Biology subjects

Ehret, F.

Publications and source records attributed to Ehret, F..

4 recordsLinked to original sources

bioRxiv2025

EGFL7 promotes immune evasion in glioma through its interaction with integrin β2

Glioblastoma is the most aggressive form of malignant brain cancer, characterized by an immunosuppressive microenvironment and immune evasion. Despite the success of immune checkpoint inhibitors in other cancers, immunotherapies such as anti-PD1 have shown limited efficacy in glioblastoma, underscoring the need to identify tumor-intrinsic mechanisms that sustain this immunosuppressive microenvironment and to develop more effective therapeutic strategies targeting them. Previously, the secreted factor epidermal growth factor-like protein 7 (EGFL7) has been shown to promote brain tumor growth by affecting the glioblastoma microenvironment (GME). However, its impact on the immune system remained enigmatic. Here, we studied the role of EGFL7 in shaping the immune landscape in glioblastoma and identified the underlying molecular mechanisms it engages to drive glioma immune evasion. Single-cell transcriptomic profiling of immune cells derived of glioblastoma revealed that EGFL7 promotes an immunosuppressive GME, characterized by enhanced T cell exhaustion and polarization of macrophages towards a protumorigenic state. Proteomic profiling of EGFL7s interactome in glioma revealed its interaction with integrin {beta}2 (ITGB2), an immune cell surface receptor involved in cell adhesion and migration. Mechanistic studies uncovered the central role of this interaction for immune evasion, which promoted T cell exhaustion and the polarization of macrophages towards a pro-tumorigenic state. Genetic perturbation of the EGFL7-ITGB2 axis attenuated immunosuppression and prolonged the survival of glioblastoma-bearing mice. Remarkably, a combinatorial regimen of anti-EGFL7 and the checkpoint inhibitor anti-PD1 improved the efficacy of this drug, which by itself did not improve glioma patient survival so far. In conclusion, our study provides unequivocal evidence that EGFL7 mediates immune evasion in glioma and has great potential to serve as an add-on drug target to improve immunotherapies not functional in glioblastoma patients so far.

cancer biology↗

bioRxiv2024

Exploring social modulation: Microglia as a key mediator of individual immune response, plasticity and pathology in App-NL-G-F mouse model of Alzheimer's disease

This study explores the influence of lifestyle on Alzheimers disease (AD) progression using App-NL-G-F mice in a complex enrichment system. Mice exhibited social deficits before plaque pathology or memory impairment, revealing a crucial link between lifestyle, behavior, and neuroinflammation. Plasma analysis indicates early inflammation and apoptosis-related changes, setting the stage for identifying markers predicting plaque manifestation. Beyond pathology, social behavior is linked to adult neurogenesis and microglia coverage, forming a dynamic connection with microglia activation. Further, sc-RNA sequencing unveiled a decrease in interferon-responsive microglia and alteration in antigen processing with enrichment. These findings underscore the beneficial impact of social housing on microglia and interconnected factors, pointing to microglia as a critical mediator of the behavior-pathology-plasticity interplay in AD. The study enhances our understanding of AD complexity and offers insights into potential therapeutic strategies, emphasizing the multifaceted nature of AD progression and the role of lifestyle in shaping its course.

neuroscience↗

bioRxiv2022

Pre-symptomatic reduction of individuality in the App NL-F knock-in model of Alzheimer's disease

While one third of the risk for Alzheimers disease (AD) is explained by environment and lifestyle, AD pathology also affects individual lifestyle, possibly long before clinical manifestation of dementia. To study this hidden disease effect with its potentially large impact on coping with AD, we examined in mice how the AppNL-F/NL-F (NL-F) knock-in mutation affects the pre-symptomatic response to environmental enrichment (ENR). We assessed the emergence of inter-individual phenotypic variation while both genetic background and the shared environment were held constant, thereby isolating the contribution of individual behavior ( non-shared environment). After 4 months of ENR, in NL-F both mean and variability of plasma ApoE were increased, suggesting a pre-symptomatic variation in pathogenic processes. Roaming entropy (RE) as a measure of behavioral activity was continuously assessed with radiofrequency identification (RFID) technology and revealed reduced habituation and variance in NL-F compared to controls. Intra-individual variation decreased but behavioral predictability and stability were reduced in NL-F. Seven months after discontinuation of ENR we found no difference in plaque size and number, but ENR increased variance in hippocampal plaque counts in NL-F. A reactive increase in adult hippocampal neurogenesis in NL-F, known from other models, was normalized by ENR. Our data suggest that, while NL-F has early effects on individual behavioral patterns in response to ENR, there are lasting effects at the level of cellular plasticity even after discontinuation of ENR. Hence, early behavior matters for maintaining individual behavioral trajectories and brain plasticity even under maximally constraint conditions.

neuroscience↗

bioRxiv2018

Selective increases in inter-individual variability in response to environmental enrichment

One manifestation of individualization is a progressively differential response of individuals to the non-shared components of the same environment. Individualization has practical implications in clinical setting, where subtle differences between patients are often decisive for the success of an intervention, yet there has been no suitable animal model to study its underlying biological mechanisms. Here we show that enriched environment (ENR) can serve as a model of brain individualization. We kept 40 isogenic mice for 3 months in ENR and compared the effects on a wide range of phenotypes on both mean and variance to an equally sized group of standard-housed control animals. While ENR influenced multiple parameters and restructured correlation patterns between them, it only increased differences among individuals in traits related to brain and behavior (adult hippocampal neurogenesis, motor cortex thickness, open field and object exploration, rotarod performance), in agreement with the hypothesis of a specific activity-dependent development of brain individuality.

neuroscience↗