TLR7 is expressed by support cells, but not sensory neurons, in ganglia

• DOI: 10.1186/s12974-021-02269-x
• Publication Date: 2021-09-16T18:02:57Z
• Authors: Becky J. Proskocil; Karol Wai; Katherine M. Lebold; Mason A. Norgard; Katherine A. Mich...; Ubaldo De La Torre; Madeline Cook; Daniel L. Marks; Allison D. Fryer; David B. Jacoby; Matthew G. Drake
• Keywords: TLR7

Toll-like receptor 7 (TLR7) is an innate immune that detects viral single-stranded RNA and triggers the production of proinflammatory cytokines type 1 interferons in cells. TLR7 agonists also modulate sensory nerve function by increasing neuronal excitability, although studies are conflicting whether neurons specifically express TLR7. This uncertainty has confounded development a mechanistic understanding nervous tissues.TLR7 expression was tested using situ hybridization with species-specific probes vagal dorsal root ganglia wild-type knockout (KO) mice guinea pigs. Since KO were generated inserting Escherichia coli lacZ gene exon 3 mouse gene, labeled for lacZ. In labeling compared to immunohistochemistry antibody probes. The effects influenza A infection on spleen assessed.In detected small support cells adjacent pigs, but not mice. co-expressed macrophage marker Iba1 satellite glial cell GFAP, PGP9.5, indicating expressed nerves either or contrast, antibodies small- medium-sized TLR7-independent manner. Influenza caused significant weight loss upregulation spleens, ganglia, mice.TLR7 macrophages cells, suggesting TLR7's neuromodulatory mediated indirectly via activation neuronally-associated through directly. Our data suggest primary role tissues related antiviral immunity.