Gadolinium-based nanoparticles AGuIX and their combination with ionizing radiation trigger AMPK-dependent proinflammatory reprogramming of tumor-associated macrophages

Muradova, Z.; Tannous, D.; Mostefa-Kara, A.; Cao-Pham, T. T.; Lamy, C.; Broutin, S.; Paci, A.; Dufort, S.; Doussineau, T.; Lux, F.; Tillement, O.; Le Duc, G.; Allouch, A.; PERFETTINI, j.-l.

doi:10.1101/2024.01.12.575217

bioRxiv · 10.1101/2024.01.12.575217

Gadolinium-based nanoparticles AGuIX and their combination with ionizing radiation trigger AMPK-dependent proinflammatory reprogramming of tumor-associated macrophages

Muradova, Z.·Tannous, D.·Mostefa-Kara, A.·Cao-Pham, T. T.·Lamy, C.·Broutin, S.·Paci, A.·Dufort, S.·Doussineau, T.·Lux, F.·Tillement, O.·Le Duc, G.·Allouch, A.·PERFETTINI, j.-l.

View original source ↗Export metadata ↓

Abstract

BackgroundTumor-associated macrophages (TAMs) are essential components of the inflammatory microenvironment of tumors and are associated with poor clinical outcomes in the majority of cancers. TAMs mainly exhibit anti-inflammatory functions that promote and support the tissue remodeling, the immune suppression and the tumor growth. Regarding their plasticity, the functional reprogramming of anti-inflammatory TAMs into proinflammatory phenotype recently emerged as a therapeutic opportunity to improve the effectiveness of anticancer treatments such as radiotherapy. ResultsHere we show that gadolinium-based nanoparticles AGuIX alone and in combination with ionizing radiation (IR) induce in a dose-dependent manner, the accumulation of DNA double strand breaks, an Ataxia telangiectasia mutated (ATM)-dependent DNA-damage response, an increased expression of the Interferon regulatory factor 5 (IRF5) and the release of proinflammatory cytokines from targeted macrophages, thus directing their proinflammatory reprogramming. This process is associated with the activating phosphorylation of the Adenosine Monophosphate (AMP) activated protein kinase on threonine 172 (AMPKT172*) and the fragmentation of mitochondria. Furthermore, we demonstrate that the inactivation of AMPK reduces the mitochondrial fragmentation and the proinflammatory reprogramming of macrophages detected in response to AGuIX and their combination with IR. These results reveal that the AMPK-dependent regulation of mitochondrial fragmentation plays a central role during the proinflammatory reprogramming of macrophages. Accordingly, a positive correlation between AMPKT172* and proinflammatory activation of TAMs is detected following IR+AGuIX combination in syngeneic mouse model of colorectal cancer. ConclusionsAltogether, our results identify a novel signaling pathway elicited by AGuIX and their combined treatment with IR, that targets macrophage polarization, skews macrophage functions toward the proinflammatory phenotype and may enhance the effectiveness of radiotherapy.

Explore related subjects

immunology Preprint

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Muradova, Z., Tannous, D., Mostefa-Kara, A., Cao-Pham, T. T., Lamy, C., Broutin, S., Paci, A., Dufort, S., Doussineau, T., Lux, F., Tillement, O., Le Duc, G., Allouch, A., PERFETTINI, j.-l.. 2024-01-15. Gadolinium-based nanoparticles AGuIX and their combination with ionizing radiation trigger AMPK-dependent proinflammatory reprogramming of tumor-associated macrophages. https://doi.org/10.1101/2024.01.12.575217

