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INBIO - 2025

2025‌Activity reportProject-TeamINBIO‌​‌

RNSR: 201722244J
  • Research center​​ Inria Paris Centre
  • In​​​‌ partnership with:Institut Pasteur‌
  • Team name: Experimental and‌​‌ Computational Methods for Modeling​​ Cellular Processes

Creation of​​​‌ the Project-Team: 2019 November‌ 01

Each year, Inria‌​‌ research teams publish an​​ Activity Report presenting their​​​‌ work and results over‌ the reporting period. These‌​‌ reports follow a common​​ structure, with some optional​​​‌ sections depending on the‌ specific team. They typically‌​‌ begin by outlining the​​ overall objectives and research​​​‌ programme, including the main‌ research themes, goals, and‌​‌ methodological approaches. They also​​ describe the application domains​​​‌ targeted by the team,‌ highlighting the scientific or‌​‌ societal contexts in which​​ their work is situated.​​​‌

The reports then present‌ the highlights of the‌​‌ year, covering major scientific​​ achievements, software developments, or​​​‌ teaching contributions. When relevant,‌ they include sections on‌​‌ software, platforms, and open​​ data, detailing the tools​​​‌ developed and how they‌ are shared. A substantial‌​‌ part is dedicated to​​ new results, where scientific​​​‌ contributions are described in‌ detail, often with subsections‌​‌ specifying participants and associated​​ keywords.

Finally, the Activity​​​‌ Report addresses funding, contracts,‌ partnerships, and collaborations at‌​‌ various levels, from industrial​​ agreements to international cooperations.​​​‌ It also covers dissemination‌ and teaching activities, such‌​‌ as participation in scientific​​ events, outreach, and supervision.​​​‌ The document concludes with‌ a presentation of scientific‌​‌ production, including major publications​​ and those produced during​​​‌ the year.

Keywords

Computer‌ Science and Digital Science‌​‌

  • A3.1.1. Modeling, representation
  • A6.1.1.​​ Continuous Modeling (PDE, ODE)​​​‌
  • A6.1.4. Multiscale modeling
  • A6.3.3.‌ Data processing
  • A9.2.1. Supervised‌​‌ learning

Other Research Topics​​ and Application Domains

  • B1.1.2.​​​‌ Molecular and cellular biology‌
  • B1.1.4. Genetics and genomics‌​‌
  • B1.1.7. Bioinformatics
  • B1.1.10. Systems​​ and synthetic biology
  • B2.2.4.​​​‌ Infectious diseases, Virology
  • B2.4.2.‌ Drug resistance
  • B5.10. Biotechnology‌​‌
  • B9.8. Reproducibility

1 Team​​ members, visitors, external collaborators​​​‌

Research Scientists

  • Gregory Batt‌ [Team leader,‌​‌ Inria, Senior Researcher​​​‌, HDR]
  • Sean​ Kennedy [Institut Pasteur​‌, Researcher, from​​ Feb 2025]

Post-Doctoral​​​‌ Fellows

  • Angelica Frusteri Chiacchiera​ [Institut Pasteur]​‌
  • Nathalie Laforge [Institut​​ Pasteur, from Apr​​​‌ 2025]
  • Esteban Lebrun​ [Institut Pasteur,​‌ until Sep 2025]​​
  • Eléonore Pourcelot [Institut​​​‌ Pasteur]

PhD Students​

  • Alicia Da Silva [​‌Inria]
  • Henri Galez​​ [Institut Pasteur]​​​‌
  • Cecilia Pires De Oliveira​ Capela [Institut Pasteur​‌]

Technical Staff

  • Agnès​​ Baud [Institut Pasteur​​​‌, Engineer]
  • Maïté​ Gomard [Institut Pasteur​‌, Technician, from​​ Feb 2025]
  • Sara​​​‌ Napolitano [Institut Pasteur​, Engineer]

Interns​‌ and Apprentices

  • Ines Dahlal​​ [Institut Pasteur,​​​‌ Apprentice]

Administrative Assistants​

  • Nelly Maloisel [Inria​‌, 25%]
  • Mélanie​​ Ridel [Institut Pasteur​​​‌, 20%]

Visiting​ Scientist

  • Lorenzo Pasotti [​‌Pavia University]

2​​ Overall objectives

The main​​​‌ objective of our research​ is to understand, control,​‌ and optimize cellular processes​​ in single cells and​​​‌ at the population level.​ We combine experimental and​‌ theoretical work within a​​ single team.

Our focus​​​‌ is on developing methods​ and models that take​‌ stochasticity of intracellular processes​​ and heterogeneity of cell​​​‌ populations into account. To​ this end, we use​‌ both mixed-effects models as​​ well as continuous-time Markov​​​‌ chains and their diffusion​ approximations. We develop methods​‌ for efficiently calculating with​​ such models and use​​​‌ them to design optimally​ informative experiments and to​‌ reverse engineer unknown cellular​​ processes from experimental data.​​​‌ Furthermore, we deploy models​ in order to optimally​‌ construct and optimally control​​ synthetic gene circuits.

