Nuclear imaging is now a key component of patient management. Monoclonal antibodies are the carriers of choice for molecular imaging, due to their exceptional affinity and selectivity for their target antigen. However, due to their large size, they diffuse poorly into tissues and are slowly eliminated. Therefore, they are traditionally radiolabeled with long half-life radioisotopes (e.g. 89Zr), responsible for indiscriminate irradiation of all organs. Moreover, sufficient contrast for imaging is only achieved several days after administration of the radioimmunoconjugate. The SUPRALABEL project aims at developing a strategy known as "pretargeting", in which the radiolabeling of the antibody is not carried out prior to administration to the patient, but is performed in vivo, once the antibody has optimally accumulated in the target tissue and has been eliminated from healthy tissues. This approach thus allows the use of short half-life radioisotopes such as 68Ga and 18F, which are the most relevant isotopes for clinical application. Pretargeting requires the use of highly reactive and selective partners, so that the conjugation reaction between the antibody and the radioactive probe can take place rapidly, in a particularly complex biological environment, such as the human body. Here, we aim to exploit the unique affinity between two small molecule partners, cucurbit[7]uril and adamantanamine, to form these radioimmunoconjugates in vivo by supramolecular assembly. We aim to develop cucurbit[7]uril radiolabeled with gallium-68 and fluorine-18 and optimize their pharmacokinetic properties in order to make them suitable for the pretargeting strategy. The added-value of the pretargeting strategy in immunoPET, in terms of dosimetry for the patient, will be demonstrated by the targeting of the protein LOXL2 on a murine model of pulmonary fibrosis.

Unconventional activity of some autophagy proteins drives the Conjugation of Atg8 proteins - such as LC3 - to Single Membrane (CASM) instead of double membrane autophagosomes in response to various stimuli including entosis, phagocytosis and some activators of Pattern Recognition Receptor (PRR) signaling. CASM has emerged as a functionally important pathway in immunity and cancer and has been proposed to suppress antitumor immune response. Our proposal aims to uncover the functional consequences of CASM, occurring in host and cancer cells both spontaneously and following activation with immunotherapies based on PPR agonists, on antitumor immunity. First, we will assess the role of spontaneous CASM on tumor burden, antitumor immune response and the efficacy of immune checkpoint inhibition (ICI)-based immunotherapy in melanoma and colorectal cancer preclinical models using spectral flow cytometry and single-cell RNAseq among other approaches. To do so, we will take advantage of the mouse model of host CASM inactivation developed by our collaborator and generate CASM-incompetent cancer cell lines by CRISPR-KI-induced ATG16L1 WD40 mutations. Indeed, while being dispensable for autophagy, ATG16L1 WD40 domain is essential for LC3 lipidation during CASM. To test the clinical relevance of immune response modulation by cancer cell-intrinsic CASM, we will screen ATG16L1 WD40 mutations and CASM functionality in cancer patients and ask whether they can be linked to patients’ survival and response to ICI-based treatment. Expanding our current data showing that agonists of STING trigger CASM in immune cells, we will explore the role of CASM induced by PRR signaling activators (STING and TLR agonists), under preclinical or clinical evaluation for their capacity to sensitize tumors to ICI-based immunotherapy, in their immune-driven antitumor efficacy. This work will not only ascribe CASM with new functions but also allow to evaluate the relevance of targeting CASM to improve cancer immunotherapies.

COVID-19 has emerged in December 2019 in Wuhan, China, caused by a novel RNA virus: SARS-CoV-2. As of March 22 2020, ~300,000 cases of COVID-19 and nearly 12,000 deaths (fatality rate ~4%) have been reported in the world. The high proportion of cases requiring respiratory assistance in intensive care units (~10%) catastrophically overwhelms health systems worldwide. The COVID-19 pandemic is a global health emergency and represents a never seen before challenge for the medical community but also for the scientific community which is appealed to provide prophylactics and treatment for this dreadful pathogen. Tremendous efforts are put together to counteract SARS-CoV-2 entry mechanisms and identify suitable targets for vaccine development. While generic treatments used for RNA virus infections (HIV, HCV, EBOV, ZIKV, HeV and NiV) and hydroxychloroquine are currently being investigated, no vaccine or effective treatment for SARS-CoV-2 is available or proven efficient as of today. We propose here an original and alternative contribution to the scientific effort aiming at combatting SARS-CoV-2/host-cell innate immune escape. Identifying the virus-host protein-protein interactions (PPIs) critical for infection will reveal mechanisms involved in pathogenesis and define promising drug targets. Through a unique combination of orthogonal state-of-the-art interactomic approaches conducted by highly qualified teams, N2H and BioID, we will timely profile the accurate interplay between SARS-CoV-2 proteins and human factors involved in anti-viral immune and consecutive inflammatory responses. As such, this project will quickly provide a wide network of potential host targets for innate immunity targeting treatment option. In a conceptually new manner, we will implement cutting-edge network modeling approaches aiming at delineating druggable disease modules. Of note, for potential transfer towards clinical applications, we will focus our testing strategies on repurposing approved drugs. Our approach could thus be exploited for developing rational and combined therapies targeting multiple elements within a disease module, at suboptimal doses, to counteract this deadly infectious process. Thus, our proposal is aligned with the topic “search for therapeutic targets and drug candidates”, especially turned here to restore the beneficial primary immune response and counter deleterious secondary inflammatory response to SARS-CoV-2 infection. Our works are of utmost importance: (i) due to the broad distribution of COVID-19 cases over the globe and its high degree of contagiousness, the virology community expects a seasonal recurrence of such infection. It is therefore important to tackle this major issue with all means and angles available; (ii) we hope a cure for SARS-CoV-2 infection will be discovered along the course of this project. However, in case of non-satisfactory response found within the next few months, or failure to treat all the patients because of the variety of the cases, our approach will bring essential rationale to the medical and scientific communities for immediate finding of efficient cure; and (iii), assembling such workforce enabling rapid characterization of emerging infectious agent, we are deeply convinced that our works will serve as a framework easily implementable to dramatically and timely expand basic knowledge on emerging infectious mechanisms. Hence, our proposal is of major importance to bring novel insights and rationales for future therapeutic approaches. Importantly, our project will bring an unprecedented knowledge on how the SARS-CoV-2 proteins hijack the innate immune response, and because of its semi-supervised nature, will greatly expand our knowledge of SARS-CoV-2 associated mechanisms beyond innate-immunity.

