Molecular characterization and diagnostic value of Taenia solium low-molecular-weight antigen genes

Neurocysticercosis (NCC) caused by infection with the larvae of Taenia soli um is an important cause of neurological disease worldwide. In order to est ablish an enzyme-linked immunosorbent assay (ELISA) for this infection usin g recombinant proteins, we carried out molecular cloning and identified fou r candidates as diagnostic antigens (designated Ag1, Ag1V1, Ag2, and Ag2V1) , Except for Ag2V1, these clones could encode a 7-kDa polypeptide, and Ag2V 1 could encode a 10-kDa polypeptide. All of the clones were very similar. E xcept for Ag2V1, recombinant proteins were successfully expressed using an Escherichia coli expression system. Immunoblot analysis of NCC patient sera detected recombinant proteins, but because reactivity to recombinant Ag1 w as too weak, Ag1 was not suitable as an immunodiagnostic antigen. So, Ag1V1 and Ag2 were chosen as ELISA antigens, and the Ag1V1/Ag2 chimeric protein was expressed. Of 49 serum samples from NCC patients confirmed to be seropo sitive by immunoblot analysis, 44 (89.7%) were positive by ELISA. No assays of serum samples from patients with other parasitic infections recognized the Ag1V1/Ag2 chimeric protein. The Ag1V1/Ag2 chimeric protein obtained in this study had a high value for differential immunodiagnosis.