Biology subjects

Fior, R.

Publications and source records attributed to Fior, R..

5 recordsLinked to original sources

bioRxiv2026

CD24 Acts as an Evolutionarily Conserved Innate Immune Checkpoint in Colorectal Cancer

Checkpoint immunotherapy has transformed cancer treatment, yet current approaches targeting adaptive immunity benefit only a subset of patients, leaving innate immunity as a largely untapped therapeutic frontier. Here, we identify CD24 as an innate immune checkpoint that protects colorectal tumors from macrophage-mediated clearance through an evolutionarily conserved recognition mechanism. Using zebrafish xenografts of isogenic colorectal cancer (CRC) cell lines, SW480 and SW620, we show that high CD24 expression in SW620 correlates with an immune-evasive, macrophage-resistant phenotype. Loss of human CD24 dramatically sensitizes tumors to clearance in zebrafish, while pharmacological macrophage depletion abolishes this effect. Mechanistically, CD24 suppresses innate immunity in a multilayered fashion, by limiting myeloid recruitment, dampening TNF-driven macrophage inflammatory polarization, and blocking phagocytosis. Live imaging further revealed that CD24 constrains macrophages to a restrained, patrol-like state, and that its loss enables them to adopt a highly motile, tumor-directed, and functionally engaged state, characterized by increased fusion activity and myeloid intercellular interactions. We show that zebrafish macrophages respond to human CD24 despite extensive evolutionary divergence, and glycocalyx profiling revealed broad remodeling of the tumor cell surface upon CD24 loss, suggesting evolutionary conservation of sialic acid-dependent receptor recognition. Transcriptomic analyses identified the Siglec-like gene si:dkey-24p1.7 as a candidate zebrafish macrophage-expressed receptor mediating this response. Finally, analysis of TCGA CRC cohorts revealed that CD24 expression is a stage-dependent prognostic marker, underscoring the clinical relevance of this axis. Together, these findings establish CD24 as a critical orchestrator of innate immune evasion in CRC, while further validating zebrafish xenografts as a powerful platform for dissecting innate immuno-oncobiology in vivo.

cancer biology↗

bioRxiv2025

Bifunctional Phagocytic Synapse Enhancers for Cancer Immunotherapy

Immunotherapy profoundly impacted cancer treatments by harnessing the patients immune system. Phagocytosis, the process whereby immune cells engulf and destroy foreign particles or cells, plays a critical role in tumour cell clearance. Herein, we introduce a novel concept termed "ENPHASYS" - Enhancement of Phagocytic Synapses - designed to direct and amplify phagocytosis of cancer cells using heterobifunctional molecules named phagocytic synapse enhancers (PSEs). By engineering a de novo PD-L1 binder linked to a natural phagocytosis promoting peptide, tuftsin, the resulting PSE combines PD-L1 blockade with enhanced tumour cell phagocytosis; in addition, the PSEs induce macrophages to internalize a membrane or extracellular target. Intratumoural treatment of colorectal carcinoma- or glioblastoma-burdened immunocompetent animals resulted in beneficial overall survival, delayed tumour growth and a potent antitumor response driven by T-cell activation and TAM reprogramming, underpinning the translational relevance of ENPHASYS. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=118 SRC="FIGDIR/small/642658v1_ufig1.gif" ALT="Figure 1"> View larger version (19K): org.highwire.dtl.DTLVardef@1673fd4org.highwire.dtl.DTLVardef@18fa319org.highwire.dtl.DTLVardef@11cf680org.highwire.dtl.DTLVardef@7b8784_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2024

Zebrafish Avatar-test predicts patient's tumor response to chemotherapy in breast cancer: a co-clinical study towards personalized medicine

Chemotherapy remains the mainstay in most high-risk breast cancer (BC) settings, with several equivalent options of treatment. However, the efficacy of each treatment varies between patients and there is currently no test to determine which option will be the most effective for each individual patient. Here, we developed a fast in-vivo test for BC therapy screening: the zebrafish patient derived xenograft model (zAvatars), where in-vivo results can be obtained in just 10 days. To determine the predictive value of the BC zAvatars we performed a clinical study, where zAvatars were treated with the same therapy as the donor-patient and their response to therapy was compared. Our data shows a 100% correlation between patients clinical response to treatment and its matching zAvatar. Altogether, our results suggest that the zAvatar model constitutes a promising in-vivo assay to optimize cancer treatments in truly personalized manner.

cancer biology↗

bioRxiv2024

Enhancing HLA-DR in Cytotoxic T Lymphocytes is crucial for the development of efficient adoptive T cell Therapies for Breast Cancer

