Acanthamoeba castellanii as an alternative interaction model for the dermatophyte Trichophyton rubrum. Issue 12 (15th September 2020)

• Record Type: Journal Article
• Authors: de Faria, Lucas V.; do Carmo, Paulo H. F.; da Costa, Marliete C.; Peres, Nalu T. A.; Rodrigues Chagas, Isabela A.; Furst, Cinthia; Ferreira, Gabriella F.; Costa, Adriana O.; Santos, Daniel A.
• Is Part Of: Mycoses. Volume 63:Issue 12(2020)
• Page Start: 1331
• Page End: 1340
• Publication Date: 2020-09-15
• Subjects: Acanthamoeba castellanii -- dermatophyte -- fungal‐host interaction -- infection model -- pathogenicity -- phagocytosis -- Trichophyton rubrum -- virulence; Pathogenic fungi -- Periodicals; Medical mycology -- Periodicals; 616.969
• DOI: 10.1111/myc.13173
• Languages: English
• ISSNs: 0933-7407

Abstract

Summary: Background: Trichophyton rubrum (Tr) is the main aetiological agent of human dermatophytosis, being isolated from the environment and keratinised tissues. In the environment, Tr can interact with other organisms, such as free‐living amoebas (FLA), which can act as an alternative host system to study the interaction between microbes and phagocytic cells. Objectives: To characterise the Acanthamoeba castellanii (ALX)‐Tr interaction. Methods: Interaction was characterised in three conditions: trophozoites (PYG), late (PYG/NES) and early (NES) encystation stimulus, evaluating encystation kinetics, phagocytosis, exocytosis and fungicidal activity dynamics. Results: Tr was able to induce ALX encystation and be internalised by ALX. The number of internalised conidia was high at 1 hour, and ALX presented fungicidal activity with increased intracellular ROS production and exocytosis. In PYG/NES, phagocytosis and ROS production were reduced, with decreased ALX's fungicidal activity. However, in NES there was an increased fungal engulfment, and a reduced ROS production and higher fungal burden. Furthermore, exogenous mannose decreased phagocytosis of Tr conidia, and divalent cations induced ROS production and increased ALX's fungicidal activity. Interestingly, phagocytosis was reduced in the presence of cytoskeleton inhibitor, but exocytosis was increased, suggesting that Tr conidia may have alternative pathways to escape ALX's cells. Conclusion: A castellanii is a proper model for studying Tr‐FLA interaction, since ALX can engulf, produce ROS and kill Tr, and all these parameters are influenced by an encystation stimulus and divalent cations. Moreover, this interaction is likely to occur in the environment implicating in the adaptation to environmental stressful conditions in both organisms.