Biology subjects

Ferreira, E.

Publications and source records attributed to Ferreira, E..

8 recordsLinked to original sources

bioRxiv2026

CD44-CD206 axis drives dendritic cell loss and immunosuppression in immaturely glycosylated bladder tumours

Antigen-presenting-cell dysfunction drives immune exclusion, but how tumour glycans disable these cells remains incompletely defined. Immature O-glycosylation, marked by Tn and sialyl-Tn antigens, drives myeloid dysfunction in bladder cancer. Transcriptomics and human tumour profiling linked this state to reduced representation of antigen-presenting myeloid cells and attenuated lymphoid-effector programmes. In glycoengineered models, immature O-glycans promoted immunoregulatory macrophage phenotypes and contact-dependent death of monocyte-derived dendritic cells (moDCs), while surviving cells showed impaired maturation and T-cell activation. Tumour-cell CD44 standard isoform was required for DC death, which was accompanied by inflammasome-associated proteins and gasdermin D cleavage, consistent with pyroptosis. Receptor-discovery approaches converged on CD206, which bound immaturely glycosylated CD44. CD206 blockade restored DC viability. In immunocompetent mice, immature glycosylation accelerated tumour growth and depleted conventional DCs, whereas CD206 blockade restrained tumour progression and restored local and nodal myeloid and lymphoid immunity. These findings identify CD44-CD206 as a targetable glycoimmune checkpoint that promotes immune exclusion.

immunology↗

bioRxiv2026

Drosophila Heat Shock Factor (HSF) Regulates Developmental Growth by Maintaining the Basal Expression of HSP83/HSP90

The heat shock transcription factor HSF1 is best known as a master regulator of the proteotoxic stress response, yet its functions in animal development remain incompletely defined. In Drosophila melanogaster, heat shock factor (HSF) is essential for viability, but the mechanisms by which it promotes development are unclear. Here, we show that Hsf null larvae arrest at the early 2nd instar stage and exhibit a significant reduction in basal levels of the chaperone HSP83/HSP90. Tissue-specific knockdown of Hsf revealed widespread and organ-specific requirements, including defects in endoreplication and cell growth in larval prothoracic and salivary glands, adult wing defects following larval imaginal disc perturbation, follicle degeneration in the ovary, and melanotic tumor upon hemocyte depletion. In these tissues, loss of HSF typically leads to reduced HSP83 levels, and restoration of HSP83 expression partially or fully rescues these defects. These findings identify HSP83 as a critical downstream effector of HSF and demonstrate that HSF promotes development largely by maintaining basal chaperone expression. Together, our results establish HSF as a key regulator of developmental progression and highlight a central role for proteostasis in supporting tissue growth under non-stress conditions.

developmental biology↗

bioRxiv2025

CD276 Immature Glycosylation Drives Colorectal Cancer Aggressiveness and T-cell Mediated Immune Escape

Colorectal cancer (CRC) progression is fueled by immune evasion, yet the underlying molecular mechanisms remain to be fully characterized. CD276 (B7-H3), an immune checkpoint glycoprotein frequently overexpressed in aggressive tumours, is extensively modified by glycosylation, a process known to regulate protein stability, localization, and immune interactions. However, its glycosylation-dependent functions in CRC remain unclear. This study shows that poor-prognosis CRC tumours exhibit dysregulated glycogene expression, leading to an immature O-glycosylation phenotype that enhances malignancy. Using C1GALT1 knockout CRC cells, which recapitulate the cancer glycocalyx, it was demonstrated that this glycosylation shift promotes proliferation and invasion. We further identify CD276 as a metastasis-associated glycoprotein whose function is shaped by O-glycan modifications. Mechanistically, immature O-glycosylation of CD276 enhances invasion, suppresses T-cell activation, and induces an immunosuppressive cytokine milieu, reinforcing its role in tumour immune escape. These findings establish CD276 as a glycosylation-dependent immune checkpoint and a promising therapeutic target to overcome immune evasion in CRC. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=184 SRC="FIGDIR/small/668091v1_ufig1.gif" ALT="Figure 1"> View larger version (101K): org.highwire.dtl.DTLVardef@2af030org.highwire.dtl.DTLVardef@fee9a8org.highwire.dtl.DTLVardef@19e1c49org.highwire.dtl.DTLVardef@152fd73_HPS_FORMAT_FIGEXP M_FIG C_FIG Table of ContentsColorectal cancer (CRC) progression is closely linked to immune evasion, yet the molecular mechanisms underlying this process remain poorly understood. This study identifies CD276 (B7-H3) as a glycosylation-driven regulator of CRC aggressiveness and demonstrates how O-glycosylation remodeling promotes tumour immune escape. These findings establish CD276 as a potential therapeutic target and highlight the role of glycoproteoform-specific immune modulation in cancer progression.

