Thèse soutenue de Nancy CHILE ANDRADE

Taenia solium Oncosphere and postoncospheral antigens as early exposition markers to parasite.

Taenia solium is a parasite that causes neurocysticercosis (NCC) in human, this disease is acquired for the ingestion of eggs from a person with taeniasis. Once ingested, the egg hatches in the intestine and release an hexacanth larvae called “oncosphere” that cross the intestinal barrier, then the oncosphere can reach the central nervous system via the bloodstream where it develops into postoncospheral form and finally to cysticercus causing epilepsy. NCC is endemic mainly in Asian, African and Latin American countries.

The oncosphere is the infective stage leading to cysticercosis and it has two stage specific antigens (22.5 kDa and 31.3kDa) that is recognized by antibodies of people with taeniasis and cysticercosis from endemic areas which suggest that they have been exposed to these antigens probably by the egg ingestion.

The postoncospheral form is an early stage of development of cysticercus, however, the proteins and antigens expressed during this stage have not been studied. Both oncosphere and postoncospheral antigens could be used as early markers for cysticercosis infection.

The principal aim of this project is to evaluate the oncosphere and postoncospheral antigens as early markers for cysticercosis exposition. For which, the postoncospheral antigens will be characterized in order to find stage specific antigens; then the presence of antibody against oncosphere and postoncosphere form will be evaluated during the development of NCC in a rat model to determine if the antibodies against oncosphere or postoncosphere antigens are present in the early infection; finally, the test (detection of antibodies against oncosphere and postoncosphere antigens by western blot) will be evaluated in an endemic area of cysticercosis.

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Mots clés : Taenia solium, Neurocysticercosis, Peru