IDENTIFICATION OF MAJOR ANTIGENIC DOMAINS OF DUCK HEPATITIS-B VIRUS PRE-S PROTEIN BY PEPTIDE SCANNING

Neutralization epitopes of duck hepatitis B virus (DHBV) have been pre viously mapped within the N-terminal portion of the pre-S protein usin g monoclonal antibodies. However, the immune response of ducks to this region is not well characterized at the amino acid level. To this end , we have immunized adult Pekin ducks with either DHBV positive serum or bacterially expressed DHBpre-S polypeptide representing the N-termi nal portion of the DHBV pre-S region. We have demonstrated that adult ducks inoculated with either antigen developed antibodies to the DHBV pre-S region starting 5 to 10 days postinjection. The sera of all duck s, irrespective of the immunogen used, exhibited a significant protect ive activity against DHBV, as assessed in vivo. To identify which pre- S domains bind antibodies from these duck sera, we have used the Pepsc an methodology with overlapping octapeptides spanning the DHBV pre-S s equence from amino acids 1 to 145. Using this approach, five major ant igenic domains, (7)KSMDVRRI(14), (22)NQLAGRMIP(30), (58)TLQNQGAW(65), (71)RRVGLSNPT(74), and (127)GDDPLLGNQ(135) were identified within the DHBV pre-S region. (C) 1994 Academic Press, Inc.