Immunology
Abstract
Human gastrointestinal (GI) tissues are a major site of HIV-1 viral persistence, but the nature of the GI reservoir remains poorly described. To characterize the GI HIV reservoir, we profiled cells from GI tissue and matched peripheral blood mononuclear cells from ten people with HIV on antiretroviral therapy using single cell RNA sequencing. We identified distinct compartment-specific patterns of gene expression, highlighting key differences between blood and colon CD4 T cell populations. vRNA+ cells from both blood and GI tissue were heterogeneous and found in multiple subtypes of CD4 T cells, although vRNA+ cells were particularly enriched in cells with Th17 or Treg17 phenotypes. Transcriptomic comparison of HIV vRNA+ and vRNA- T cells revealed 116 differentially expressed genes that were associated with HIV infection including ZBED2, MAF and IL17F. These data provide novel information regarding the GI-resident HIV reservoir and suggest that compartment-specific patterns of gene expression are associated with HIV infection.
Authors
Jackson J. Peterson, Shipra Chandel, Katherine James, Elizabeth S. Bennett, Vincent Wu, Cory H. White, Brigitte Allard, Matthew Clohosey, Taylor Whitaker, Caroline Baker, Susan Pedersen, Anne F. Peery, Cynthia L. Gay, Michael R. Betts, David M. Margolis, Nancie M. Archin, Edward P. Browne
Abstract
Mutations in DNA mismatch repair (MMR) pathway genes (MSH2, MSH6, MLH1, and PMS2) are linked to acquired resistance to temozolomide (TMZ) and high tumor mutation burden (TMB) in high-grade gliomas (HGG), including glioblastoma (GBM). However, the specific roles of individual MMR genes in the initiation, progression, TMB, microsatellite instability (MSI), and resistance to TMZ in glioma remain unclear. Here, we developed de novo mouse models of germline and somatic MMR-deficient (MMRd) HGG. Surprisingly, loss of Msh2 or Msh6 does not lead to high TMB, MSI, nor confer response to anti-PD-1 in GBM. Similarly, human GBM shows discordance between MMR gene mutations and TMB/MSI.Germline MMRd leads to promoted progression from low-grade to HGG and reduced survival compared to MMR-proficient (MMRp) tumor-bearing mice. This effect is not tumor cell intrinsic but is associated with MMRd in the tumor immune microenvironment, driving immunosuppressive myeloid programs, reduced lymphoid infiltration, and CD8+ T cell exhaustion. Both MMR-reduced (MMRr) and MMRd GBM are resistant to temozolomide (TMZ), unlike MMRp tumors. Our study shows that KL-50, a imidazotetrazine-based DNA targeting agent inducing MMR-independent cross-link–mediated cytotoxicity, was effective against germline and somatic MMRr/MMRd GBM, offering a potential therapy for TMZ-resistant HGG with MMR alterations.
Authors
Montserrat Puigdelloses Vallcorba, Nishant Soni, Seung-Won Choi, Kavita Rawat, Tanvi Joshi, Sam Friedman, Alice Buonfiglioli, Angelo Angione, Zhihong Chen, Gonzalo Piñero, Gabrielle Price, Mehek Dedhia, Raina Roche, Emir Radkevich, Anne M. Bowcock, Deepti Bhatt, Winfried Edelmann, Robert M. Samstein, Timothy E. Richardson, Nadejda M. Tsankova, Alexander M. Tsankov, Ranjit S. Bindra, Raul Rabadan, Juan C. Vasquez, Dolores Hambardzumyan
Abstract
PP2A B55α, a regulatory subunit of protein phosphatase 2 (PP2A), is underexpressed in over 40% of non-small cell lung cancer (NSCLC) cases due to loss of heterozygosity of PPP2R2A, the gene encoding this protein. Given that low PPP2R2A expression correlates with poor prognosis, treating PPP2R2A-deficient NSCLC represents an unmet medical need. Here, we show that PPP2R2A knockdown or its heterozygosity (PPP2R2A+/–) increases cytosolic DNA, leading to cGAS-STING-type I interferon (IFN) pathway activation. PPP2R2A deficiency results in elevated expression of immune checkpoint protein PD-L1 via GSK-3β- and STING-dependent mechanisms. PPP2R2A+/– cancer cells have enhanced sensitivity to PD-L1 blockade in a mouse model of lung cancer due to modulation of the tumor immune microenvironment, resulting in increased NK cells and reduced infiltration and function of regulatory T cells (Tregs). Consequently, PD-L1 antibody treatment increases CD8+ T infiltration and activity, especially in tumors with PPP2R2A heterozygosity. Further, systemic or Treg-specific IFNAR1 blockade reduces the efficacy of PD-L1 blockade in PPP2R2A+/– tumors. Patients with NSCLC with a low PPP2R2A/PD-L1 ratio respond better to immune checkpoint blockade (ICB). These findings underscore the therapeutic potential of ICB in treating PPP2R2A-deficient NSCLC while suggesting that PPP2R2A deficiency could serve as a biomarker for guiding ICB-based therapies.
