Exometabolites of Leishmania donovani promastigotes. II. Spontaneous changes of exometabolite after isolation

Detection and characterization of leishmania antigens from an American cutaneous leishmaniasis vaccine for diagnosis of visceral leishmaniasis

Antigens were isolated from vaccines against American Cutaneous Leishmaniasis (ACL) and their reactivity tested against nine different groups of human sera and two groups of dog sera. These antigens react specifically with human and dog visceral leishmaniasis sera when compared to sera from non-infected individuals. Sera from humans from endemic areas of ACL before, or one year after, vaccination, and ACL patients treated and cured by immunotherapy with polyvalent vaccine, did not display significant differences of reactivity to these antigens. In contrast, they displayed a significantly higher reactivity to the antigens when compared to sera from healthy humans from non-endemic areas. No sera reactivity was observed with patients carrying Chagas' disease or tuberculosis. These antigens are polysaccharides aggregates and present molecular masses ranging from 90 to over 200 KDa. These data suggest the use of these antigens for sero-diagnosis of human and canine visceral leishmaniasis.

Leishmanial excreted factors (EFs): purification by affinity chromatography

Leishmania species grown in culture excrete a polyanionic, carbohydrate-rich factor (EF) which binds to antibodies produced in rabbits against the parent Leishmania species. EF, previously purified by physical and chemical methods, was purified by affinity chromatography on a Ricinus lectin column. The purified samples were characterised and analysed. The results show a notable proportion of galactose in EF and clarify the reasons for its polyanionic properties. Heterogenicity of EF is demonstrated and discussed.