Calcium phosphate coprecipitation greatly enhances transduction of cardiac myocytes and vascular smooth muscle cells by lentivirus vectors.

Background: Lentivirus vectors provide a delivery system that can both transduce nondividing cells and integrate transgenes into the genome of target cells without cytotoxicity. However, their relatively low transduction efficiency presents a significant obstacle to progress.

Objectives: In the present paper, a simple and easy method using calcium phosphate (CaPi) to enhance the efficiency of lentivirus gene transfer in both vascular smooth muscle cells and cardiac myocytes is reported.

Methods And Results: Delivery of lentivirus vectors in the presence of CaPi coprecipitates increased vector-encoded transgene expression up to 13-fold. Of interest, the magnitudes of enhancement of transgene expression by CaPi coprecipitates in 293T cells, vascular smooth muscle cells and cardiac myocytes were greater during brief periods (10 min and 120 min) of virus-cell contact than during long periods (16 h). Moreover, with a short duration of incubation with CaPi coprecipitates (up to 120 min), there was little evidence of direct cell toxicity. CaPi coprecipitates had no effect on host range specificity of ecotropic viruses and thus appears to enhance transduction efficiency physiologically by facilitating physical interaction between virus and cell.

Conclusions: These data show that lentivirus with CaPi coprecipitates increases both the efficiency and the speed of gene transfer. These approaches provide an efficient method and an improved tool for research and possibly for therapy of cardiovascular diseases.