Hematology
Abstract
Loss-of-function mutation in the human gene dipeptidyl peptidase 9 (DPP9) causes Hatipoglu syndrome leading to severe inflammasomopathy. A key feature of the disease is pancytopenia, and patients require bone marrow transplantation, but the mechanism of cell loss is unclear, since Dpp9-mutant mice have normal hematopoiesis, suggesting that a distinct mechanism of disease occurs in humans. Here, we present a model of human DPP9 deficiency leveraging reverse genetics in the MISTRG6 humanized mice. We found that CRISPR editing of human CD34+ hematopoietic stem and progenitor cells (HSPCs) led to very efficient and persistent gene deletion in vivo. Human DPP9 deletion recapitulated cytopenia in peripheral blood and in the bone marrow, and cell loss was cell intrinsic. However, DPP9 deletion led to few transcriptional changes suggesting posttranscriptional regulation in human HSPCs. Mechanistically, DPP9 deficiency led to activation of the CARD8 inflammasome, resulting in HSPC pyroptosis, whereas NLRP1 was dispensable for cell death. Thus, our results reveal a unique human mechanism of disease and offer therapeutic insight for this inflammasomopathy.
Authors
Tianli Xiao, J. Richard Brewer, Maximillian Carlino, Ailin Han, Yamato J. Takabe, Chia-Yi Lee, Fengrui Zhang, Mi Chen, Holly Nicole Blackburn, Amin H. Nassar, Qiankun Wang, Kristen Brennand, Liang Shan, Esen Sefik, Diane S. Krause, Richard A. Flavell
Abstract
Activating mutations in FMS-like tyrosine kinase 3 (FLT3) drive aggressive acute myeloid leukemia (AML) and confer poor prognosis. Although FLT3 inhibitors have improved outcomes, their efficacy is frequently limited by microenvironment-mediated signaling and treatment-emergent resistance. XY0206 is a structurally optimized derivative of sunitinib, an inhibitor approved for multiple solid tumors. Biochemical, multi-omics, and functional analyses showed that XY0206 directly engages FLT3 and suppresses downstream STAT5, AKT, and ERK signaling, resulting in apoptosis in FLT3-ITD AML cells. Across models of FLT3-dependent resistance, XY0206 retained antileukemic activity, including in FLT3-ITD cells harboring the F691L gatekeeper mutation, a recurrent alteration conferring resistance to approved FLT3 inhibitors. In primary AML blasts and xenograft models, XY0206 exhibited enhanced antileukemic activity with favorable tolerability relative to gilteritinib. In a phase I/II trial (NCT04471064) of XY0206 monotherapy in patients with relapsed or refractory (R/R) AML, XY0206 achieved a composite complete remission rate (CRc) of 45.7% overall, with a notable 60.0% CRc rate among patients with FLT3-ITD mutations. Three of eight patients with prior FLT3 inhibitor-exposed R/R AML also achieved CRc. Together, these findings support further clinical evaluation of XY0206 as a FLT3-directed therapeutic in AML, particularly in disease settings with reduced sensitivity to existing FLT3 inhibitors.