We​​​‌ have recently started to​ set up our own​‌ biology laboratory at Institut​​ Pasteur. We develop novel​​​‌ experimental platforms that are​ designed to be fully​‌ automated, controllable by our​​ own software, and capabale​​​‌ of updating the experimental​ plan in response to​‌ incoming measurements. Optogenetic actuation​​ of intracellular processes, coupled​​​‌ to real time fluorescence​ measurements by microscopy or​‌ flow cytometry, then allows​​ us to connect cellular​​​‌ processes with models and​ algorithms in real time.​‌

The spritit of our​​ work is that experimental​​​‌ platforms and circuits should​ be constructed with our​‌ theoretical work in mind,​​ while our mathematical methods​​​‌ should be usable to​ adress concrete experimental questions​‌ in the lab.

3​​ Research program

3.1 Cybergenetics​​​‌ – real time control​ of biological processes

Cells​‌ have evolved uncountable numbers​​ of feedback circuits to​​​‌ regulate their functionalities in​ the presence of changing​‌ environmental conditions. But can​​ such feedback control also​​​‌ be externalized and placed​ under control of scientists?​‌ Early work on this​​ topic suggested that optogenetic​​​‌ systems, allowing for external​ regulation of gene expression​‌, have the potential​​ to serve as an​​​‌ interface between cells and​ experimental platform that gives​‌ a computer the power​​ to stir the functioning​​​‌ of cells via the​ application of light. We​‌ develop all the tools​​ required to realize automated​​​‌ computer control of intracellular​ processes. On the experimental​‌ side, we develop yeast​​ strains that are equipped​​ with optogenetic promoters to​​​‌ drive various functionalities. On‌ the mathematical side, we‌​‌ develop models and software​​ to equip our experimental​​​‌ platforms with the appropriate‌ programs to realize sucessful‌​‌ feedback control, both at​​ the level of single​​​‌ cells (microscopy) and at‌ the level of populations‌​‌ (bioreactors and plate reader).​​

3.2 Platforms for automated​​​‌ reactive experiments

The core‌ scientific activity of the‌​‌ team is to connect​​ mathematical methods with biological​​​‌ applications in our lab.‌ The interface between the‌​‌ two sides, that is​​ the experimental platforms, is​​​‌ therefore of crucial importance‌ for the success of‌​‌ our activities. However, platforms​​ that can be purchased​​​‌ by vendors are typically‌ delivered without the capacity‌​‌ to adapt the experimental​​ plan in response to​​​‌ incoming measurements, a functionality‌ that is crucially needed‌​‌ for deploying our computational​​ methods (e.g. feedback control).​​​‌ Therefore, we develop novel‌ experimental platforms and/or extend‌​‌ existing platforms with additional​​ software and hardware that​​​‌ allows us to perform‌ automated reactive experiments. Concretely,‌​‌ we develop a microscopy​​ platform and control software​​​‌ for yeast that uses‌ a digital micromirror device‌​‌ to expose single cells​​ to targeted light signals​​​‌ that can be adjusted‌ in real time in‌​‌ response to measurements taken​​ from the cell. Furthermore,​​​‌ we develop a platform‌ of 16 parallel small‌​‌ scale automated bioreactors,​​ each equipped with controllable​​​‌ LEDs to allow for‌ optogenetic gene expression and‌​‌ long-term reactive experiments in​​ tightly controlled conditions. Automation​​​‌ of the platform is‌ achieved via a low-cost‌​‌ open-source pipetting robot that​​ samples all reactors to​​​‌ a benchtop cytometer in‌ which single cell gene‌​‌ expression is measured in​​ all sampled cells of​​​‌ all reactors. Finally, we‌ develop software to take‌​‌ full control of a​​ commercial plate reader with​​​‌ liquid injection capabilities (Tecan‌ Spark). This platform allows‌​‌ us to use a​​ Raspberry Pi to pilot​​​‌ 96 parallel reactive experiments‌ where optical density is‌​‌ used as a readout​​ of bacterial growth.

4​​​‌ Application domains

4.1 Preamble‌

Since most of our‌​‌ research is at the​​ interface of mathematics and​​​‌ biology, there often is‌ no clear split between‌​‌ mathematical reaseach objectives and​​ applications. For instance, feedback​​​‌ control of gene expression‌ is simultaneously a mathematical‌​‌ and an applied problem.​​

