Fine mapping of virus-neutralizing epitopes on hepatitis B virus PreS1

We identified the epitopes on the preS1 which induce antibodies that neutralize both ad and ay subtypes of hepatitis B virus (HBV). Previously we generated murine monoclonal antibodies KR359 and KR127 that bind specifically to the preS1 of HBV. In this study we have performed fine mappings of the epitopes of the antibodies by examining their reactivity with GST fusion proteins, which contain a series of deletion mutants of the preS1. KR359 and KR127 specifically recognize aa 19-26 and 37-45 of the preS1, respectively. The antibodies neutralized both adr and ayw subtypes of the virus in an in vitro neutralization assay using in vitro infection of adult human hepatocyte primary culture by HBV. The epitopes showed little sequence divergence and the antibodies bound to the preS1 of all the HBV subtypes and variants tested.