Alphaherpesvirus infection of mice primes PNS neurons to an inflammatory state regulated by TLR2 and type I IFN signaling. Author Kathlyn Laval, Jolien Van Cleemput, Jonah Vernejoul, Lynn Enquist Publication Year 2019 Type Journal Article Abstract Pseudorabies virus (PRV), an alphaherpesvirus closely related to Varicella-Zoster virus (VZV) and Herpes simplex type 1 (HSV1) infects mucosa epithelia and the peripheral nervous system (PNS) of its host. We previously demonstrated that PRV infection induces a specific and lethal inflammatory response, contributing to severe neuropathy in mice. So far, the mechanisms that initiate this neuroinflammation remain unknown. Using a mouse footpad inoculation model, we found that PRV infection rapidly and simultaneously induces high G-CSF and IL-6 levels in several mouse tissues, including the footpad, PNS and central nervous system (CNS) tissues. Interestingly, this global increase occurred before PRV had replicated in dorsal root ganglia (DRGs) neurons and also was independent of systemic inflammation. These high G-CSF and IL-6 levels were not caused by neutrophil infiltration in PRV infected tissues, as we did not detect any neutrophils. Efficient PRV replication and spread in the footpad was sufficient to activate DRGs to produce cytokines. Finally, by using knockout mice, we demonstrated that TLR2 and IFN type I play crucial roles in modulating the early neuroinflammatory response and clinical outcome of PRV infection in mice. Overall, these results give new insights into the initiation of virus-induced neuroinflammation during herpesvirus infections. Keywords Animals, Mice, Mice, Inbred C57BL, Male, Neurons, Virus Replication, Interferon Type I, Inflammation, Alphaherpesvirinae, Peripheral Nervous System, Antiviral Agents, Toll-Like Receptor 2, Herpesviridae Infections Journal PLoS Pathog Volume 15 Issue 11 Pages e1008087 Date Published 2019 Nov ISSN Number 1553-7374 DOI 10.1371/journal.ppat.1008087 Alternate Journal PLoS Pathog PMCID PMC6824567 PMID 31675371 PubMedPubMed CentralGoogle ScholarBibTeXEndNote X3 XML