4.2 Understanding resistance and​​​‌ tolerance to antibiotic treatments‌

The non-susceptibility of pathogenic‌​‌ bacteria to antibiotic treatments​​ is a major health​​​‌ problem. Bacteria might escape‌ treatments in two ways:‌​‌ being resistant or being​​ tolerant. Whereas resistant bacteria​​​‌ can multiply in presence‌ of antibiotics, tolerant bacteria‌​‌ can merely survive. Yet,​​ tolerance is increasingly recognized​​​‌ as a major player‌ in treatment failure. In‌​‌ particular, an increasing fraction​​ of commensal and pathogenic​​​‌ E coli bacteria express‌ extended-spectrum β-lactamases and/or carbapenemases.‌​‌ When individual bacteria die​​ as a consequence of​​​‌ antibiotic treatments, these enzymes‌ are released and hydrolyze‌​‌ the antibiotic molecules in​​ the environment, conveying a​​​‌ transient protection to the‌ remaining bacteria that lasts‌​‌ until the enzymes are​​ degraded themselves. Understanding how​​​‌ this collective antibiotic tolerance‌ (CAT) shapes population dynamics‌​‌ is difficult yet important​​​‌ for optimally killing bacterial​ populations: when a​‌ second antibiotic dose is​​ applied directly after a​​​‌ first dose it will​ not be effective since​‌ the antibiotics will be​​ degraded by the enzymes​​​‌ released from bacteria killed​ after the first dose;​‌ when the second dose​​ is applied too late​​​‌ the surviving bacterial population​ will have regrown to​‌ a large size. Our​​ plate reader platform allows​​​‌ us to apply complex​ temporal patterns of antibiotic​‌ treatments to bacteria over​​ nearly two days. Parallezing​​​‌ such treatments in the​ 96 well plates allows​‌ us to generate rich​​ data sets and to​​​‌ calibrate population dynamics models​ that can be used​‌ to optimize temporal treatment​​ plans. One of the​​​‌ applied objectives of our​ team is to use​‌ these capacities to study​​ a collection of fully-sequenced​​​‌ clinical isolates treated with​ a broad range of​‌ clinically important antibiotics and​​ grown in various media.​​​‌ Ideally, this will lead​ to an approach that​‌ can be used to​​ assay tolerance to antibiotics​​​‌ in hospitals instead of,​ or in addition to,​‌ standard antibiotic susceptibility tests,​​ detecting resistance.

4.3 Optimization​​​‌ of protein production in​ yeast

Many proteins are​‌ of technological or therapeutical​​ importance. The yeast S.​​​‌ cerevisiae is an interesting​ organism for protein bioproduction​‌ since it combines a​​ relatively fast growth rate​​​‌ with good capacities to​ perform post-translational modifications needed​‌ for protein maturation and​​ full functionality. However, imposing​​​‌ a strong demand on​ protein production to the​‌ cell places a significant​​ burden on its physiology,​​​‌ either at the protein​ production level or at​‌ the maturation and secretion​​ levels. Using systems and​​​‌ synthetic biology approaches, we​ aim at better understanding​‌ the origins of the​​ production bottlenecks and then​​​‌ using modeling and control​ approaches, we aim at​‌ finding optimal control solutions​​ for bioproduction. Three different​​​‌ strategies are envisioned. In​ the first approach, bioproduction​‌ stress sensors are used​​ to observe in real​​​‌ time the physiological state​ of the cell, and​‌ the demand is externally​​ tuned based on the​​​‌ stress level of the​ cell population. In the​‌ second approach, the stress​​ sensor is used to​​​‌ tune the response capacities​ of the cell to​‌ the external demand, thus​​ creating an internal feedback​​​‌ loop. In the third​ approach, we control the​‌ fraction of the producing​​ cells by engineering an​​​‌ artificial differentiation system that​ implements the partial differentiation​‌ of grower cells into​​ producer cells. The optimization​​​‌ problem is then to​ find the optimum ratio​‌ based on the external​​ environment of the cells.​​​‌

5 Latest software developments,​ platforms, open data

5.1​‌ New platforms

Participants: Henri​​ Galez, Gregory Batt​​​‌.

We have developped​ InSillyClo, an open-source web​‌ application to assist large-scale​​ Golden Gate cloning and​​​‌ MoClo workflows. It is​ a convenient platform to​‌ support laboratory work.

Systems​​ and synthetic biology developments​​​‌ often require the construction​ of many variants of​‌ a genetic circuit of​​ interest, resulting in large-scale​​​‌ cloning campaigns. Golden Gate​ and Modular Cloning (MoClo),​‌ two powerful technologies enabling​​ the scale-up of cloning​​ workflows, play a central​​​‌ role for efficient circuit‌ construction. These workflows include‌​‌ a number of dry-lab​​ tasks, which are time-consuming​​​‌ and error-prone at scale.‌ No software tool was‌​‌ available to handle these​​ tasks in a dedicated,​​​‌ time-saving, and user-friendly manner.‌

InSillyClo supports an easy‌​‌ specification of genetic designs​​ at any scale, followed​​​‌ by the automated generation‌ of comprehensive workflow-related data.‌​‌ Moreover, InSillyClo leverages Modular​​ Cloning with a versatile​​​‌ typing system of parts‌ to generate user-defined workflows.‌​‌ InSillyClo is open source,​​ accessible with or without​​​‌ user registration, and can‌ also be used locally.‌​‌

The webapp is accessible​​ at https://insillyclo.pasteur.cloud.

