IMMUNO-CROSS-REACTIVITY OF CUT-1 AND CUTICLIN EPITOPES BETWEEN ASCARIS-LUMBRICOIDES, CAENORHABDITIS-ELEGANS, AND HETERORHABDITIS

Cuticlin is the insoluble residue of nematode cuticle. It has been pro ved that cuticlin and CUT-1-like epitopes are conserved between the fr ee-living Caenorhabditis elegans and the entomopathogenic nematode Het erorhabditis sp. The cloning of a cut-1 homologous gene from the anima l intestinal parasite Ascaris lumbricoides has allowed us to extend th e study of immuno-cross-reactivity at the ultrastructural level to thi s important species. Antibodies against recombinant CUT-1 protein and against cuticlin from Ascaris as well as from C. elegans were used for immuno-labeling ultrathin sections of high-pressure cryoprocessed wor ms. All the antisera used showed the same specific pattern of localiza tion on sections of C. elegans of Heterorhabditis dauer larvae, and of Ascaris larvae in mature eggs. It was also shown that sera raised aga inst the cuticlin residue contain anti-CUT-1 antibodies. CUT-1-like pr oteins are thus possibly important components in the immune response o f hosts to invading nematodes. The results presented support the use o f C. elegans as a model for the study of vertebrate parasitic nematode s. (C) 1998 Academic Press.