Rotavirus Degrades Multiple Interferon (IFN) Type Receptors To Inhibit IFN Signaling and Protects against Mortality from Endotoxin in Suckling Mice Adrish Sen, a,b,c Ayushi Sharma, b,c,d Harry B. Greenberg a,b,c a Department of Microbiology and Immunology, Stanford University, Stanford, California, USA b Department of Medicine, Stanford University, Stanford, California, USA c Veterans Affairs Palo Alto Health Care System, Palo Alto, California, USA d Emory College of Arts and Sciences, Emory University, Atlanta, Georgia, USA ABSTRACT STAT1 phosphorylation in response to exogenous interferon (IFN) ad- ministration can be inhibited by rotaviral replication both in vitro and in vivo. In ad- dition many rotavirus strains are resistant to the actions of different IFN types. The regulation by rotaviruses (RVs) of antiviral pathways mediated by multiple IFN types is not well understood. In this study, we find that during infection in vitro and in vivo, RVs significantly deplete IFN type I, II, and III receptors (IFNRs). Regula- tion of IFNRs occurred exclusively within RV-infected cells and could be abrogated by inhibiting the lysosomal-endosomal degradation pathway. In vitro, IFNR degrada- tion was conserved across multiple RV strains that differ in their modes of regulating IFN induction. In suckling mice, exogenously administered type I, II, or III IFN in- duced phosphorylation of STAT1-Y701 within intestinal epithelial cells (IECs) of suck- ling mice. Murine EW strain RV infection transiently activated intestinal STAT1 at 1 day postinfection (dpi) but not subsequently at 2 to 3 dpi. In response to injection of purified IFN-/ or -, IECs in EW-infected mice exhibited impaired STAT1-Y701 phosphorylation, correlating with depletion of different intestinal IFNRs and impaired IFN-mediated transcription. The ability of EW murine RV to inhibit multiple IFN types led us to test protection of suckling mice from endotoxin-mediated shock, an out- come that is dependent on the host IFN response. Compared to mortality in con- trols, mice infected with EW murine RV were substantially protected against mortal- ity following parenteral endotoxin administration. These studies identify a novel mechanism of IFN subversion by RV and reveal an unexpected protective effect of RV infection on endotoxin-mediated shock in suckling mice. IMPORTANCE Antiviral functions of types I, II, and III IFNs are mediated by receptor-dependent activation of STAT1. Here, we find that RV degrades the types I, II, and III IFN receptors (IFNRs) in vitro. In a suckling mouse model, RV ef- fectively blocked STAT1 activation and transcription following injection of differ- ent purified IFNs. This correlated with significantly decreased protein expression of intestinal types I and II IFNRs. Recent studies demonstrate that in mice lipo- polysaccharide (LPS)-induced lethality is prevented by genetic ablation of IFN signaling genes such as IFNAR1 and STAT1. When suckling mice were infected with RV, they were substantially protected from lethal exposure to endotoxin. These findings provide novel insights into the mechanisms underlying rotavirus regulation of different interferons and are likely to stimulate new research into both rotavirus pathogenesis and endotoxemia. KEYWORDS rotavirus, interferon, innate immunity, interferon receptor, endotoxin Received 15 August 2017 Accepted 17 October 2017 Accepted manuscript posted online 25 October 2017 Citation Sen A, Sharma A, Greenberg HB. 2018. Rotavirus degrades multiple interferon (IFN) type receptors to inhibit IFN signaling and protects against mortality from endotoxin in suckling mice. J Virol 92:e01394-17. https://doi .org/10.1128/JVI.01394-17. Editor Susana López, Instituto de Biotecnologia/UNAM Copyright © 2017 American Society for Microbiology. All Rights Reserved. Address correspondence to Adrish Sen, adrishs@stanford.edu, or Harry B. Greenberg, hbgreen@stanford.edu. PATHOGENESIS AND IMMUNITY crossm January 2018 Volume 92 Issue 1 e01394-17 jvi.asm.org 1 Journal of Virology on June 4, 2020 by guest http://jvi.asm.org/ Downloaded from