A team Insert discovered that magnetic stimulation of Macrophages Infected people help these immune cells get rid of the pathogen they contain. Unexpectedly revealed during experiments in vitroThis result was protected by a patent application: it actually opens up the possibility of using magnetic stimulation in the field of immunology.
Repetitive transcranial magnetic stimulation (rTMS) is now part of routine practice in hospital departments: it is used to treat neuropsychiatric diseases such as resistant depression or to relieve certain chronic pain that cannot be relieved by drug treatments. Applying the magnetic field to excitable cells such as neurons induces an electrical current that can lead to therapeutic effects. Marcel Bonay’s Inserm team at the University of Versailles-Saint-Quentin-en-Yvelines/Paris-Saclay is studying rTMS in mouse models for its effects on functional recovery in the event of a spinal cord injury. The application of the magnetic field was tested on neuronal cells, but also on so-called non-excitable cells that support the nervous system, especially macrophages.
To do this, the researchers used human macrophages in culture dishes. First, they verified the absence of toxicity from the magnetic field on these cells by testing different levels of power and frequency. Thresholds consistent with current clinical practice have been shown to be risk-free for macrophages. Secondly, the “behavior” of the cells was studied, in particular by focusing on the activity of a signaling pathway involved in protecting cells from different types of stress: “ This pathway relies on the protein Nrf2, which is activated during aggression and triggers cellular defense mechanisms. », explains Thérèse Deramaudt, first author of this work. The team found that the magnetic field stimulates this important signaling pathway.
An improvement in bactericidal activity
The researchers decided to take their investigations further: “ Since the Nrf2 pathway is particularly involved in the elimination of infectious pathogens trapped in cells, we tested the effect of magnetic stimulation on macrophages infected with Staphylococcus aureus (Staphylococcus aureus)a potentially very virulent bacterium that can colonize the skin and mucous membranes and cause pneumonia, endocarditis, etc. », continues the scientist. The results of this experiment are clear: the magnetic field helped the macrophages get rid of the infectious agent. This improved the bactericidal function of these cells, which play a crucial role in the body’s antimicrobial defense system. The involvement of Nrf2 in this phenomenon was confirmed by preventing its synthesis in cells or by using macrophages genetically lacking it. “ Inactivation or absence of Nrf2 blocks the anti-infectious effect of magnetic stimulation », summarizes Thérèse Deramaudt. The magnetic field additionally affects other processes that reduce inflammation and survival of staphylococci. Molecular analyzes have shown that these protective mechanisms are chemical modifications that affect the activity of various proteins.
“ I have to say we were surprised by these resultsadmits Marcel Bonay. We will continue these investigations, but with our research themes focused on improving the treatment of neuromuscular or musculoskeletal dysfunctionOur laboratory is not intended to use magnetic stimulation in the area of immunity. But other teams will certainly be interested too! » Due to the therapeutic potential of this discovery, the team filed a patent for protection with the support of Inserm Transfert. “ By stimulating macrophages with a magnetic field in vitro We elicited anti-infective activity for five minuteshe remembers. We can think about taking cells from the blood of an infected person and stimulating them Ex vivo, and then re-administer it to the same patient to boost their immune system. And why not imagine an effect of magnetic fields on other types of immune cells? » Assessment of the effects of magnetic stimulation on immunity is just beginning.
Thérèse Deramaudt is a researcher in the team obstruction and inflammation under the direction of Marcel Bonay within the Department of Neuromuscular Disability: Biotherapies and Technological Innovations (End-Icap, Unit 1179 Inserm/UVSQ, Montigny-Le-Bretonneux).
source : T. Deramaudt et al. High-frequency repetitive magnetic stimulation activates the bactericidal activity of macrophages by modulating the p62/Keap1/Nrf2 and p38 MAPK pathways. Antioxidants, online edition from August 30, 2023; doi:10.3390/antiox12091695
Author: AR
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