establishing this small-molecule compound as an ERAD pathway–exploiting immune checkpoint modulator with promising translational potential for cancer therapy.
Authors
Mengting Xu, Xuwen Lin, Hanchi Xu, Hongmei Hu, Xinying Xue, Qing Zhang, Dianping Yu, Saisai Tian, Mei Xie, Linyang Li, Xiaoyu Tao, Xinru Li, Simeng Li, Shize Xie, Yating Tian, Xia Liu, Hanchen Xu, Qun Wang, Weidong Zhang, Sanhong Liu
Abstract
Traditional polysaccharide vaccines are constrained by streptococcus pneumoniae diversity. We propose a protein-based pneumococcal vaccine (PBPV) — formulated with conserved surface proteins P3296, P5668, PRx1, and pneumolysin (Ply) — that could potentially offer superior immune breadth independent of capsular polysaccharide serotypes. Here, we evaluated the multifunctional antibody responses induced by PBPV, including immunogenicity, Ply neutralization, opsonophagocytic activity (OPA), and such nonopsonic functions as NK cell activation (ADNKA), antibody-dependent cellular phagocytosis, and neutrophil phagocytosis (ADNP) in a cohort of 50- to 69-year-olds. While PBPV showed shorter-lasting immune responses, including reduced Ply-neutralizing capacity, it provided broader cross-serotype protection than 23-valent pneumococcal polysaccharide vaccine. Correlation analysis identified distinct PspA-specific IgG subclass roles: P3296-IgG1 correlated with OPA, and IgG3 correlated with ADNKA/ADNP; P5668-IgG2 correlated with ADNKA/ADNP, and IgG3 correlated with OPA; and PRx1-IgG2 correlated with OPA, and IgG3 correlated with ADNKA. Critically, while no efficacy data have yet confirmed the protective effect of PBPV, its targeting of conserved proteins rather than capsular polysaccharides enables simplified manufacturing and expanded coverage, positioning it as a promising alternative to traditional multipolysaccharide vaccines.
Authors
Kaiyi Li, Jinglu Yang, Xiaobing Zhai, Jinbo Gou, Xiuwen Sui, Bochao Wei, Yuan Wang, Xiaoling Su, Xiaoyun Yang, Shiqin Jin, Xuan Zhou, Yuxuan Zhang, Tao Zhu, Junxiang Wang, Zhongfang Wang
Abstract
Although mammals generally demonstrate limited regenerative capacity compared with amphibians, the digit tip retains remarkable regenerative potential, providing a useful model to study successful mammalian regeneration. This process involves coordinated immune cell activity, vascular remodeling, and tissue reconstruction, yet the molecular checkpoints controlling regenerative versus fibrotic outcomes remain poorly understood. In mammals, regeneration of the digit tip (P3) proceeds through myeloid cell migration, early osteoclast-mediated osteolysis of the distal bone, and subsequent blastema-mediated regeneration. Here we test the hypothesis that lymphatic vessels regulate regenerative capacity by modulating local immune cell dynamics and osteoclast function. Using a lymphatic system–specific reporter line, we discovered that lymphatic vessels grow toward the nail region from the ventral side of the digit during quiescence and after amputation. These lymphatics closely surround, but do not invade, the native or regenerated bone. Unexpectedly, genetic, pharmacological, and surgical inhibition of lymphangiogenesis accelerated early osteolysis through enhanced transition of myeloid cells to osteoclasts, resulting in faster and more robust regeneration. These findings reveal a mechanism linking lymphatic vessel, immune regulation, and bone remodeling, suggesting that targeted manipulation of lymphatics dynamics may enhance regenerative outcomes after musculoskeletal injury.
