Immunological properties of multiple repeats of a linear epitope of herpes simplex virus type 1 glycoprotein D

Several peptides containing the amino acid sequence 9–21 of glycoprotein D of herpes simplex virus type 1 (HSV-1) were synthesized and investigated for reactivity with monoclonal antibody LP14 in a competition enzyme-linked immunosorbent assay (ELISA). Peptides containing two or four repeats of sequence 9–21 reacted at least one order of magnitude better with LP14 than with the monomeric form of sequence 9–21. Dimers in which one of the repeats of one or more essential residues were absent did not show this increased reactivity. Antisera obtained from rabbits immunized with a peptide containing two repeats of sequence 9–21 coupled to bovine serum albumin showed high antipeptide antibody titers with this peptide and were able to neutralize virus infectivity in vitro. Sera obtained from rabbits immunized with the free dimer could not neutralize virus infectivity.