Authors
Long Shen, Yang Yang, Chenghua Xu, Bo Jiang, Xiaoxiao Duan, Xianfeng Shao, Simeng Li, Siyi Liu, Chao Huang, Lin Song, Mingyuan Sun, Jinting Fan, Ning Wang, Dong Zhang, Youyang Fang, Lichun Kang, Yajun Jiang, Mingming Niu, Junyuan Qi, Tao Cheng, Hong Wang
Abstract
The success of allogeneic hematopoietic cell transplantation (allo-HCT) is limited by acute graft-versus-host disease (aGVHD). We have previously reported that neutrophils can exacerbate tissue damage caused by conditioning regimens. Pegtarazimod is a synthetic peptide, derived from the capsid protein of human astrovirus serotype 1, that was shown to reduce neutrophil effector functions. Therefore, we evaluated the therapeutic activity of pegtarazimod against aGVHD. Pegtarazimod significantly reduced aGVHD-related mortality, histological aGVHD severity, and pro-inflammatory cytokines in multiple in vivo mouse models, while maintaining the anti-leukemia effect. Mechanistically, pegtarazimod reduced inflammation by decreasing ROS production as investigated using allo-HCT recipient mice with genetic inactivation of NADPH oxidase (NOX2) in the bone marrow. In addition to the anti-inflammatory effect, pegtarazimod protected intestinal organoids against TNF-induced toxicity and oxidative DNA damage. In the phase-2 clinical trial AURORA, pegtarazimod treatment was well-tolerated in patients with corticosteroid-refractory (SR) aGVHD (NCT06343792) with an overall response rate (ORR) of 4/7 patients at day 28. In summary, pegtarazimod reduced aGVHD in mice by suppressing pro inflammatory neutrophil effector functions and preserving enterocyte integrity. The clinical trial data support tolerability of pegtarazimod in aGVHD patients and further studies are needed to determine efficacy.
Authors
Verena Holzmüller, Jana Gawron, Ann-Cathrin Burk, Anna-Verena Stell, Anna-Sophia Baur, Alexander Zähringer, Viktor Fetsch, Annika Mäder, Alina Hartmann, Nana Talvard-Balland, Neel Krishna, Kenji Cunnion, Ulrich Thienel, Paolo Martini, Lindsey Glenn, James L.M. Ferrara, Monzr M. Al Malki, Hannah Choe, José Antonio Pérez-Simón, Annette Schmitt-Graeff, Joerg Buescher, Natalie Köhler, Zohreh Mansoori Moghadam, Philipp Henneke, Geoffroy Andrieux, Melanie Boerries, Robert Zeiser
Abstract
Ex vivo engineering strategies for adoptive αβ T-cell therapies increasingly use pharmacological modulation to improve survival, expansion, and antitumor activity. Short-term exposure to the BCL-2 inhibitor venetoclax during αβ T-cell manufacturing enhances apoptotic priming and effector persistence, suggesting a route to strengthen other T-cell lineages. γδ T cells share cytotoxic properties with αβ T cells but recognize targets independently of major histocompatibility complex (MHC) and show low alloreactivity, supporting off-the-shelf use in acute myeloid leukemia (AML). Whether such conditioning benefits γδ T cells was unknown. Here, we show that ex vivo venetoclax pretreatment enhances the antileukemic efficacy of therapeutic γδ T cells and chimeric antigen receptor (CAR) γδ T cells. Venetoclax-pretreated γδ T cells displayed increased cytotoxicity and proliferation with reduced exhaustion, yielding superior control of AML blasts and xenografts. These functional gains coincided with elevated mitochondrial content and a fatty acid oxidation metabolic profile. In vivo, venetoclax-pretreated γδ T cells achieved durable disease suppression, and the same conditioning improved CAR γδ T-cell efficacy. Together, these results show that short-term BCL-2 inhibition enhances γδ T-cell cytotoxicity and persistence. Incorporating venetoclax pretreatment into γδ T-cell manufacturing may improve therapeutic efficacy and inform next-generation γδ T-cell therapies for AML.
