Ultrastructural localization of an Echinococcus granulosus laminin-bindingprotein

Murine antibodies, raised against a purified recombinant 30 kDa laminin-bin ding protein from Echinococcus granulosus, were used to investigate the tis sue 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 regi ons 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 syst em. The protein was associated with amorphous regions of the cytoplasm, and was not expressed at the surfaces of cells. This distribution resembles th ose of other invertebrate laminin-binding proteins, which are thought to ac t in the cell cycle and cell proliferation events. A low degree of label wa s consistently detected in extracellular matrices of the protoscolex.