Identification of the proteomic variability of the promastigote form of the species Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis, and Leishmania (Leishmania) chagasi, using shotgun proteomics approaches.

Author(s)

Joyce Silva Saad

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2019-05-28

Examining board members

Giuseppe Palmisano; Danilo Ciccone Miguel; Sayuri Miyamoto; Marta Maria Geraldes Teixeira

• Advisor: Giuseppe Palmisano

Abstract

Leishmaniasis is a group of neglected diseases caused by a trypanosomatid parasite belonging to the genus Leishmania and can manifest itself in different ways according to the infecting species and the immune response of the host. Leishmaniasis is classified as tegumentary (cutaneous) and visceral. Tegumentary can manifest itself in localized, diffuse, disseminated and mucocutaneous forms. Phylogenetic analyses have revealed a parental relationships between different species of Leishmania, however for many species, the phylogenetic state has not yet been solved. The objective of this study was to compare the promastigote proteome of three species of Leishmania: Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis and Leishmania (Leishmania) infantum chagasi, identifying protein differences between the exponential and stationary phases between the species and within a same species, in order to help the characterization of the different species of the genus Leishmania. In addition, to mimic the event of these parasites when transferred from the phlebotomine sandflies to the mammalian host during the blood repast, a part of the parasites were incubated on day 6 at 34° C for 24 h. As a result we identified a total of 6494, 3800 and 4155 for the exponential, stationary conditions at 25°C and stationary at 34°C respectively. A higher number of proteins was identified for L. (V.) braziliensis. Among the conditions analyzed, the exponential phase was the one with the highest amount of identified proteins classes. Ribosomal proteins, heat shock proteins, kinases and proteins involved in metabolic pathways were highlighted. The L. (V.) braziliensis and L. (L.) infantum species are the ones that present the most differences among them, while L. (L.) amazonensis presents an intermediate profile. The three species present a distinction between growth condition (exponential) and stationary as expected, but the novelty is to see differentiation in the proteome between the two stationary conditions for L. (L.) amazonensis and L. (L.) infantum not being observed the same for L. (V.) braziliensis. The comparative results between the proteomics based on mass spectrometry and western blot showed a diversity of results demonstrating that the methodology used in this study is more accurate in the identification of proteoforms and could be used as a complement for that technique. This study shows for the first time the modulation of specific pathways in the transition between growth phases and temperature shift in L. (L.) amazonensis, L. (V.) braziliensis and L. (L.) infantum, improving the knowledge about the key pathways for parasite response to the environment. (AU)

• FAPESP's process: 16/23689-2 - Proteomic and post-translation modification characterization of Leishmanias L. (V.) braziliensis, L. (L.) amazonensis and L. (L.) chagasi using a shotgun protemics approaches.
• Grantee: Joyce Silva Saad
• Support Opportunities: Scholarships in Brazil - Master