cancer biology↗

bioRxiv2025

GlycoAvatars: Bead-Coated Membrane Models for Studying the Cancer-Immune Cells Interactome

Immature O-glycosylation of plasma membrane proteins, characterized by the presence of glycosites with a single GalNAc residue (the Tn antigen) rather than more extended and complex glycans, is a prominent feature of many advanced solid tumors across different origins and aetiologies. This form of glycosylation has been strongly associated with poor prognosis and is known to play a crucial role in the progression of the disease. Notably, it has been directly implicated in the crosstalk with the immune system, inducing tolerogenic phenotypes in both innate and adaptive immune cells. Despite this, the specific receptors involved in these interactions remain largely unidentified. To address this gap, we propose a novel high-throughput proteomics assisted strategy for characterizing the glycan interactome using plasma membrane-derived glycoprotein coated magnetic beads. Glycoproteins were isolated from plasma membranes of glycoengineered cell models with immature glycosylation and were then cloaked on the surface of magnetic beads, creating simplified cell "GlycoAvatars." These GlycoAvatars were primarily employed to characterize the interactome between gastric and colorectal cancer cell lines and immune cells (dendritic cells and macrophages), providing a tool for identifying potentially relevant molecular nodes in glycan-mediated immune synapses, foreseeing their application in deciphering tumor-immune interactions.

biochemistry↗

bioRxiv2023

Multilevel Plasticity and Altered Glycosylation Drive Aggressiveness in Hypoxic and Glucose-Deprived Bladder Cancer Cells

Bladder tumours with aggressive characteristics often present with microenvironmental niches marked by low oxygen levels (hypoxia) and limited glucose supply due to inadequate vascularization. The molecular mechanisms facilitating cellular adaptation to these stimuli remain largely elusive. Employing a multi-omics approach, we discovered that hypoxic and glucose- deprived cancer cells enter a quiescent state supported by mitophagy, fatty acid {beta}-oxidation, and amino acid catabolism, concurrently enhancing their invasive capabilities. Reoxygenation and glucose restoration efficiently reversed cell quiescence without affecting cellular viability, highlighting significant molecular plasticity in adapting to microenvironmental challenges. Furthermore, cancer cells exhibited substantial perturbation of protein O-glycosylation, leading to simplified glycophenotypes with shorter glycosidic chains. Exploiting glycoengineered cell models, we established that immature glycosylation contributes to reduced cell proliferation and increased invasion. Our findings collectively indicate that hypoxia and glucose deprivation trigger cancer aggressiveness, reflecting an adaptive escape mechanism underpinned by altered metabolism and protein glycosylation, providing grounds for clinical intervention.

biochemistry↗

bioRxiv2022

Inventa: a computational tool to discover chemical novelty in natural extracts libraries