6​​​‌ New results

6.1 InSillyClo,‌ a user-friendly web application‌​‌ to assist large-scale Golden​​ Gate cloning and MoClo​​​‌ workflows

Participants: Henri Galez‌, Gregory Batt.‌​‌

Systems and synthetic biology​​ developments often require the​​​‌ construction of many variants‌ of a genetic circuit‌​‌ of interest, resulting in​​ large-scale cloning campaigns. Golden​​​‌ Gate and Modular Cloning‌ (MoClo), two powerful technologies‌​‌ enabling the scale-up of​​ cloning workflows, play a​​​‌ central role for efficient‌ circuit construction. These workflows‌​‌ include a number of​​ dry-lab tasks, which are​​​‌ time-consuming and error-prone at‌ scale. Currently, no software‌​‌ tool is available to​​ handle these tasks in​​​‌ a dedicated, time-saving, and‌ user-friendly manner. We present‌​‌ InSillyClo, an open-source web​​ application to assist large-scale​​​‌ Golden Gate cloning and‌ MoClo workflows. It supports‌​‌ an easy specification of​​ genetic designs at any​​​‌ scale, followed by the‌ automated generation of comprehensive‌​‌ workflow-related data. Moreover, InSillyClo​​ leverages Modular Cloning with​​​‌ a versatile typing system‌ of parts to generate‌​‌ user-defined workflows. InSillyClo is​​ open source, accessible with​​​‌ or without user registration,‌ and can also be‌​‌ used locally.

6.2 Harnessing​​ CRISPR interference to resensitize​​​‌ laboratory strains and clinical‌ isolates to last resort‌​‌ antibiotics

Participants: Angelica Frusteri​​, Gregory Batt,​​​‌ Lorenzo Pasotti.

The‌ global race against antimicrobial‌​‌ resistance requires novel antimicrobials​​ that are not only​​​‌ effective in killing specific‌ bacteria, but also minimize‌​‌ the emergence of new​​ resistances. Recently, CRISPR/Cas-based antimicrobials​​​‌ were proposed to address‌ killing specificity with encouraging‌​‌ results. However, the emergence​​ of target sequence mutations​​​‌ triggered by Cas-cleavage was‌ identified as an escape‌​‌ strategy, posing the risk​​ of generating new antibiotic-resistance​​​‌ gene (ARG) variants. Here,‌ we evaluated an antibiotic‌​‌ re-sensitization strategy based on​​ CRISPR interference (CRISPRi), which​​​‌ inhibits gene expression without‌ damaging target DNA. The‌​‌ resistance to four antibiotics,​​ including last resort drugs,​​​‌ was significantly reduced by‌ individual and multi-gene targeting‌​‌ of ARGs in low-​​ to high-copy numbers in​​​‌ recombinant E. coli.‌ Escaper analysis confirmed the‌​‌ absence of mutations in​​ target sequence, corroborating the​​​‌ harmless role of CRISPRi‌ in the selection of‌​‌ new resistances. E. coli​​ clinical isolates carrying ARGs​​​‌ of severe clinical concern‌ were then used to‌​‌ assess the robustness of​​ CRISPRi under different growth​​​‌ conditions. Meropenem, colistin and‌ cefotaxime susceptibility was successfully‌​‌ increased in terms of​​ MIC (up to >​​​‌ 4-fold) and growth delay‌ (up to 11 h)‌​‌ in a medium dependent​​​‌ fashion. ARG repression also​ worked in a pathogenic​‌ strain grown in human​​ urine, as a demonstration​​​‌ of CRISPRi-mediated re-sensitization in​ host-mimicking media. This study​‌ laid the foundations for​​ further leveraging CRISPRi as​​​‌ antimicrobial agent or research​ tool to selectively repress​‌ ARGs and investigate resistance​​ mechanisms.

6.3 Investigation of​​​‌ dynamic regulation of TFEB​ nuclear shuttling by microfluidics​‌ and quantitative modelling

Participants:​​ Sara Napolitano.

Transcription​​​‌ Factor EB (TFEB) controls​ lysosomal biogenesis and autophagy​‌ in response to nutritional​​ status and other stress​​​‌ factors. Although its regulation​ by nuclear translocation is​‌ known to involve a​​ complex network of well-studied​​​‌ regulatory processes, the precise​ contribution of each of​‌ these mechanisms is unclear.​​ Using microfluidics technology and​​​‌ real-time imaging coupled with​ mathematical modelling, we explored​‌ the dynamic regulation of​​ TFEB under different conditions.​​​‌ We found that TFEB​ nuclear translocation upon nutrient​‌ deprivation happens in two​​ phases: a fast one​​​‌ characterised by a transient​ boost in TFEB dephosphorylation​‌ dependent on transient calcium​​ release mediated by mucolipin​​​‌ 1 (MCOLN1) followed by​ activation of the Calcineurin​‌ phosphatase, and a slower​​ one driven by inhibition​​​‌ of mTORC1-dependent phosphorylation of​ TFEB. Upon refeeding, TFEB​‌ cytoplasmic relocalisation kinetics are​​ determined by Exportin 1​​​‌ (XPO1). Collectively, our results​ show how different mechanisms​‌ interact to regulate TFEB​​ activation and the power​​​‌ of microfluidics and quantitative​ modelling to elucidate complex​‌ biological mechanisms.

