Related Experiment Videos
An alternative approach to somatic cell gene therapy
1Molecular Biology and Virology Laboratory, Salk Institute, San Diego, CA 92138.
Summary
Retroviral-infected fibroblasts delivered human factor IX in mice for over 10 days. Anti-human factor IX antibodies, not graft rejection, caused protein loss, suggesting a somatic cell gene therapy approach.
Area of Science:
- Biotechnology
- Gene Therapy
- Immunology
Background:
- Hemophilia B is a genetic disorder caused by a deficiency in functional coagulation factor IX.
- Somatic cell gene therapy offers a potential treatment by introducing functional genes into a patient's cells.
- Retroviral vectors are commonly used for gene delivery in somatic cell gene therapy.
Purpose of the Study:
- To investigate the potential of using retroviral-infected primary skin fibroblasts for somatic cell gene therapy.
- To assess the production and secretion of biologically active human factor IX protein by these engineered cells in vivo.
- To evaluate the duration of human factor IX protein expression and identify factors contributing to its clearance.
Main Methods:
- Primary mouse skin fibroblasts were genetically modified using a recombinant retrovirus carrying human factor IX cDNA.
- Engineered fibroblasts were embedded in collagen and grafted subcutaneously in mice.
- Serum levels of human factor IX protein were monitored over time using immunoassay.
Main Results:
- Transplanted mice exhibited detectable levels of human factor IX protein in their serum for 10-12 days post-transplantation.
- The decline in human factor IX protein levels was attributed to the development of anti-human factor IX antibodies in the mice.
- Graft rejection was ruled out as the cause for the loss of immunoreactive human factor IX protein.
Conclusions:
- Retroviral-infected primary skin fibroblasts can synthesize and secrete biologically active human factor IX protein in vivo.
- The development of anti-human factor IX antibodies presents a challenge for sustained therapeutic protein levels in this model.
- This study suggests that retroviral-mediated gene transfer into primary fibroblasts is a viable strategy for somatic cell gene therapy, warranting further investigation into immune responses.