Production of Lentivirus for the Establishment of CAR-T Cells

One of the most versatile gene transfer methods involves the use of recombinant lentiviral vectors since they can transduce both dividing and nondividing cells, are considered to be safe and provide long-term transgene expression since the integrated viral genome, the provirus, is passed on to daughter cells. These characteristics are highly desirable when a modified cell must continue to express the transgene even after multiple cell divisions. Lentiviral vectors are often used to introduce protein encoding cDNAs, such as reporter genes, or for noncoding sequences, such as mediators of RNA interference or genome editing, including shRNA or gRNA, respectively. In the gene therapy setting, lentiviral vectors have been used successfully for the modification of hematopoietic stem cells, resulting in restored immune function or correction of defects in hemoglobin, to name but a few examples. The success of chimeric antigen receptor (CAR) T cells for the treatment of B cell leukemias and lymphomas has been particularly striking and this approach has relied heavily on lentivirus-mediated gene transfer. Here we present a typical protocol for the production of lentivirus, concentration by ultracentrifugation and determination of virus titer. The resulting virus can then be used in laboratory assays of gene transfer, including the establishment of CAR T cells.