Schwann cell promotes macrophage recruitment through IL-17B/IL-17RB pathway in injured peripheral nerves

• Published in: Cell reports (Cambridge) 2024-02, Vol.43 (2), p.113753-113753, Article 113753
• Main Authors: Huang, Yanju, Wu, Liwen, Zhao, Yueshan, Guo, Jia, Li, Ruoyi, Ma, Suchen, Ying, Zhengxin
• Format: Article
• Language: English
• Subjects: CP: Immunology; CP: Neuroscience; IL-17; macrophage; nerve injury; nerve regeneration; Schwann cell
• ISSN: 2211-1247; 2211-1247
• DOI: 10.1016/j.celrep.2024.113753

Macrophage recruitment to the injured nerve initiates a cascade of events, including myelin debris clearance and nerve trophic factor secretion, which contribute to proper nerve tissue repair. However, the mechanism of macrophage recruitment is still unclear. Here, by comparing wild-type with Mlkl−/− and Sarm1−/− mice, two mouse strains with impaired myelin debris clearance after peripheral nerve injury, we identify interleukin-17B (IL-17B) as a key regulator of macrophage recruitment. Schwann-cell-secreted IL-17B acts in an autocrine manner and binds to IL-17 receptor B to promote macrophage recruitment, and global or Schwann-cell-specific IL-17B deletion reduces macrophage infiltration, myelin clearance, and axon regeneration. We also show that the IL-17B signaling pathway is defective in the injured central nerves. These results reveal an important role for Schwann cell autocrine signaling during Wallerian degeneration and point to potential mechanistic targets for accelerating myelin clearance and improving demyelinating disease. [Display omitted] •IL-17B binds to IL-17RB and acts in an autocrine manner•IL-17B/IL-17RB regulates the production of chemokines in Schwann cells•IL-17B/IL-17RB promotes macrophage infiltration, myelin degradation, and axon regeneration•IL-17B promotes macrophage activation in the retina Huang et al. discover the activation of IL-17B/IL-17RB signaling in Schwann cells following peripheral nerve injury. This activation triggers an upregulation of several chemokines involved in macrophage recruitment. Consequently, this recruitment aids in clearing myelin debris and enhancing axon regeneration.