Characterization of cloned antigens of Taenia ovis

Fusion proteins derived from recombinant clones of Escherichia coli carrying the pEX series of expression vectors with cDNA inserts of the tapeworm, Taenia ovis, were characterized by their antigenicity when administered to mice and sheep. Antisera derived from these hosts were shown to react with a number of T. ovis adult worm and oncospheral antigens in Western blots, and to bind to oncospheres and worm tissue in fluorescent antibody tests. Epitopes produced by two clones (designated T07 and T08) are found on several antigenic polypeptides of T. ovis and a related species T. hydatigena. Those produced by a third clone (T03) are specific to T. ovis. The immunological results were confirmed by Northern blotting of T. ovis and T. hydatigena RNA: RNA transcripts corresponding to T07 and T08 are found in both T. ovis and T. hydatigena, whereas RNA corresponding to T03 is found in T. ovis only. Cross reacting epitopes in fusion proteins from T07 and T08 appear to have different amino acid sequences, and T. ovis antigenic epitopes are shared by a number of polypeptides in and between adult worms and oncospheres.