�����ƽ��

Adeno-associated viral (AAV) vector-based gene therapy is gaining foothold as treatment for genetic neurological diseases with encouraging clinical results. Nonetheless, dose-dependent adverse events have emerged in recent clinical trials through mechanisms that remain unclear. We have modelled here the impact of AAV transduction in cell models of the human central nervous system (CNS), taking advantage of induced pluripotent stem cells. Our work uncovers vector-induced innate immune mechanisms that contribute to cell death. While empty AAV capsids were well tolerated, the AAV genome triggered p53-dependent DNA damage responses across CNS cell types followed by the induction of inflammatory responses. In addition, transgene expression led to MAVS-dependent activation of type I interferon responses. Formation of DNA damage foci in neurons and gliosis were confirmed in murine striatum upon intraparenchymal AAV injection. Transduction-induced cell death and gliosis could be prevented by inhibiting p53 or by acting downstream on STING- or IL-1R-mediated responses. Together, our work identifies innate immune mechanisms of vector sensing in the CNS that can potentially contribute to AAV-associated neurotoxicity. Subject terms: Neuroimmunology, Innate immunity, Neural stem cells

SOT201 and its murine surrogate mSOT201 are novel cis-acting immunocytokines consisting of a humanized/murinized/, Fc-silenced anti-programmed cell death protein 1 (PD-1) monoclonal antibody (mAb) fused to an attenuated human interleukin (IL)-15 and the IL-15Rα sushi+ domain. Murine mPD1-IL2v is a conjugate of a murinized, Fc silenced anti-PD-1 mAb bearing human IL-2 with abolished IL-2Rα binding. These immunocytokines spatiotemporally reinvigorate PD-1 + CD8 + tumor-infiltrating lymphocytes (TILs) via cis-activation and concomitantly activate the innate immunity via IL-2/15Rβγ signaling. Human peripheral blood mononuclear cell and cell lines were used to evaluate cis/trans activity of SOT201. Anti-PD-1 mAb responsive (MC38, CT26) and resistant (B16F10, CT26 STK11 KO) mouse tumor models were used to determine the anticancer efficacy, and the underlying immune cell activity was analyzed via single-cell RNA sequencing and flow cytometry. The expansion of tumor antigen-specific CD8 + T cells by mSOT201 or mPD1-IL2v and memory CD8 + T-cell generation in vivo was determined by flow cytometry. SOT201 delivers attenuated IL-15 to PD-1 + T cells via cis-presentation, reinvigorates exhausted human T cells and induces higher interferon-γ production than pembrolizumab in vitro. mSOT201 administered as a single dose exhibits strong antitumor efficacy with several complete responses in all tested mouse tumor models. While mPD1-IL2v activates CD8 + T cells with a 50-fold higher potency than mSOT201 in vitro, mSOT201 more effectively reactivates effector exhausted CD8 + T cells (Tex), which demonstrate higher cytotoxicity, lower exhaustion and lower immune checkpoint transcriptional signatures in comparison to mPD1-IL2v in MC38 tumors in vivo. This can be correlated with a higher rate of complete responses in the MC38 tumor model following mSOT201 treatment when compared with mPD1-IL2v. mSOT201 increased the relative number of tumor antigen-specific CD8 + T cells, and unlike mPD1-IL2v stimulated greater expansion of adoptively transferred ovalbumin-primed CD8 + T cells simultaneously limiting the peripheral CD8 + T-cell sink, leading to the development of memory CD8 + T cells in vivo. SOT201 represents a promising therapeutic candidate that preferentially targets PD-1 + TILs, delivering balanced cytokine activity for reviving CD8 + Tex cells in tumors. SOT201 is currently being evaluated in the Phase I clinical study VICTORIA-01 ( NCT06163391 ) in patients with advanced metastatic cancer.

