HIGHLY EFFICIENT AND CONSISTENT GENE-TRANSFER INTO DENDRITIC CELLS UTILIZING A COMBINATION OF ULTRAVIOLET-IRRADIATED ADENOVIRUS AND POLY(L-LYSINE) CONJUGATES

Dendritic cells (DCs) are capable of presenting tumor-associated antig ens and subsequently play an essential role in T-cell activation, The aim of this study was to develop an efficient method for gene transfer into DCs. These genetically transduced DCs can then be used as potent inducers of specific cell-mediated immune response, When compared wit h physical methods for gene transfer (Lipofection and calcium phosphat e precipitation), adenovirus (AdV) vectors proved to he highly efficie nt for gene transfer into DCs, To overcome concomitant AdV gene expres sion and potential immunogenicity, AdVs were irradiated with UV. The U V dose was optimized to block AdV transcription without altering AdV r eceptor binding and endocytosis capacity. We subsequently used a polyc ationic amino acid compound, poly(L-lysine), to conjugate the irradiat ed AdVs to transgenes. The resulting complexes were found to mediate a highly efficient transfer of transgenes into DCs, without concomitant expression of AdV gene products, Low titers of irradiated AdVs were s ufficient for a consistent gene transfer into DCs, This is the first s tudy to demonstrate efficient, consistent, and practical gene transfer using an UV approach to irradiated AdV-poly(L-lysine) conjugates and should be useful for the development of DC-based tumor vaccine therapi es.