NANOPT-X is a forefront program aimed at realizing a new generation of X-ray detectors of improved performances (high sensitivity, high resolution, faster response time) available in ultra-compact and flexible architectures compatible with endoscopy. The main objective of NANOPTiX is to miniaturize X-ray detectors. We target tiny X-ray probes integrated at the end of narrow fibers of the size of a human hair (125 µm down to 80 µm outer diameters). To this end, NANOPTiX will exploit for the first time the concept of Nano-Optical Antenna (NOA) for controlling the X-ray excited luminescence (XEL) from scintillators. The NOA will be engineered as a key-connection between scintillators and a narrow optical fiber, aimed at (1) dramatically increasing the XEL signal out-coupled into the fiber, and (2), controlling the emission rate of the scintillators. We thus provide the first nano-optically driven approach in the development of X-ray imaging and real-time dosimetry. This represents a breakthrough in the engineering of X-ray detectors. While NOAs have attracted huge interest for enhancing fluorescence rate and directionality from molecules and quantum dots, their ability to control the XEL from scintillators has never been reported yet. With NANOPTiX project, nano-optics will make a first key-contribution to X-ray architectures and protocols. The miniaturization opportunity provided by the proposed disruptive approach will overcome obstacles in dosimetry and imaging. Negligible footprint endoscopic sensors, of high resolution and sensitivity, will emerge from NANOPTiX. These world premieres will impact a large field of scientific, medical and industrial domains of high economic and societal perspectives. In that context, despite high scientific challenges, NANOPTiX is geared toward prototyping, up to TRL 4, and the valorization of patentable outcomes. We target pre-industrial prototypes for endoscopic dosimetry in radiotherapy. Such prototypes will include encapsulated optimized probes, and their plug-and-play associated instrumentation, for the real-time monitoring of an irradiation dose applied in clinical environment. NANOPTiX will thus bridge the gap between fundamental concepts and market-ready prototypes. Therefore, the key fundamental issues of NANOPTiX will be industrially and medically addressed from the very outset of the project in order to achieve short term out-of-lab prototyping. Such an ambition required the creation of a highly pluridisciplanary consortium combining two industrial companies and three academic institutes, including a University Hospital with its clinical and translational-research services,. The consortium behind this project is unique and will enable the development and validation of this new technological approach with ambitious and highly complementary objectives dealing with clinical X-ray endoscopic dosimetry (up to TRL4) and the frontier investigation of X-ray digital detection and imaging down to the nanoscale. The related important technology challenges will be taken up thanks to the fabrication facilities of the consortium, involving one of the five technology platforms of the French “Renatech” network. NANOPTiX spin-offs go well beyond X-ray dosimetry and imaging. By implementing fiber detectors sensitive to other ionizing radiations, such as charged elemental particles, real-time radiation dose monitoring will become possible for Hadron therapy and Brachytherapy with completely new versatility and accuracy. Security applications have also been envisaged.

Primary tumors are currently treated by a combination of therapies including, in most cases, surgery, local radiotherapy, and adjuvant chemotherapy. Even when the tumor has apparently been defeated, micrometastases of dormant tumor cells frequently lead to tumor relapse and final therapeutic failure. Accumulating evidence indicates that the innate and adaptive immune systems can make a crucial contribution to the antitumor effects of conventional chemotherapy-based cancer treatments. However, the tumor-mediated immunosuppression of the host often limits the initiation of an effective anticancer immune response. Therefore, to defeat cancer, it is essential to relieve host immunosuppression to unleash an immune response that eradicates residual tumor cells. We have identified that 5-Fluorouracil (5-FU), a pyrimidine analog that is mainly used in the treatment of breast and colon cancer, has a superior and selective ability to deplete Myeloid derived suppressor cells (MDSC) in vivo. The elimination of MDSC by 5-FU partly restored anticancer responses and improved 5-FU therapeutic effect. However, our preliminary data indicate that an additional molecular pathway activated by the 5-FU-mediated cell death of MDSC limits the efficacy of 5-FU and contributes to immune evasion. Specifically, we hypothesize that 5-FU triggers an inflammatory, caspase-1-dependent cell death of MDSC, which supports the IL-1ß-mediated polarization of intratumor Th17 cells that impair the development of anticancer responses. Thus, by identifying the molecular mechanisms by which 5-FU affects MDSC, this project ultimately aims at unraveling new molecular targets that could be modulated to achieve optimal anticancer responses.