Construction of the expression plasmid coding for complete gB has been described previously [32] . Carboxyterminal truncated forms of gB were expressed using pcDNA3 as plasmid. Aminoterminal truncations were expressed using the vector pcUL132sigHA. This pcDNA3.1 based plasmid contains the coding sequence of the HCMV gpUL132 authentic signal sequence aa 1-27, followed by the coding sequence for the influenza hemagglutinin (HA) epitope YPYDVPDYA [70] . To express Dom II (AD-4), the nucleotide sequence coding for aa 112-132 and 344-438 was chemically synthesized by GeneArt, Germany. The two parts were joined by a nucleotide linker coding for the sequence Ile-Ala-Gly-Ser-Gly and inserted in pcUL132-sigHA to give rise to pcAD-4. To express Dom I (pcAD-5) the nucleotide sequence coding for aa 133-343 were inserted into pcUL132sigHA. To generate plasmids for expression of AD-4-GST (Glutathion-S-transferase) fusion proteins in E. coli we used the expression vector pGEX-6P-1 (Pharmacia Biotech, Germany).