Volatile Anesthetic Sevoflurane Attenuates Toll-Like Receptor 1/2 Activation

Area of Science:

• Immunology
• Pharmacology
• Molecular Biology

Background:

• Anesthetics' immunomodulatory effects are recognized but poorly understood at the molecular level.
• Toll-like receptors (TLRs) are crucial for initiating immune responses to pathogens and tissue damage.
• TLR2 and TLR4 are key players in perioperative pathophysiology, recognizing diverse ligands.

Purpose of the Study:

• To investigate the impact of common anesthetics on Toll-like receptor 2 (TLR2) function.
• To determine if volatile anesthetics, like sevoflurane, modulate TLR2 activation.
• To elucidate the molecular mechanisms underlying anesthetic-TLR2 interactions.

Main Methods:

• Reporter assays were used to assess the effects of isoflurane, sevoflurane, propofol, and dexmedetomidine on TLR2 activation.
• In silico rigid docking simulations were performed to predict binding interactions.
• Competitive binding assays and human neutrophil function tests were conducted to validate findings.

Main Results:

• Sevoflurane significantly attenuated TLR1/TLR2 activation, while other tested anesthetics did not.
• In silico analysis and competitive binding assays confirmed that sevoflurane directly binds to the TLR1/TLR2 complex.
• Sevoflurane inhibited neutrophil L-selectin shedding, a process crucial for immune cell migration.

Conclusions:

• Sevoflurane directly interacts with TLR2, leading to the attenuation of TLR1/TLR2 activation at clinically relevant concentrations.
• The findings provide molecular insights into how sevoflurane modulates immune responses during anesthesia.
• Sevoflurane's specific inhibition of neutrophil L-selectin shedding highlights its potential role in perioperative immune modulation.