Defects in T-cell–mediated immunity to influenza virus in murine Wiskott-Aldrich syndrome are corrected by oncoretroviral vector–mediated gene transfer into repopulating hematopoietic cells

Abstract

AbstractThe Wiskott-Aldrich syndrome (WAS) is an X-linked disorder characterized by immune dysfunction, thrombocytopenia, and eczema. We used a murine model created by knockout of the WAS protein gene (WASP) to evaluate the potential of gene therapy for WAS. Lethally irradiated, male WASP— animals that received transplants of mixtures of wild type (WT) and WASP— bone marrow cells demonstrated enrichment of WT cells in the lymphoid and myeloid lineages with a progressive increase in the proportion of WT T-lymphoid and B-lymphoid cells. WASP— mice had a defective secondary T-cell response to influenza virus which was normalized in animals that received transplants of 35% or more WT cells. The WASP gene was inserted into WASP— bone marrow cells with a bicistronic oncoretroviral vector also encoding green fluorescent protein (GFP), followed by transplantation into irradiated male WASP— recipients. There was a selective advantage for gene-corrected cells in multiple lineages. Animals with higher proportions of GFP+ T cells showed normalization of their lymphocyte counts. Gene-corrected, blood T cells exhibited full and partial correction, respectively, of their defective proliferative and cytokine secretory responses to in vitro T-cell–receptor stimulation. The defective secondary T-cell response to influenza virus was also improved in gene-corrected animals.