Molecular cloning and characterization of a T24-like protein in Echinococcus multilocularis

One tetraspanin, designated as E24, was cloned from a full-length enriched vector-capping cDNA library of Echinococcus multilocularis metacestode. The amino acid sequence and phylogenetic analysis suggested that E24 is a T24-like protein. The crucial, functional large extracellular loop (LEL) domain of E24 was expressed and characterized using a polyclonal antiserum by Western blot and immunohistochemistry. The results showed that anti-recombinant-E24 (anti-recE24) antibody can specifically recognize approximately 25 kDa recombinant protein and 25 kDa cyst-extracted antigen; the germinal layer of both the protoscolex-free and protoscolex-formed cysts were intensely labeled by immunofluorescent antibody. This study revealed that E24 is an antigenic, germinal layer-located protein of E. multilocularis metacestode, implying for its potential in diagnostic and vaccine development.