Partial Purification of Integral Membrane Antigenic Proteins fromTrypanosoma evansiThat Display Immunological Cross-Reactivity withTrypanosoma vivax

Abstract

Trypanosoma evansiandTrypanosoma vivax, which are the major causative agents of animal trypanosomosis in Venezuela, have shown a very high immunological cross-reactivity. Since the production ofT. vivaxantigens is a limiting factor as this parasite is difficult to propagate in experimental animal models, our goal has been to identify and isolate antigens fromT. evansithat cross-react withT. vivax. Here, we used the VenezuelanT. evansiTEVA1 isolate to prepare the total parasite lysate and its corresponding cytosolic and membranous fractions. In order to extract theT. evansiintegral membrane proteins, the particulate portion was further extracted first with Triton X-100, and then with sodium dodecyl sulfate. After discarding the cytosolic and Triton X-100 solubilized proteins, we employed sedimentation by centrifugation on linear sucrose gradients to partially purify the sodium dodecyl sulfate-solubilized proteins from the Triton X-100 resistant particulate fraction ofT. evansi. We obtained enriched pools containing polypeptide bands with apparent molecular masses of 27 kDa, 31 kDa, and 53 kDa, which were recognized by anti-T. vivaxantibodies from experimentally and naturally infected bovines.