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Extracellular Vesicles from Naegleria fowleri Induce IL-8 Response in THP-1 Macrophage
Sakaorat Lertjuthaporn1, Jinjuta Somkird2, Kittima Lekmanee3
1Center for Research and Innovation, Faculty of Medical Technology, Mahidol University, Nakhon Pathom 73170, Thailand.
Abstract:
Extracellular vesicles (EVs) released from pathogenic protozoans play crucial roles in host-parasite communication and disease pathogenesis. Naegleria fowleri is a free-living protozoan causing primary amoebic meningoencephalitis, a fatal disease in the central nervous system. This study aims to explore the roles of N. fowleri-derived EVs (Nf-EVs) in host-pathogen interactions using the THP-1 cell line as a model. The Nf-EVs were isolated from the N. fowleri trophozoite culture supernatant using sequential centrifugation and characterized by nanoparticle tracking analysis and transmission electron microscopy. The functional roles of Nf-EVs in the apoptosis and immune response induction of THP-1 monocytes and macrophages were examined by flow cytometry, quantitative PCR, and ELISA. Results showed that Nf-EVs displayed vesicles with bilayer membrane structure approximately 130-170 nm in diameter. The Nf-EVs can be internalized by macrophages and induce macrophage responses by induction of the expression of costimulatory molecules CD80, CD86, HLA-DR, and CD169 and the production of cytokine IL-8. However, Nf-EVs did not affect the apoptosis of macrophages. These findings illustrate the potential role of Nf-EVs in mediating the host immune cell activation and disease pathogenesis.
Insights
Naegleria fowleri-derived extracellular vesicles (Nf-EVs) activate immune cells but do not induce apoptosis. These Nf-EVs play a role in host-pathogen interactions and disease pathogenesis.
Area of Science:
- Parasitology
- Immunology
- Cell Biology
Background:
- Pathogenic protozoans release extracellular vesicles (EVs) critical for host-parasite communication.
- Naegleria fowleri causes fatal primary amoebic meningoencephalitis.
- Understanding Naegleria fowleri-derived EVs (Nf-EVs) is key to elucidating disease mechanisms.
Purpose of the Study:
- To investigate the role of Nf-EVs in host-pathogen interactions.
- To examine the impact of Nf-EVs on THP-1 monocyte and macrophage apoptosis and immune responses.
Main Methods:
- Isolation and characterization of Nf-EVs using sequential centrifugation, nanoparticle tracking analysis, and transmission electron microscopy.
- Assessment of Nf-EVs' effects on THP-1 cells via flow cytometry, quantitative PCR, and ELISA.
- Analysis of macrophage apoptosis and immune response markers.
Main Results:
- Nf-EVs are vesicles of 130-170 nm in diameter.
- Macrophages internalized Nf-EVs, leading to increased expression of costimulatory molecules (CD80, CD86, HLA-DR, CD169) and IL-8 production.
- Nf-EVs did not induce apoptosis in macrophages.
Conclusions:
- Nf-EVs are involved in activating host immune cells.
- These findings highlight the potential role of Nf-EVs in mediating host immune responses and disease pathogenesis.
- Nf-EVs contribute to host-parasite communication in Naegleria fowleri infections.
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