6.4 Predicting​​ neonatal infection in PPROM​​​‌ with vaginal microbiology and​ metagenomics: a prospective cohort​‌ study

Participants: Sean Kennedy​​, Agnès Baud.​​​‌

Early-onset neonatal sepsis (EONS)​ due to ascending infection​‌ is a potentially preventable​​ complication of preterm premature​​​‌ rupture of membranes (PPROM).​ Our objective was to​‌ determine whether the analysis​​ of bacteria from vaginal​​​‌ swab samples is predictive​ of the risk of​‌ EONS in PPROM. In​​ a prospective 3-center observational​​​‌ cohort, patients with PPROM​ were enrolled between 22​‌ and 36 weeks’ gestation​​ (WG) + 6 days.​​​‌ Vaginal swab samples at​ delivery were analyzed using​‌ two different approaches, classical​​ bacterial cultures and shotgun​​​‌ metagenomic sequencing analysis. A​ metagenomics score was constructed​‌ combining the characterization of​​ the vaginal microbiome and​​​‌ the presence of pathogens​ and the optimal cut-off​‌ to predict EONS was​​ tested on a receiver​​​‌ operating curve. 563 PPROM​ cases were enrolled, with​‌ 646 liveborn neonates. PPROM​​ occurred < 32 WG​​​‌ in 41.9 % and​ deliveries were < 34​‌ WG in 41.0%. The​​ incidence of EONS was​​​‌ 29/646 (4.5%). When considering​ all central and peripheral​‌ microbiological samples available for​​ 26 neonates, the main​​​‌ pathogens isolated were Escherichia​ coli in 14 cases​‌ (53.8 %), other gram-negatives​​ in 5 (19.2%), strict​​​‌ anaerobes in 3 (11.5%);​ there was a single​‌ case (3.8%) each with​​ Group B Streptococcus (GBS),​​​‌ Streptococcus anginosus, Staphylococcus aureus​ and Ureaplasma urealyticum. We​‌ studied the prediction of​​ EONS among 272 mothers​​​‌ and their 310 neonates​ (20 EONS, 6.4%) with​‌ both culture and metagenomic​​ data available. A culture​​​‌ positive for a major​ or intermediate pathogen in​‌ the vaginal sample at​​ delivery had a sensitivity​​ of 80.0 % and​​​‌ a specificity of 37.9%,‌ adjusted odds ratio (aOR)‌​‌ of 1.6 to predict​​ EONS. The presence of​​​‌ E. coli was associated‌ with an EONS risk‌​‌ of 10.6% vs 4.9%,​​ in the absence of​​​‌ E. coli. The metagenomics‌ score was highly associated‌​‌ with EONS, with an​​ area under the receiver​​​‌ operating curve of 0.75.‌ At the optimal cutoff‌​‌ value, sensitivity was 70%,​​ specificity was 85%. A​​​‌ metagenomics score greater than‌ 40 was associated with‌​‌ a significantly increased risk​​ of EONS with an​​​‌ aOR of 8.9 in‌ multivariate analysis adjusted for‌​‌ latency period and gestational​​ age. In conclusion, in​​​‌ PPROM, conventional microbial culture‌ of maternal vaginal samples‌​‌ was associated with EONS,​​ but its predictive values​​​‌ remain insufficient to guide‌ perinatal care. Metagenomic microbial‌​‌ signatures improved predictive values.​​ This opens the perspective​​​‌ for a rapid point-of-care‌ test.

7 Partnerships and‌​‌ cooperations

7.1 Visits of​​ international scientists

Participants: Lorenzo​​​‌ Pasotti.

Lorenzo Pasotti,‌ assistant professor at the‌​‌ Department of Electrical, Computer​​ and Biomedical Engineering and​​​‌ at the Centre for‌ Health Technologies of the‌​‌ University of Pavia (Italy)​​ has been invited for​​​‌ three months in the‌ InBio team.

7.2 National‌​‌ initiatives

  • PPR Antibiorésistance Anoruti​​ (2021-2025) on the “Analysis​​​‌ of non-response to antibiotics‌ in vivo: application to‌​‌ Escherichia coli urinary tract​​ infections”, coordinated by I.​​​‌ El Meouche (Inserm).

    The‌ objective of Anoruti is‌​‌ to identify the different​​ factors involved in the​​​‌ fact that some bacteria‌ sensitive to an antibiotic‌​‌ in vitro do not​​ respond to treatment in​​​‌ vivo.

  • PPR Antibiorésistance Seq2Diag‌ (2021-2026) on “Whole genome‌​‌ sequencing and artificial intelligence​​ to characterize and diagnose​​​‌ antibiotic resistance and capacity‌ to escape treatment”, coordinated‌​‌ by P. Glaser (Institut​​ Pasteur).

    Genomic sequencing has​​​‌ revolutionized microbiological surveillance and‌ molecular epidemiology. The objective‌​‌ of the Seq2Diag project​​ is to provide a​​​‌ proof of concept for‌ its use in hospital‌​‌ and veterinary laboratories as​​ a diagnostic tool for​​​‌ in silico antibiotic sensitivity‌ testing.

  • ANR JCJC SmartSec‌​‌ (2022-2025) on “Matching maximal​​ host capacities: stress-informed, self-tuning​​​‌ bioproduction circuits”, coordinated by‌ Francois Bertaux (Lesaffre) with‌​‌ Gregory Batt and Sara​​ Napolitano (Inria and Institut​​​‌ Pasteur).

