Mapping of the antigenic determinants of the T-cruzi kinetoplastid membrane protein-11. Identification of a linear epitope specifically recognized byhuman Chagasic sera

The high variability among strains and isolates of Trypanosoma cruzi and th e existence of shared antigenic determinants with other pathogens, particul arly with members of the Leishmania genus make difficult the specific diagn osis of Chagas' disease. The data reported in this paper show that the T. c ruzi KMP11 protein is an immunodominant antigen highly recognized by the se ra from chagasic and leishmaniasis patients. By the use of amino- and carbo xyl-terminal truncated KMP11 recombinant proteins and synthetic peptides, e vidence is provided that while the sera from chagasic patients recognize li near peptides the sera from patients with visceral leishmaniasis must be pr edominantly directed against conformational epitopes. We found that a parti cular linear determinant, located in the carboxyl-terminal region of the pr otein, is recognized with high specificity and sensitivity only by sera fro m Chagas' disease patients, suggesting it could be a good candidate for dif ferential serodiagnosis of Chagas' disease.