Hepatocellular carcinoma (HCC) is the 3th cause of cancer-related death worldwide. Among HCC tumors, one group harboring activating mutations into the beta-catenin gene (CTNNB1) constitutes a specific cold HCC entity. Immune Check points Inhibitors are now in first line but with only a minority of responders. Our forthcoming challenge is to unravel immune escape mechanisms underlying the response failure to treatment. Our pilot study demonstrates that 1)- MAIT cells functionality is associated with Atezo/Beva (anti-PDL1/-VEGF) treatment response in HCC patients, 2)- MAIT cells are reshaped by signals from CTNNB1-HCC tumor impairing their immunosurveillance capacities. Their emerging role in liver cancer is promising, placing them as good candidates for the design of anti-cancer treatment. Our goal is to decipher the molecular dialogue of MAIT cells within tumor microenvironment of cold CTNNB1-HCC which still remains a major therapeutic challenge. In 4 axes, we aim at defining how MAIT cells are shaped and corrupted by the tumor microenvironment in order to identify molecular targets to improve CTNNB1-HCC immunotherapy: WP1: Deciphering MAIT cells interactions, phenotype and location in human CTNNB1-HCC will be deciphered. WP2: Deciphering the role of MAIT cells in CTNNB1-HCC within their microenvironment WP3: Unraveling MAIT cells heterogeneity and corruptive mechanisms orchestrated by CTNNB1-HCC within their microenvironment from initial to progression steps of tumorigenesis WP4: Determination of MAIT cell heterogeneity in both PBMC/HCC tumor from HCC patients treated with AtezoBev, and prediction response to treatment. To overcome the poor response using ICIs, there is still a tremendous need to unravel the molecular mechanisms underlying immune escape. In that sense, MAIT-CanLIV project will answer these points due to its fundamental and translational aspects exploring MAIT cell biology during HCC and notably the therapeutically challenging cold CTNNB1-HCC.

In the retina, the metabolic activity of photoreceptors relies on choroidal blood flow, tightly regulated by nerves from the autonomous nervous system (ANS). Retinal imaging has recognized “pachychoroid”, defined as thick choroid, dilation of choroidal vessels and attenuation of the choriocapillaris, suggesting choroidal blood flow deregulation. But the neural component of pachychoroid is not described. Pachychoroid leads to a spectrum of diseases, including central serous chorioretinopathy (CSCR). Highest associated risk factorfor CSCR is intake of glucocorticoids that act through binding to gluco and mineralocorticoid receptors (MR). Our group has demonstrated MR pathway overactivation causes choroidal pathology close to pachychoroid. Recently, we observed morphologic alterations of choroidal nerves in transgenic rodents knock in for human MR, most suggestive of peripheral neuropathy. Systemic deregulation of the ANS, measured by the heart rate variability or by pupillometry have been shown in CSCR. But, choroidal nerves have never been explored in pachychoroid or in CSCR and no link is been made between corticoids, ANS deregulations and pachychoroid. The NEUROCOR project objectives are: - to characterize in depth choroidal innervation and its link with vessels in rodents and in humans, -to evaluate whether specific choroidal nerves alterations induce vasculopathy observed in pachychoroid eyes, - to decipher the link between choroidal neuropathy and corticoids, - to analyze the metabolism of corticoids and ANS parameters in a cohort of patients with pachychoroid and explore choroidal nerves. Result from the present project will elucidate the link between choroidal neuropathy, pachychoroid and MR pathway and help to identify surrogate markers of choroidal neuropathy. These markers could serve as clinical endpoint in trials evaluating mineralocorticoid receptor antagonists in patients with pachychoroid and associated complications.

The outbreak of SARS-CoV-2, the etiological agent of COVID-1 is daunting and challenging event for the scientific community, health authorities and governments worldwide. Our understanding of the virus biology or the pathogenesis of the COVID-19 remains limited. In addition to the promise that vaccination will contain the spread of the virus, novel therapeutic approaches to limit infection and/or reduce its short and/or long-term damaging consequences are a major challenge. Repositioning of pharmaceutical agents that would interfere with one or several steps in the infection process, cellular and systemic consequences and/or limit the deleterious long-term consequences is of great interest, especially since this will allow rapid and low-cost intervention worldwide. The working hypothesis of the MIRCOV project, based on preclinical preliminary data and a strong clinical rationale, is that Mineralocorticoid Receptor Antagonists (MRAs), especially spironolactone and its derivative canrenoate, will reduce 1) inflammation, thrombosis and fibrosis in human pulmonary alveolar epithelial and endothelial cells challenged with recombinant Spike protein 2) cardiovascular, pulmonary, renal, liver, and metabolic damages as well as systemic inflammation and morbimortality in a mouse model of COVID-19.

