Ss. Hong et al., Enhancement of adenovirus-mediated gene delivery by use of an oligopeptidewith dual binding specificity, HUM GENE TH, 10(16), 1999, pp. 2577-2586
The efficiency of human adenovirus serotype 5 (Ad5) transgene delivery was
tested on several human and animal cell lines in vitro, by using a bimodula
r 35-mer oligopeptide carrying two peptide domains with different ligand sp
ecificities. One domain mimicked the fiber knob-binding region of the alpha
(2) domain of human MHC-1 molecules (MH20), and the other corresponded to t
he gastrin-releasing peptide (GRP). Two synthetic peptides with different c
onfigurations were analyzed in Ad-mediated gene transfer assays using Ad5Lu
c3 vector carrying the luciferase reporter gene. One peptide (GRP-MH20) had
the GRP domain on the N-terminal side of MH20, while the other (MH20-GRP),
the C-terminally amidified GRP, was on the C-terminal side of MH20. The GR
P-MH20 peptide, but not MH20-GRP, was capable of enhancing luciferase gene
delivery to Ad-susceptible cells in a GRP receptor-dependent manner. More i
mportantly, GRP-MH20 could also confer susceptibility to Ad infection to no
rmal or cancer cells that lack fiber receptors for the virus. Our data sugg
ested that GRP receptors could function efficiently as alternative attachme
nt receptors for Ad5, but that Ad5 bound to GRP receptors still depended, a
t least partially, on the penton base-mediated endocytotic pathway for subs
equent cell entry.