MAPPING OF THE LINEAR ANTIGENIC DETERMINANTS OF THE LEISHMANIA-INFANTUM HSP70 RECOGNIZED BY LEISHMANIASIS SERA

Mapping of antigenic determinants of the Leishmania infantum Hsp70 was studied by analysis of the reactivity of sera from dogs with natural visceral leishmaniasis against a collection of peptides representing o verlapping sequences of the Hsp70. Despite the considerable variation in the immune response among individuals three immunodominant regions were revealed encompassing residues 241 to 260 (region I), 435 to 469 (region II) and from amino acid 601 to the carboxyl-terminal end of th e protein (region III). Since anti-peptide H17 antibodies purified fro m a pool of leishmaniasis sera recognized the L. infantum Hsp70 and si nce they did not react with the homologous Hsp70s from other trypanoso matids, such as Trypanosoma cruzi, Trypanosoma rangeli and Leishmania panamensis, it was concluded that peptide H17 (region I) contains an i mmunodominant B cell species-specific epitope. Our data indicate, howe ver, that the complete recombinant L. infantum Hsp79 protein cannot be used as a disease-specific tool for serodiagnosis since it is also re cognized by the sera from patients with Chagas' disease.