Background:

Hemophilia B is an X-linked bleeding disorder caused by a mutation in the gene responsible for encoding coagulation factor IX (FIX). Gene therapy offers promising potential for curing this disease. However, the current method of relatively high dosage of virus injection carries inherent risks. The purpose of this study was to introduce a novel scAAV-DJ/8-LP1-hFIXco vector transduced human umbilical cord blood derived mesenchymal stem cells (HUCMSCs) as an alternative cell-based gene therapy to conventional gene therapy for Hemophilia B.

Methods:

The human FIX activation system was employed for detection. The RNA and protein expression levels were evaluated using PCR and western blot techniques. In animal studies, clotting time was utilized as a parameter for bleeding assessment. The immunohistochemical analysis was used to assess the distribution of HUCMSCs. The safety of this cell-based gene therapy was evaluated using hematoxylin-eosin staining.

Results:

Our findings demonstrate that transduction of HUCMSCs with the scAAV-DJ/8-LP1-hFIXco vector results in consistent and sustainable secretion of human FIX both in vitro and in vivo. The secretion level is comparable to that observed following intravenous injection with a high dose of the viral vector. After a 5-month observation period, no tumor-related tissues were observed in any of the mice studied.

Conclusions:

we have successfully developed a novel cell-based gene therapy for the potential and safer treatment option for Hemophilia B.