    Bioproduction requires diverting‌ resources normally used by‌​‌ host cells for growth​​ and self-replication towards the​​​‌ production of desired molecules.‌ Achieving maximal resource diversion‌​‌ without compromising the essential​​ functions of the host​​​‌ is of critical importance,‌ but is particularly challenging.‌​‌ To tackle this challenge,​​ SmartSec aims at designing​​​‌ host-aware circuits, with application‌ to the production of‌​‌ secreted proteins.

  • Inria/IFPEN PhD​​ fellowship Screen2learn (2023-2026) on​​​‌ “A screening and learning‌ approach for protein secretion‌​‌ in yeast", obtained by​​ Alicia da Silva, supervised​​​‌ by Gregory Batt (Inria/Institut‌ Pasteur) and Senta Blanquet‌​‌ (IFPEN).

    This project aims​​ to generate data and​​​‌ train a prediction tool‌ for optimizing the production‌​‌ of secreted proteins in​​ yeast. We will quantify​​​‌ secretion levels in different‌ genetic contexts and for‌​‌ libraries of enzyme variants.​​ We will screen for​​​‌ libraries of novel enzymes‌ involved in vegetable biomass‌​‌ degradation, with application to​​​‌ second generation biofuel production.​

  • Ferments du Futur Precompetitive​‌ projects Screen2Drive (2024-2026) on​​ “CRISPR-based screens to identify​​​‌ key factors to drive​ yeast consortia dynamics in​‌ fermented food ", cooddinated​​ by Gregory Batt (Inria​​​‌ and Institut Pasteur) and​ Thibault Nidelet (INRAE).

    The​‌ optimization of fermentation processes​​ is hindered by a​​​‌ too superficial understanding of​ interactions between yeast species.​‌ The Screen2Drive project uses​​ CRISPR-based functional screens and​​​‌ deep-sequencing to identify key​ genes altering yeast interactions.​‌ Our expected goals are​​ to improve fermentation results​​​‌ and develop genetic tools​ to engineer non-model yeasts.​‌

  • ANR Générique TrojanYeast (2024-2028)​​ on “Engineering probiotic yeasts​​​‌ to prevent and treat​ Clostridia-induced intestinal infections", cooddinated​‌ by Gregory Batt (Inria​​ and Institut Pasteur), with​​​‌ Bruno Dupuy (Institut Pasteur)​ and Pierre Lafaye (Institut​‌ Pasteur).

    This project aims​​ to engineer a probiotic​​​‌ yeast to fight Clostridioides​ difficile and Clostridium perfringens​‌ gut infections. This yeast​​ will produce endolysins to​​​‌ kill the bacteria and​ nanobodies to neutralize their​‌ toxins. We will utilize​​ modular cloning, lab automation,​​​‌ and anaerobic culture platforms​ to screen and optimize​‌ these constructs. If successful,​​ this approach could offer​​​‌ a novel and effective​ alternative to antibiotics.

  • ABIES​‌ doctoral school PhD fellowship​​ CyberStable (2024-2028) on “​​​‌ Cybergenetic solutions to enforce​ genetic stability in synthetic​‌ biology applications ", obtained​​ by Cecilia Capela, supervised​​​‌ by Gregory Batt (Inria​ and Institut Pasteur) and​‌ Sara Napolitano (Institut Pasteur​​ and Inria).

    In CyberStable,​​​‌ we investigate the effects​ of a bioproduction burden​‌ on genetic stability in​​ yeast. We will quantify​​​‌ the impact of induction​ demands on cell physiology,​‌ stress, and genetic stability​​ for various hard-to-secrete proteins.​​​‌ We will also use​ an artificial differentiation system​‌ to engineer more stable​​ production systems. By understanding​​​‌ these complex processes, our​ research aims to improve​‌ the efficiency and reliability​​ of synthetic biology applications.​​​‌

  • PPR Antibiorésistance NASPEC (2021-2026)​ on “Narrow spectrum antibiotics​‌ to fight the convergence​​ of bacterial resistance”, coordinated​​​‌ by M. Arthur (Paris​ Cité University).

    The NASPEC​‌ project aims to develop​​ antibiotics that target multi-resistant​​​‌ Gram-negative bacteria, while reducing​ the collateral damage caused​‌ by antibiotic therapy on​​ the commensal flora. In​​​‌ order to achieve selective​ activity on pathogens, two​‌ antibiotics from the beta-lactam​​ family will be combined​​​‌ within the same molecule​ to obtain inactive pro-drugs.​‌ Metagenomic analyses will be​​ used to study the​​​‌ potential impact of these​ molecules on the intestinal​‌ flora. The results of​​ this project will provide​​​‌ a rational pipeline for​ the development of new​‌ therapeutic molecules, which will​​ undergo preclinical development with​​​‌ an industrial partner at​ the end of the​‌ project.

7.3 Regional initiatives​​

  • Equipment grant BioConvS Region​​​‌ Ile-de-France PlatPath (2024-2025) on​ “Automated platform to engineer​‌ pathogenic strain libraries via​​ optimized conjugation", coordinated by​​​‌ Sara Napolitano (Institut Pasteur​ and Inria) and Angelica​‌ Frusteri (Institut Pasteur and​​ Inria).

