Cutaneous TRPV1 + Neurons Trigger Protective Innate Type 17 Anticipatory Immunity

Cell. 2019 Aug 8;178(4):919-932.e14. doi: 10.1016/j.cell.2019.06.022. Epub 2019 Jul 25.

Abstract

Cutaneous TRPV1+ neurons directly sense noxious stimuli, inflammatory cytokines, and pathogen-associated molecules and are required for innate immunity against some skin pathogens. Important unanswered questions are whether TRPV1+ neuron activation in isolation is sufficient to initiate innate immune responses and what is the biological function for TRPV1+ neuron-initiated immune responses. We used TRPV1-Ai32 optogenetic mice and cutaneous light stimulation to activate cutaneous neurons in the absence of tissue damage or pathogen-associated products. We found that TRPV1+ neuron activation was sufficient to elicit a local type 17 immune response that augmented host defense to C. albicans and S. aureus. Moreover, local neuron activation elicited type 17 responses and augmented host defense at adjacent, unstimulated skin through a nerve reflex arc. These data show the sufficiency of TRPV1+ neuron activation for host defense and demonstrate the existence of functional anticipatory innate immunity at sites adjacent to infection that depends on antidromic neuron activation.

Keywords: C. albicans; CGRP; S. aureus; TRPV1; antidromic; host defense; innate immunity; neuroimmunology; optogenetics; skin.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Candida albicans / immunology
  • Immunity, Innate / immunology*
  • Inflammation / immunology
  • Interleukin-23 / metabolism*
  • Interleukin-6 / metabolism*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Optogenetics / methods
  • Sensory Receptor Cells / immunology*
  • Skin / immunology*
  • Skin / microbiology
  • Staphylococcus aureus / immunology
  • TRPV Cation Channels / genetics
  • TRPV Cation Channels / metabolism*
  • Tumor Necrosis Factor-alpha / metabolism*

Substances

  • Interleukin-23
  • Interleukin-6
  • TRPV Cation Channels
  • TRPV1 protein, mouse
  • Tumor Necrosis Factor-alpha
  • interleukin-6, mouse