Nongenotoxic antibody-drug conjugate conditioning enables safe and effective platelet gene therapy of hemophilia A mice. Blood Adv 2019 Sep 24;3(18):2700-2711
Date
09/14/2019Pubmed ID
31515232Pubmed Central ID
PMC6759737DOI
10.1182/bloodadvances.2019000516Scopus ID
2-s2.0-85072272107 (requires institutional sign-in at Scopus site) 35 CitationsAbstract
Gene therapy offers the potential to cure hemophilia A (HA). We have shown that hematopoietic stem cell (HSC)-based platelet-specific factor VIII (FVIII) (2bF8) gene therapy can produce therapeutic protein and induce antigen-specific immune tolerance in HA mice, even in the presence of inhibitory antibodies. For HSC-based gene therapy, traditional preconditioning using cytotoxic chemotherapy or total body irradiation (TBI) has been required. The potential toxicity associated with TBI or chemotherapy is a deterrent that may prevent patients with HA, a nonmalignant disease, from agreeing to such a protocol. Here, we describe targeted nongenotoxic preconditioning for 2bF8 gene therapy utilizing a hematopoietic cell-specific antibody-drug conjugate (ADC), which consists of saporin conjugated to CD45.2- and CD117-targeting antibodies. We found that a combination of CD45.2- and CD117-targeting ADC preconditioning was effective for engrafting 2bF8-transduced HSCs and was favorable for platelet lineage reconstitution. Two thirds of HA mice that received 2bF8 lentivirus-transduced HSCs under (CD45.2+CD117)-targeting ADC conditioning maintained sustained therapeutic levels of platelet FVIII expression. When CD8-targeting ADC was supplemented, chimerism and platelet FVIII expression were significantly increased, with long-term sustained platelet FVIII expression in all primary and secondary recipients. Importantly, immune tolerance was induced and hemostasis was restored in a tail-bleeding test, and joint bleeding also was effectively prevented in a needle-induced knee joint injury model in HA mice after 2bF8 gene therapy. In summary, we show for the first time efficient engraftment of gene-modified HSCs without genotoxic conditioning. The combined cocktail ADC-mediated hematopoietic cell-targeted nongenotoxic preconditioning that we developed is highly effective and favorable for platelet-specific gene therapy in HA mice.
Author List
Gao C, Schroeder JA, Xue F, Jing W, Cai Y, Scheck A, Subramaniam S, Rao S, Weiler H, Czechowicz A, Shi QAuthors
Sridhar Rao MD, PhD Associate Professor in the Pediatrics department at Medical College of WisconsinQizhen Shi MD, PhD Professor in the Pediatrics department at Medical College of Wisconsin
Hartmut Weiler PhD Associate Professor in the Physiology department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AnimalsBlood Platelets
Genetic Therapy
Hemophilia A
Humans
Immunoconjugates
Male
Mice
