Figure 1

Analysis of the pre-S1 amino acid sequences of 26 clones derived from the plasma sample. A minor population clustering with genotype D showed glutamic acid/aspartic acid (E/D) amino acid substitution within the immunodominant epitope responsible for the hepatocyte binding site, and lysine/asparagine (K/N), valine/leucine (V/L), asparagine/proline (N/P) aa changes in the epitopes recognized by B and T lymphocytes. The alignment of clones 1-24 clustering with type D, and clones 25 and 26 clustering with genotype F, was made on the basis of the sequence of the HBV prototype. The numbers in parentheses refer to the total number of clones with identical amino acid sequences. The empty box indicates identical amino acid; the black box indicates the amino acid substitution (found in at least nine genotype D clones and the two genotype F clones; the grey box indicates a randomly detected amino acid mutation; and the striped box indicates an aa deletion. The pre-S1 epitopes responsible for immune response at T-cell level or thought to contain the hepatocyte binding site are respectively boxed in black and grey; the asterisk indicates the start of the sequence of the pre-S epitope that elicits the B cell immune response.