Authors
Xingchi Chen, Lin Zhang, Bingbing Yan, Yinqiang Sui, Weiwei Ma, Hui Zhao, Yining Wang, Kepeng Yang, Jiewen Ma, Baolin Tang, Yonghui Zhang, Xiaoyu Zhu
Abstract
Antimetabolites, chemotherapy targeting nucleotide biosynthesis, are among the oldest and most widely used cancer treatments, yet resistance remains a daunting barrier, especially in the fight against B cell lymphomas. However, the underlying mechanisms of this resistance have long remained elusive. Using an innovative, integrated omics approach, we unexpectedly identified that the accumulation of dipeptides and upregulation of the dipeptide transporter SLC15A3 underlie resistance to nucleotide deficiency in a Myc-driven large B cell lymphoma mouse model. A similar mechanism occurred after long treatment of human B cell lymphoma cells with the chemotherapeutic purine synthesis inhibitor 6-mercaptopurine (6MP). Mechanistically, we demonstrated that dipeptides containing essential amino acids activated the growth and survival mTOR complex 1 (mTORC1) signaling pathway. Notably, SLC15A3 specifically interacted with mTOR on the lysosome, boosting mTORC1 activity selectively in resistant lymphoma cells but not in parental cancer cells. Silencing SLC15A3 diminished mTORC1 activity and restored resistant lymphoma sensitivity to 6MP. Strikingly, resistant lymphomas, but not primary tumors, exhibited heightened sensitivity to the clinical mTOR inhibitor, rapamycin, in culture and in vivo. We extended these findings in human lymphoma biopsies, which revealed increased SLC15A3 expression following antimetabolite therapy. Together, our study uncovered a metabolic adaptation that fuels cancer resistance to nucleotide deficiency and positions the mTORC1 inhibitor, rapamycin, as a potential therapeutic strategy for transforming the management of chemotherapy-resistant lymphomas.
Authors
Haojun Yang, Vincenzo Andrea Zingaro, Kevin Boardman, Ashish Noronha, Ekin Guney, Lingru Xue, Saishma Hoigebazar, Isabelle Liu, Sohit Miglani, Siyu Chen, Hieu Vu, Kwun Wah Wen, Hao G. Nguyen, Hani Goodarzi, Ralph J. DeBerardinis, Davide Ruggero
Abstract
Methionine cycle plays critical roles in cell fate determination by shaping epigenetic landscape, yet its function in human erythropoiesis remains undefined. Here, we show that disruption of methionine metabolism by compromising key enzyme adenosylhomocysteinase (AHCY) reshapes H3K4me3 landscape, causing erythroid cell fate reprogramming. AHCY deficiency severely impaired erythroid differentiation and expansion, leading to the generation of non-erythroid lineage hematopoietic cells, including stem/progenitor cells and immune cells, as evidenced by single-cell RNA sequencing, Pseudo temporal analysis delineated a precise dedifferentiation trajectory, revealing erythroblasts transitioning back to MEPs and HSCs. Moreover, human hematopoietic system could be reconstituted in the immunodeficient NCG-X mice by transplanting AHCY deficient erythroblasts. Mechanistically, AHCY deficiency reduced global H3K4me3 levels and altered its genomic distribution, resulting in the upregulated expression of non-erythroid transcription factors and downregulated expression of erythrocyte lineage-specific transcription factors. Integrated single-cell analyses identified transitional states with diminished AHCY in the erythroblasts of acute myeloid leukemia (AML) patient. Further flow cytometry confirmed the reduced H3K4me3 level in patient derived erythroid cells. Erythroblasts isolated from AML patients with reduced H3K4me3 exhibited dedifferentiation potential into progenitor-like states. Our findings reveal a metabolic-epigenetic axis governing cell fate reprogramming in human erythropoiesis and provide insights into leukemia associated anemia.
