Mapping T and B lymphocyte epitopes of bovine herpesvirus-1 glycoprotein B.

Glycoprotein B (gB) is a major envelope protein of bovine herpesvirus-1 (BHV-1). As a subunit vaccine, the extracellular domain of recombinant gB induces neutralizing antibody and T cell responses that engender protection against virus challenge. Here, lymphocytes from animals of different parentage were analysed for T cell proliferation to the gB extracellular domain for immune recognition. Four truncated overlapping gB gene segments encoding 742 amino acids were expressed from a baculovirus vector to identify antigenic regions. One immunodominant region (amino acids 254-532) was recognized by T cells from immune individuals of different parentage. Serial synthetic peptides spanning this region localized the T cell (amino acids 319-340 and 415-436) and B cell (amino acids 331-352, 475-496 and 487-508) epitopes. Elucidation of gB epitopes indicates the diverse and distinctive recognition by T cells and antibodies of this envelope glycoprotein by cattle, the natural host of BHV-1.