Biology subjects

Texeraud, E.

Publications and source records attributed to Texeraud, E..

3 recordsLinked to original sources

bioRxiv2025

Unveiling the temporal impact: Exploring dynamic changes in the paediatric solid tumour immune microenvironment through time

The composition of the tumour immune microenvironment (TIME) influences tumour evolution and responsiveness to immunotherapy. While longitudinal changes in TIME have been well-characterized in adult cancers, its dynamics in childhood cancers remain poorly documented, limiting our ability to predict treatment responses and tailor immunotherapeutic strategies. This study aimed to evaluate the plasticity of TIME in paediatric solid tumours, investigate its longitudinal evolution, and identify time-dependent immune alterations. Transcriptomic data from longitudinal samples of 27 paediatric patients (<21 years old) with relapsed or refractory solid tumours were analysed, encompassing 70 timepoints: 16 diagnoses and 54 successive relapses. TIME plasticity was assessed using gene expression clustering and immune cell infiltration enumeration. Patient-adjusted longitudinal analyses were performed using generalised linear mixed models (glmmSeq), adjusted for age and sex. Temporal associations of immune changes were further explored using dynamic regression models. Thirteen patients exhibited significant changes in their TIME profile, indicating high TIME plasticity. Over time, the TIME shifted toward a tolerogenic and immunosuppressive state, characterised by decreased activity in immune pathways (e.g., T cell receptor signalling) and enrichment of tolerogenic (e.g., macrophage differentiation) and oncogenic pathways (e.g., IL6-JAK-STAT3). The core enrichment of upregulated pathways contained key immunosuppressive factors: immune checkpoints (CTLA-4), tumour-associated macrophage activators (CSF1/CSF1R), T-regulatory cell activators (TGFB1), and immunosuppressive genes (IL10RA). This study provides evidence that the TIME in paediatric solid tumours is plastic and remodels towards immune depletion and tolerogenicity. This evolution may underlie treatment resistance and disease progression, underscoring the need for TIME-informed therapeutic approaches in paediatric oncology. Significance StatementThis article demonstrates the plasticity of the tumour immune micro-environment (TIME) of paediatric solid tumours throughout disease evolution. Longitudinal transcriptomic analyses of 70 tumour samples from 27 patients showed a progressive remodelling towards tolerogenicity and immune depletion. Key immunosuppressive factors, including immune checkpoints and tumour-associated macrophages, were identified as potential contributors to immune escape. These findings support the relevance of longitudinal immune monitoring in paediatric oncology and may inform future strategies for immunotherapeutic interventions.

cancer biology↗

bioRxiv2025

Concomitant acetylation and loading of H2A.Z by NuA4/TIP60 regulate target gene transcription

The human NuA4/TIP60 complex is a multi-subunit, dual enzymatic epigenetic factor and gene regulator. It bears histone acetyltransferase (HAT) activity towards the canonical histones H2A and H4 and the histone variant H2A.Z, a function that has been linked to gene activation. It also acts as a chromatin remodeling enzyme through ATP-dependent exchange of nucleosomal H2A-H2B dimers with H2A.Z-H2B, leading to incorporation of H2A.Z into chromatin at gene regulatory elements. NuA4/TIP60 is unique in merging two enzymatic activities targeting H2A.Z. Both NuA4/TIP60-dependent H2A.Z acetylation and remodeling have been linked to several physiological functions and pathologies, but studies have only focused on either one or the other enzymatic activity, and insights on functional coordination between them are lacking. Here, we leverage our EP400 rapid depletion system to explore and untangle the intricate links between H2A.Z acetylation by Tip60 (the HAT subunit) and loading on chromatin by EP400 (the remodeling subunit) through functional genomic and biochemical analyses. Our data support a mechanism in which H2A.Z is first pre-acetylated to allow for H2A.Zac-H2B dimer association with the complex before incorporation into chromatin, particularly at gene promoters to positively regulate transcription. As both H2A.Z-targeted enzymatic functions of NuA4/TIP60 have been linked to disease, albeit separately, our findings hold important implications for therapeutic intervention, where combinatorial targeting is a promising avenue.

molecular biology↗

bioRxiv2022

Single cell analysis of the dorsal V-SVZ reveals differential quiescence of postnatal pallial and subpallial neural stem cells driven by TGFbeta/BMP-signalling

The ventricular-subventricular zone (V-SVZ) is the largest neurogenic region of the postnatal forebrain, containing neural stem cells (NSCs) that emerge from both the embryonic pallium and subpallium. Despite of this dual origin, glutamatergic neurogenesis declines rapidly after birth, while gabaergic neurogenesis persists throughout life. Here, we performed single-cell RNA-sequencing (scRNA-Seq) of the postnatal dorsal V-SVZ for unravelling the mechanisms leading to pallial lineage germinal activity silencing. We identify cell lineage-specific NSCs primed for the generation of neurons or glial cells, as well as a large population of so far uncharacterized quiescent NSCs (qNSC). Pallial qNSCs enter a state of deep quiescence, characterized by persistent TGFbeta/BMP signalling, reduced transcriptional activity and Hopx expression, whilst in contrast, subpallial qNSCs remain transcriptionally primed for activation. Induction of deep pallial quiescence is paralleled by a rapid blockade of glutamatergic neuron production and differentiation. Finally, manipulation of the TGFbeta/BMP receptor Bmpr1a demonstrate its key role in mediating these effects at early postnatal times. Together, our results highlight a central role of TGFbeta/BMP-signalling in synchronizing quiescence induction and blockade of neuronal differentiation to rapidly silence pallial germinal activity after birth.

neuroscience↗