Lentiviral gene therapy for X-linked chronic granulomatous disease recapitulates endogenous<i>CYBB</i>regulation and expression
Ryan L. Wong, Sarah Sackey, Devin Brown, Shantha Senadheera, Katelyn E. Masiuk, Jason P. Quintos, Nicole Colindres, Luke Riggan, Richard A. Morgan, Harry L. Malech, Roger P. Hollis, Donald B. Kohn
Abstract
X-linked chronic granulomatous disease (X-CGD) is a primary immunodeficiency caused by mutations in the CYBB gene, resulting in the inability of phagocytic cells to eliminate infections. To design a lentiviral vector (LV) capable of recapitulating the endogenous regulation and expression of CYBB, a bioinformatics-guided approach was used to elucidate the cognate enhancer elements regulating the native CYBB gene. Using this approach, we analyzed a 600-kilobase topologically associated domain of the CYBB gene and identified endogenous enhancer elements to supplement the CYBB promoter to develop MyeloVec, a physiologically regulated LV for the treatment of X-CGD. When compared with an LV currently in clinical trials for X-CGD, MyeloVec showed improved expression, superior gene transfer to hematopoietic stem and progenitor cells (HSPCs), corrected an X-CGD mouse model leading to complete protection against Burkholderia cepacia infection, and restored healthy donor levels of antimicrobial oxidase activity in neutrophils derived from HSPCs from patients with X-CGD. Our findings validate the bioinformatics-guided design approach and have yielded a novel LV with clinical promise for the treatment of X-CGD.