BackgroundDespite advances in breast cancer (BC) therapies, more effective interventions are needed, especially for chemotherapy-resistant tumors. Immune checkpoint inhibitors show promise for triple-negative breast cancer, but their effectiveness across all BC subtypes remains challenging. Therefore, novel strategies, including adoptive cellular therapy, employing patients own T lymphocytes expanded ex vivo, are under investigation. Previously, we demonstrated that cytotoxic T lymphocytes (CTLs) expressing high HLA-DR levels in the tumor microenvironment are associated with a good response to neoadjuvant chemotherapy (NACT), due to their pronounced anti-tumor properties compared to CTLs with low or no HLA-DR expression. In this paper, we demonstrated that HLA-DR expression in CTLs is crucial for efficient T lymphocytes-based therapies. MethodsTo clarify the role of HLA-DR in CTLs anti-tumor abilities, we performed in vitro and in vivo experiments. We also improved a protocol to expand ex vivo HLA-DR-expressing CTLs and employed a 3D co-culture platform to test the potential of different immune agents, namely an anti-PD1, anti-OX40, anti-VEGF and anti-CD137, on CTLs cytotoxicity against BC cells. Additionally, we conducted a bioinformatic analysis of scRNA-seq data of BC patients to better understand the modulation of HLA-DR expression in CTLs. ResultsOur findings revealed that CTLs require HLA-DR expression to eliminate tumor cells. Additionally, we unveiled that blocking HLA-DR or depleting CD4+ T cells compromised CTLs activation and cytotoxicity, suggesting antigen presentation by CTLs through HLA-DR, and CD4+ T cells, as probable mechanisms for CTLs increased anti-tumor immune response and treatment efficacy. We refined an ex vivo stimulation and cytokine supplementation protocol, observing that short-term stimulation increases HLA-DR expression while boosting CTLs functionality, unlike prolonged expansion. This result highlights the importance of prioritizing cell quality, over quantity, for therapy efficiency. Additionally, we verified that anti-PD-1 further increases HLA-DR levels in CTLs, enhancing their anti-tumor efficiency. Notably, an in silico analysis revealed that PD-1 in CTLs shares 34 co-expressed genes with HLA-DR, including several non-coding RNAs, suggesting a PD-1-mediated regulation of HLA-DR expression. ConclusionsGlobally, our findings underscore that heightening HLA-DR expression in CTLs, by combining anti-PD-1 with short-term stimulation, offers promise for improving T lymphocyte-based therapies for BC. Key MessageO_LIWhat is already known on this topic: While immunotherapy holds promise for breast cancer (BC), its success is still limited. Novel strategies are under investigation to improve outcomes across all BC subtypes. Previously we established a correlation between HLA-DR expression on CTLs and a positive response to neoadjuvant chemotherapy, likely due to enhanced anti-tumor properties of HLA-DR-expressing CTLs. However, the specific role of HLA-DR on CTLs and its implications for T lymphocyte-based therapies requires further investigation. C_LIO_LIWhat this study adds: This study revealed that HLA-DR expression is essential for CTLs to effectively eliminate tumor cells. Blocking HLA-DR or depleting CD4+ T cells impairs CTLs activation and cytotoxicity, indicating that HLA-DR-mediated antigen presentation and interaction with CD4+ T cell are crucial for CTLs function. The study also shows that combining ex vivo short-term stimulation and anti-PD-1 treatment increases HLA-DR levels in CTLs, enhancing their anti-tumor activity. C_LIO_LIHow this study might affect research, practice or policy: By emphasizing the importance of optimizing CTLs quality over quantity, this approach has the potential to improve the design of more efficient T lymphocyte-based therapies for BC. This could influence future research directions, clinical practices, and treatment policies, leading to improved therapeutic outcomes. C_LI

immunology↗

bioRxiv2024

Macrophages drive the earliest anti-tumoral response to BCG therapy by directly killing bladder cancer through TNF signaling

The Bacillus Calmette-Guerin (BCG) vaccine is the cancer immunotherapy longest in use. Despite its effectiveness in bladder cancer (BC), its initial mechanisms of action remain largely unknown. Therefore, proper diagnostic assessments to identify patients who will not respond to treatment or develop resistance are lacking. Here, we set-out to unravel the earliest innate cellular mechanisms involved in BCG-induced clearance of tumors. We show that BCG induces a massive recruitment of macrophages to the tumor microenvironment and modulates their morphology and behavior towards a proinflammatory phenotype, while also promoting macrophage fusion-like events. We demonstrate that macrophages directly induce apoptosis and clearance of cancer cells through TNF-signaling and that they are indispensable for this antitumoral response since their depletion completely abrogates the BCG-anti tumor effect. Contrary to the general concept that macrophage antitumoral activities uniquely rely on stimulating an effective adaptive response, we demonstrate that macrophages alone can directly induce tumor killing and clearance; revealing an additional step to the BCG-induced tumor immunity model, that was not previously considered. In addition, we also provide proof-of-concept experiments demonstrating the potential of this unique in vivo preclinical model to test new innate immunomodulators.

cancer biology↗