LACK OF CROSS-REACTIVITY OF LYTIC ANTIBODIES WITH BLOOD-STREAM FORMS OF TRYPANOSOMA-CRUZI ZYMODEMES GENERATED IN A MOUSE EXPERIMENTAL-MODEL

Immune sera from mice infected with specific Zymodemes of Trypanasoma cruzi parasites displayed preferential in vitro complement-mediated tr ypanolytic activity with homologous or genetically related bloodstream trypomastigotes. Culture-derived and metacyclic trypomastigotes were more susceptible to lytic antibodies than bloodstream trypomastigote f orms when the same serum panel was tested. Different levels of maximal trypanolytic reaction were observed when several parasites and sera w ere tested, suggesting that T. cruzi stocks are dissimilar in their ef ficiency to evade the lytic reaction, probably by capping and shedding mechanisms. A discussion based on the heterogeneity of surface antige ns able to elicit the lytic response among different T. cruzi populati ons is presented. (C) 1995 Academic Press, Inc.