The competitive advantage of mutant hematopoietic stem and progenitor cells (HSPCs) underlies clonal hematopoiesis (CH). Drivers of CH include aging and inflammation; however, how CH-mutant cells gain a selective advantage in these contexts is an unresolved question. Using a murine model of CH ( Dnmt3a R878H/+ ), we discover that mutant HSPCs sustain elevated mitochondrial respiration which is associated with their resistance to aging-related changes in the bone marrow microenvironment. Mutant HSPCs have DNA hypomethylation and increased expression of oxidative phosphorylation gene signatures, increased functional oxidative phosphorylation capacity, high mitochondrial membrane potential (Δψm), and greater dependence on mitochondrial respiration compared to wild-type HSPCs. Exploiting the elevated Δψm of mutant HSPCs, long-chain alkyl-TPP molecules (MitoQ, d-TPP) selectively accumulate in the mitochondria and cause reduced mitochondrial respiration, mitochondrial-driven apoptosis and ablate the competitive advantage of HSPCs ex vivo and in vivo in aged recipient mice. Further, MitoQ targets elevated mitochondrial respiration and the selective advantage of human DNMT3A -knockdown HSPCs, supporting species conservation. These data suggest that mitochondrial activity is a targetable mechanism by which CH-mutant HSPCs gain a selective advantage over wild-type HSPCs. Subject terms: Ageing, Haematopoietic stem cells, Mitochondria

This study aimed to assess the efficacy of Quality and Quantity media-cultured mononuclear cells (QQ-MNCs) for promoting nerve regeneration in a mouse sciatic nerve transection model. Human peripheral blood mononuclear cells (PB-MNCs) and QQ-MNCs derived from healthy volunteers were used/compared. The left sciatic nerve was surgically transected in 27 mice. After complete nerve transection was confirmed, end-to-end direct epineurial nerve repair was performed using 9–0 nylon. Fibrin glue was applied to the tissue around the injury site to limit diffusion of the study treatment followed by application of 0.5 ml phosphate buffered saline (PBS) or PB-MNCs (2x10 6 cells) or QQ-MNCs (2x10 6 cells) to the injury site. The skin was then closed using 6–0 nylon. Histomorphology, immunohistochemistry, electrophysiologic examination, and functional assessment were evaluated at 12-weeks followed by euthanasia and subsequent harvesting of the left sciatic nerves and the left and right gastrocnemius muscles for examination. QQ-MNCs mice exhibited significant improvement in all histomorphologic parameters (axon fiber diameter, myelin thickness, percentage of nerve density) and immunohistochemistry assays (S100, SOX10, GFAP, neurofilament, IL-1β, VEGF, anti-HNA, TNF-α, vWF) compared to PBS mice (all p < 0.05). QQ-MNCs mice also had a significantly higher Basso Mouse Scale score compared to PBS mice ( p = 0.018). The percentage of nerve density adjacent to the injury site was significantly higher in QQ-MNCs mice than in PB-MNCs mice ( p = 0.049). IL-1β expression was significantly lower in QQ-MNCs mice than in PB-MNCs mice ( p = 0.01). QQ-MNCs mice demonstrated significantly better functional and histomorphologic outcomes of nerve regeneration compared to PB-MNCs mice and PBS mice.

Germline activating and deactivating mutations of STAT5b , part of the JAK-STAT signaling pathway, push the immune system and hematopoiesis in opposing directions, tuning systems either up or down.

The complete array of genes required for terminal erythroid differentiation remains unknown. To address this knowledge gap, we perform a genome-scale CRISPR knock-out screen in the human erythroid progenitor cell line HUDEP-2 and validate candidate regulators of erythroid differentiation in a custom secondary screen. Comparison of sgRNA abundance in the CRISPR library, proerythroblasts, and orthochromatic erythroblasts, resulted in the identification of genes that are essential for proerythroblast survival and genes that are required for terminal erythroid differentiation. Among the top genes identified are known regulators of erythropoiesis, underscoring the validity of this screen. Notably, using a Log2 fold change of <−1 and false discovery rate of <0.01, the screen identified 277 genes that are required for terminal erythroid differentiation, including multiple genes not previously nominated through GWAS. NHLRC2 , which was previously implicated in hemolytic anemia, was a highly ranked gene. We suggest that anemia due to NHLRC2 mutation results at least in part from a defect in erythroid differentiation. Another highly ranked gene in the screen is VAC14 , which we validated for its requirement in erythropoiesis in vitro and in vivo. Thus, data from this CRISPR screen may help classify the underlying mechanisms that contribute to erythroid disorders. Subject terms: Erythropoiesis, CRISPR-Cas9 genome editing, Haematopoietic stem cells

