Comparison of the cuticular structure of parasitic nematodes recognized by immunocytochemical and lectin binding studies.

The cuticle structure of some nematode species was studied by immunogold and lectin-gold techniques. The gold labelling made it possible to distinguish the cuticle layers by the distribution and/or the density of the marker. On the other hand, no labelling pattern was found which led to a clear grouping of the layers into larger 'zones', since there were no subunits consisting of more than one layer which reacted in a characteristic way as compared to the rest of the cuticle. The outer surface of the epicuticle of parasitic adult worms turned out to be highly inert; it did not react with any of the antibodies or lectins tested. The cuticle of parasitic nematodes seems to function as a protection against the host's defense mechanisms rather than as an interaction site. An immunogenic component on the surface was only found in infective larvae. All antibodies and lectins showed a preferential binding to the electron dense layers and fibrous structures (HPL/GalNAc, WGA/GlcNAc) or to the amorphous ground-substance (Con A/Glc, RCA I/Gal).