Characterization of components secreted by extracellular amastigotes of Trypanosoma cruzi and their role in cell invasion

• Grant number: 21/02881-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): July 01, 2021
• Effective date (End): June 30, 2022
• Field of knowledge: Biological Sciences - Parasitology - Protozoology of Parasites
• Principal Investigator: Renato Arruda Mortara
• Grantee: Nathália Giulia Rizzo
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil
• Associated research grant: 16/15000-4 - Trypanosoma cruzi: intra and interspecific genomic variability and mechanisms of cell invasion/egress, AP.TEM

Abstract

Chagas disease is an infection caused by the flagellated protozoan Trypanosoma cruzi, which is mainly transmitted by triatomine insect vectors, known as kissing bug. The disease still represents a serious public health issue, with more than six million people infected worldwide. The causative agent has a complex life cycle, with different forms of infection and invasion in different hosts. Among these infectious forms, extracellular amastigotes (EAs) are able to invade cells without the need for differentiation into trypomastigotes, in mammalian hosts. It was observed in previous studies that these same cellular forms secrete vesicles and other molecules, around the host cell, which may be associated with the process of invasion and modulation of infectivity. Therefore, this study aims to evaluate the importance of proteins released by extracellular vesicles for the invasion of different T. cruzi strains with different levels of infectivity in host cells. First, the most activated proteins found in the secretome of G (high infectivity) and Y (low infectivity) strains of the EA phase of T. cruzi will be selected. The chosen protein will be deleted from the respective strains of the parasite, using the CRISPR/CAS9 method, which will then be evaluated for their ability to invade HeLa cells and modulate the invasion levels of other strains, using trans well assays. The results from these analyzes will contribute to the identification of the main components released by the parasite in the invasion process and will lead to a greater understanding of the mode of action of extracellular amastigote invasion. (AU)