Stress Induces Release of Extracellular Vesicles by Trypanosoma cruzi Trypomastigotes

Abstract

All extracellular forms of Trypanosoma cruzi, the causative agent of Chagas disease, release extracellular vesicles (EVs) containing major surface molecules of the parasite. EV release depends on several mechanisms (internal and external). However, most of the environmental conditions affecting this phenomenon are still unknown. In this work, we evaluated EV release under different stress conditions and their ability to be internalized by the parasites. In addition, we investigated whether the release conditions would affect their immunomodulatory properties in preactivated bone marrow-derived macrophages (BMDM). Sodium azide and methyl-cyclo-β-dextrin (CDB) reduced EV release, indicating that this phenomenon relies on membrane organization. EV release was increased at low temperatures (4°C) and acidic conditions (pH 5.0). Under this pH, trypomastigotes differentiated into amastigotes. EVs are rapidly liberated and reabsorbed by the trypomastigotes in a concentration-dependent manner. Nitrosative stress caused by sodium nitrite in acid medium or S-nitrosoglutathione also stimulated the secretion of EVs. EVs released under all stress conditions also maintained their proinflammatory activity and increased the expression of iNOS, Arg 1, IL-12, and IL-23 genes in IFN-γ and LPS preactivated BMDM. In conclusion, our results suggest a budding mechanism of release, dependent on the membrane structure and parasite integrity. Stress conditions did not affect functional properties of EVs during interaction with host cells. EV release variations under stress conditions may be a physiological response against environmental changes.

Extracellular vesicles from Trypanosoma cruzi-dendritic cell interaction show modulatory properties and confer resistance to lethal infection as a cell-free based therapy strategy

“…In addition, it was also demonstrated a Ca 2+ dependent up-regulation in the secretion of membrane derived vesicles in THP-1 monocytes induced by Tp ( Cestari et al., 2012 ); nevertheless, the precise mechanism and the signaling cascades stimulated by the parasite are still unknown. Interestingly, previous reports show that low pH and other stress signals increment the release of EVs by the parasite which reach a peak at 120 min at 37°C in vitro ( Vasconcelos et al., 2021 ), suggesting its possible participation in parasite invasion.…”

Biogenesis of extracellular vesicles in protozoan parasites: The ESCRT complex in the trafficking fast lane?

“…Little is currently known about the EV biogenesis pathways in kinetoplastid parasites [88,126]. Yet, at least in the case of in T. cruzi, multiple stress conditions, such as nutrient starvation [15], low temperature and pH [131], nitrosative stress [131], and challenges with host cells [95], trigger EV release. In Leishmania, changes in extracellular temperature and pH can trigger EV secretion too [100].…”

Guidelines for the purification and characterization of extracellular vesicles of parasites

“…They can induce an immune response (activating or suppressing the immune cells), facilitate the parasite attachment to the host cells, participate in parasite-parasite communication, and contribute to the parasite-parasite communications, among other functions (b). (Evans-Osses et al, 2017)1 and 2; (Ma'ayeh et al, 2017)−3; (Sharma et al, 2020)−4; (Costa et al, 2021)−5; (Goncalves et al, 2018)−6;(Olmos-Ortiz et al, 2017)−7; (Twu et al, 2013)−8; (Silva et al, 2018)−9; (Atayde et al, 2016;Silverman et al, 2010b)−10; (Madeira et al, 2021;Torrecilhas et al, 2012;Trocoli Torrecilhas et al, 2009)−11 and 12; (Mantel & Marti, 2014)−13; (Toda et al, 2020)−14; (Sisquella et al, 2017)-15;(Regev-Rudzki et al, 2013)-16; (Marcilla et al, 2014)−17. mediate parasite-parasite communication (Torrecilhas et al, 2012(Torrecilhas et al, , 2020Trocoli Torrecilhas et al, 2009;Vasconcelos et al, 2021). Furthermore, the fact that EVs have been found in most biological fluids (Yáñez-Mó et al, 2015) makes them an important target for the identification of new biomarkers in parasitic infections (Marcilla et al, 2014).…”

“…In some cases, EVs transfer information that allow drug resistance (Regev‐Rudzki et al., 2013). EVs can also mediate parasite‐parasite communication (Torrecilhas et al., 2012, 2020; Trocoli Torrecilhas et al., 2009; Vasconcelos et al., 2021). Furthermore, the fact that EVs have been found in most biological fluids (Yáñez‐Mó et al., 2015) makes them an important target for the identification of new biomarkers in parasitic infections (Marcilla et al., 2014).…”