InVivoMAb anti-mouse CSF1R (CD115)

Cancer-induced cachexia and anorexia are debilitating complications across many cancers, yet effective treatments remain limited due to a poor understanding of the underlying mechanisms. Here, we identify an uncharacterized tumor-immune-neural circuit driving these syndromes, centered on growth and differentiation factor 15 (GDF15). Using genetically engineered mouse models, we find that loss of GDF15 protects against appetite loss, muscle wasting, and fat loss in pancreatic, lung, and skin cancers. Single-cell RNA sequencing reveals macrophages as a major source of GDF15, induced by tumor-derived colony-stimulating factor 1 (CSF1). GDF15 acts via the central nervous system to enhance β-adrenergic signaling in the tumor microenvironment, thereby amplifying cachexia. The disruption of this feedforward loop with GDF15-neutralizing antibody, anti-CSF1R antibody, or Rearranged during Transfection (RET) inhibitor markedly reduces both cachexia and anorexia. These findings reveal a non-cell-autonomous mechanism linking tumor signals, macrophage-derived GDF15, and neural pathways, highlighting the tumor-immune-neural triad as a promising therapeutic target.

Tumour-associated macrophages (TAMs) contribute to immune checkpoint blockade resistance, but their impact on intratumoural CD8⁺ T cell distribution remains unclear. Here we show that the expression of the glucose transporter SLC2A1 is spatially negatively correlated with CD8⁺ T cell distribution in both non-small-cell lung cancer (NSCLC) biopsies and murine tumour models. Tumour cell-specific Slc2a1 knockdown fails to reproduce the therapeutic benefit of SLC2A1 inhibition, whereas TAM-specific deletion of Slc2a1 suppresses tumour growth by enhancing the spatial homogeneity and effector function of intratumoural CD8⁺ T cells, thereby improving αPD-L1 efficacy. Spatial profiling of NSCLC specimens further revealed that SLC2A1⁺ TAM-enriched regions exhibit reduced CD8⁺ T cell density, and spatial proximity between these populations predicts resistance to αPD-(L)1 therapy. These findings identify SLC2A1⁺ TAMs as drivers of spatial CD8⁺ T cell exclusion and highlight TAM-specific SLC2A1 as a therapeutic target to overcome immune checkpoint blockade resistance in NSCLC.

Tumor-specific antigens (TSAs) are crucial for activating T cells against cancer, but traditional discovery methods focusing on exonic mutations overlook non-canonical TSAs from non-coding regions. We employed an integrative proteogenomic strategy combining whole-genome and RNA sequencing with immunoprecipitation mass spectrometry to comprehensively explore TSA generation in colorectal cancer patients. Analysis of 10 paired tumor samples identified 96 mutated major histocompatibility complex class I-presented neo-epitopes, with 80.21% originating from non-coding regions. In hypermutated tumors with high mutational burden, neo-epitopes predominantly arose from intergenic and intronic areas, while in non-hypermutated tumors with low mutational burden, they mainly stemmed from coding variations and alternative splicing events. Functional validation in mouse models demonstrated that mutated non-canonical neo-epitopes effectively activated CD8+ T cells and significantly suppressed tumor growth. These findings underscore the importance of considering the entire genomic landscape in TSA discovery, suggesting new avenues for personalized immunotherapy.

Neutrophil extracellular traps (NETs) are associated with cancer progression; however, the functional role and clinical importance of NET-DNA in therapeutic resistance remain unclear. Here, we show that chemotherapy and radiotherapy provoke NET-DNA formation in primary tumor and metastatic organs in breast cancer patients and mouse models, and the level of NET-DNA correlates with treatment resistance. Mechanistically, the cathepsin C in tumor debris generated by anticancer therapy is phagocytosed by macrophages and drives CXCL1/2 and complement factor B production via activating the TLR4/NF-κB signaling pathway, subsequently promoting NETosis and impairing therapeutic efficacy. Importantly, we demonstrate that NET-DNA sensor CCDC25 is indispensable in NET-mediated treatment resistance by inducing cancer cell epithelial-mesenchymal transition via pyruvate kinase isoform M2-mediated STAT3 phosphorylation. Clinically, tumoral CCDC25 abundance is closely associated with poor prognosis in patients who underwent chemotherapy. Overall, our data reveal the mechanism of NET formation and elucidate the interaction of NET-CCDC25 in therapy resistance, highlighting CCDC25 as an appealing target for anticancer interventions.

