Immune system response, reproduction, and competition during Chagas infection

S. COSSY ISASI; G.J. SIBONA; C.A. CONDAT

S. Carlos de Bariloche

Congreso; 32a Reunión de la Sociedad Argentina de Biofísica; 2003

Sociedad Argentina de Biofísica

The biology and pathogenesis of the Chagas disease are not yet completely understood. Biochemical and anatomopathological observations in experimental Chagas and in the human disease indicate a strong involvement of both humoral and cellular immunities. Recently (J. Theor. Biol. 208, 1-13, 2001), we presented a model for the interaction between T. cruzi and its specific antibodies, which includes parasite reproduction, parasite-generated decoys and immune system learning. The parasite-antibodies interaction can lead to either the coexistence between species (chronicity) or to the exclusion of one of them (healing or death). We have also remarked upon the analogies between parasite-immune system interactions and virus-immune system interactions (Comm. Theor. Biol. 8, 1-21, 2003). We now use these analogies to model the simultaneous action of the humoral and cellular responses during the Chagas infection. With this extended model we find the conditions that determine whether one of the responses becomes dominant or whether a competitive coexistence develops between the responses. On the other hand, modeling intracellular amastigotes and invasive tripomastigotes as separate populations allows us to substantially improve our fittings to the available data.