Transfer of activation-dependent gene expression into T cell lines by recombinant adeno-associated virus

We examined the ability of recombinant adeno-associated virus (rAAV) to tra nsfer regulated gene expression into T cell lines. An AAV-based vector cont aining the neomycin resistance gene and expressing the firefly luciferase ( luc) gene under the regulatory control of the interleukin 2 promoter (pAAV- luc) was generated and adenovirus-free rAAV(rAAV-luc) was produced from thi s vector. Transfection of pAAV-luc into the human T cell line Jurkat result ed in luciferase expression while infection of Jurkat T cells with rAAV-luc resulted in significant luciferase expression only after selection for neo mycin-resistant cells. Long-term growth of transduced Jurkat T cells showed that there was no detectable constitutive expression of luciferase and tha t luciferase gene expression remained inducible for at least 180 days. Luci ferase expression was activated by PMA and ionomycin and by anti-CD3 antibo dies and was inhibited by cyclosporin A. Examination of G418-resistant clon es showed that rAAV-luc had integrated into the host chromosomes but that s ome of the clones lost some of the transferred DNA or lost expression from the transferred DNA. These results indicate that rAAV can transfer and inte grate regulated gene expression into T cell lines but that the transferred genetic material may be lost or its expression may be silenced over time.