Authors
Lei Sun, Hengchao Zhang, Mengjia Li, Quande Lin, Xiuyun Wu, Ying Cheng, Shihui Wang, Yan Hou, Yaomei Wang, Yue Sheng, Jing Liu, Xiuli An, Ting Wang, Lixiang Chen
Abstract
Cerebral malaria (CM) from Plasmodium falciparum is a major cause of death in African children. Since bradykinin (BK) is a mediator of vasogenic edema, we hypothesized that it contributes to the pathogenesis of CM in Kenyan children and Plasmodium berghei ANKA (PbA) infected C57BL/6J mice in experimental cerebral malaria (ECM). Cleaved plasma high molecular weight kininogen (cHK) is a marker for BK release. 40% of children with central nervous system malaria had plasma cHK versus 18% of children with uncomplicated malaria. Wild-type PbA-infected mice with ECM had circulating cHK, elevated BK levels, and reduced HK and prekallikrein activity/antigen levels. HK null (Kng1–/–), combined BK B1 and B2 receptor null (Bdkrb1–/–/Bdkrb2–/–), BK B2 (Bdkrb2–/–) or BK B1 (Bdkrb1–/–) receptor null mice were protected significantly from neurologic deterioration and brain edema compared to wild-type mice. F12–/– mice were not protected from neurological deterioration. Prekallikrein null (Klkb1–/–), prolylcarboxypeptidase hypomorphs (Prcpgt/gt), and brain endothelial cell conditional knockout of PRCP (Prcpfl/fl Cre) mice with ECM had reduced neurologic deterioration and brain edema. Adjuvant plasma kallikrein inhibition combined with artesunate treatment in PbA-infected mice reversed neurologic deterioration and brain edema and significantly prolonged survival over artesunate alone. BK-induced vasogenic edema contributes to human and murine CM.
Authors
Alessandro S. de Sa Pinheiro, Douglas E. Teixeira, Rodrigo P. Silva-Aguiar, Young Jun Shim, Alona A. Merkulova, Sadiq Silbak, Yelenna Skomorovska-Prokvolit, David Midem, Sidney Ogolla, Bjoern B. Burckhardt, Tanja Gangnus, Julio Scharfstein, Celso Caruso-Neves, Owen J.T. McCarty, David Gailani, Michael Bader, Philip J. Rosenthal, Arlene E. Dent, Chris J. Janse, Keith R. McCrae, Ana Acacia de Sa Pinheiro, James W. Kazura, Alvin H. Schmaier
Abstract
BACKGROUND. B cell maturation antigen (BCMA) is a key therapeutic target in multiple myeloma (MM), yet its whole-body in vivo distribution and role in disease assessment remain incompletely defined. We aimed to evaluate the safety, diagnostic performance, and clinical utility of a novel BCMA-targeted PET tracer, 68Ga-PFBC01, in patients with plasma cell disorders. METHODS. We conducted a single-center, prospective, single-arm phase I trial (ClinicalTrials.gov NCT06717113). Fifty patients underwent 68Ga-PFBC01 PET/CT, including 40 with paired 18F-FDG PET/CT for head-to-head comparison. Primary outcomes included diagnostic performance (sensitivity, specificity, PPV, NPV, and inter-reader agreement). Secondary outcomes included correlations with clinical biomarkers, treatment response assessment, impact on clinical decision-making, and safety. RESULTS.68Ga-PFBC01 PET/CT demonstrated superior diagnostic performance compared with 18F-FDG PET/CT (sensitivity 96.9% vs 84.6%; specificity 71.4% vs 60.0%). Quantitative PET-derived tumor burden correlated with M protein (R = 0.325, P = 0.026), free light chains (R = 0.340–0.437, P ≤ 0.015), soluble BCMA (R = 0.433, P = 0.050), and bone marrow plasma cells (R = 0.682, P < 0.001). Imaging findings altered clinical management in multiple cases, enabling both therapy escalation and de-escalation. Blood-pool uptake strongly correlated with soluble BCMA (R = 0.899, P < 0.001) and overall disease burden (R = 0.736, P < 0.001). No serious tracer-related adverse events were observed; two patients (4%) experienced mild events. CONCLUSION.68Ga-PFBC01 PET/CT provides biologically specific, whole-body assessment of MM, outperforming 18F-FDG and enabling integrated evaluation of tumor burden and systemic disease activity, with direct implications for clinical decision-making. TRIAL REGISTRATION. ClinicalTrials.gov NCT06717113. FUNDING. National Natural Science Foundation of China (82472018, 82402320) to Prof. Lei Kang, 82402320 to Dr. Tianyao Wang); Beijing Nova Program (20240484725) to Prof. Lei Kang; National High Level Hospital Clinical Research Funding (Interdisciplinary Research Project of Peking University First Hospital, 2024IR07, Scientific and Technological Achievements Transformation Incubation Guidance Fund Project of Peking University First Hospital, 2025CX38, 2024CX18) to Prof. Lei Kang.