Authors
Zhaojun Qiu, No-Joon Song, Anqi Li, Deepika Singh, Chandra B. Prasad, Chunhong Yan, David P. Carbone, Qi-en Wang, Xiaoli Zhang, Zihai Li, Junran Zhang
Abstract
Type 1 Diabetes Mellitus (T1D) is a chronic disease caused by an unremitting autoimmune attack on pancreatic beta cells. This autoimmune chronicity is mediated by stem-like progenitor CD8+ T cells that continually repopulate the pool of beta cell-specific cytolytic effectors. Factors governing the conversion of progenitors to effectors, however, remain unclear. T1D has been linked to a chromosomal region (Xp13-p11) that contains the epigenetic regulator UTX, which suggests a key role for UTX in T1D pathogenesis. Here, we show that T cell-specific UTX deletion in NOD mice protects against T1D development. In T cells of NOD mice and T1D patients, UTX ablation resulted in the accumulation of CD8+ progenitor cells with concomitant deficiency of effectors, suggesting a key role for UTX in poising progenitors for transition to effectors. Mechanistically, UTX’s role in T1D was independent of its inherent histone demethylase activity but instead relied on binding with transcription factors (TCF1 and STAT3) to co-regulate genes important in the maintenance and differentiation of progenitor CD8+ T cells. Together, these findings identify a critical role for UTX in T1D and the UTX:TCF1:STAT3 complex as a therapeutic target for terminating the long-lived autoimmune response.
Authors
Ho-Chung Chen, Madison F. Bang, Hsing-Hui Wang, Karl B. Shpargel, Lisa A. Kohn, David Sailer, Shile Zhang, Ethan C. McCarthy, Maryamsadat Seyedsadr, Satchel Stevens, Caitlyn L. H. Pham, Zikang Zhou, Xihui Yin, Nicole M. Wilkinson, Esther M. Peluso, Christian Bustillos, Jessica G. Ortega, Lixin Yang, Ashlyn A. Buzzelli, Reina C. Capati, Dennis J. Chia, Steven D. Mittelman, Christina M. Reh, Jason K. Whitmire, Melissa G. Lechner, Willy Hugo, Maureen A. Su
Abstract
Neutrophils play a critical role in sepsis-induced acute lung injury (ALI). Extracellular cold-inducible RNA-binding protein (eCIRP), a damage-associated molecular pattern, promotes neutrophil heterogeneity. While delta-like ligand 4 (DLL4) expression has been studied in various cell populations, its expression in neutrophils and impact on inflammation remain unknown. Here, we discovered that eCIRP induces DLL4+ neutrophils. These neutrophils trigger PANoptosis, a novel proinflammatory form of cell death initiated by Z-DNA–binding protein-1 (ZBP1) in pulmonary vascular endothelial cells (PVECs). In sepsis, DLL4+ neutrophils increase in the blood and lungs, upregulating ZBP1, cleaved gasdermin D, cleaved caspase-3, and phosphorylated MLKL, all of which are markers of PANoptosis, exacerbating ALI. DLL4 binds to Notch1 on PVECs and activates Notch1 intracellular domain to increase ZBP1-mediated endothelial PANoptosis. We discovered what we believe to be a novel Notch1-DLL4 inhibitor (NDI), derived from Notch1 to specifically block this interaction. Our findings reveal that NDI reduced endothelial PANoptosis in vitro and in vivo, attenuated pulmonary injury induced by DLL4+ neutrophils, and decreased lung water content and permeability, indicating improved barrier function. NDI also reduced serum injury and inflammatory markers and improved survival rate in sepsis. These findings underscore the Notch1-DLL4 pathway’s critical role in DLL4+ neutrophil–mediated ALI. Targeting the Notch1-DLL4 interaction with an NDI represents a promising therapeutic strategy for sepsis-induced ALI.
