Abstract

PONCE DE LEON, Patricia; FORESTO, Patricia  and  VALVERDE, Juana. Ascaris lumbricoides: Molecular mimicry by P₁ epitope absorption. Acta bioquím. clín. latinoam. [online]. 2010, vol.44, n.2, pp.253-257. ISSN 0325-2957.

Molecular mimicry has been associated with chronicity of parasitic infections. This mechanism can be due to absorption of the host's molecules or to synthesis of similar molecules. P₁ has been detected in various parasite species. Previous experiences have shown P₁ epitopes in Ascaris lumbricoides's adult parasites. The aim of this study was to analyse absoption of these epitopes by nematode larvae in order to determine the mechanism by which the parasite can express these antigens on their cuticle. Larvae were hatched from the faeces with helminth eggs. Larvae were cultivated in RPMI medium with P₁ red cells. The Quantitative Inhibition Agglutination Test was performed using 4 anti- P₁ monoclonal antibodies. P₁ fresh red cells in bromelin enzymatic medium was used as revealing system. Simil P₁ excretory-secretory products were investigated using larvae cultivated in RPMI medium without P₁ erythrocytes by the same technique. The larvae which were cultivated with red cells inhibited the agglutination between all anti- P₁ monoclonal antibodies and P₁ erythrocytes. Simil P₁ excretory-secretory products were not identified. It was demonstrated that A. lumbricoides larvae absorb P₁ epitopes from the culture medium. It can be concluded that the parasite can absorb this antigen during its life cycle in order to use it in molecular mimicry.

Keywords : Ascaris lumbricoides; Absorption; P₁ epitopes.

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