Immunochemical analysis ofTaenia taeniaeformisantigens expressed inEscherichia coli

Abstract
SUMMARY: Previously we reported the isolation of severalEscherichia coliclones expressing fragments ofTaenia taeniaeformisantigens as β-galactosidase fused proteins (Bowtell, Saint, Rickard & Mitchell, 1984). Here we describe the isolation of additional antigen-expressing clones from a larval cDNA library and the assignment of these clones to 7 antigen families. These were isolated with a polyspecific rabbit antiserum raised to the oncosphere. Since this serum was capable of reacting with a large number of antigens, it was important to develop techniques for rapidly determining the identity of the nativeT. taeniaeformismolecule corresponding to a cloned antigen gene. These included active immunization of rabbits with fused proteins and several techniques involving affinity purification on immobilized fused proteins. The reactivity of the antigen-positive clones with sera from humans infected with related parasites was also assessed. Finally, immunization of mice with several fused proteins failed to protect against subsequent infection, although antigens previously identified as candidate host-protective antigens (Bowtell, Mitchell, Anders, Lightowlers & Rickard, 1983) have yet to be identified in the expression library.