Authors
Hui Jin, Saoirse Holland, Alok Jha, Gaifeng Ma, Jingsong Li, Atsushi Murao, Monowar Aziz, Ping Wang
Abstract
Mitochondrial metabolism orchestrates T cell functions, yet the role of specific mitochondrial components in distinct T cell subsets remains poorly understood. Here, we explored the role of mitochondrial complex II (MC II), the only complex from the electron transport chain (ETC) that plays a role in both ETC and metabolism, in regulating T cell functions. Surprisingly, MC II exerts divergent effects on CD4+ and CD8+ T cell activation and function. Using T cell–specific MC II subunit, succinate dehydrogenase A–deficient (SDHA-deficient) mice, we integrated single-cell RNA-seq and metabolic profiling, with in vitro and in vivo T cell functional assays to illuminate these differences. SDHA deficiency induced metabolic changes and remodeled gene expression exclusively in activated T cells. In CD4+ T cells, SDHA loss dampened both oxidative phosphorylation (OXPHOS) and glycolysis, impaired cytokine production, proliferation, and reduced CD4+ T cell–mediated graft-versus-host disease after allogeneic stem cell transplantation (SCT). In contrast, SDHA deficiency in CD8+ T cells reduced OXPHOS but paradoxically upregulated glycolysis and demonstrated enhanced cytotoxic functions in vitro and in vivo. This metabolic reprogramming endowed SDHA-KO CD8+ T cells with superior in vivo antitumor efficacy after immune checkpoint inhibitor therapy and allogeneic SCT. These findings reveal MC II as a bifurcation point for metabolic and functional specialization in CD4+ and CD8+ T cells.
Authors
Keisuke Seike, Shih-Chun A. Chu, Yuichi Sumii, Takashi Ikeda, Meng-Chih Wu, Laure Maneix, Dongchang Zhao, Yaping Sun, Marcin Cieslik, Pavan Reddy
Abstract
Periodontal disease, a bacterial infection affecting a large percentage of the world's population, is an important risk factor for several systemic diseases and is significantly worsened by diabetes. To investigate how diabetes exacerbates the inflammatory response to bacteria in this disease, we combined insights from murine and human studies. Through single-cell RNA sequencing, we identified a compelling hyperglycemia-driven molecular pathway: the upregulation of CD137L in dendritic cells and increased expression of its receptor, CD137, in γδ T-cells. The CD137L-CD137 axis emerged as a pivotal mediator of diabetes-induced inflammatory tissue destruction. Antibody-mediated inhibition of CD137L markedly reduced the diabetes-driven bone loss, neutrophil recruitment, expansion of γδ T-cells, and excessive infiltration by IL17A+ cells. In vitro studies further validated these findings and established that high glucose-mediated dysregulation of dendritic cells dramatically altered γδ T-cell activity in co-culture systems via CD137L. The essential role of dendritic cells as CD137L producers in vivo was definitively established through lineage-specific Akt1 deletion, which abrogated CD137L expression in these cells and reversed the adverse effects of hyperglycemia on leukocyte responses to bacterial pathogens in vivo. Conversely, activation of CD137 with an agonist in normal animals recapitulated diabetes-induced abnormalities in the inflammatory response and accelerated bone loss. These findings elucidate a key mechanism underlying diabetes-induced immune dysregulation and inflammatory damage, and point to the CD137L-CD137 pathway as a promising therapeutic target, offering potential insights into mitigating other diabetes-associated complications linked to inflammatory changes.
Authors
Xin Huang, Min Liu, Michael V. Gonzalez, Rahul Debnath, Hamideh Afzali, Yongwon Choi, Su Ah Kim, Kang I. Ko, Dana T. Graves
Abstract
The role of the tumor immune microenvironment (TIME) in modulating responses to antiestrogen therapy in hormone receptor-positive (HR+) breast cancers remains unclear. We analyzed pre- and on-treatment biopsies from patients with HR+ breast cancer treated with letrozole to induce estrogen deprivation (ED). Stromal tumor-infiltrating lymphocytes, assessed by H&E-staining, and immune-related gene sets, including IFNɣ signaling, measured by RNA sequencing, were increased in ED-resistant tumors. Cyclic immunofluorescence and spatial transcriptomics revealed an abundance of CD8+ T cells and enhanced antigen processing and immune gene signatures in ED-resistant tumors. In this group, the expression of CXCL9, CXCL10, and CXCL11 — chemokine genes involved in CD8+ T cell recruitment — and the CXCR3 receptor were upregulated both before and after letrozole. CXCL11 levels were higher in conditioned media from HR+ breast cancer cells co-cultured with CD8+ T cells. Both recombinant CXCL11 and co-culture with CD8+ T cells promoted MCF7 and T47D cell growth in estrogen-free conditions. Finally, deletion combined with silencing of the CXCL11 receptors CXCR3 and CXCR7 in MCF7 cells impaired proliferation in response to exogenous CXCL11 and to co-culture with CD8+ T cells in estrogen-free conditions. These findings suggest that CD8+ T cell-associated CXCL11 in the TIME modulates the response of HR+ breast cancer cells to estrogen suppression.
