Characterization of Endotrypanum parasites using specific monoclonal antibodies

ABSTRACT

A large number of Endotrypanum stocks (representing an heterogeneous population of strains) have been screened against a panel of monoclonal antibodies (MAbs) derived for selected species of Endotrypanum or Leishmania, to see wether this approach could be used to group/differentiate further among these parasites. Using different immunological assay systems, MAbs considered specific for the genus Endotrypanum (E-24, CXXX-3G5-F12) or strain M6159 of E. schaudinni (E-2, CXIV-3C7-F5) reacted variably according to the test used but in the ELISA or immunoflurescence assay both reacted with all the strains tested. Analysis using these MAbs showed antigenic diversity occuring among the Endotrypanum strains, but no qualitative or quantitative reactivity pattern could be consistently related toparasite origin (i.e., host species involved) or geographic area of isolation. Western blot analysis of the parasites showed that these MAbs recognized multiple components. Differences existed either in the epitope density or molecular forms associated with the antigenic determinants and therefore allowed the assignment of the strains to specific antigenic groups. Using immunoflurescence or ELISA assay, clone E-24 produced reaction with L. equatorensis (which is a parasite of sloth and rodent), but not with other trypanosomatids examined. Interestingly, the latter parasite and the Endotrypanum strains cross-reacted with a number of MAbs that were produced against members of the L. major-L. tropica complex.