Adenovirus-mediated gene transfer to the ocular surface epithelium

Gene transfer to the ocular surface epithelium is of potential therapeutic value. It was determined whether a reporter gene can be introduced into the ocular surface epithelium in vitro (human cell lines), ex vivo (human tiss ues), and in vivo (rats) by treating with a recombinant, replication-defici ent, adenovirus type 5. Human and conjunctival cell lines were cultured wit h various multiplicities of infection (MOI; 3.2 x 10(-5)-5 x 10(-1)) of ade novirus vector (Ad5: Adex1CAlacZ) containing the reporter gene lacZ (1.3-2. 0 x 10(4) PFU ml(-1)). The ex vivo study used human corneal and conjunctiva l tissues obtained from an eye bank and during surgery. Non-specific upregu lation of inflammatory cytokines of conjunctival epithelium infected by Ad5 was assayed and its suppression by steroids. For the in vivo study, Ad5 (5 x 10(5) PFU, 5-10 mu l) was applied to the eyes of 8-12-week-old cotton ra ts, which were enucleated 24 and 48 hr later. The maximum lacZ expression i n vitro was demonstrated in the corneal epithelial cell line at 7 days (1 x 10(-1) MOI) and conjunctival epithelial cell line at 2 days (4 x 10(-4) MO I). furthermore, lacZ was also expressed in the superficial corneal and con junctival epithelium in the ex vivo study. IL-6, IL-8, and ICAM-1 expressio n from conjunctival epithelium by Ad5 was significantly inhibited by treatm ent with betamethasone (BM). For the in vivo study, only the conjunctival e pithelium demonstrated beta-Gal activity at 24 and 48 hr after application. These data indicate that adenovirus Vector is capable of directly deliveri ng gene to the corneal and conjunctival epithelium, suggesting a variety of possible gene therapy uses. The concomitant application of steroid eye dro ps may avoid inflammation. (C) 1998 Academic Press.