IN VITRO INHIBITION OFATTACHMENT OF THE AMERICAN TRYPANOSOME, Trypanosoma rangeli   ON THE SALIVARY GLAND OF ITS VECTOR, Rhodnius prolixus  , USING THE PARASITE EXTRACT AND PARTIAL PURIFICATION OFAN ATTACHMENT INHIBITOR PROTEIN

The life cycle of the American trypanosome, Trypanosoma rangeli, in its invertebrate host, Rhodnius prolixus, is completed by invasion into the insect salivary glands. As a prerequisite, there is an initial recognition of the salivary gland receptors for the adhesion/invasion by T. rangeli. Therefore, the purpose of this study was to investigate the putative receptor molecules on either the salivary gland or parasites surfaces, which mediate the adhesion/invasion. Initially, the possible agglutination activity of T. rangeli epimastigotes against blood cell was examined. Then, in order to investigate the role of any receptor ligands on the surface of T. rangeli in adhesion/invasion of the parasite, GlcNAc was preferentially used to isolate a ligand protein. A 60kDa protein bound to the GlcNAc column and was isolated from T. rangeli (Tr-60) and the purity of this protein was confirmed by reverse phase HPLC. Tr-60 also exhibited a potent parasite inhibitory effect indicating! that this protein (most probably a glycoprotein) may act as a ligand receptor. In vivo, the development and invasion of T. rangeli into the salivary gland was not interfered with by the presence of a sugar inhibitor of the R. prolixus hemolymph lectin.

Keywords
Trypanosoma rangeli, Rhodnius prolixus, Salivary glands, Proteins, attachment.