Chemistry-mediated synthetic virus-cell interaction as a generic approach to enhance gene delivery to mammalian cells.

Lentiviral vectors (LVs) that facilitate gene delivery to desired cell types have been widely used in routine laboratory research and therapeutic cell engineering. However, the lack of proper entry receptors on many cell types often results in poor gene delivery. Here, we leveraged biocompatible chemistries to establish a synthetic virus-cell interaction for enhancing virus entry. LVs are dual-pseudotyped with the G protein from vesicular stomatitis virus (VSV-G) and a chimeric envelope protein specifically recognizing a small molecule fluorescein (αFITC-Env). We created surrogate receptors for LV attachment by leveraging N-hydroxysuccinimide (NHS) chemistry to create a covalent bond between lysine on cell surface proteins and a small molecule fluorescein isothiocyanate (FITC) or by labeling cells with a FITC-conjugated antibody. The synthetic virus-cell interaction promotes robust virus docking and transgene delivery in a range of mammalian cell lines and primary T cells. We showed that this approach enabled efficient delivery of a CD19-targeted chimeric antigen receptor (CAR) into naive human T cells that are naturally refractory to conventional VSV-G LVs. These naive CD19-CAR T cells, upon activation, rapidly eradicated CD19+ leukemic cells in vitro. This chemistry-mediated synthetic virus-cell interaction may serve as a generic method for promoting gene delivery to mammalian cells ex vivo.