Ultrastructural localization of an Echinococcus granulosus laminin-binding protein

Murine antibodies, raised against a purified recombinant 30 kDa laminin-binding protein from Echinococcus granulosus, were used to investigate the tissue distribution of the native protein in protoscoleces and brood capsules. Immunofluorescence, in combination with confocal microscopy, revealed that the protein was distributed in small annular foci near the peripheral regions of the protoscoleces. Immunoelectron microscopy of thawed cryosections demonstrated that the laminin-binding protein was present in the cytoplasm of tegumentary cytons and myocytons, but not in cells of the excretory system. The protein was associated with amorphous regions of the cytoplasm, and was not expressed at the surfaces of cells. This distribution resembles those of other invertebrate laminin-binding proteins, which are thought to act in the cell cycle and cell proliferation events. A low degree of label was consistently detected in extracellular matrices of the protoscolex.