Characterization of GP39-42 and GP24 antigens from Taenia solium cysticerci and of their antigenic GP10 subunit

Diagnosis of neurocysticercosis is performed by Western blotting with an enriched fraction of glycoproteins (LLGP). GP39-42 and GP24 are immunodominant antigens. These antigens were electroeluted and characterized by biochemical methods. When GP39-42 or GP24 were reduced, a band of 10 kDa (named GP10) appeared; this band was also analyzed. The most abundant amino acids in the three GPs were lysine, phenylalanine, asparagine, glycine, and leucine. The amino terminal portion was sequenced, and the following order was obtained for the three GPs: EKNKPKNVAXSTKKGYEYVXEF. The glycan portion was 8.4%, 18.2%, and 18.3% in GP39-42, GP24, and GP10, respectively. The three GPs contained mannose, N-acetyl-D-glucosamine, and galactose. GP39-42 and GP24 seem to be oligomeric forms of GP10. When reduced LLGP was reacted with samples obtained from patients with neurocysticercosis or pigs with cysticercosis, a band corresponding to GP10 was always observed. Furthermore, hyperimmune serum from rabbits immunized with GP39-42 or with GP24 recognized GP10 as well as GP39-42 and GP24. The data obtained in this paper suggest that GP10 might be a useful tool for diagnosis.