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

ATF3 Preserves Macrophage Cholesterol Homeostasis during Metabolic Stress

Background: Macrophages must coordinate immune activation with maintenance of cellular cholesterol homeostasis, yet the transcriptional mechanisms integrating these processes remain incompletely understood. Activating transcription factor 3 (ATF3) suppresses inflammatory and interferon responses and has been implicated in macrophage lipid metabolism, suggesting a role in coordinating immune and sterol-responsive transcriptional programs. Methods: Wild-type and ATF3-deficient bone marrow-derived macrophages were analyzed by bulk RNA sequencing following Toll-like receptor stimulation and under conditions of sterol loading or depletion. Cholesterol content, cytokine production, and sterol-responsive gene expression were quantified. Human metabolic dysfunction-associated steatotic liver disease (MASLD) datasets and Kupffer cell-specific ATF3 knockout mice were used to assess disease relevance in vivo. Results: ATF3 deficiency enhanced inflammatory and interferon-responsive transcriptional programs while suppressing a sterol-responsive gene module enriched for SREBP2 target genes. This phenotype was conserved across diverse Toll-like receptor stimuli and accompanied by persistent Ch25h upregulation. Despite exhibiting elevated cellular cholesterol, ATF3-deficient macrophages retained transcriptional responsiveness to sterol loading and depletion while demonstrating reduced induction of SREBP2-dependent genes across conditions. IFNAR blockade reduced interferon-responsive gene expression but did not normalize Ch25h or sterol-responsive gene expression. In contrast, CRISPR-mediated reduction of Ch25h partially restored sterol-responsive gene expression in inflammatory ATF3-deficient macrophages. In human MASLD, hepatic ATF3 expression positively correlated with disease severity. In mice, ATF3 was preferentially induced in Kupffer cells during metabolic stress, and Kupffer cell-specific deletion of ATF3 increased liver injury and Kupffer cell lipid accumulation. Conclusions: ATF3 supports sterol-responsive transcriptional programs while restraining inflammatory activation in macrophages. ATF3 loss results in elevated cellular cholesterol, impaired SREBP2-dependent gene expression, and persistent derepression of Ch25h, which contributes to but does not fully explain the sterol phenotype. These findings identify ATF3 as a coordinator of macrophage adaptation to inflammatory and metabolic stress and support a protective role for Kupffer cell ATF3 during metabolic liver disease.

immunology↗

bioRxiv2026

Circulating CD4 regulatory T cells are broadly preserved in Parkinson's disease despite altered HELIOS expression

Background Regulatory T cells (Tregs) are an important component of adaptive immune regulation and have been implicated in Parkinson's disease (PD), with previous studies suggesting altered Treg proportions, phenotype and, in some cases, function. However, existing studies have been limited by variable phenotyping approaches and a lack of detailed functional assessment. Given the growing interest in Tregs as potential therapies in PD, better understanding of their phenotype and function in the disease is important. Methods Circulating FOXP3+ Tregs were characterised in individuals with PD and age-matched healthy controls (HC) using a 24-colour spectral flow cytometry panel. Treg suppressive function was assessed by their ability to inhibit proliferation and cytokine production by polyclonally stimulated autologous T effector cells in vitro. Treg lineage stability was assessed by analysis of FOXP3 TSDR demethylation. Results The proportions and phenotypic characteristics of circulating CD4 Tregs were broadly similar between individuals with PD and HCs, as were Treg suppressive function and FOXP3 TSDR demethylation. However, naive CD4 Tregs from individuals with PD showed reduced HELIOS expression, with a similar but non-significant trend in FOXP3 expression. Reduced HELIOS expression was also observed in the CD8 naive Treg compartment. Conclusions Major quantitative or functional abnormalities in circulating Tregs do not appear to be a dominant feature PD. However, reduced HELIOS expression in naive Tregs suggests more subtle phenotypic alterations that warrant further investigation. The broadly preserved suppressive function is reassuring for therapeutic approaches aimed at increasing Treg numbers, although it will be important to establish that expanded Tregs retain a stable phenotype and suppressive function in inflammatory and tissue environments.

immunology↗

bioRxiv2026

Therapeutic anti-IgE antibodies generate distinct functional immune complex signatures

Therapeutic IgG anti-IgE antibodies are benchmarked by their ability to interfere with IgE-Fc[epsilon]RI binding, but their activity within IgE and IgG-containing immune complexes remains poorly defined. Here we show that omalizumab and ligelizumab form binary IgE-IgG and ternary allergen-containing immune complexes with distinct functional properties. In primary human leukocytes, these complexes exhibited antibody- and composition-dependent patterns of cellular association and activation. Using multiplexed focal molography, we resolved Fc receptor engagement across free and complexed antibody states and identified distinct receptor-binding signatures for omalizumab- and ligelizumab-containing complexes. Notably, allergen incorporation reversed the relative ability of the two antibodies to neutralize IgE-Fc[epsilon]RI interactions and remodelled Fc[gamma]R binding. Thus, immune-complex composition is a determinant of therapeutic antibody function.

immunology↗