Figure 1.

Lentiviral HSV-tk reporter gene construct. Viral vector map of HSV-tk positron emission tomography reporter gene construct used to transfect a subpopulation (≈15 million of 80 million total) hAMSCs prior to cell transplantation. This construct contains dual reporter genes Fluc and HSVtk. HSVtk confers the ability to metabolize and retain the radioisotope ¹⁸F-FHBG.⁹ AmpR indicates ampicillin resistance; bp, base pairs; Fluc, firefly luciferase; hAMSCs, human amniotic mesenchymal stem cells; HSV-tk, herpes simplex virus thymidine kinase; LVLTR, lentiviral long terminal repeat; LV-TF, triple fusion lentiviral vector; SINLTR, self-inactivating long terminal repeat; WPRE, woodchuck hepatitis virus post-transciptional response element.