Development of a Trypanosoma cruzi strain typing assay using MS2 peptide spectral libraries (Tc-STAMS2)

Author(s)

de Oliveira, Gilberto Santos ^[1] ; Kawahara, Rebeca ^[1] ; Rosa-Fernandes, Livia ^[2] ; Mule, Simon Ngao ^[1] ; Avila, Carla Cristi ^[1] ; Teixeira, Marta M. G. ^[1] ; Larsen, Martin R. ^[2] ; Palmisano, Giuseppe ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Biomed Sci, Dept Parasitol, Sao Paulo - Brazil

^[2] Univ Southern Denmark, Dept Biochem & Mol Biol, Odense - Denmark

• Document type: Journal article
• Source: PLoS Neglected Tropical Diseases; v. 12, n. 4 APR 2018.
• Web of Science Citations: 3

Abstract

Background Chagas disease also known as American trypanosomiasis is caused by the protozoan Trypanosoma cruzi. Over the last 30 years, Chagas disease has expanded from a neglected parasitic infection of the rural population to an urbanized chronic disease, becoming a potentially emergent global health problem. T. cruzistrains were assigned to seven genetic groups (TcI-TcVI and TcBat), named discrete typing units (DTUs), which represent a set of isolates that differ in virulence, pathogenicity and immunological features. Indeed, diverse clinical manifestations (from asymptomatic to highly severe disease) have been attempted to be related to T.cruzi genetic variability. Due to that, several DTU typing methods have been introduced. Each method has its own advantages and drawbacks such as high complexity and analysis time and all of them are based on genetic signatures. Recently, a novel method discriminated bacterial strains using a peptide identification-free, genome sequence-independent shotgun proteomics workflow. Here, we aimed to develop a Trypanosoma cruzi Strain Typing Assay using MS/MS peptide spectral libraries, named TcSTAMS2. Methods/Principal findings The Tc-STAMS2 method uses shotgun proteomics combined with spectral library search to assign and discriminate T. cruzistrains independently on the genome knowledge. The method is based on the construction of a library of MS/MS peptide spectra built using genotyped T. cruzi reference strains. For identification, the MS/MS peptide spectra of unknown T. cruzi cells are identified using the spectral matching algorithm SpectraST. The Tc-STAMS2 method allowed correct identification of all DTUs with high confidence. The method was robust towards different sample preparations, length of chromatographic gradients and fragmentation techniques. Moreover, a pilot inter-laboratory study showed the applicability to different MS platforms. Conclusions and significance This is the first study that develops a MS-based platform for T. cruzi strain typing. Indeed, the Tc-STAMS2 method allows T. cruzistrain typing using MS/MS spectra as discriminatory features and allows the differentiation of Tcl-TcVI DTUs. Similar to genomic-based strategies, the Tc-STAMS2 method allows identification of strains within DTUs. Its robustness towards different experimental and biological variables makes it a valuable complementary strategy to the current T. cruzi genotyping assays. Moreover, this method can be used to identify DTU-specific features correlated with the strain phenotype. (AU)

• FAPESP's process: 14/06863-3 - Post-translational modifications in cancer and parasite infection diagnosis: methodological approaches and biological implications
• Grantee: Giuseppe Palmisano
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 15/02866-0 - DISCOVERY AND VERIFICATION OF INTACT GLYCOPEPTIDES AS CANDIDATE PROSTATE CANCER BIOMARKERS USING MASS SPECTROMETRY-BASED PROTEOMICS APPROACHES
• Grantee: Rebeca Kawahara Sakuma
• Support Opportunities: Scholarships in Brazil - Post-Doctoral