SLAMF8 is predominantly expressed in macrophages and plays an important role in autoimmune diseases and inflammation. Our previous studies have focused on SLAMF8, however, the potential of SLAMF8 as an immunotherapeutic target and its role in regulating the tumor immune microenvironment remain to be elucidated. This study demonstrated that macrophage-specific SLAMF8 is significantly associated with a poor prognosis for colorectal cancer (CRC). Additionally, M2 macrophage and tumor-associated macrophages (TAMs) models were used to verify that SLAMF8 induces an immunosuppressive phenotype in macrophages and regulates antitumor immunity by inhibiting the activation and function of CD8+ T cells. In vivo, we confirmed that SLAMF8 inhibition promoted remodeling of the immunosuppressive microenvironment and augmented immunotherapy sensitivity in CRC. Mechanistically, we demonstrated that SLAMF8 promotes the polarization of macrophages toward the M2 phenotype via the PI3K/AKT and JAK/STAT3 signaling pathways. In summary, this study confirmed that inhibiting SLAMF8 exerts an antitumor effect by reversing the immunosuppressive tumor microenvironment in CRC, providing new therapeutic targets and strategies for combined immunotherapy.

Subarachnoid hemorrhage (SAH) frequently results in early brain injury (EBI), which remains a major barrier to favorable neurological recovery. Understanding the molecular underpinnings of EBI is crucial for developing targeted therapeutics. Circular RNAs (circRNAs) have emerged as influential molecular players in various brain injury contexts. This study focuses on one such molecule, circ_0004058, examining its impact on EBI through interaction with miR-221-3p and the VE1 signaling pathway. Utilizing an established SAH rodent model, our team conducted a detailed investigation of the expression patterns and interactions involving circ_0004058. Our analyses revealed a significant post-SAH upregulation of circ_0004058, which affected miR-221-3p activity and VE1 signaling. Furthermore, functional modulation of circ_0004058 expression altered the severity of EBI, presenting evidence that it serves as a critical determinant in the injury process. The results suggest that circ_0004058 holds promise as a therapeutic target, offering new possibilities for the development of strategies to mitigate SAH-induced brain damage. Through this study, circ_0004058 is highlighted not only as a biomarker but also as a possible avenue for therapeutic modulation in SAH management.

Immune checkpoint inhibitors (ICIs) have transformed the treatment strategy for bladder cancer (BLCA), but primary resistance still occurs in most patients. Recent evidence suggests that neutrophil extracellular traps (NETs) play a key role in cancer therapy resistance, but their specific role in BLCA remains unclear.

Uncontrolled hypertension is a global health issue with 40 % of hypertensive patients not achieving blood pressure control with current therapies. Previously, we demonstrated renal macrophage infiltration during hypertension development with macrophage depletion leading to reduced blood pressure and renal fibrosis. However, the effect of macrophage depletion in existing hypertension has not been evaluated. We induced hypertension in mice then depleted macrophages and assessed blood pressure and renal fibrosis. Separately induced hypertension and assessed renal macrophage population and fibrosis early in hypertension. Results showed increased renal macrophage, Acta2 early in hypertension development. Macrophage depletion led to reduced blood pressure in the hypertensive mice, decreased kidney Col1a1, Acta2, Col3a1 and Fn1. This study shows that renal macrophage infiltration and fibrosis begin early in hypertension development and depleting macrophages in hypertension reduces blood pressure and suppress renal fibrosis. This shows macrophages are a potential target in treatment of hypertension.

