A critical role for MSR1 in vesicular stomatitis virus infection of the central nervous system

Abstract

Macrophage scavenger receptor 1 (MSR1) plays an important role in host defense to bacterial infections, M2 macrophage polarization and lipid homeostasis. However, its physiological function in viral pathogenesis remains poorly defined. Herein, we report that MSR1 facilitates vesicular stomatitis virus (VSV) infection in the spinal cord. Msr1-deficient (Msr1-/-) mice presented reduced morbidity and mortality following lethal VSV infection, along with normal viremia and antiviral innate immune responses, compared to Msr1+/- littermates and wild-type mice. Msr1 expression was selectively upregulated in the spinal cord, which was the predominant target of VSV infection. The viral load in the spinal cord was positively correlated with Msr1 expression level and was reduced in Msr1-/- mice. Through its extracellular domain, MSR1 interacted with VSV surface glycoprotein and facilitated its cellular entry. In conclusion, our results demonstrate that MSR1 serves as a cellular entry receptor for VSV and facilitates its infection specifically in the spinal cord.