PARTIAL CONTROL OF HEPATITIS-DELTA VIRUS SUPERINFECTION BY IMMUNIZATION OF WOODCHUCKS (MARMOTA-MONAX) WITH HEPATITIS DELTA-ANTIGEN EXPRESSED BY A RECOMBINANT VACCINIA OR BACULOVIRUS

We have successfully limited the level of hepatitis delta viraemia occ urring after superinfection of hepadna-virus infected woodchucks by pr ior immunisation with the short form of the hepatitis delta virus anti gen expressed by a recombinant baculovirus or vaccinia virus. This phe nomenon occurred in the absence of detectable circulating antibody to hepatitis delta virus antigen and in the absence of evidence of primin g of the humoral immune response and may reflect the induction of a cy totoxic T-cell response. The latter would control viraemia by rapid ly sis of delta antigen expressing hepatocytes. It is suggested that the T-cell epitopes involved may be located on the carboxyl end of the del ta protein (amino acids 77-195). (C) 1993 Wiley-Liss, Inc.