rypanosoma cruzi extracellular amastigotes engage Rac1 and Cdc42 to invade RAW macrophage

Author(s)

Medina, Camila Macedo ^[1] ; Ferreira, Eden Ramalho ^[1] ; Bonifacio, Bruno Souza ^[1] ; Mortara, Renato Arruda ^[1] ; Bonfim-Melo, Alexis ^{[1, 2]}

Affiliation

^[1] Univ Fed Sao Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, Sao Paulo - Brazil

^[2] Univ Queensland, Inst Mol Biosci, Div Cell Biol & Mol Med, Brisbane, Qld 4072 - Australia

• Document type: Journal article
• Source: Microbes and Infection; v. 23, n. 8 SEP-OCT 2021.
• Web of Science Citations: 0

Abstract

Cell invasion by Trypanosoma cruzi extracellular amastigotes (EAs) relies significantly upon the host cell actin cytoskeleton. In past decades EAs have been established as a reliable model for phagocytosis inducer in non-phagocytic cells. Our current hypothesis is that EAs engage a phagocytosis-like mechanism in non-professional phagocytic cells; however, the molecular mechanisms in professional phagocytes still remain unexplored. In this work, we evaluated the involvement of Rac1 and Cdc42 in the actindependent internalization of EAs in RAW 264.7 macrophages. Kinetic assays showed similar internalization of EAs in unstimulated RAW and non-phagocytic HeLa cells but increased in LPS/IFN-gamma stimulated RAW cells. However, depletion of Rac1, Cdc42 or RhoA inhibited EA internalization similarly in both unstimulated and stimulated RAW cells. Overexpression of active, but not the dominant-negative, construct of Rac1 increased EA internalization. Remarkably, for Cdc42, both the active and the inactive mutants decreased EA internalization when compared to wild type groups. Despite that, both Rac1 and Cdc42 activation mutants were similarly recruited to and colocalized with actin at the EA-macrophage contact sites when compared to their native isoforms. Altogether, these results corroborate that EAs engage phagocytic processes to invade both professional and non-professional phagocytic cells providing evidences of converging actin mediated mechanisms induced by intracellular pathogens in both cell types. (C) 2021 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved. (AU)

• FAPESP's process: 17/20432-3 - The role of N-WASP, WAVE2 and cortactin in the internalization by extracellular amastigotes of Trypanosoma cruzi in professional phagocytic cells (THP-1)
• Grantee: Camila Macedo Medina
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 16/15000-4 - Trypanosoma cruzi: intra and interspecific genomic variability and mechanisms of cell invasion/egress
• Grantee: Renato Arruda Mortara
• Support Opportunities: Research Projects - Thematic Grants