The Trypanosoma rangeli trypomastigote surfaceome reveals novel proteins and targets for specific diagnosis.

Sympatric distribution and sharing of hosts and antigens by Trypanosoma rangeli and Trypanosoma cruzi, the etiological agent of Chagas' disease, often incur in misdiagnosis and improper epidemiological inferences. Many secreted and surface proteins (SP) have been described as important antigens shared by these species. This work describes the T. rangeli surfaceome obtained by gel-free (LC-ESI-MS/MS) and gel-based (GeLC-ESI-MS/MS) proteomic approaches, and immunoblotting analyses and the comparison of these SP with T. cruzi. A total of 138 T. rangeli proteins and 343 T. cruzi proteins were obtained, among which, 42 and 157 proteins were exclusively identified in T. rangeli or T. cruzi trypomastigotes, respectively. Immunoblotting assays using sera from experimentally infected mice revealed a distinct band pattern for each species. MS/MS analysis of T. rangeli exclusive bands revealed two unique GP63-related proteins and flagellar calcium-binding protein. Also, a ~32kDa band composed of 12 distinct proteins was exclusively recognized by anti-T. cruzi serum. This highly sensitive proteomic assessment of surface proteins characterized the T. rangeli surfaceome, revealing several differences and similarities between these two parasites. The study reports new T. rangeli-specific proteins with promising use in differential diagnosis from T. cruzi. BIOLOGICAL SIGNIFICANCE: In this manuscript, we report the first proteomic analysis of the T. rangeli surface (surfaceome), a non-pathogenic parasite occurring in sympatry with T. cruzi, the etiological agent of Chagas disease. This comparative proteomic analysis was performed using high-throughput in-gel and gel-free proteomic approaches combined with immunoblotting, allowing us to identify new T. rangeli-specific proteins with promising use in differential serodiagnosis, among several other protein not previously reported for this taxon. Additionally, cross-recognition assays showed that T. cruzi surface proteins were recognized by heterologous serum (anti-T. rangeli) that strengthens the possibility of misdiagnosis of Chagas disease in humans and other mammals. Thus, this work provides new insights to understand the serological cross-reactivity between T. cruzi and T. rangeli, as well as, the identification of targets for specific T. rangeli diagnosis as revealed by the comparative surfaceome analysis. We strongly believe that this research is of importance to the readers of Journal of Proteomics since it provides new potential markers for diagnosis of both T. cruzi and T. rangeli parasites increasing the spectrum of specific targets for unambiguous diagnosis of T. rangeli and T. cruzi infections, besides describing new approaches to assess the trypanosomatids proteome.

Trypanosoma rangeli protein tyrosine phosphatase is associated with the parasite's flagellum.

Protein tyrosine phosphatases (PTPs) play an essential role in the regulation of cell differentiation in pathogenic trypanosomatids. In this study, we describe a PTP expressed by the non-pathogenic protozoan Trypanosoma rangeli (TrPTP2). The gene for this PTP is orthologous to the T. brucei TbPTP1 and Trypanosoma cruzi (TcPTP2) genes. Cloning and expression of the TrPTP2 and TcPTP2 proteins allowed anti-PTP2 monoclonal antibodies to be generated in BALB/c mice. When expressed by T. rangeli epimastigotes and trypomastigotes, native TrPTP2 is detected as a ~65 kDa protein associated with the parasite's flagellum. Given that the flagellum is an important structure for cell differentiation in trypanosomatids, the presence of a protein responsible for tyrosine dephosphorylation in the T. rangeli flagellum could represent an interesting mechanism of regulation in this structure.

Trypanosoma rangeli protein tyrosine phosphatase is associated with the parasite's flagellum

Protein tyrosine phosphatases (PTPs) play an essential role in the regulation of cell differentiation in pathogenic trypanosomatids. In this study, we describe a PTP expressed by the non-pathogenic protozoan Trypanosoma rangeli (TrPTP2). The gene for this PTP is orthologous to the T. brucei TbPTP1 and Trypanosoma cruzi (TcPTP2) genes. Cloning and expression of the TrPTP2 and TcPTP2 proteins allowed anti-PTP2 monoclonal antibodies to be generated in BALB/c mice. When expressed by T. rangeli epimastigotes and trypomastigotes, native TrPTP2 is detected as a ~65 kDa protein associated with the parasite's flagellum. Given that the flagellum is an important structure for cell differentiation in trypanosomatids, the presence of a protein responsible for tyrosine dephosphorylation in the T. rangeli flagellum could represent an interesting mechanism of regulation in this structure.