The CEBPA transcription factor is frequently mutated in acute myeloid leukemia (AML). Mutations in the CEBPA gene, which are typically biallelic, result in the production of a shorter isoform known as p30. Both the canonical 42-kDa isoform (p42) and the AML-associated p30 isoform bind chromatin and activate transcription, but the specific transcriptional programs controlled by each protein and how they are linked to a selective advantage in AML is not well understood. Here, we show that cells expressing the AML-associated p30 have reduced baseline inflammatory gene expression and display altered dynamics of transcriptional induction in response to LPS, consequently impacting cytokine secretion. This confers p30-expressing cells an increased resistance to the adverse effects of prolonged exposure to inflammatory signals. Mechanistically, we show that these differences primarily arise from the differential regulation of AP-1 family proteins. In addition, we find that the impaired function of the AP-1 member ATF4 in p30-expressing cells alters their response to ER stress. Collectively, these findings uncover a link between mutant CEBPA, inflammation and the stress response, potentially revealing a vulnerability in AML. Subject terms: Gene regulation, Acute myeloid leukaemia, Transcriptional regulatory elements, Epigenetics in immune cells

Osteosarcoma is the most prevalent primary malignant bone tumor affecting pediatric and adolescent individuals. However, despite the passage of three decades, there has been no notable enhancement in the overall survival rate of patients with osteosarcoma. In recent years, CD155 has been reported to exhibit abnormal amplification in a range of tumors, yet the precise underlying mechanism remains elusive. The objective of this study is to investigate the role of CD155 in osteosarcoma, and to identify drugs that specifically target this molecule, thereby offering a novel direction for the treatment of osteosarcoma. The prognosis of patients with osteosarcoma with high and low expression of CD155 was verified by immunohistochemistry. CCK-8 and colony formation assays were used to detect cell proliferation and drug resistance. Transwell experiments were used to detect cell migration and invasion. The sphere formation experiment was used to evaluate the stemness of tumor cells. Additionally, in vivo animal models were utilized to assess the functional role of CD155 in a biological context. RNA-seq and co-immunoprecipitation methods were used to search for downstream target molecules and signaling pathways of CD155. Finally, virtual screening was used to find drugs targeting CD155. In this study, we have established the significant amplification of CD155 in osteosarcoma. Utilizing a comprehensive array of experimental methods, including CCK-8 assay, colony formation assay, Transwell assay, and in vivo animal models, we unequivocally demonstrate that CD155 significantly potentiates the malignancy of osteosarcoma both in vitro and in vivo. Additionally, our findings reveal that CD155 promotes osteosarcoma stemness by modulating the Wnt/β-catenin signaling pathway. Advanced molecular techniques, such as RNA sequencing and co-immunoprecipitation, have been instrumental in elucidating the mechanism of CD155 in activating the Wnt/β-catenin pathway via the SRC/AKT/GSK3β signaling axis, thereby enhancing the stem-cell-like properties of osteosarcoma cells. To explore targeted therapeutic options, we conducted virtual screening and identified troxerutin as a promising CD155 inhibitor. Our findings reveal that troxerutin effectively inhibits CD155, attenuates the SRC/AKT/GSK3β signaling cascade, diminishes the nuclear localization of β-catenin, and consequently mitigates osteosarcoma stemness. These discoveries position troxerutin as a promising candidate for targeted osteosarcoma therapy. The online version contains supplementary material available at 10.1186/s11658-025-00724-8.

Biliverdin IXβ reductase (BLVRB) is an NADPH-dependent enzyme previously implicated in a redox-regulated mechanism of thrombopoiesis distinct from the thrombopoietin (TPO)/c-MPL axis. Here, we apply computational modeling to inform molecule design, followed by de novo syntheses and screening of unique small molecules retaining the capacity for selective BLVRB inhibition as a novel platelet-enhancing strategy. Two distinct classes of molecules are identified, and NMR spectroscopy and co-crystallization studies confirm binding modes within the BLVRB active site and ring stacking between the nicotinamide moiety of the NADP + cofactor. A diazabicyclo derivative displaying minimal off-target promiscuity and excellent bioavailability characteristics promotes megakaryocyte speciation in biphenotypic (erythro/megakaryocyte) cellular models and synergizes with TPO-dependent megakaryocyte formation in hematopoietic stem cells. Upon oral delivery into mice, this inhibitor expands platelet recovery in stress thrombopoietic models with no adverse effects. In this work, we identify and validate a cellular redox inhibitor retaining the potential to selectively promote megakaryocytopoiesis and enhance stress-associated platelet formation in vivo distinct from TPO receptor agonists. Subject terms: Target validation, Medicinal chemistry, X-ray crystallography, Computational biophysics