1. ¹Institute for Virology, University of Mainz, Mainz, Germany
2. ²Department of Medical Virology, University of Tübingen, Tübingen, Germany

Correspondence: B Plachter, Institut für Virologie, Johannes Gutenberg-Universität Mainz, Obere Zahlbacher Str. 67, 55101 Mainz, Germany.

Received 17 April 2002; Accepted 1 August 2002.

Abstract

Direct protein delivery is an emerging technology in vaccine development and gene therapy. We could previously show that subviral dense bodies (DB) of human cytomegalovirus (HCMV), a beta-herpesvirus, transport viral proteins into target cells by membrane fusion. Thus these non-infectious particles provide a candidate delivery system for the prophylactic and therapeutic application of proteins. Here we provide proof of principle that DB can be modified genetically. A 55 kDa fusion protein consisting of the green fluorescent protein and the neomycin phosphotransferase could be packed in and delivered into cells by recombinant DB in a functional fashion. Furthermore, transfer of protein into fibroblasts and dendritic cells by DB was efficient, leading to exogenous loading of the MHC-class I antigen presentation pathway. Thus, DB may be a promising basis for the development of novel vaccine strategies and therapeutics based on recombinant polypeptides.