SARS-CoV-2 papain-like protease activates nociceptors to drive sneeze and pain

Abstract

SARS-CoV-2, the virus responsible for COVID-19, triggers symptoms such as sneezing, aches and pain. ¹ These symptoms are mediated by a subset of sensory neurons, known as nociceptors, that detect noxious stimuli, densely innervate the airway epithelium, and interact with airway resident epithelial and immune cells. ^{2– 6} However, the mechanisms by which viral infection activates these neurons to trigger pain and airway reflexes are unknown. Here, we show that the coronavirus papain-like protease (PLpro) directly activates airway-innervating trigeminal and vagal nociceptors in mice and human iPSC-derived nociceptors. PLpro elicits sneezing and acute pain in mice and triggers the release of neuropeptide calcitonin gene-related peptide (CGRP) from airway afferents. We find that PLpro-induced sneeze and pain requires the host TRPA1 ion channel that has been previously demonstrated to mediate pain, cough, and airway inflammation. ^{7– 9} Our findings are the first demonstration of a viral product that directly activates sensory neurons to trigger pain and airway reflexes and highlight a new role for PLpro and nociceptors in COVID-19.