Cyclosporine H Improves Lentiviral Transduction of Murine Hematopoietic Stem and Progenitor Cells

Hematopoietic Stem Cells (HSCs) have the potential for lifetime production of blood and immune cells. Introduction of transgenes into HSCs is important for basic research, as well as for multiple clinical applications thanks to the fact that HSC-transplantation is already established. However, the efficient introduction of a transgene into HSCs had been proven challenging. Recently, a major advancement was reported with the use of Cyclosporine H (CsH), that can significantly enhance lenti-viral (LV) transduction of human Hematopoietic Stem- and Progenitor Cells (HSPCs). In this study we applied CsH for LV transduction of murine HSCs, or defined progenitors, having improved resolution of cell-types. Our data confirm increased efficiencies, in agreement with the published data. We further challenged cells with multi-vector transduction, gaining robust increase with CsH for either Progenitors or pure HSCs. CsH was reported to reduce innate-resistance mechanism against LV, and indeed we found that pre-treatment of cells could increase transduction even better than the original protocol. However, prolonged CsH treatment also inhibited cell proliferation in vitro. Therefore, we had transplanted HSCs after multi-vector transduction with or without CsH, to test for their actual abilities to perform Stem Cell function in vivo after ex-vivo manipulations. Our data suggest that CsH can robustly increase the levels of LV transduction, without perturbing HSC`s function for transplantation. This new additive will surely help many studies in animal models and is suggesting for potent option towards clinical utilization.