Therapeutic gene editing of T cells to correct CTLA-4 insufficiency
Thomas A. Fox, Benjamin C. Houghton, Lina Petersone, Erin Waters, Natalie M. Edner, Alexander J. McKenna, Olivier Preham, Claudia Hinze, Cayman Williams, Adriana S. Albuquerque, Alan Kennedy, Anne M. Pesenacker, Pietro Genovese, Lucy S. K. Walker, Siobhan O. Burns, David M. Sansom, Claire Booth, Emma Morris
Abstract
Heterozygous mutations in CTLA-4 result in an inborn error of immunity with an autoimmune and frequently severe clinical phenotype. Autologous T cell gene therapy may offer a cure without the immunological complications of allogeneic hematopoietic stem cell transplantation. Here, we designed a homology-directed repair (HDR) gene editing strategy that inserts the CTLA-4 cDNA into the first intron of the CTLA-4 genomic locus in primary human T cells. This resulted in regulated expression of CTLA-4 in CD4 + T cells, and functional studies demonstrated CD80 and CD86 transendocytosis. Gene editing of T cells isolated from three patients with CTLA-4 insufficiency also restored CTLA-4 protein expression and rescued transendocytosis of CD80 and CD86 in vitro. Last, gene-corrected T cells from CTLA-4 −/− mice engrafted and prevented lymphoproliferation in an in vivo murine model of CTLA-4 insufficiency. These results demonstrate the feasibility of a therapeutic approach using T cell gene therapy for CTLA-4 insufficiency.