1. ¹Institut National de la Santé et de Recherche Médicale, Unit 768, Necker site, Paris, France
2. ²Faculté de Médecine René Descartes, Université Paris–Descartes, Necker site, Paris, France
3. ³Cythéris, Issy-les-Moulineaux, France
4. ⁴Service d'Hématologie Adultes, Assistance Publique, Hôpitaux de Paris, Hôpital Necker Enfants, Malades, Paris, France
5. ⁵Département de Biotherapie, Assistance Publique, Hôpitaux de Paris, Hôpital Necker Enfants, Malades, Paris, France
6. ⁶Service d'Hématologie, Assistance Publique, Hôpitaux de Paris, Hôpital Necker Enfants, Malades, Paris, France
7. ⁷Département de virologie moléculaire et vectorologie, Institut Pasteur, Paris, France
8. ⁸Service d'Immunologie et d'Hématologie Pédiatriques, Assistance Publique, Hôpitaux de Paris, Hôpital Necker Enfants, Malades, Paris, France

Correspondence: Chantal Lagresle-Peyrou, Institut National de la Santé et de Recherche Médicale, Unit 768, site Necker, 149 rue de Sèvres, F-75743 Paris Cedex15, France. E-mail:lagresle@necker.fr

The first three authors contributed equally to this work.

Received 25 July 2007; Accepted 13 October 2007; Published online 27 November 2007.

Abstract

Severe combined immunodeficiency (SCID) caused by mutation of the recombination-activating gene 1 (RAG1) or Artemis gene lead to the absence of B- and T-cell differentiation. The only curative treatment is allogeneic bone marrow (BM) transplantation, which displays a high survival rate when an HLA compatible donor is available but has a poorer prognosis when the donor is partially compatible. Consequently, gene therapy may be a promising alternative strategy for these diseases. Here, we report that lentiviral gene-corrected BM CD34⁺ cells (isolated from Artemis- or RAG1-deficient patients) sustain human B-cell differentiation following injection into non-obese diabetic/SCID (NOD-SCID) mice previously infused with anti-interleukin-2 receptor chain monoclonal antibody. In most of the mice BM, engrafted with Artemis-transduced cells, human B-cell differentiation occurred until the mature stage. The B cells were functional as human immunoglobulin M (IgM) was present in the serum. Following injection with RAG1-transduced cells, human engraftment occurred in vivo but B-cell differentiation until the mature stage was less frequent. However, when it occurred, it was always associated with human IgM production. This overall approach represents a useful tool for evaluating gene transfer efficiency in human SCID forms affecting B-cell development (such as Artemis deficiency) and for testing new vectors for improving in vivo RAG1 complementation.