RAPID PRODUCTION OF INTERLEUKIN-2-SECRETING TUMOR-CELLS BY HERPES-SIMPLEX VIRUS-MEDIATED GENE-TRANSFER - IMPLICATIONS FOR AUTOLOGOUS VACCINE PRODUCTION

Production of autologous tumor vaccines would be facilitated by the de velopment of a rapid and efficient method for the transfer of genes in to freshly isolated cells, To evaluate the potential of replication de fective herpes simplex viral (HSV) amplicon vectors as gene transfer v ehicles for tumor vaccine generation, a vector that expresses the huma n interleukin-2 (IL-2) gene (HSV-IL2) and one that expresses Escherich ia coil beta-galactosidase (HSVlac) were tested in hepatoma cells of b oth murine and human origin, Gene transfer into murine hepatoma cells (HEPA 1-6) was both rapid and highly efficient: greater than 50% of ce lls expressed beta-Gal when infected at a multiplicity of infection (m .o.i.) of 1 with an exposure period of 20 min, Moreover, gene transfer was as efficient in tumor cells after irradiation with 10,000 rads as in nonirradiated tumor cells, Irradiated HEPA 1-6 cells infected with HSV-IL2 for 20 min secreted IL-2 at a sate of 1,200 +/- 160 ng/10(6) cells per day, C57Bl/6J mice immunized with irradiated, HSV-IL-2-trans duced tumor cells produced in this way demonstrated specific tumor imm unity by in vitro splenocyte tumoricidal activity and by in vivo prote ction against tumor challenge, Human hepatobiliary tumor specimens har vested at the time of operation, irradiated, and infected with HSV-IL- 2 also produced nanogram quantities of IL-2/10(6) cells per 24 hr, The se results indicate that the HSV amplicon vector is a good candidate v ehicle for gene transfer in the production of autologous tumor vaccine s, By allowing rapid gene transfer to freshly harvested tumor specimen s, these vectors bypass the requirement for cell culture and make feas ible reinfusion of genetically modified and irradiated autologous cell s within hours of tumor harvest.