Publications de Bruno Lemaitre

Bacterial-induced Duox-ROS regulates the Imd immune pathway in the gut by modulating the peritrophic matrix

The Duox-reactive oxygen species (ROS) system and the immune deficiency (Imd) pathway play a major role in insect gut immunity. However, their interaction to accomplish an effective immune response is still unclear. Here, we show that Duox regulates the pe ...

2025

An updated proteomic analysis of Drosophila haemolymph after bacterial infection

Bruno Lemaitre, Fanny Schüpfer, Samuel Rommelaere

Using an in-depth Mass Spectrometry-based proteomics approach, we provide a comprehensive characterization of the hemolymphatic proteome of adult flies upon bacterial infection. We detected and quantified changes in abundance of several known immune regula ...

2025

The secreted Nimrod protein NimB1 negatively regulates early steps of apoptotic cell phagocytosis in Drosophila

Bruno Lemaitre, Samuel Rommelaere, Bianca Marie Petrignani

Efferocytosis, the efficient clearance of apoptotic cells (ACs) by phagocytes, is vital for maintaining tissue homeostasis. Here, we reveal the role of the secreted protein NimB1 in reducing apoptotic cell recognition and binding in the early stages of eff ...

2025

Gut commensal bacteria-derived methionine is required for host reproduction by modulating RNA m6A methylation of the insulin receptor

Bruno Lemaitre

Gut commensal bacteria promote host reproduction by modulating metabolism and nutrition, but the molecular mechanisms by which microbes regulate reproduction remain unclear. Here, we show that gut commensal bacteria promote host reproduction by providing t ...

2025

SAM transmethylation pathway and adenosine recycling to ATP are essential for systemic regulation and immune response

Bruno Lemaitre

During parasitoid wasp infection, activated immune cells of Drosophila melanogaster larvae release adenosine to conserve nutrients for immune response. S-adenosylmethionine (SAM) is a methyl group donor for most methylations in the cell and is synthesized ...

eLife Sciences Publications, Ltd2025

Pathobiont and symbiont contribute to microbiota homeostasis through Malpighian tubules–gut countercurrent flow in Bactrocera dorsalis

Bruno Lemaitre

Host–gut microbiota interactions are more complex than good or bad. Both gut symbiotic bacteria and pathobionts can provide essential functions to their host in one scenario and yet be detrimental to host health in another. So, these gut-dwelling bacteria ...

2024

The Drosophila immunity handbook

Bruno Lemaitre, Mark Austin Hanson

Animals possess efficient mechanisms for detecting and neutralizing infection. The application of Drosophila genetics to the study of these mechanisms has generated insights into insect immunity and uncovered general principles of animal host defense. Thes ...

EPFL Press2024

Duox activation in Drosophila Malpighian tubules stimulates intestinal epithelial renewal through a countercurrent flow

Bruno Lemaitre, Xiaoxue Li

The gut must perform a dual role of protecting the host against toxins and pathogens while harboring mutualistic microbiota. Previous studies suggested that the NADPH oxidase Duox contributes to intestinal homeostasis in Drosophila by producing reactive ox ...

Elsevier BV2024

Dietary L-Glu sensing by enteroendocrine cells adjusts food intake via modulating gut PYY/NPF secretion

Bruno Lemaitre, Zongzhao Zhai

Amino acid availability is monitored by animals to adapt to their nutritional environment. Beyond gustatory receptors and systemic amino acid sensors, enteroendocrine cells (EECs) are believed to directly percept dietary amino acids and secrete regulatory ...

Nature Portfolio2024

A humoral stress response protects Drosophila tissues from antimicrobial peptides

Jean Philippe Boquete, Bruno Lemaitre, Matteo Dal Peraro, Alexia Laurie Carboni, Samuel Rommelaere, Chan Cao, Fernando Augusto Teixeira Pinto Meireles

An efficient immune system must provide protection against a broad range of pathogens without causing excessive collateral tissue damage. While immune effectors have been well characterized, we know less about the resilience mechanisms protecting the host ...

Elsevier BV2024

The conceptual foundations of innate immunity: Taking stock 30 years later

Bruno Lemaitre

While largely neglected over decades during which adaptive immunity captured most of the attention, innate immune mechanisms have now become central to our understanding of immunology. Innate immunity provides the first barrier to infection in vertebrates, ...