Chimeric antigen receptor (CAR) T cell therapy has shown promise in treating hematologic malignancies, but it still faces challenges, including high costs, a time-consuming manufacturing process, and the necessity of lymphodepletion. Here, we generate circular RNAs (circRNAs) encoding CAR proteins, referred to as circRNACAR, which mediates remarkable tumor killing in human primary T cells. We demonstrate that circRNACAR, delivered with immunocyte-tropic lipid nanoparticles (LNPs), can form in vivo panCAR cells (CAR-T, CAR-natural killer [NK], and CAR-macrophage), significantly inhibit tumor growth, and reshape the tumor microenvironment in mice. Importantly, combining in vivo panCAR with circRNA-based vaccines encoding the corresponding HER2 antigens exhibits synergistically enhanced anti-tumor immunity. Notably, circRNACAR can in return boost the level of vaccination-elicited HER2-specific antibodies, mediating effective killing of tumor cells by macrophages. In combination with vaccination, in vivo panCAR demonstrates a synergistic enhancement of anti-tumor immunity across various mouse models, thereby establishing a framework for the synergistic in vivo panCAR-VAC immunotherapy.

Optimizing intratumoral dendritic cell (DC)-T cell responses is pivotal for effective cancer immunotherapy. However, the mechanistic governing these dynamics within the tumor microenvironment (TME) remains unclear, and strategies to improve their therapeutic potential are underexplored. Here, we show that precise radiotherapy activates the pro-TLR7/8 agonist imidazoquinoline (IMDQ) locally in preclinical tumor models, stimulating DCs to elicit T cell immunity without the need for further recruitment or causing systemic toxicity. Mechanistically, this synergistic approach triggers type I interferon via STING and MyD88 signaling pathways, strengthening local immune responses. Importantly, we reveal that fractionated, low-dose radiotherapy can effectively optimize local DC-T cell dynamics to control the irradiated tumor, while also promoting abscopal effect. Thus, our findings underscore the critical role of harnessing intratumoral DCs to reinvigorate pre-existing T cell immunity and provide mechanistic insights into improving both local and distal tumor control, opening new avenues for advancing cancer immunotherapy.

Bone metastasis is a major cause of cancer death; however, the epigenetic determinants driving this process remain elusive. Here, we report that histone methyltransferase ASH1L is genetically amplified and is required for bone metastasis in men with prostate cancer. ASH1L rewires histone methylations and cooperates with HIF-1α to induce pro-metastatic transcriptome in invading cancer cells, resulting in monocyte differentiation into lipid-associated macrophage (LA-TAM) and enhancing their pro-tumoral phenotype in the metastatic bone niche. We identified IGF-2 as a direct target of ASH1L/HIF-1α and mediates LA-TAMs' differentiation and phenotypic changes by reprogramming oxidative phosphorylation. Pharmacologic inhibition of the ASH1L-HIF-1α-macrophages axis elicits robust anti-metastasis responses in preclinical models. Our study demonstrates epigenetic alterations in cancer cells reprogram metabolism and features of myeloid components, facilitating metastatic outgrowth. It establishes ASH1L as an epigenetic driver priming metastasis and macrophage plasticity in the bone niche, providing a bona fide therapeutic target in metastatic malignancies.

The study identifies GPR65 as an important determinant of B-cell acute lymphoblastic leukemia response to CAR T-cell therapy. Notably, GPR65 absence signals CAR T resistance. By emphasizing the therapeutic potential of targeting VEGFA or host macrophages, our study identifies routes to optimize CAR T-cell therapy outcomes in hematologic malignancies via tumor microenvironment manipulation.

The tumor microenvironment in solid tumors contains myeloid cells that modulate local immune activity. Stimulator of IFN gene (STING) signaling activation in these myeloid cells enhances local type-I IFN production, inducing an innate immune response that mobilizes adaptive immunity and reprograms immunosuppressive myeloid populations to drive antitumor immunity. In this study, we generated TAK-500, an immune cell-directed antibody-drug conjugate, to deliver a STING agonist to CCR2+ human cells and drive enhanced antitumor activity relative to nontargeted STING agonists. Preclinically, TAK-500 triggered dose-dependent innate immune activation in vitro. In addition, a murine TAK-500 immune cell-directed antibody-drug conjugate surrogate enhanced innate and adaptive immune responses both in in vitro and murine tumor models. Spatially resolved analysis of CCR2 and immune cell markers in the tumor microenvironment of >1,000 primary human tumors showed that the CCR2 protein was predominantly expressed in intratumoral myeloid cells. Collectively, these data highlight the clinical potential of delivering a STING agonist to CCR2+ cells.

