Abstract: Gene therapy of SCO is based on the transplantation of genetically modified HSCs. Several LV approaches based on gene addition consist in transducing patient HSCs with a lentiviral vector expressing an anti-sickling ?-like globin chain such as use of ?AS3 HBB anti-sickling variants. Here, the inventors have improved the design of the LV-AS3 vector to treat SCO patients. These LVs allow the simultaneous expression of the potent anti-sickling ?AS3-globin and an artificial miR (amiR) silencing the ?S-globin. The reduction of ?S-globin levels will increase the incorporation of ?AS3-globin in Hb tetramers, which should increase the proportion of corrected RBCs in SCO patients. The inventors selected the best-performing miRs, and modified the therapeutic ?AS3-globin transgene by inserting silent mutations to avoid the recognition by the amiR and the silencing of the transgene.

Abstract: The invention relates to an in vitro method to generate T cell progenitors, comprising the step of culturing CD34+ cells in a medium containing TNF-alpha and/or an antagonist of the Aryl hydrocarbon/Dioxin receptor, in particular StemRegenin 1 (SR1), in presence of a Notch ligand and optionally a fibronectin fragment.

Abstract: The clinical history of ?-hemoglobinopathies shows that the severity is mitigated by the synthesis of the fetal ?-globin in adulthood, typically associated with genetic variants the HBB cluster known as hereditary persistence of fetal hemoglobin (HPFH) mutations. The inventors identified that most of the known HPFH mutations in the ?-globin promoters (C>T, G>A, T>C or A>G) can be recapitulated using CBE- and ABE-mediatedbase-editing approaches. In particular, the inventors designed gRNAs that, when combined with CBEs or ABEs, generate HPFH mutations, and either disrupt binding sites for transcriptional repressors (-200 and -115 sites) or generate de novo DNA motifs recognized by transcriptional activators (e.g., -198 T>C, the -175 T>C and -113 A>G).

Abstract: The invention relates to an in vitro method to generate T cell progenitors, comprising the step of culturing CD34+ cells in a medium containing TNF-alpha and/or an antagonist of the Aryl hydro-carbon/Dioxin receptor, in particular StemRegenin 1 (SR1), in presence of a Notch ligand and optionally a fibronectin fragment.

Abstract: Maple syrup urine disease (MSUD) is a rare autosomal recessive disease with an incidence that is caused by a defective activity of the branched-chain 2-keto acid dehydrogenase (BCKD) leading to accumulation of branched-chain amino acids (BCAA) leucine, isoleucine, valine and their corresponding alpha-ketoacids (BCKA) in tissues and body fluids. The inventors herein characterized the Bckdha?/? mouse and Bckdhb?/? mouse recapitulating the classical forms of MSUD. As a proof of concept, they developed a (liver-directed) AAV gene therapy based on the transfer of human BCKDHA (hBCKDHA) or BCKDHB (hBCKDHB) mediated by AAV8 during immediate neonatal period in Bckdha?/? or Bckdhb?/? mice. The inventors demonstrated that hBCKDHA gene transfer completely rescued the lethal early-onset phenotype of Bckdha?/? mice allowing long-term survival to age 12 months, at which they were systematically sacrificed, without overt phenotypic abnormalities.

Abstract: The invention relates to an in vitro method to generate T cell progenitors, comprising the step of culturing CD34+ cells in a medium containing TNF-alpha and/or an antagonist of the Aryl hydrocarbon/Dioxin receptor, in particular StemRegenin 1 (SR1), in presence of a Notch ligand and optionally a fibronectin fragment.

Abstract: The invention relates to an in vitro method to generate T cell progenitors, comprising the step of culturing CD34+ cells in a medium containing TNF-alpha and/or an antagonist of the Aryl hydro-carbon/Dioxin receptor, in particular StemRegenin 1 (SR1), in presence of a Notch ligand and optionally a fibronectin fragment.

Abstract: The inventors have identified an autosomal dominant (AD) missense mutation in the RAC2 gene (coding for Ras-related botulinum toxin substrate 2 (RAC2)) in three Severe combined immunodeficiencies (SCID) patients whose clinical presentation overlaps with the RD SCID form but who lack AK2 mutations and deafness. Using biochemical and in vitro differentiation assays, the inventors demonstrated that the RAC2 mutation was closely related to an impairment in cell differentiation capacity and defects in cellular and mitochondrial networks. Taken as a whole, the data demonstrate that a dominant gain-of-function (GOF) mutation in the RAC2 protein's GDP/GTP binding site inhibits HSPC differentiation and leads to a severe AD form of SCID with a clinical presentation of RD. Accordingly, the results prompt to consider that introduction of the identified RAC2 mutein in the hematopoietic lineage would be suitable for inducing full ablation of hematopoiesis.

