Molecular cloning and expression of receptor peptides that block human cytomegalovirus/cell fusion

Clones expressing a partial human cytomegalovirus putative fusion receptor were selected by binding specifically to monoclonal anti-idiotypic antibodies that mimic glycoprotein H. cDNA was isolated from 2 of the clones (131 and 611) and fused in frame with the glutathione S-transferase gene in a pGEX-4T-1 vector. Two purified peptides (FR131 and FR611) were produced: both were shown to bind specifically to the monoclonal anti-idiotypic antibodies and inhibit virus/cell fusion and viral plaque formation in a specific and dose-dependent manner. This is the first demonstration of cloned peptides encoding a putative cell membrane receptor that are able to block cytomegalovirus infection.