Radiotherapy (RT) resistance in head and neck squamous cell carcinoma (HNSCC) significantly hampers local control and patient prognosis. This study investigated the efficacy and molecular mechanisms of high-energy X-ray-based ultra-high dose rate radiotherapy (UHDR-RT) in overcoming RT resistance. The established RT-resistant HNSCC cell lines and animal models were subjected to UHDR-RT or conventional RT (Conv-RT) via a high-power rhodotron accelerator. Cellular assays assessed the malignant phenotype, viability, and degree of DNA damage, whereas in vivo evaluations focused on tumor proliferation and the tumor immune microenvironment (TiME). Transcriptome sequencing and Olink proteomics were employed to explore the underlying mechanisms involved. In vitro experiments indicated that UHDR-RT suppressed radioresistant cell proliferation and invasion, while promoting apoptosis and exacerbating DNA damage. In contrast, its efficacy in radiosensitive cells was comparable to that of Conv-RT. In vivo studies using patient-derived xenograft nude mice models demonstrated that UHDR-RT only partially reversed RT resistance. Transcriptomic and proteomic analyses of C57BL/6J mice models revealed the predominant role of TiME modulating in reversing radioresistance. Immunofluorescence and flow cytometry confirmed increased CD8+ T cells and an increased M1/M2 macrophage ratio post-UHDR-RT. Mechanistically, UHDR-RT activated CD8+ T cells, which stimulated M1 macrophages through paracrine IFN-γ signaling, thereby enhancing TiME activation. Furthermore, the activated M1 macrophages secreted CXCL9, which in turn reactivated CD8+ T cells, forming a feedforward loop that amplified TiME activation. This study elucidates the dual role of UHDR-RT in directly inducing DNA damage and modulating the TiME, highlighting its potential in treating radioresistant HNSCC.

Oncolytic viruses have been considered promising cancer immunotherapies. However, oncovirotherapy agents impart durable responses in only a subset of cancer patients. Thus, exploring the cellular and molecular mechanisms underlying the heterogeneous responses in patients can provide guidance to develop more effective oncolytic virus therapies. Single-cell RNA sequencing (scRNA-seq) analysis of tumors responsive and non-responsive to oncovirotherapy revealed signatures of the tumor immune microenvironment associated with immune response. Thus, we designed and constructed an armed oncolytic virus, OV-5A, that expressed five genes with non-redundant functions. OV-5A treatment exhibits robust immune response against various tumors in multiple mouse models, peripheral blood mononuclear cell -patient-derived xenograft models, organoid-immune cell co-culture systems, and patient tissue sections by activating a cooperative innate-adaptive immune response against tumor cells. scRNA-seq analysis of complete responders and partial responders to OV-5A treatment guided the design of combination therapy of OV-5A. This data-driven approach paves an innovative way to rationalize the design of oncolytic virus and multi-agent combination therapies.

The response of breast cancer to neoadjuvant chemotherapy (NAC) varies substantially, even when tumours belong to the same molecular or histological subtype1. Here we identify the oestrous cycle as an important contributor to this heterogeneity. In three mouse models of breast cancer, we show reduced responses to NAC when treatment is initiated during the dioestrus stage, when compared with initiation during the oestrus stage. Similar findings were observed in retrospective premenopausal cohorts of human patients. Mechanistically, the dioestrus stage exhibits systemic and localized changes, including (1) an increased number of cells undergoing epithelial-to-mesenchymal transition linked to chemoresistance2-4 and (2) decreased tumour vessel diameter, suggesting potential constraints to drug sensitivity and delivery. In addition, an elevated presence of macrophages, previously associated with chemoresistance induction5, characterizes the dioestrus phase. Whereas NAC disrupts the oestrous cycle, this elevated macrophage prevalence persists and depletion of macrophages mitigates the reduced therapy response observed when initiating treatment during dioestrus. Our data collectively demonstrate the oestrous cycle as a crucial infradian rhythm determining chemosensitivity, warranting future clinical studies to exploit optimal treatment initiation timing for enhanced chemotherapy outcomes.