The pathogenesis and pathophysiology of Acanthamoeba infections remain incompletely understood. Phos-pholipases are known to cleave phospholipids, suggesting their possible involvement in the host cell plasma membrane disruption leading to host cell penetration and lysis. The aims of the present study were to determine phospholipase activities in Acanthamoeba and to determine their roles in the pathogenesis of Acanthamoeba. Using an encephalitis isolate (T1 genotype), a keratitis isolate (T4 genotype), and an environmental isolate (T7 genotype), we demonstrated that Acanthamoeba exhibited phospholipase A2 (PLA2) and phospholipase D (PLD) activities in a spectrophotometry-based assay. Interestingly, the encephalitis isolates of Acanthamoeba exhibited higher phospholipase activities as compared with the keratitis isolates, but the environmental isolates exhibited the highest phospholipase activities. Moreover, Acanthamoeba isolates exhibited higher PLD activities compared with the PLA2. Acanthamoeba exhibited optimal phospholipase activities at 37℃ and at neutral pH indicating their physiological relevance. The functional role of phospholipases was determined by in vitro assays using human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier. We observed that a PLD-specific inhibitor, i.e., compound 48/80, partially inhibited Acanthamoeba encephalitis isolate cytotoxicity of the host cells, while PLA2-specific inhibitor, i.e., cytidine 5'-diphosphocholine, had no effect on parasite-mediated HBMEC cytotoxicity. Overall, the T7 exhibited higher phospholipase activities as compared to the T4. In contract, the T7 exhibited minimal binding to, or cytotoxicity of, HBMEC.
Citations
Citations to this article as recorded by
Detection of immunogenic protein components in excretion/secretion products of Acanthamoeba T5 using polyclonal antibodies Lissette Retana-Moreira, Elizabeth Abrahams-Sandí, Marco Ruiz-Campos, Johan Alvarado-Ocampo, Julián Castro, Jacob Lorenzo-Morales, Giovanni Sáenz-Arce, Antonio Osuna Memórias do Instituto Oswaldo Cruz.2025;[Epub] CrossRef
Comprehensive characterization of extracellular vesicles produced by environmental (Neff) and clinical (T4) strains of
Acanthamoeba castellanii
Elisa Gonçalves Medeiros, Michele Ramos Valente, Leandro Honorato, Marina da Silva Ferreira, Susana Ruiz Mendoza, Diego de Souza Gonçalves, Lucas Martins Alcântara, Kamilla Xavier Gomes, Marcia Ribeiro Pinto, Ernesto S. Nakayasu, Geremy Clair, Isadora Fil mSystems.2024;[Epub] CrossRef
Epidemiology of and Genetic Factors Associated with Acanthamoeba Keratitis Muhammad Ilyas, Fiona Stapleton, Mark D. P. Willcox, Fiona Henriquez, Hari Kumar Peguda, Binod Rayamajhee, Tasbiha Zahid, Constantinos Petsoglou, Nicole A. Carnt Pathogens.2024; 13(2): 142. CrossRef
Biological characteristics and pathogenicity of Acanthamoeba Yuehua Wang, Linzhe Jiang, Yitong Zhao, Xiaohong Ju, Le Wang, Liang Jin, Ryan D. Fine, Mingguang Li Frontiers in Microbiology.2023;[Epub] CrossRef
Extracellular Vesicles Secreted by Acanthamoeba culbertsoni Have COX and Proteolytic Activity and Induce Hemolysis Francisco Sierra-López, Ismael Castelan-Ramírez, Dolores Hernández-Martínez, Lizbeth Salazar-Villatoro, David Segura-Cobos, Catalina Flores-Maldonado, Verónica Ivonne Hernández-Ramírez, Tomás Ernesto Villamar-Duque, Adolfo René Méndez-Cruz, Patricia Talam Microorganisms.2023; 11(11): 2762. CrossRef
The gene expression and proteomic profiling of Acanthamoeba isolates Chayan Sharma, Sumeeta Khurana, Alka Bhatia, Amit Arora, Amit Gupta Experimental Parasitology.2023; 255: 108630. CrossRef
Therapeutic agents and biocides for ocular infections by free-living amoebae of Acanthamoeba genus Linda Christian Carrijo-Carvalho, Viviane Peracini Sant'ana, Annette Silva Foronda, Denise de Freitas, Fabio Ramos de Souza Carvalho Survey of Ophthalmology.2017; 62(2): 203. CrossRef
Single-Step Assembly of Multifunctional Poly(tannic acid)–Graphene Oxide Coating To Reduce Biofouling of Forward Osmosis Membranes Hanaa M. Hegab, Ahmed ElMekawy, Thomas G. Barclay, Andrew Michelmore, Linda Zou, Christopher P. Saint, Milena Ginic-Markovic ACS Applied Materials & Interfaces.2016; 8(27): 17519. CrossRef
In vitro inhibition of protease-activated receptors 1, 2 and 4 demonstrates that these receptors are not involved in an Acanthamoeba castellanii keratitis isolate-mediated disruption of the human brain microvascular endothelial cells Junaid Iqbal, Komal Naeem, Ruqaiyyah Siddiqui, Naveed Ahmed Khan Experimental Parasitology.2014; 145: S78. CrossRef