Improved gene expression in resting macrophages using an oligopeptide derived from Vpr of human immunodeficiency virus type-1

Vpr, an accessory gene product of human immunodeficiency virus type-1, is thought to transport a viral DNA from the cytoplasm to the nucleus in resting macrophages. Previously, we reported that a peptide encompassing amino acids 52-78 of Vpr (C45D18) promotes the nuclear trafficking of recombinant proteins that are conjugated with C45D18. Here, we present evidence that C45D18, when conjugated with a six-branched cationic polymer of poly(N,N-dimethylaminopropylacrylamide)-block-oligo(4-aminostyrene) (SV: star vector), facilitates gene expression in resting macrophages. Although there was no difference between SV alone and C45D18-SV with respect to gene transduction into growing cells, C45D18-SV resulted in more than 40-fold greater expression of the exogenous gene upon transduction into chemically differentiated macrophages and human quiescent monocyte-derived macrophages. The data suggest that C45D18 contributes to improving the ability of a non-viral vector to transduce macrophages with exogenous genes and we discuss its further application.