4.2 Article

Acanthamoeba (T4) trophozoites cross the MDCK epithelium without cell damage but increase paracellular permeability and transepithelial resistance by modifying tight junction composition

Journal

EXPERIMENTAL PARASITOLOGY
Volume 183, Issue -, Pages 69-75

Publisher

ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.exppara.2017.10.013

Keywords

Acanthamoeba (T4); MDCK cells; Permeability; TER; Claudins

Categories

Funding

  1. CONACYT (Consejo Nacional de Ciencia y Tecnologia, Fondo Sectorial de Investigation en Salud y Seguridad Social) [115403]

Ask authors/readers for more resources

Free-living amoebae of the genus Acanthamoeba are protozoa ubiquitously found in nature. Some species of the genus are potentially pathogenic for humans provoking keratitis in healthy individuals, often in contact lens wearers and opportunistic infections such as pneumonitis, fatal granulomatous encephalitis and skin infections, particularly in immunocompromised individuals. The pathogenic mechanisms of these amoebae are poorly understood, however it had been suggested that contact dependent mechanisms are important during invasion, regardless of the epithelia type, since amoebae penetrate epithelia separating tight junction (TJ). This study was undertaken to determine whether Acanthamoeba sp. (T4) damages the barrier function of the TJ in MDCK epithelial monolayers. Actin cytoskeleton staining and electron microscopy analyses were performed; paracellular permeability and TJ sealing were evaluated by apicobasolateral diffusion of ruthenium red and transepithelial resistance (TER) measurements; immunofluorescence and Western blot assays were performed to locate and estimate expression of TJ protein claudins 2 (Cldn2) and 4 (Cldn4). The results show that Acanthamoeba sp. crosses the MDCK monolayer without altering the actin cytoskeleton or the morphology of the cells. When trophozoites or conditioned medium interact with the monolayer, paracellular diffusion of ruthenium red increases. After 6 h, the amoebae, but not their conditioned medium, increase the TER, and Cldn2 is removed from the TJ, and its overall content in the cells diminishes, while Cldn4 is targeted to the TJ without changing its expression level. In conclusion Acanthamoeba (T4) crosses MDCK monolayer without damaging the cells, increasing permeability and TER through Cldn2 degradation, and redirecting Cldn4 to TJ. These results strongly suggest that contact-dependent mechanisms are relevant during amoebae invasion. (C) 2017 Elsevier Inc. All rights reserved.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.2
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available