Authors
Neda Vishlaghi, Trisha K. Ghotra, Monisha Mittal, Ji Hae L. Choi, Sneha Korlakunta, Mingquan Yan, Janna L. Crossley, Danielle Griswold-Wheeler, Elnaz Ghotbi, Conan Juan, Shiri Gur-Cohen, Babak Mehrara, David A. Brown, Michael T. Dellinger, Lindsay A. Dawson, Benjamin Levi
Abstract
Metastatic progression in aggressive breast cancer (BC) depends on a tightly controlled vesicular recycling network regulated by RAB11, a small guanosine triphosphate enzyme (GTPase). In a cohort of more than 1,000 patients with BC, we identified SH3BP5L as the most highly expressed guanine nucleotide exchange factor (GEF) for RAB11A. High SH3BP5L expression marked an advanced tumor stage, distant metastasis, and poor prognosis, with significant associations in human epidermal growth factor receptor 2–positive (HER2+) and triple-negative breast cancer (TNBC). Using Förster resonance energy transfer (FRET) sensors and artificial intelligence– (AI-assisted) microscopy, we showed that cargo delivery to the plasma membrane required SH3BP5L-dependent activation of RAB11A and assembly of a complex with the anterograde motor KIF5B. This trafficking governed key metastatic features of TNBC, including β1 integrin recycling and α3β1 integrin surface exposure. Inhibition of SH3BP5L or its GEF activity reduced cell spreading in zebrafish and lung metastasis in mouse models, revealing a previously unidentified driver of BC dissemination and a potential therapeutic vulnerability.
Authors
Huayi Li, Maria Chiara De Santis, Francesco A. Tucci, Daniela Tosoni, Ping Zhang, Meredith L. Jenkins, Giulia Villari, Maria Grazia Filippone, Elisa Guerrera, Simone Tealdi, Luca Gozzelino, Federico Gulluni, Lorenzo Prever, Cristina Zanini, Marco Forni, Irene Franco, Miriam Martini, John E. Burke, Guido Serini, Carlo Cosimo Campa, Salvatore Pece, Jean Piero Margaria, Emilio Hirsch
Abstract
SCN8A encodes the voltage-gated sodium channel Nav1.6, which plays a key role in facilitating neuronal excitability. Mutations in SCN8A, particularly gain-of-function variants, cause SCN8A developmental and epileptic encephalopathy (DEE), a severe epilepsy syndrome characterized by seizures, cognitive dysfunction, movement disorders, and sudden unexpected death in epilepsy (SUDEP). The recurrent SCN8A variant R1872W impairs channel inactivation, causing neuronal hyperexcitability and seizures. Current treatments, including antiseizure medications, are often ineffective for patients with SCN8A DEE, highlighting the need for targeted therapies. We employed base editing to correct the R1872W SCN8A variant. An adenine base editor and guide RNA (SCN8A-ABE) were packaged within dual PhP.eB-adeno-associated viruses (AAVs) and administered to R1872W mice at P2. SCN8A-ABE significantly increased survival of mice expressing R1872W and either reduced seizure incidence and severity or eliminated seizure occurrence. Electrophysiological recordings revealed a rescue of seizure-associated neuronal hyperexcitability and suppression of the pathogenic persistent sodium current (INaP) in treated mice. Comorbidities, including diminished mobility and anxiety-like behaviors, were improved by SCN8A-ABE. These effects were achieved by a 32% absolute reduction in mutant transcripts, accompanied by conversion to SCN8A WT transcripts. Our findings demonstrate base editing as an effective targeted therapeutic approach for SCN8A DEEs by addressing the underlying genetic cause.
Authors
Caeley M. Reever, Alexis R. Boscia, Tyler C.J. Deutsch, Mansi P. Patel, Raquel M. Miralles, Shrinidhi Kittur, Erik J. Fleischel, Atum M.L. Buo, Matthew S. Yorek, Miriam H. Meisler, Charles R. Farber, Manoj K. Patel
Abstract
TFE3 translocation renal cell carcinoma (tRCC), an aggressive kidney cancer driven by TFE3 gene fusions, is frequently misdiagnosed owing to morphologic overlap with other kidney cancer subtypes. Conventional liquid biopsy assays that detect tumor DNA via somatic mutations or copy number alterations are unsuitable for tRCC since it often lacks recurrent genetic alterations and because fusion breakpoints are highly variable between patients. We reasoned that epigenomic profiling could more effectively detect tRCC because the driver fusion constitutes an oncogenic transcription factor that alters gene regulation. By defining a TFE3-driven epigenomic signature in tRCC cell lines and detecting it in patient plasma using ChIP-seq, we distinguished tRCC from clear-cell RCC (AUC = 0.86) and samples of individuals without evidence of cancer (AUC = 0.92) at low tumor fractions (<1%). This work establishes a framework for noninvasive epigenomic detection, diagnosis, and monitoring of tRCC, with implications for other mutationally quiet, fusion-driven cancers.