    This project aims​​​‌ to develop an automated​ platform for constructing collections​‌ of engineered pathogenic bacteria​​ through optimized bacterial conjugation.​​​‌ The platform will include​ a liquid handler robot,​‌ a plate reader, a​​ biosafety cabinet, and control​​ software. It will enable​​​‌ the high-throughput and robust‌ engineering of bacterial collections,‌​‌ particularly for studying antimicrobial​​ resistance in clinical isolates.​​​‌

8 Dissemination

8.1 Promoting‌ scientific activities

8.1.1 Scientific‌​‌ events

Gregory Batt has​​ been a member of​​​‌ the scientific committee of‌ the 32nd International Conference‌​‌ on Yeast Genetics and​​ Molecular Biology (Yeast 2025,​​​‌ Paris).

8.1.2 Journal

  • Gregory‌ Batt has been a‌​‌ reviewer for Cell Reports​​ Methods.
  • Sean Kennedy​​​‌ has been a reviewer‌ for Microbial Drug Resistance‌​‌, Scientific Reports,​​ and mBio.
  • Lorenzo​​​‌ Pasotti has been a‌ reviewer for Science Advances‌​‌, ACS Synthetic Biology​​, and Frontiers in​​​‌ Lab on a Chip‌ Technologies.

8.1.3 Invited‌​‌ talks

  • Gregory Batt has​​ been an invited speaker​​​‌ at the 2nd Berlin-BioTECH‌ Symposium “Autonomus Discovery in‌​‌ Bio- and Chemical-Engineering” (Berlin​​ Nov 2025) and at​​​‌ the "FdF Scientific Day"‌ organized by Ferments du‌​‌ Futur (Saclay, Oct 2025).​​
  • Sean Kennedy gave an​​​‌ invited presentation at the‌ Medical Center of Tromsø‌​‌ (Norway, Oct 2025).
  • Lorenzo​​ Pasotti gave an invited​​​‌ presentation at the 34th‌ Annual Conference of the‌​‌ European Society for Biomaterials​​ (ESB 2025), September 7-11,​​​‌ Turin, Italy.

8.1.4 Scientific‌ expertise

  • Gregory Batt has‌​‌ been a jury member​​ for the PhD of​​​‌ Nattawt Leelakorn (University of‌ Copenhagen, October 2025) and‌​‌ of Cyprien Guerin (Université​​ Paris Saclay, December 2025).​​​‌ He is also a‌ member of the thesis‌​‌ advisory committees of Manon​​ Perrot (Institut Pasteur) and​​​‌ Felix Knote (University of‌ Würzburg). Gregory Batt is‌​‌ also a core member​​ of the coordination group​​​‌ of the AI initiative‌ at Pasteur, led by‌​‌ Laurent Essioux.
  • Henri Galez​​ recieved a Best Poster​​​‌ Award at the Yeast‌ 2025 conference for his‌​‌ work on InSillyClo.
  • Sean​​ Kennedy served as the​​​‌ primary examiner for the‌ PhD defense of Typhaine‌​‌ Le Doujet at the​​ Arctic University of Norway​​​‌ in October 2025. He‌ has also been a‌​‌ reviewer for the INSERM​​ internal review. He is​​​‌ also a member of‌ the selection committee of‌​‌ the Pasteur Roux-Cantarini call​​ for proposals.
  • Sara Napolitano​​​‌ has been a reviewer‌ for the annual general‌​‌ call for proposals (AAPG)​​ of the French National​​​‌ Research Agency (ANR).
  • Lorenzo‌ Pasotti has been a‌​‌ committee member for PhDs​​ in Information Engineering -​​​‌ Control, Optimization and Complex‌ Systems (Jun 2025) at‌​‌ the University of Florence,​​ Italy. He has also​​​‌ been a reviewer and‌ a jury member for‌​‌ the PhD thesis of​​ Sara Letrari (Dep. Molecular​​​‌ Medicine) at the University‌ of Padua, Italy. He‌​‌ has also been a​​ reviewer for the annual​​​‌ general call for proposals‌ (AAPG) of the French‌​‌ National Research Agency (ANR).​​

8.1.5 Research administration

Gregory​​​‌ Batt is the director‌ of the Computational Biology‌​‌ department at Institut Pasteur.​​ Department heads are responsible​​​‌ for research animation (organization‌ of department seminars and‌​‌ of department retreats), are​​ involved in group leader​​​‌ recruitments (regular G5 calls),‌ are involved in the‌​‌ mentoring of recently hired​​ group leaders, have a​​​‌ campus-wide coordination role as‌ representatives of the group‌​‌ leaders and of all​​​‌ department members, and have​ an advisory role to​‌ the direction on scientific​​ and administrative topics (department​​​‌ head meetings).

Moreover, he​ is a representative of​‌ the department directors (DDrep)​​ to discuss with the​​​‌ direction, and participates to​ the comité de direction​‌ (CoDir) of Institut Pasteur.​​

He is also a​​​‌ member of the freeze​ clean initiative, aiming at​‌ rationalizing the park of​​ -80°C fridges at Pasteur​​​‌ (the larger in Europe,​ costing > 3M€/year in​‌ electricity).

