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Single-Cell Calcium Imaging for Studying the Activation of Calcium Ion Channels
Published on: December 13, 2024
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Streptococcus pyogenes CAMP factor promotes calcium ion uptake in RAW264.7 cells
Mie Kurosawa1,2, Masataka Oda1,3, Hisanori Domon1,4
1Division of Microbiology and Infectious Diseases, Graduate School of Medical and Dental Sciences, Niigata University, 2-5274 Gakkocho-dori, Chuo-ku, Niigata 951-8514, Japan.
Microbiology and Immunology
|September 14, 2018
Summary
Streptococcus pyogenes CAMP factor triggers macrophage vacuolation by increasing calcium ion uptake. This process involves L-type calcium channels and phosphoinositide 3-kinase signaling, leading to clathrin-dependent endosomes.
Area of Science:
- Microbiology
- Immunology
- Cell Biology
Background:
- Streptococcus pyogenes causes systemic diseases by inhibiting the human immune system.
- S. pyogenes CAMP factor is known to induce vacuolation in macrophages, but the mechanism is unclear.
Purpose of the Study:
- To investigate the mechanism by which S. pyogenes CAMP factor induces vacuolation in macrophages.
- To elucidate the role of calcium ion uptake and signaling pathways in this process.
Main Methods:
- Investigated calcium ion uptake in murine macrophage RAW264.7 cells treated with CAMP factor.
- Utilized EDTA, L-type calcium channel blockers (nifedipine, verapamil), and phosphoinositide 3-kinase inhibitors (LY294002, wortmannin).
- Employed fluorescent microscopy to observe clathrin localization.
Main Results:
- CAMP factor induced calcium ion uptake and vacuolation in RAW264.7 cells.
- EDTA, calcium channel blockers, and phosphoinositide 3-kinase inhibitors reduced vacuolation.
- Clathrin was observed to localize to the induced vacuoles.
Conclusions:
- Vacuolation is linked to calcium ion uptake via L-type voltage-dependent calcium ion channels.
- S. pyogenes CAMP factor induces clathrin-dependent endosomes in macrophages.
- This process is mediated by phosphoinositide 3-kinase pathway activation through calcium ion uptake.
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