Isolation and antigenic characterization of calcareous corpuscle-associated proteins from Taenia solium cysticerci.

BACKGROUND: Calcareous corpuscles are mineralized structures characteristic of cestodes, including Taenia solium, yet their protein composition and antigenic properties remain poorly characterized. Existing studies have focused mainly on calcium-binding fractions, limiting understanding of the broader molecular content of these structures. METHODS: A two-phase methodology was developed to isolate calcareous corpuscles from viable T. solium cysticerci obtained from naturally infected pigs and to recover their associated proteins. Corpuscles were isolated by mechanical homogenization and differential centrifugation, followed by controlled chemical dissolution. Protein recovery was assessed by Bradford assay and SDS-PAGE. Antigenic properties were evaluated using immunofluorescence and Western blot with a panel of monoclonal antibodies raised against whole cysticercus extract, vesicular fluid, and excretion-secretion antigens. RESULTS: The optimized protocol consistently yielded intact calcareous corpuscles and enabled complete dissolution of the mineral matrix with sequential release of proteins. Electrophoretic analysis revealed a heterogeneous protein profile comprising at least 23 distinct protein bands. Several proteins were recurrently detected by multiple monoclonal antibodies, particularly bands around 66.9 kDa and in the low-molecular-weight range. Western blot analysis confirmed specific recognition of corpuscle-associated proteins by a subset of monoclonal antibodies. CONCLUSIONS: Calcareous corpuscle-enriched preparations yielded a diverse set of immunoreactive proteins. The methodology described here provides a reproducible framework for further proteomic characterization and may facilitate future proteomic, diagnostic, and immunological studies in cysticercosis and neurocysticercosis.