Authors
Fabiana Napolitano, Yunguan Wang, Dhivya R. Sudhan, Paula I. Gonzalez-Ericsson, Luigi Formisano, Nisha Unni, Shahbano Shakeel, James Z. Zhu, Khushi Ahuja, Lei Guo, María Rosario Chica-Parrado, Yuki Matsunaga, Pamela Luna, Chang-Ching A. Lin, Yasuaki Uemoto, Kyung-Min Lee, Hongli Ma, Nathaniel J. Evans, Alberto Servetto, Saurabh Mendiratta, Spencer D. Barnes, Roberto Bianco, Yisheng V. Fang, Lin Xu, Jeon Lee, Tao Wang, Justin M. Balko, Gordon B. Mills, Marilyne Labrie, Ariella B. Hanker, Carlos L. Arteaga
Abstract
Adoptive cell therapy (ACT) relies on durable and functional T cells to mediate tumor clearance. Th9 cells are a metabolically fit CD4+ T cell subset with strong persistence but limited cytotoxicity. Here, we identified endomelipeptide A (EpA), a cyclic peptide isolated from Ganoderma lucidum–associated endophytic fungi, as a potent enhancer of Th9 differentiation. EpA promoted a cytotoxic Th9 phenotype with enhanced mitochondrial function and metabolic fitness. Mechanistically, EpA dually targeted ZAP70 and SREBP1, coupling T cell receptor (TCR) signaling activation with lipid metabolism suppression. EpA-treated Th9 cells mediated robust, CD8+ T cell–dependent tumor control and enhanced the efficacy of human Th9 CAR-T therapy in vivo. These findings establish EpA as a distinct cyclic peptide that reprograms Th9 cells and provides a potential approach to boost ACT efficacy.
Authors
Wenli Zhao, Yang Zhou, Yuyang Chen, Yicheng Sun, Jiaxin Tang, Yihan Zhu, Jie Ren, Tianxu Du, Handuo Wang, Yuan Gao, Yu Hu, Ling Jiang, Tomohiko Ohwada, Qi Luo, Enguang Bi
Abstract
During vascular injury, platelets are essential for halting bleeding and recruiting neutrophils to prevent microbial invasion. However, in antibody-mediated autoimmune diseases occurring without vascular damage, neutrophils infiltrate tissues and contribute to pathology. Here, we investigated whether the dependence of neutrophils on platelets is conserved in the context of antibody-driven inflammation. Using human cells from individuals with rheumatoid arthritis and a microfluidic system mimicking physiological shear over IgG-containing immune complexes, we demonstrate that despite expressing Fc receptors, neutrophils require platelets to stably adhere to immune complexes under flow. Platelet FcγRIIA binding was critical for resisting shear stress, while neutrophils used FcγRIIA and FcγRIIIB for immune complex recognition. Platelet P-selectin binding to neutrophil PSGL-1 was essential for recruitment, whereas Mac-1 was dispensable. In a mouse model of autoantibody-mediated arthritis, intravital imaging confirmed that neutrophil recruitment critically relies on PSGL-1. Importantly, expression of FcyRIIA aggravated arthritis, and blockade of PSGL-1 in these mice, but not of Mac-1, abrogated both the platelet and neutrophil interactions and disease. These findings identify key molecular interactions in platelet–neutrophil cooperation and reveal that platelets are essential enablers of FcR-mediated neutrophil adhesion in antibody-driven inflammation.
Authors
Marie Bellio, Isabelle Allaeys, Etienne Doré, Myriam Vaillancourt, Tania Lévesque, Mélina Monteil, Nicolas Vallières, Philippe Desaulniers, Nicolas Bertrand, Valance A. Washington, Yotis Senis, Steve Lacroix, Paul Fortin, Clémence Belleannée, Eric Boilard
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)