TRPV1+ neurons alter Staphylococcus aureus skin infection outcomes by affecting macrophage polarization and neutrophil recruitment

Abstract

Background: The interaction between the nervous system and the immune system can affect the outcome of a bacterial infection. Staphylococcus aureus skin infection is a common infectious disease, and elucidating the relationship between the nervous system and immune system may help to improve treatment strategies.

Results: In this study, we found that the local release of calcitonin gene-related peptide (CGRP) increased during S. aureus skin infection, and S. aureus could promote the release of CGRP from transient receptor potential cation channel subfamily V member 1 (TRPV1⁺) neurons in vitro. The existence of TRPV1⁺ neurons inhibited the recruitment of neutrophils to the infected region and regulated the polarization of macrophages toward M2 while inhibiting polarization toward M1. This reduces the level of inflammation in the infected area, which aggravates the local infection. Furthermore, this study demonstrates that TRPV1 may be a target for the treatment of S. aureus skin infections and that botulinum neurotoxin A (BoNT/A) and BIBN4096 may reverse the inhibited inflammatory effect of CGRP, making them potential therapeutics for the treatment of skin infection in S. aureus.

Conclusions: In S. aureus skin infection, TRPV1⁺ neurons inhibit neutrophil recruitment and regulate macrophage polarization by releasing CGRP. BoNT/A and BIBN4096 may be potential therapeutic agents for S. aureus skin infection.

Keywords: Calcitonin gene-related peptide; Macrophage; Neutrophile; Nociceptor neuron; Skin infection; Staphylococcus aureus.