Authors
Simon Garinet, Karl Semaan, Jiao Li, Ze Zhang, Prathyusha Konda, Ananthan Sadagopan, John Canniff, Noa Phillips, Kelly Klega, Medha Pandey, Hunter Savignano, Matthew P. Davidsohn, Kevin Lyons, Alessandro Medda, Prateek Khanna, Mingkee Achom, Brad J. Fortunato, Rashad Nawfal, Razane El Hajj Chehade, Jillian O’Toole, Jack Horst, Dory Freeman, Rachel Trowbridge, Cindy H. Chau, William D. Figg, Jacob E. Berchuck, Brian D. Crompton, Ji-Heui Seo, Toni K. Choueiri, Matthew L. Freedman, Sylvan C. Baca, Srinivas R. Viswanathan
Abstract
The regulation of the programmed cell death protein 1 (PD-1) gene, PDCD1, has been widely explored at transcription and posttranslational levels in T cell function and tumor immune evasion. However, the mechanism for PDCD1 dysregulation at the posttranscriptional level remains largely unknown. Here, we identify protein arginine methyltransferase 5 (PRMT5) as a RNA binding protein in a methyltransferase activity–independent manner, which promotes PDCD1 decay with WD repeat domain 77 protein (WDR77) and Argonaute2. Furthermore, the type-I IFN/STAT1 pathway transcriptionally activates PRMT5 and WDR77, thus enhancing PRMT5/WDR77 binding on a conserved AU-rich element of PDCD1 3′ UTR. Functionally, conditional knockout of either PRMT5 or WDR77 in T cells disrupts T cell effector function and sensitizes the tumors to anti–PD-1 therapy. Clinically, PRMT5 and WDR77 expression in tumor-infiltrating T cells are negatively correlated with PDCD1 expression and renders tumors resistant to PD-1–targeted immunotherapy. Moreover, fludarabine targeting STAT1 in combination with anti–PD-1 has a synergetic effect on suppressing tumor growth in mice. Overall, this study reveals that the RNA binding–dependent function of PRMT5 regulates PDCD1 and T cell effector function with WDR77 and identifies potential combinatorial therapeutic strategies for enhancing antitumor efficacy.
Authors
Yinmin Gu, Yongbo Pan, Chang Pan, Qiang Pang, Zhantong Tang, Yiwen Chen, Haojing Zang, Xiaodong Wang, Chang Huang, Qingqing Zhang, Facai Yang, Xiaofeng Zhu, Yibi Zhang, Xujie Zhao, Shan Gao
Abstract
In pancreatic β cells, misfolded proinsulin is a substrate for ER-associated protein degradation (ERAD) via HRD1/SEL1L. Alternately, β cell HRD1 activity is reported to improve, or impair, insulin biogenesis. Further, while β cell SEL1L deficiency causes HRD1 hypofunction and diminishes islet insulin content, reports conflict as to whether β cell ERAD deficiency increases or decreases proinsulin levels. Here, we examined β cell–specific Hrd1-KO mice (chronic deficiency) and rodent (and human islet) β cells treated acutely with HRD1 inhibitor. β-Hrd1–KO mice developed diabetes with decreased islet proinsulin, yet a relative increase of misfolded proinsulin redistributed to the ER. They also showed upregulated biochemical markers of β cell ER stress and autophagy, electron microscopy evidence of ER enlargement and decreased insulin granule content, and increased glucagon-positive islet cells. Misfolded proinsulin was also increased in islets treated with inhibitors of lysosomal degradation. Preceding any loss of total proinsulin, acute HRD1 inhibition triggered increased nonnative proinsulin, increased phospho-eIF2α with inhibited proinsulin synthesis, and increased LC3b-II (the abundance of which requires expression of ΣR1). We posit a subset of proinsulin molecules undergo HRD1-mediated disposal. When HRD1 is unavailable, misfolded proinsulin accumulates, accompanied by increased phospho-eIF2α that limits further proinsulin synthesis, plus ΣR1-dependent autophagy activation, ultimately lowering steady-state β cell proinsulin (and insulin) levels and triggering diabetes.
Authors
Anoop Arunagiri, Leena Haataja, Maroof Alam, Noah F. Gleason, Emma Mastroianni, Chao-Yin Cheng, Sami Bazzi, Jeffrey Knupp, Ibrahim Metawea, Anis Hassan, Dennis Larkin, Deyu Fang, Billy Tsai, Ling Qi, Peter Arvan
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Copyright © 2026 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)