RECOMBINANT ADENOVIRUS-MEDIATED GENE-TRANSFER INTO THE ADULT-RAT RETINA

Purpose. The present study was designed to evaluate the feasibility of gene transfer into the retina of adult rats, using a recombinant repl ication-defective adenovirus vector expressing a reporter gene. Method s. Purified recombinant adenovirus expressing beta-galactosidase (lacZ ) (Ad5.hCMV.lacZ) at doses ranging from 1.4 X 10(2) to 1.4 x 10(6) pla que-forming units (pfu) were injected into the subretinal space of adu lt Lewis rats. The presence of lacZ was determined by histochemical as say and reverse transcription and polymerase chain reaction analysis ( RT PCR) of total RNA extracted from eyes injected with recombinant ade novirus expressing lacZ. Results. As assessed by biomicroscopy, the ex pression of lacZ was highest in the retinal pigment epithelium in a lo calized area corresponding to the site of injection. The level of lacZ expression was correlated with the amount of virus delivered to the s ubretinal space. Persistent but decreasing expression of lacZ was note d over time. RT PCR revealed the expression of messenger RNA for at le ast sixty days. Conclusions. The results of this study demonstrate tha t efficient and stable transfer of genetic material into the subretina l space of adult fats may be achieved using a recombinant adenoviral v ector The use of such vectors should prove useful in developing novel applications and approaches to the study of recombinant protein expres sion in vivo.