Despite advances in immunotherapy, metastatic melanoma remains a considerable therapeutic challenge due to the complexity of the tumor microenvironment. Intratumoral type I interferon (IFN-I) has long been associated with improved clinical outcomes. However, several IFN-I subtypes can also paradoxically promote tumor growth in some contexts. We investigated this further by engineering murine B16 melanoma cells to overexpress various IFN-I subtypes, where a spectrum of outcomes was observed. Characterization of these tumors by RNA sequencing revealed a tumor immune phenotype, where potent IFN-I signaling concomitant with diminished type 2 inflammation failed to confer durable tumor control. T cell-mediated rejection of these tumors was restored by introducing interleukin-4 (IL-4) into the tumor microenvironment, either through ectopic expression or in a preclinical adoptive T cell therapy model. Collectively, our findings highlight the IFN-I/IL-4 axis in promoting antitumor immunity, which could be harnessed to target and stratify solid tumors that are nonresponsive to frontline therapies.

Rationale: Short-term starvation (STS) has been shown to enhance the sensitivity of tumors to chemotherapy while concurrently safeguarding normal cells from its detrimental side effects. Nonetheless, the extent to which STS relies on the anti-tumor immune response to impede the progression of hepatocellular carcinoma (HCC) remains uncertain. Methods: In this study, we employed mass cytometry, flow cytometry, immunoprecipitation, immunoblotting, CUT&Tag, RT-qPCR, and DNA pull-down assays to evaluate the relationship between STS and T-cell antitumor immunity in HCC. Results: We demonstrated that STS alleviated T cell exhaustion in HCC. This study elucidated the mechanism by which STS blocked CD36 N-glycosylation, leading to the upregulation of AMPK phosphorylation and the downregulation of USP7 UFMylation, thus enhancing ubiquitination and destabilized USP7. Consequently, diminished USP7 levels facilitated the ubiquitination and subsequent degradation of RBPJ, thereby inhibiting T cell exhaustion through the IRF4/TNFRSF1B axis. From a therapeutic standpoint, STS not only suppressed the growth of patient-derived orthotopic xenografts but also enhanced their sensitivity to immunotherapy. Conclusions: These findings uncovered a novel mechanism by which N-glycosylation participated in UFMylation/ubiquitination to regulate T cell exhaustion, and we underscored the potential of targeting USP7 and RBPJ in anti-tumor immunotherapy strategies.
© The author(s).

Impaired differentiation is a hallmark of myeloid malignancies1,2. Therapies that enable cells to circumvent the differentiation block, such as all-trans retinoic acid (ATRA) and arsenic trioxide (ATO), are by and large curative in acute promyelocytic leukaemia3, but whether 'differentiation therapy' is a generalizable therapeutic approach for acute myeloid leukaemia (AML) and beyond remains incompletely understood. Here we demonstrate that simultaneous inhibition of the histone demethylase LSD1 (LSD1i) and the WNT pathway antagonist GSK3 kinase4 (GSK3i) robustly promotes therapeutic differentiation of established AML cell lines and primary human AML cells, as well as reducing tumour burden and significantly extending survival in a patient-derived xenograft mouse model. Mechanistically, this combination promotes differentiation by activating genes in the type I interferon pathway via inducing expression of transcription factors such as IRF7 (LSD1i) and the co-activator β-catenin (GSK3i), and their selective co-occupancy at targets such as STAT1, which is necessary for combination-induced differentiation. Combination treatment also suppresses the canonical, pro-oncogenic WNT pathway and cell cycle genes. Analysis of datasets from patients with AML suggests a correlation between the combination-induced transcription signature and better prognosis, highlighting clinical potential of this strategy. Collectively, this combination strategy rewires transcriptional programs to suppress stemness and to promote differentiation, which may have important therapeutic implications for AML and WNT-driven cancers beyond AML.
© 2025. The Author(s).

Flow cytometry characterization of antigen-specific polyfunctional T cells is a valuable tool to study adaptive immunity. Here, we present a protocol for flow cytometry immunophenotyping of human antigen-specific T cells by activation-induced marker (AIM) and Th1 cytokine detection. We describe steps for preparing peripheral blood mononuclear cells (PBMCs) for stimulation followed by washing and staining PBMCs for flow cytometry. We then detail procedures for acquisition and analysis. This protocol has potential applications in the field of vaccine immunology and immuno-oncology. For complete details on the use and execution of this protocol, please refer to Altosole et al.1.
Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.

Efficient tumor T-cell infiltration is crucial for the effectiveness of T-cell-based therapies against solid tumors. Eosinophils play crucial roles in recruiting T cells in solid tumors. Our group has previously generated induced eosinophils (iEOs) from human pluripotent stem cells and exhibited synergistic efficacy with CAR-T cells in solid tumor inhibition. However, administrated eosinophils might influx into inflammatory lungs, posing a potential safety risk. Mitigating the safety concern and enhancing efficacy is a promising development direction for further application of eosinophils.
We developed a new approach to generate eosinophils with enhanced potency from human chemically reprogrammed induced pluripotent stem cells (hCiPSCs) with the Toll-like receptor (TLR) 7/8 signaling agonist R848.
R848-activated iEOs (R-iEOs) showed significantly decreased influx to the inflamed lungs, indicating a lower risk of causing airway disorders. Furthermore, these R-iEOs had enhanced anti-tumor functions, preferably accumulated at tumor sites, and further increased T-cell infiltration. The combination of R-iEOs and CAR-T cells suppressed tumor growth in mice. Moreover, the chemo-trafficking signaling increased in R-iEOs, which may contribute to the decreased lung influx of R-iEOs and the increased tumor recruitment of T cells.
Our study provides a novel approach to alleviate the potential safety concerns associated with eosinophils while increasing T-cell infiltration in solid tumors. This finding offers a prospective strategy for incorporating eosinophils to improve CAR-T-cell immunotherapy for solid tumors in the future.
© 2025. The Author(s).