Retrovirus-mediated transfer of the herpes simplex virus thymidine kinase and enhanced green fluorescence protein genes in primary T lymphocytes

The EGFP-tk retroviral vector, encoding enhanced green fluorescent protein (EGFP) and the herpes simplex virus thymidine kinase (HSV-tk) packaged in a Phoenix amphotropic cell line, was used to transduce healthy donor T lymph ocytes. Infection yielded a mean of 41.8 +/- 9.3% SD (range 31.1-48.4%) EGF P-positive cells and a mean of 92 +/- 2% SD (range 90-94%) after cell sorti ng. EGFP expression remained stable for 30 d after infection. The entire ge ne transfer procedure had no significant effect on lymphocyte subsets and s lightly reduced clonogenicity. Ganciclovir (gcv) treatment (1 mu g/ml x 10 d) killed all EGFP-positive cells in the transduced and transduced/sorted p opulations, but had no effect on untransduced controls. Our results show th at primary T lymphocytes can be transduced using an EGFP-tk vector that yie lds a homogeneous infected population without affecting lymphocyte subsets, function and clonogenicity.