The present disclosure relates to retroviral vectors comprising polynucleotides encoding hapten-binding receptors and T cell activating receptors. The retroviral vectors may also comprise transduction enhancers. Also disclosed are adaptor molecules and their use in conjunction with the retroviral vectors and T cells transduced with the retroviral vectors.

The disclosure provides modified plant viruses designed for delivering a nucleotide of interest into mammalian cells. The modified plant viruses include a plant virus nucleotide sequence (e.g. fragment) that is capable of transfecting a mammalian cell when that mammalian cell expresses a receptor for the modified plant virus. Accordingly, the disclosure also provides receptors for the modified plant viruses as well as methods of using the receptor or the modified plant virus and receptor.