Collections of natural extracts hold potential for the discovery of novel natural products with original modes of action. The prioritization of extracts from collections remains challenging due to the lack of workflow that combines multiple-source information to facilitate the data interpretation. Results from different analysis techniques and literature reports need to be organized, processed, and interpreted to enable optimal decision-making for extracts prioritization. Here, we introduce Inventa, a computational tool that highlights the chemical novelty potential within extracts, considering untargeted mass spectrometry data, spectral annotation, and literature reports. Based on this information, Inventa calculates multiple scores that inform their chemical potential. Thus, Inventa has the potential to accelerate new natural products discovery. Inventa was applied to a set of plants from the Celastraceae family as a proof of concept. The Pristimera indica (Willd.) A.C.Sm roots extract was highlighted as a promising source of potentially novel compounds. Its phytochemical investigation resulted in the isolation and de novo characterization of thirteen new dihydro-{beta}-agarofuran sesquiterpenes, five of them presenting a new 9-oxodihydro-{beta}-agarofuran base scaffold.

bioinformatics↗

bioRxiv2020

LRP::FLAG reduces phosphorylated tau levels in Alzheimer's Disease

Alzheimers disease (AD) is characterized by amyloid beta (A{beta}) plaque and neurofibrillary tangle formation, respectively. Neurofibrillary tangles form as a result of the intracellular accumulation of hyperphosphorylated tau. Telomerase activity and levels of the human reverse transcriptase (hTERT) subunit of telomerase are significantly decreased in AD. Recently it has been demonstrated that the 37kDa/67kDa laminin receptor (LRP/LR) interacts with telomerase and is implicated in A{beta} pathology. Here we show that LRP/LR co-localizes with tau in the perinuclear cell compartment and FRET confirmed a direct interaction between LRP/LR and tau in HEK-293 cells. Overexpression of LRP::FLAG in HEK-293 and SH-SY5Y cells decreased total and phosphorylated tau levels with a concomitant decrease in PrPc levels, a tauopathy-related protein. Additionally, LRP::FLAG overexpression resulted in increased hTERT levels. These data indicate for the first time a role of LRP/LR in tauopathy of Alzheimers Disease and recommend LRP::FLAG as a potential alternative therapeutic tool for Alzheimers Disease treatment through rescuing cells from A{beta} induced cytotoxicity and, as shown in this report, decreased phosphorylated tau levels.

neuroscience↗

bioRxiv2019

Post-translational epigenetics: PRMT7 regulates RNA-binding capacity and protein stability to control Leishmania parasite virulence

RNA binding proteins (RBPs) are the primary gene regulators in kinetoplastids as transcriptional control is nearly absent, making Leishmania an exceptional model for investigating methylation of non-histone substrates. Arginine methylation is an evolutionarily conserved protein modification catalyzed by Protein aRginine MethylTransferases (PRMTs). The chromatin modifier PRMT7 is the only Type III PRMT found in higher eukaryotes and a restricted number of unicellular eukaryotes. In Leishmania major, PRMT7 is a cytoplasmic protein implicit in pathogenesis with unknown substrates. Using comparative methyl-SILAC proteomics for the first time in protozoa, we identified 40 putative targets, including 17 RBPs hypomethylated upon PRMT7 knockout. PRMT7 can modify Alba3 and RBP16 trans-regulators (mammalian RPP25 and YBX2 homologs, respectively) as direct substrates in vitro. The absence of PRMT7 levels in vivo selectively reduces Alba3 mRNA-binding capacity to specific target transcripts and can impact the relative stability of RBP16 in the cytoplasm. RNA immunoprecipitation analyses demonstrate PRMT7-dependent methylation promotes Alba3 association with select target transcripts and stability of{delta} -amastin surface antigen. These results highlight a novel role for PRMT7-mediated arginine methylation upon RBP substrates, suggesting a regulatory pathway controlling gene expression and virulence in Leishmania. This work introduces Leishmania PRMTs as epigenetic regulators of mRNA metabolism with mechanistic insight into the functional manipulation of RBPs by methylation.

genetics↗