INTRAVESICAL GENE-THERAPY - IN-VIVO GENE-TRANSFER USING RECOMBINANT VACCINIA VIRUS VECTORS

Intratumoral gene transfer may be a significant tool in active immunot herapy. The ability to insert functional genes into a tumor in vitro a nd in vivo using recombinant vaccinia vectors was examined in the muri ne bladder tumor model. Vaccinia recombinants expressing the influenza hemagglutinin or nucleoprotein antigens infected/transfected murine ( MB-49 and MBT-2) and human (T24) bladder tumor cell lines in vitro. Sy stemic vaccinia immunity was induced with as few as 10 plaque-forming units of recombinant vaccinia instilled intravesically, and the encode d protein was expressed in vivo in tumor and urothelium. However, prei mmunity to vaccinia did not inhibit intravesical tumor transfection. T hus, recombinant vaccinia virus is effective in introducing foreign an tigens locally into tumor in vivo, supporting its use in clinical immu notherapy.