2024

Protein target highlights in CASP15: Analysis of models by structure providers

Bruno Lemaitre, Luciano Andres Abriata, Kuan-Lin Wu, Samuel Rommelaere, Han Xiao

We present an in-depth analysis of selected CASP15 targets, focusing on their biological and functional significance. The authors of the structures identify and discuss key protein features and evaluate how effectively these aspects were captured in the su ...

WILEY2023

Ecology-relevant bacteria drive the evolution of host antimicrobial peptides in Drosophila

Bruno Lemaitre, Mark Austin Hanson

Antimicrobial peptides are host-encoded immune effectors that combat pathogens and shape the microbiome in plants and animals. However, little is known about how the host antimicrobial peptide repertoire is adapted to its microbiome. Here, we characterized ...

American Association for the Advancement of Science2023

CERT1 mutations perturb human development by disrupting sphingolipid homeostasis

Paolo De Los Rios, Bruno Lemaitre, Evelyne Ruchti, Sylvia Ho, Anthony Vocat, Samuel Rommelaere, Greta Limoni, Stefano Zamuner, Giovanni D'Angelo, Laura Capolupo, Charlotte Julie Caroline Gehin, Huixin Guo

Neural differentiation, synaptic transmission, and action potential propagation depend on membrane sphingolipids, whose metabolism is tightly regulated. Mutations in the ceramide transporter CERT (CERT1), which is involved in sphingolipid biosynthesis, are ...

American Society for Clinical Investigation2023

Antimicrobial peptides do not directly contribute to aging in Drosophila, but improve lifespan by preventing dysbiosis

Bruno Lemaitre, Mark Austin Hanson

Antimicrobial peptides (AMPs) are innate immune effectors first studied for their role in host defence. Recent studies have implicated these peptides in the clearance of aberrant cells and in neurodegenerative syndromes. In Drosophila, many AMPs are produc ...

COMPANY BIOLOGISTS LTD2023

Repeated truncation of a modular antimicrobial peptide gene for neural context

Bruno Lemaitre, Mark Austin Hanson

Antimicrobial peptides (AMPs) are host-encoded antibiotics that combat invading pathogens. These genes commonly encode multiple products as post-translationally cleaved polypeptides. Recent studies have highlighted roles for AMPs in neurological contexts s ...

PUBLIC LIBRARY SCIENCE2022

Compartmentalized PGRP expression along the dipteran Bactrocera dorsalis gut forms a zone of protection for symbiotic bacteria

Ping Zhang, Bruno Lemaitre, Yichen Wang

All metazoan guts are subject to opposing pressures wherein the immune system must eliminate pathogens while tolerating the presence of symbiotic microbiota. The Imd pathway is an essential defense against invading pathogens in insect guts, but tolerance m ...

Cell Press2022

Cecropins contribute to Drosophila host defense against a subset of fungal and Gram-negative bacterial infection

Bruno Lemaitre, Alexia Laurie Carboni, Mark Austin Hanson

Cecropins are small helical secreted peptides with antimicrobial activity that are widely distributed among insects. Genes encoding Cecropins are strongly induced upon infection, pointing to their role in host defense. In Drosophila, four cecropin genes cl ...

OXFORD UNIV PRESS INC2022

Disproportionate investment in Spiralin B production limits in-host growth and favors the vertical transmission of Spiroplasma insect endosymbionts

Jean Philippe Boquete, Bruno Lemaitre, Fanny Schüpfer, Samuel Rommelaere, Florent François Masson

Insects frequently harbor endosymbionts, which are bacteria housed within host tissues. These associations are stably maintained over evolutionary timescales through vertical transmission of endosymbionts from host mothers to their offspring. Some endosymb ...

National Academy of Sciences2022

Drosophila immunity: the Drosocin gene encodes two host defence peptides with pathogen-specific roles

Bruno Lemaitre, Mark Austin Hanson

Antimicrobial peptides (AMPs) are key to defence against infection in plants and animals. Use of AMP mutations in Drosophila has now revealed that AMPs can additively or synergistically contribute to defence in vivo. However, these studies also revealed hi ...

ROYAL SOC2022