The Atg8/LC3/GABARAP family of ubiquitin-like proteins is a main player of the macroautophagy pathway, a stress-resistance process that maintains cellular homeostasis by promoting the degradation of cytoplasmic components and organelles within lysosomes. Atg8s are addressed to double membrane vesicles termed autophagosomes (AP), participating to the initiation, cargo recognition/engulfment, and vesicle closure. In addition, Atg8s also function in autophagy unrelated pathways, either conjugated to single-membrane vesicles (CASM) or independently of membrane anchorage. However, the molecular mechanisms and the regulations underlying the multiple roles of Atg8s are not well understood. The Janus consortium federate partners working on Autophagy, Proteostasis and Stress, and complementary expertise on cellular biology, genetics, proteomics and big data analyses. The Janus project explores the two faces of LC3/GABARAP functions within the cell and aims to characterize the molecular mechanisms allowing "spatio-temporal functionality" in autophagy-related and unrelated processes. Janus will describe and quantify the variability and versatility of LC3/GABARAP functions. It takes advantage of C. elegans for in vivo studies of several autophagy processes, but also CASM processes and developmental functions. This tiny animal with multiple tissues but with only two LC3/GABARAP proteins (six in humans) will foster the exploration of their specific roles and the elaboration of a functional model for LC3/GABARAP repertoire. The novelty and ambition of Janus is to obtain a detailed and comprehensive view of Atg8s functions and to better understand how they participate to stress sensing and homeostasis through autophagy-related and unrelated processes.

Hemophilia A and B are inherited bleeding disorders that result in impaired thrombin generation. Correction of bleeding in hemophilia patients is best achieved by the therapeutic administration of factor VIII (FVIII) or factor IX (FIX), the respective missing coagulation factors. Replacement therapy is however complicated by the short half-lives and immunogenicity of the therapeutic molecules. Alternatives to replacement therapy include bypassing agents such as activated factor VII or Emicizumab, a bispecific monoclonal antibody (mAb), or molecules that neutralize natural anticoagulant proteins such as TFPI, antithrombin or activated protein C. These molecules are delivered systemically and do not accumulate at the site bleeding. Hence, they do not fully compensate for the missing coagulation factor and may trigger potentially life-threatening thrombotic events. AAV-based gene therapy has brought encouraging results for hemophilia but is restricted to patients who have not developed anti-drug antibodies (ADA) to the therapeutic coagulation factor or to AAV, and may be associated with liver toxicity, at least in HA patients. There is thus a need for novel therapeutic molecules that specifically reinforce thrombin generation at the very bleeding site and only at the time of vessel injury. Our previous work demonstrates the importance of the natural anticoagulant protease nexin-1 (PN-1, or serpinE2) as a major but somewhat ignored regulator of thrombin. We demonstrated that blocking PN-1 corrects the hemophilia phenotype. PN-1 is expressed ubiquitously including by platelets. Our working hypothesis proposes that the targeted neutralization of platelet-released PN-1 should reinforce thrombin generation at the very bleeding site and only when it is required. To validate our hypothesis, we will develop an array of bispecific chimeric molecules made of different nanobodies (VHH), which we refer to as Nanochimeras: a pole of the Nanochimeras will neutralize PN-1 activity; the second pole will bind GPVI, a transmembrane glycoprotein protein specifically expressed by platelets and megakaryocytes. The Nanochimeras will thus concentrate PN-1-neutralizing VHHs at the platelet surface. Some of the Nanochimeras will be fused to the Fc portion of the human (hu) IgG1 to confer increased in vivo half-life, and potentially longer therapeutic efficacy. Our preliminary data include 3 VHHs that neutralize hu and mouse PN-1 to different extents, 6 VHHs that bind two different epitopes on huGPVI with nanomolar affinities and do not activate platelets or prevent collagen-induced platelet activation, and the proof that huPN-1 is functional in mouse plasma. We also started backcrossing knock-in huGPVI transgenic (Tg) mice on FVIII-deficient (HA) mice. Using these molecules and the technologies already in place in the two partner laboratories, we will pursue the following objectives: i) generate VHHs binding huGPVI with subnanomolar affinities that do not interfere with platelet functions, and VHHs with optimized PN-1 neutralizing activity, ii) generate and functionally validate recombinant bispecific Nanochimeras, iii) generate and validate a novel preclinical model of huPN-1 Tg huGPVI Tg HA mice, and iii) determine the in vivo half-life of the Nanochimeras, confirm their therapeutic potential in correcting thrombin generation, delineate the extent of thrombus formation and predict their immunogenicity. While the proof of concept will be obtained in a preclinical model of HA, our Nanochimeras will be suitable to patients with HA or HB, irrespective of whether they have developed ADA to FVIII or FIX, patients with other bleeding disorders characterized by insufficient thrombin generation, as well as HA patients who experience breakthrough bleeds while treated with Emicizumab.