Differential expression of cell surface polypeptides and ecto-phosphatase activities of different Trypanosoma cruzi isolates.
Souza, D. M.1; Fonseca de Souza, A. L. 3; Silva B. A.2; Santos A. L. S.2; Gonçalves T. C.M.1; Gomes S. A. O.1 ; Meyer-Fernandes, J. R 3.
1Núcleo de Morfologia e Ultraestrutura de Artrópodes, Departamento de Entomologia, Instituto Oswaldo Cruz - FIOCRUZ.
2Laboaratório de Estudos Integrados em Bioquímica Microbiana, Instituto de Microbiologia Paulo de Góes (IMPPG), Bloco I, CCS, UFRJ, Rio de Janeiro, Brasil.
3Laboratório de Bioquímica Celular, IBqM, CCS, UFRJ.
e-mail: alfonseca@bioqmed.ufrj.br
Trypanosoma cruzi (Chagas, 1909) is an ethiologic agent of Chagas disease. These parasites are digenetic protozoa, i.e., present different hosts, as men, triatominae and wild animals. The genotypic variability presented by T. cruzi strains can be related with different forms of Chagas disease manifestation observed in different geographic regions.
The aim of this study is characterize the profile of polypeptides cell surface expression in samples of T. cruzi (SMM10, SMM36, SMM53, SMM88 and SMM98) isolated from different sources – xenodiagnosis, haemoculture or wild triatominae.
Previous reports of our group demonstrated great differences on the cell surface enzymes expression such as ecto-phosphatases activities in trypanosomatids. So, the parasites surface proteins are involved in host cell recognition and penetration. In addition, the majority of surface antigens in trypanosomatids are glycosylated and some of them function as receptors that are involved in a variety of processes including signal transduction, environment sensing and cell adhesion. In this context a comparative study of cell surface protein composition between T. cruzi isolates was carried out using biotinylation methodology. These isolates presented minor quantitative differences in protein profiles when analyzed by SDS-PAGE. Significant differences were detected when the cell surface biotinylated polypeptides were analyzed. A 116 KDa band was conserved in all isolates. In addition, SMM36, SMM53 and SMM98 revealed biotinylated bands with 66 and 50 KDa, and SMM10 presented a band of 40 KDa, suggesting some isolate-specific antigens expression. T. cruzi isolates also present different ecto-phosphatase activities, SMM10 exhibiting a lower level of activity (around 2.5-fold).
Our results suggest that the differential polypeptides expression and ecto-phosphatase activity may be associated with the origin of the isolates: SMM10 – xenodiagnosis; SMM88 – haemoculture; SMM36, SMM53 and SMM98 – wild triatominae. This hypothesis is supported by the data obtained with isoenzyme analysis where the samples were clustered in two groups: SMM36, SMM53 and SMM98, associated to the zymodemes 1 and 3 (Z1 and Z3) of the wild cycle, identified as ZTv10, ZTv1 and ZTv2; and SMM10 and SMM88, associated to the zymodeme 2 (Z2) of the domestic cycle, identified ZTv8 and ZTv7.
This work was supported by grants from FUJB, CNPq and FAPERJ/FIOCRUZ.
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