Authors
Tingfei Gu, Zhao Chen, Bo Tang, Tianyao Wang, Qi Yang, Huihui Liu, Zeyin Liang, Qian Wang, Yang Zhang, Yuhua Sun, Mingyi Di, Tingting Yuan, Yongkang Qiu, Yimeng Du, Lele Song, Shengnan Wu, Wei Wang, Xiaojie Xu, Yujun Dong, Lei Kang
Abstract
Obesity is increasingly implicated in hematopoietic malignancies, yet its role in mutation-driven myeloid leukemias remains unclear. Using UK Biobank data from over 440,000 individuals, we found obesity traits including elevated BMI and waist-to-hip ratio were associated with type 2 diabetes, increased plasma IL-17A (interleukin-17A), reduced GLP-1R (glucagon like peptide 1 receptor) expression, and heightened risk of myeloid malignancies. Transplantation of protein tyrosine phosphatase non-receptor type 11, PTPN11 (Shp2E76K/+) mutant hematopoietic stem/progenitors into obese mice demonstrated that metabolic inflammation accelerates leukemogenesis via myeloid cell expansion, lipid metabolic rewiring, IL-17A activation, and accumulation of M2-like tumor-associated macrophages (TAMs), accompanied by T-cell exhaustion and impaired antigen presentation. Notably, dual therapy with an anti-IL-17A antibody and a GLP-1R agonist reversed these effects, by reducing M2-like TAMs, restoring Ciita-dependent antigen presentation, Tyk2-mediated IFNγ signaling, reactivated T-cell responses, and reducing leukemic burden. These findings establish IL-17A driven, metabolism-coupled immunosuppression as a mechanistic link between obesity and SHP2-mutant myeloid leukemias, highlighting a tractable therapeutic strategy for high-risk obese patients.
Authors
Reuben Kapur, Linke Li, Rahul Kanumuri, Kanaka Sai Ram Padam, Baskar Ramdas, Chiranjeevi Pasala, Gabriela Chiosis, Lakshmi Reddy Palam, Ramesh Kumar, Satoshi Koyama, Pradeep Natarajan, Laura S. Haneline, Zhi Yu, Santhosh Kumar Pasupuleti
Abstract
Typ515 (W515) mutations in the protein MPL are one of key driver mutations promoting BCR/ABL-negative myeloproliferative neoplasms (MPNs), but their effects on hematopoietic stem cells (HSCs) and MPN-related hematological abnormalities have not been studied in physiological contexts. Here, we established a MplW514L knock-in mouse model which largely mimics human MPLW515L mutation during hematopoiesis. The mutant mice developed an essential thrombocythemia (ET)-like MPN phenotypes, displaying excess megakaryopoiesis and thrombocytosis and progressive myelofibrosis. Mechanistically we observed that MplW514L-conditioned HSC compartment had a unique disease-initiating capacity however it did not exhibit a obvious advantage of competitive repopulation over wild-type control. Notably, single-cell analysis and flow cytometry profiles support that MplW514L expression led to a significant expansion of megakaryocyte-biased stem cell fate within the HSC pool. Finally, JAK2 inhibitor treatment phenotypically alleviated the ET signs but failed to eliminate the disease-initiating HSCs. These findings underscore the etiology of physiological expression of MPLW515L mutation in HSCs, and also provide a valuable in vivo model to evaluate potential therapeutic options for patients with MPLW515L-positive MPN.
Authors
Shujing Zhang, Jingjing Liu, yuan li, Yi Wang, Lingling Wang, Miaomiao Xu, Yanxia Li, Ge Dong, Shanshan Wang, Yanmei Li, Zhigang Cai, Baobing Zhao
Copyright © 2026 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)