Abstract: Some rare and very severe autoimmune conditions are of hereditary origin such as APECED and IPEX syndrome due to altered negative selection of autoreactive T cells in the thymus or absence of regulatory T cells (Treg). Innovative strategies based on the use of regulatory T cells have been developed. The inventors have now compared 7 different experimental protocols to identify the one allowing to get the most efficacy of Treg to treat Scurfy autoimmune syndrome, a severe autoimmune model mimicking IPEX syndrome. The optimized protocol comprised a preconditioning step using cyclophosphamide and a post-conditioning step using IL-2. Thus, to present invention relates to a method for the treatment of autoimmunity in patient in need thereof comprising the steps of i) administering the patient with an amount of cyclophosphamide, ii) then engrafting the patient with an amount of the population of Treg cells, and iii) finally administering the patient with an amount of IL-2.

Abstract: The #?-hemoglobinopathies #?-thalassemia (BT) and sickle cell disease (SCD) are the most frequent genetic disorders worldwide. These diseases are caused by mutations causing reduced or abnormal synthesis of the ?-globin chain of the adult hemoglobin (Hb) tetramer. Here, the inventors intend to improve HSC-based gene therapy for ?-thalassemia and SCD by developing an innovative, highly infectious LV vector expressing a potent anti-sickling ?-globin transgene and a second biological function either increasing fetal ?-globin expression (for ?-thalassemia and SCD). More particularly, the inventors have designed a novel lentivirus (LV), which carry two different functions: ?AS3 gene addition and gene silencing. This last strategy allows the re-expression of the fetal ?-globin genes (HBG1 and HBG2) and production of the endogenous fetal hemoglobin (HbF).

Abstract: IPEX (Immune dysregulation Polyendocrinopathy X linked) syndrome is a primary immunodeficiency caused by mutations in the gene encoding the transcription factor forkhead box P3 (FOXP3), which leads to the loss of function of thymus-derived CD4+CD25+ regulatory T (tTreg) cells. Preclinical and clinical studies suggest that T cell gene therapy approaches designed to selectively restore the repertoire of Treg cells by transfer of wild type FOXP3 gene is a promising potential cure for IPEX. However, there is still a need for a vector that can be used efficiently for the preparation of said Treg cells. The inventors thus compared 6 different lentiviral constructs according to 4 criteria (vector titers, level of transduction of human CD4+ T cells, level of expression of FOXP3 and ?LNGFR genes, degree of correlation between both expression) and selected one construct comprising a bidirectional PGK-EF1a promoter that showed remarkable efficiency.

Abstract: The invention relates to an in vitro method to generate T cell progenitors, comprising the step of culturing CD34+ cells in a medium containing TNF-alpha and/or an antagonist of the Aryl hydrocarbon/Dioxin receptor, in particular StemRegenin 1 (SR1), in presence of a Notch ligand and optionally a fibronectin fragment.

Abstract: The invention relates to an in vitro method to generate T cell progenitors, comprising the step of culturing CD34+ cells in a medium containing TNF-alpha and/or an antagonist of the Aryl hydro-carbon/Dioxin receptor, in particular StemRegenin 1 (SR1), in presence of a Notch ligand and optionally a fibronectin fragment.

Abstract: The invention relates to an in vitro method to generate T cell progenitors, comprising the step of culturing CD34+ cells in a medium containing TNF-alpha and/or an antagonist of the Aryl hydro-carbon/Dioxin receptor, in particular StemRegenin 1 (SR1), in presence of a Notch ligand and optionally a fibronectin fragment.

Abstract: The invention relates to an in vitro method to generate T cell progenitors, comprising the step of culturing CD34+ cells in a medium containing TNF-alpha and/or an antagonist of the Aryl hydro-carbon/Dioxin receptor, in particular StemRegenin 1 (SR1), in presence of a Notch ligand and optionally a fibronectin fragment.

Abstract: N—{(R)-1-[8-Chloro-2-(1-oxypyridin-3-yl)-quinolin-3-yl]-2,2,2-trifluoroethyl}-pyrido[3,2-d]pyrimidin-4-ylamine is effective in the treatment and/or prevention of activated phosphoinositide 3-kinase delta syndrome (APDS).

Abstract: The invention relates to the field of cell therapy and to an in vitro method for generating T-cell progenitors, comprising the step of exposing CD34+ cells in a medium containing a Notch ligand, a soluble domain of the Delta-like ligand 4, joined to an Fc region of a protein IgG, in the presence of a fragment of fibronectin comprising the motifs RGDS and CS-1 and a heparin-binding domain.