He is also​​ a member of the​​​‌ Comité des Equipes Projets​ and the Bureau du​‌ Comité des Equipes Projets​​ at Inria Paris.

Alicia​​​‌ da Silva and Henri​ Galez are PhD student​‌ representatives, Sara Napolitano is​​ a engineer representative, and​​​‌ Mélanie Ridel is an​ administrative support representative at​‌ the Computational Biology Department​​ Council at Institut Pasteur.​​​‌

8.2 Teaching - Supervision​ - Juries - Educational​‌ and pedagogical outreach

8.2.1​​ Teaching

  • Henri Galez took​​​‌ part in a three-day​ code development hackathon focused​‌ on the Python package​​ pyDNA, which supports biological​​​‌ sequence manipulation. The hackathon​ was held at the​‌ Technical University of Denmark​​ (DTU) in September 2025.​​​‌
  • Sean Kennedy gave a​ course on "the vaginal​‌ axis" as part of​​ a teaching session entiteld​​​‌ "The Power of the​ Microbiota" at the "Institut​‌ de Formation Supérieure Biomédicale"​​ (Paris-Saclay University).
  • Lorenzo Pasotti​​​‌ gave courses on "Bioinformatics​ and Synthetic Biology" at​‌ the Bioengineering Master of​​ University of Pavia, on​​​‌ "Bioinformatics" at the Biotechnology​ Master of University of​‌ Pavia (Italy), and on​​ "Bioengineering and Instrumentation in​​​‌ Sport" at the Sport​ Science Bachelor of University​‌ of Pavia (Italy).

8.2.2​​ Supervision

  • Gregory Batt is​​​‌ co-supervising with Senta Blanquet​ and Etienne Jourdier (IFPEN)​‌ the PhD work of​​ Alicia da Silva, “A​​​‌ screening and learning approach​ for protein secretion in​‌ yeast". Started in Oct.​​ 2023.
  • Sara Napolitano and​​​‌ Gregory Batt are co-supervising​ two PhD students:
    • Henri​‌ Galez , “Engineering an​​ autocrine-like system for screening​​​‌ libraries of protein secreting​ strains in yeast". Started​‌ in Sept. 2022.
    • Cecilia​​ Pires De Oliveira Capela​​​‌ , “Cybergenetic solutions to​ enforce genetic stability in​‌ bioproduction applications". Started in​​ Nov. 2024.
  • Sara Napolitano​​​‌ supervised the work of​ Ines Dahlal, a dual-education​‌ student in "bachelor universitaire​​ de technologie" with specialization​​​‌ in Medical Technology and​ Biotechnology at Cergy Paris​‌ University.

9 Scientific production​​

9.1 Publications of the​​​‌ year

International journals

  • 1​ articleA.Angelica Frusteri​‌ Chiacchiera, M.Michela​​ Casanova, M.Massimo​​​‌ Bellato, A.Aurora​ Piazza, R.Roberta​‌ Migliavacca, G.Grégory​​ Batt, P.Paolo​​​‌ Magni and L.Lorenzo​ Pasotti. Harnessing CRISPR​‌ interference to resensitize laboratory​​ strains and clinical isolates​​​‌ to last resort antibiotics​.Scientific Reports15​‌1January 2025,​​ 261HALDOI
  • 2​​​‌ articleH.Henri Galez​, B.Bryan Brancotte​‌, J.Juliette Bonche​​, J.Julien Fumey​​​‌, S.Sara Napolitano​ and G.Gregory Batt​‌. InSillyClo, a User-Friendly​​ Web Application to Assist​​​‌ Large-Scale Golden Gate Cloning​ and MoClo Workflows.​‌ACS Synthetic Biology15​​1December 2025,​​ 353-358HALDOI
  • 3​​​‌ articleL.Laurent Mandelbrot‌, S. P.Sean‌​‌ P. Kennedy, J.​​Jessica Rousseau, F.​​​‌François Goffinet, L.‌Luce Landraud, C.‌​‌Céline Plainvert, V.​​Valérie Marcou, L.​​​‌Luc Desfrère, T.‌Tiphaine Barral, L.‌​‌Lahçene Allal, A.​​Agnès Baud, N.​​​‌Nathalie Grall, C.‌Claire Poyart, P.-Y.‌​‌Pierre-Yves Ancel and A.​​Asmaa Tazi. Predicting​​​‌ neonatal infection in PPROM‌ with vaginal microbiology and‌​‌ metagenomics: a prospective cohort​​ study.American Journal​​​‌ of Obstetrics and Gynecology‌December 2025. In‌​‌ press. HALDOI
  • 4​​ articleI.Iacopo Ruolo​​​‌, S.Sara Napolitano‌, L.Lorena Postiglione‌​‌, G.Gennaro Napolitano​​, A.Andrea Ballabio​​​‌ and D.Diego Di‌ Bernardo. Investigation of‌​‌ dynamic regulation of TFEB​​ nuclear shuttling by microfluidics​​​‌ and quantitative modelling.‌Communications Biology81‌​‌March 2025, 443​​HALDOI