PT  - JOURNAL ARTICLE
AU  - Wenjie Ouyang
AU  - Guoyi Dong
AU  - Weihua Zhao
AU  - Jing Li
AU  - Ziheng Zhou
AU  - Gaohui Yang
AU  - Rongrong Liu
AU  - Yue Li
AU  - Qiaoxia Zhang
AU  - Xin Du
AU  - Haixi Sun
AU  - Ying Gu
AU  - Yongrong Lai
AU  - Sixi Liu
AU  - Chao Liu
TI  - Restoration of β-globin expression with optimally designed lentiviral vector for β-thalassemia treatment in Chinese patients
AID  - 10.1101/2020.07.18.209759
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.07.18.209759
4099  - http://biorxiv.org/content/early/2020/07/21/2020.07.18.209759.short
4100  - http://biorxiv.org/content/early/2020/07/21/2020.07.18.209759.full
AB  - β-thalassemia is one of the most prevalent genetic diseases worldwide. The current treatment for β–thalassemia is allogeneic hematopoietic stem cell transplantation (HSCT), which is limited due to lack of matched donors. Gene therapy has been developed as an alternative therapeutic option for transfusion-ependent β-thalassemia (TDT). However, successful gene therapy for β-thalassemia patients in China has not been reported. Here we present the results of preclinical studies of an optimally designed LV named LentiHBBT87Q in hematopoietic stem cells (HSCs) derived from Chinese TDT patients. LentiHBBT87Q was selected from a series of LVs with optimized backbone and de novo cloning strategy. It contains an exogenous T87Q β-globin gene (HBBT87Q) driven by a specific reconstituted locus control region (rLCR) and efficiently express HBB mRNA and HBB protein in erythroblasts derived from cord blood (CB) HSCs. To facilitate clinical transformation, we manufactured clinical grade LentiHBBT87Q (cLentiHBBT87Q) and optimized its transduction procedure. Importantly, transduction of cLentiHBBT87Qrestored expression of HBB monomer and adult hemoglobin (HbA) tetramer to relatively normal level in erythroblasts from bone marrow (BM) HSCs of Chinese TDT patients, that carry the most common mutation types and cover various genotypes, including β0/β0. Furthermore, viral integration sites (VIS) of cLentiHBBT87Q were similar to other LVs safely used in previous clinical trials and the associated risk of tumorigenesis was not observed in cLentiHBBT87Q transduced HSCs through comprehensive analysis. Taken together, we have engineered the cLentiHBBT87Q that can restore β-globin expression in the HSCs-derived erythroblasts of Chinese TDT patients with minimal risk on tumorigenesis, providing a favorable starting point for future clinical application.Competing Interest StatementThe authors have declared no competing interest.