Immune Modulatory Cell Therapy for Hemophilia B Based on CD20-Targeted Lentiviral Gene Transfer to Primary B Cells

• Main Authors: Xiaomei Wang, Roland W. Herzog, Barry J. Byrne, Sandeep R.P. Kumar, Qi Zhou, Christian J. Buchholz, Moanaro Biswas
• Format: Article
• Language: English
• Published: Elsevier 2017-06-01
• Series: Molecular Therapy: Methods & Clinical Development
• Subjects: hemophilia B; CD20; SCFV; lentivirus; gene transfer; measles virus; psuedotype
• Online Access: http://www.sciencedirect.com/science/article/pii/S2329050117300505

Gene-modified B cells expressing immunoglobulin G (IgG) fusion proteins have been shown to induce tolerance in several autoimmune and other disease models. However, lack of a vector suitable for gene transfer to human B cells has been an obstacle for translation of this approach. To overcome this hurdle, we developed an IgG-human factor IX (hFIX) lentiviral fusion construct that was targeted to specifically transduce cells expressing human CD20 (hCD20). Receptor-specific retargeting by mutating envelope glycoproteins of measles virus (MV)-lentiviral vector (LV) and addition of a single-chain variable fragment specific for hCD20 resulted in gene delivery into primary human and transgenic hCD20 mouse B cells with high specificity. Notably, this protocol neither required nor induced activation of the B cells, as confirmed by minimal activation of inflammatory cytokines. Using this strategy, we were able to demonstrate induction of humoral tolerance, resulting in suppression of antibody formation against hFIX in a mouse model of hemophilia B (HB). In conclusion, transduction of receptor-specific retargeted LV into resting B cells is a promising method to develop B cell therapies for antigen-specific tolerance induction in human disease.