A recombinant chimeric antigen toward a standardized serodiagnosis of Taenia solium neurocysticercosis

Neurocysticercosis (NC) invokes formidable neurological problems worldwide. Previous proteomic analyses revealed most of the low-molecular-weight proteins might derive from two macromolecules of 120 kDa (consisting of 14-38 kDa subunits) and 150 kDa (7-15 kDa subunits) of Taenia solium metacestode (TsM) cyst fluid (CF). We characterized serological properties of these two proteins and established an immunopotent chimera. The 120 and 150 kDa proteins harbored 54-81 and 94-98% of the antibody-binding activity of the crude CF with minimal antigenic cross-reactivity to each other. The expression and immune recognition of the 150 kDa subunits were relatively constant, regardless of the different geographical origins of the CF collected, while those of the 120 kDa subunits varied by their origins (Asia vs. America). We cloned four representative proteins (one from the 120 kDa and three from the 150 kDa) that showed different epitope specificities, generated a chimera, and demonstrated that this regimen may bolster serodiagnostic reliability. Overall sensitivity and specificity, against sera from active-/mixed-stage NC and those from other infections, and healthy-controls, were determined to be 97.5% (156/160 samples) and 97.8% (265/271 cases). Patient sera from adult taeniases, sparganosis, and fascioliasis showed weak cross-reactions. Micro-ELISA showed similar results. This chimera may prove useful in the construction of standardized platform for NC serodiagnosis.