Funding transnational collaborative research through joint transnational calls is one of the major objectives of E-Rare. This is the most important and effective joint activity to enhance the cooperation between European scientists working on rare diseases and thus reducing the fragmentation of research in this field. E-Rare launches calls on a yearly basis. The topic and eligibility criteria are specified every year and therefore may vary from one call to the other.

Gene edited lymphoid progenitors for adoptive transfer as a treatment of primary immunodeficiency

Project Coordinator

Ospedale San Raffaele


Isabelle André-Schmutz INSERM - Institut des Maladies Génétiques Paris, France
Tom Taghon Ghent University Gent, Belgium
Hermann Eibel Universitaetsklinikum Freiburg - Center for Chronic Immunodeficiency Freiburg, Germany
Claudia Waskow Technische Universitaet Dresden - Institute for Immunology Dresden, Germany

Our project provides a new gene and cell therapy-based strategy to treat severe combined immunodeficiency (RAG-SCID) and hyper-IgM syndrome 1 (HIGM1). Both rare primary immunodeficiencies (PIDs) manifest during the first year of life and are caused by mutations in RAG1 and CD40LG. The expression of both genes is tightly regulated. Therefore, the genetic defects cannot be treated by classical gene transfer methodology. Our strategy is therefore based on the correction of RAG1 and CD40LG mutations by a gene-editing approach which is followed by the adoptive transfer of gene-edited lymphoid progenitor cells (GE-LP). Both genetic defects affecting B and T lymphopoiesis were chosen because they can be cured by transplanting even small numbers of corrected lymphoid progenitor cells. To correct RAG1 and CD40LG mutations in situ we will apply nuclease-mediated homologous recombination as this restores gene function while retaining the endogenous control of gene expression. Gene therapy options are also limited by the access to hematopoietic precursor cells (HSC) from the young RAG-SCID and HIGM1 patients. To overcome this limitation, we will compare our gene-editing strategy human in bone marrow-derived HSC and in multipotent hematopoietic progenitors derived from induced pluripotent stem cells (iPSCs), which can be generated from almost any human cell type. We will first validate gene-editing of RAG1 and CD40LG mutations in human HSC in vitro by measuring both functionality and molecular signatures of GE-LPs. We will then evaluate in vivo functionality of GE-LPs using unique innovative mouse tools that are optimized for the engraftment of human human hematopoietic stem and progenitor cells (HSPC) populations and allow for multilineage differentiation read-out because the generation of all hematopoietic lineages is strongly supported in these NSGW41hIL7tg mice.
This can be summarized by the following Work Packages (WPs; Fig. 1):
1) To correct disease-causing mutations by gene editing technology in situ.
2) To generate GE-LPs from patient-derived iPSCs
3) To generation GE-LPs from patient-derived hematopoietic stem cells
4) To validate B and T cell development from GE-LPs in vitro
5) To evaluate the engraftment capacity and function of GE-LPs in vivo
Our combined expertise will allow the functional validation of a GE-LPs based therapy both in vitro and in vivo. Several aspects of the our approach have been already adapted to GMP conditions. Together with our proven experience in translating gene therapy to the clinic, this warrants the sustained and seamless transfer of the methodology developed in this project into clinical application. We expect, that our study will provide an innovative tailored and precise gene-based treatment of PIDs.

E-Rare 2012 - Created by Toussaint Biger