SEQUENCE VARIATION OF THE AMINO-TERMINAL ANTIGENIC DOMAINS OF GLYCOPROTEIN-B OF HUMAN CYTOMEGALOVIRUS STRAINS ISOLATED FROM CHINESE PATIENTS

To study the genetic variation of human cytomegalovirus (HCMV) in Asia n populations, the amino-terminal antigenic domains of glycoprotein B of HCMVs isolated from ethnic Chinese transplant patients were cloned and sequenced. The nucleotide and encoded amino acid sequences were co mpared with published sequences of AD169 and Towne laboratory strains. Within the region sequenced, 9 out of 15 clinical isolates (60%) poss essed a peptide configuration similar to that of strain AD169 while 6 isolates (40%) displayed a peptide configuration similar to that of st rain Towne. The nucleotide and amino acid identities of AD169-like cli nical isolates exhibited variations of 95.4%-99.6% and 95.4%-100% resp ectively, whereas the identities of Towne-like clinical isolates were within the range of 97.3%-100% and 96.6%-100% at the nucleotide and am ino acid levels. The previously defined neutralizing epitope was conse rved among the clinical isolates sequenced while unique non-conservati ve amino acid substitutions were detected in the non-neutralizing epit ope within the amino-terminal antigenic domain of glycoprotein B of al l AD169-like isolates (Y - > S) and one of the Towne-like isolates (R - > Q).