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Casanova-Acebes, M.

Publications and source records attributed to Casanova-Acebes, M..

4 recordsLinked to original sources

NGFR-driven suppression of antigen presentation limits CD8+ T cell immunity and response to checkpoint blockade

Immune checkpoint blockade has revolutionized cancer therapy; however, numerous tumors remain resistant by adopting cellular states that impede immune recognition. In this study, we identify the nerve growth factor receptor (NGFR) as a regulator of immune evasion in head and neck squamous cell carcinoma (HNSCC). Genetic ablation of Ngfr resulted in impaired tumor growth in immunocompetent MOC2 HNSCC, while pharmacological inhibition with THX-B reduced primary tumor growth and spontaneous metastatic dissemination. Single-cell profiling of MOC2 tumors demonstrated that Ngfr loss redirected tumor cells away from invasive EMT-like states and enhanced antigen-processing and presentation programs. This was accompanied by increased presentation of tumor antigens and expansion of effector CD8+ T-cells in vivo. Functionally, CD8+ T-cell depletion, Batf3 deficiency, and JAK1/2 inhibition restored the growth of Ngfr-deficient tumors, indicating that NGFR loss exposes tumors to CD8+ T-cell-mediated control through a JAK-associated antigen-presentation program. Notably, NGFR blockade sensitized otherwise resistant MOC2 tumors to anti-PD1 therapy, and the combination of THX-B with anti-PD1 significantly improved tumor control and survival. In human HNSCC, spatial profiling revealed that NGFR+ tumor regions exhibited reduced HLA-DR expression and limited CD3+ T-cell infiltration. Notably, an NGFR-associated antigen-presentation signature stratified survival and response in HNSCC patients undergoing immune checkpoint blockade. Interestingly, this signature was also linked to improved outcomes in melanoma patients. We also observed a significant increase in the effector CD8+ T-cell fraction in melanoma NGFR KO tumors linked to a significant decrease in tumor growth. These findings position NGFR as a regulator of tumor immune visibility and support NGFR inhibition as a strategy to enhance immunotherapy response.

cancer biology↗

Spatial positioning and matrix programs of cancer-associated fibroblasts promote T cell exclusion in human lung tumors

It is currently accepted that activated cancer-associated fibroblasts (CAF) participate in T cell exclusion from tumor nests, but it remains unclear how they promote barrier phenotypes, and whether specific subsets are involved. Here, using single-cell RNA sequencing coupled with multiplex imaging on a large cohort of lung tumors, we identify four main CAF populations, of which only two are associated with T cell exclusion: (i) MYH11+SMA+ CAF, which are present in early-stage tumors and form a single-cell layer lining cancer aggregates, and (ii) FAP+SMA+ CAF, which appear in more advanced tumors and organize in patches within the stroma or in multiple layers around tumor nests. Both CAF populations show a contractility phenotype together with dense and aligned matrix fiber deposition compared to the T cell-permissive CAF. Yet they express distinct matrix genes, including COL4A1/COL9A1 (MYH11+SMA+ CAF) and COL11A1/COL12A1 (FAP+SMA+ CAF). Hereby, we uncovered unique molecular programs of CAF driving T cell marginalization, whose targeting should increase immunotherapy efficacy in patients bearing T cell-excluded tumors. SIGNIFICANCEThe cellular and molecular programs driving T cell marginalization in solid tumors remain unclear. Here, we describe two CAF populations associated with T cell exclusion in human lung tumors. We demonstrate the importance of pairing molecular and spatial analysis of the tumor microenvironment, a prerequisite to develop new strategies targeting T cell-excluding CAF.

cancer biology↗

Disruption of the CSF-1-CSF-1R axis alters cerebellar microglia and is associated with motor and social interaction defects

Microglia, the brain resident macrophages, critically shape forebrain neuronal circuits. However, their precise function in the cerebellum is unknown. Here we show that human and mouse cerebellar microglia express a unique molecular program distinct from forebrain microglia. Cerebellar microglial identity was driven by the CSF-1R ligand CSF-1, independently of the alternate CSF-1R ligand, IL-34. Accordingly, CSF-1 depletion from Nestin+ cells led to severe depletion and transcriptional alterations of cerebellar microglia, while microglia in the forebrain remained intact. Strikingly, CSF-1 deficiency and alteration of cerebellar microglia were associated with reduced Purkinje cells, altered neuronal function, and defects in motor learning and social novelty interactions. These findings reveal a novel CSF-1-CSF-1R signaling-mediated mechanism that contributes to motor function and social behavior.\n\nSummaryMicroglia are a heterogeneous population whose identity and function are dictated by signals from their microenvironment. Kana et al. show that CSF-1 signaling is critical for maintaining cerebellar microglial transcriptional identity and homeostasis, and that altering the CSF-1 - CSF-1R axis leads to motor and behavioral defects.

neuroscience↗

Dietary intake regulates the circulating inflammatory monocyte pool

Caloric restriction is known to improve inflammatory and autoimmune diseases. However, the mechanisms by which reduced caloric intake modulates inflammation are poorly understood. Here we show that short-term fasting reduced monocyte metabolic and inflammatory activity and drastically reduced the number of circulating monocytes. Regulation of peripheral monocyte numbers was dependent on dietary glucose and protein levels. Specifically, we found that activation of the low-energy sensor 5-AMP-activated protein kinase (AMPK) in hepatocytes and suppression of systemic CCL2 production by peroxisome proliferator-activator receptor alpha (PPAR) reduced monocyte mobilization from the bone marrow. Importantly, while caloric restriction improves chronic inflammatory diseases, fasting did not compromise monocyte emergency mobilization during acute infectious inflammation and tissue repair. These results reveal that caloric intake and liver energy sensors dictate the blood and tissue immune tone and link dietary habits to inflammatory disease outcome.\n\nHighlightsO_LIFasting reduces the numbers of peripheral pro-inflammatory monocytes in healthy humans and mice.\nC_LIO_LIA hepatic AMPK-PPAR energy-sensing axis controls homeostatic monocyte numbers via regulation of steady-state CCL2 production.\nC_LIO_LIFasting reduces monocyte metabolic and inflammatory activity.\nC_LIO_LIFasting improves chronic inflammatory diseases but does not compromise monocyte emergency mobilization during acute infectious inflammation and tissue repair.\nC_LI

immunology↗