Stage–specific antigens of Hymenolepis microstoma recognized in BALB/c mice

Abstract

Antigenicity of eggs (oncospheres), cysticercoids and adults (with immature segments only) of the bile duct tapeworm Hymenolepsis microstoma was analysed using immunoblotting techniques and indirect immunofluorescent antibody (IFA) techniques with immune sera of BALB/c mice (i) infected with different doses of cysticercoids, (ii) during patent or prepatent infection with the lumen phase of the parasite or (iii) sensitized with live or dead eggs. Antibody responses detected by IFA test and immunoblotting showed that antigenicity of eggs (oncospheres) differed from that of cysticercoids and adults. Single worm infections were sufficient to stimulate antibody responses. Mice which had patent infection showed strong antibody responses to all three (egg (oncosphere), cysticercoid, adult) antigens, while mice given two prepatent infections showed some antibody responses to cysticercoid and adult antigens only. Although the normal intermediate hosts of this parasite are arthropods, antibodies to some major egg (oncosphere) antigens were produced in mice given eggs of this parasite orally, either through inoculation of eggs or ingestion of faeces contaminated with eggs. Antibodies were not produced in mice dosed with non-viable eggs. The results are consistent with the hypothesis that cestode parasites express phase- (or stage-) specific antigens.

Hymenolepis microstoma: direct life cycle in immunodeficient mice

“…During the experiments, uninfected control mice were kept in a similar way in the same animal room, and none of these mice were infected with any stage of the tapeworms. Ito et al (1989) showed that the mice were coprophagous, and this was verified again during these experiments. Furthermore, NMRI/nu mice have been infected with H. diminuta for many years in our laboratory, and, although we have observed coprophagy in these mice, naïve mice have not been infected with any tapeworm and infected mice never harboured more worms than the number of cysticercoids administered.…”

“…The present discovery that orally inoculated or eaten eggs of H. microstoma may develop into cysticercoids in the tissue of the small intestine and further excyst and develop into adult worms in the bile duct and/or in the lumen of the small intestine of immunodeficient, NMRInu, NOD-scid and NOG mice was unexpected. However, this could have been predicted because it has been shown that specific antibodies to oncospheres are produced in immunocompetent mice either orally inoculated with viable eggs or through coprophagy of faeces from mice harbouring mature adult worms of H. microstoma (Ito et al, 1989). Furthermore, when shell-free eggs were inoculated orally into naïve mice, oncospheres were able to hatch and invade the tissue in the anterior third of the small intestine, but these oncospheres did not develop into cysticercoids (Onitake et al, 1990).…”

Description of Hymenolepis microstoma (Nottingham strain): a classical tapeworm model for research in the genomic era

“…[27] found that autoinfection was possible, showing that oncospheres penetrated the intestinal tissues and developed into cysticeroids that subsequently excysted and developed normally in the bile duct and duodenum, in a manner similar to the direct cycle of H. nana . Autoinfection of BALB/c mice was also implied by the detection of stage-specific antigens [28]. …”

Basic and applied problems in developmental biology and immunobiology of cestode infections: Hymenolepis,Taenia and Echinococcus

“…The presence of developmental stage-specific antigens of H. nana and H. microstoma that are recognized by infected mice has been shown by immunofluorescent antibody (38) and immunochemical studies (32,51). Antibody responses to different stages of H. nana that are visible using immunofluorescent secondary antibodies suggest antigenic differences between the scolex and neck and other parts of the proglottids for H. nana (38), but not for H. diminuta (A.…”

“…Although H. microstoma develops into mature adult worms from ingested cysticercoids but not from eggs, mice harbouring adult worms produce antibodies to egg (oncosphere) and cysticercoid antigens differently (51). It has been suggested that H. microstoma oncospheres may invade intestinal tissue and stimulate antibody responses to eggs (51,70). Andreassen et al (18) observed that very few H. microstoma cysticercoids could develop in the intestinal tissue of nude mice.…”