PMID- 32047126 OWN - NLM STAT- MEDLINE DCOM- 20201016 LR - 20240214 IS - 2150-7511 (Electronic) VI - 11 IP - 1 DP - 2020 Feb 11 TI - Encephalitic Alphaviruses Exploit Caveola-Mediated Transcytosis at the Blood-Brain Barrier for Central Nervous System Entry. LID - 10.1128/mBio.02731-19 [doi] LID - e02731-19 AB - Venezuelan and western equine encephalitis viruses (VEEV and WEEV, respectively) invade the central nervous system (CNS) early during infection, via neuronal and hematogenous routes. While viral replication mediates host shutoff, including expression of type I interferons (IFN), few studies have addressed how alphaviruses gain access to the CNS during established infection or the mechanisms of viral crossing at the blood-brain barrier (BBB). Here, we show that hematogenous dissemination of VEEV and WEEV into the CNS occurs via caveolin-1 (Cav-1)-mediated transcytosis (Cav-MT) across an intact BBB, which is impeded by IFN and inhibitors of RhoA GTPase. Use of reporter and nonreplicative strains also demonstrates that IFN signaling mediates viral restriction within cells comprising the neurovascular unit (NVU), differentially rendering brain endothelial cells, pericytes, and astrocytes permissive to viral replication. Transmission and immunoelectron microscopy revealed early events in virus internalization and Cav-1 association within brain endothelial cells. Cav-1-deficient mice exhibit diminished CNS VEEV and WEEV titers during early infection, whereas viral burdens in peripheral tissues remained unchanged. Our findings show that alphaviruses exploit Cav-MT to enter the CNS and that IFN differentially restricts this process at the BBB.IMPORTANCE VEEV, WEEV, and eastern equine encephalitis virus (EEEV) are emerging infectious diseases in the Americas, and they have caused several major outbreaks in the human and horse population during the past few decades. Shortly after infection, these viruses can infect the CNS, resulting in severe long-term neurological deficits or death. Neuroinvasion has been associated with virus entry into the CNS directly from the bloodstream; however, the underlying molecular mechanisms have remained largely unknown. Here, we demonstrate that following peripheral infection alphavirus augments vesicular formation/trafficking at the BBB and utilizes Cav-MT to cross an intact BBB, a process regulated by activators of Rho GTPases within brain endothelium. In vivo examination of early viral entry in Cav-1-deficient mice revealed significantly lower viral burdens in the brain than in similarly infected wild-type animals. These studies identify a potentially targetable pathway to limit neuroinvasion by alphaviruses. CI - Copyright (c) 2020 Salimi et al. FAU - Salimi, Hamid AU - Salimi H AD - Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA. FAU - Cain, Matthew D AU - Cain MD AD - Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA. FAU - Jiang, Xiaoping AU - Jiang X AD - Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA. FAU - Roth, Robyn A AU - Roth RA AD - Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA. FAU - Beatty, Wandy L AU - Beatty WL AD - Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA. FAU - Sun, Chengqun AU - Sun C AD - Department of Immunology and Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA. FAU - Klimstra, William B AU - Klimstra WB AD - Department of Immunology and Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA. FAU - Hou, Jianghui AU - Hou J AD - Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA. FAU - Klein, Robyn S AU - Klein RS AD - Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA rklein@wustl.edu. AD - Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, Missouri, USA. AD - Department of Neuroscience, Washington University School of Medicine, St. Louis, Missouri, USA. LA - eng GR - R01 AI095436/AI/NIAID NIH HHS/United States GR - R01 AI101400/AI/NIAID NIH HHS/United States GR - R01 NS052632/NS/NINDS NIH HHS/United States GR - U19 AI083019/AI/NIAID NIH HHS/United States PT - Journal Article PT - Research Support, N.I.H., Extramural PT - Research Support, U.S. Gov't, Non-P.H.S. DEP - 20200211 PL - United States TA - mBio JT - mBio JID - 101519231 RN - 0 (Cav1 protein, mouse) RN - 0 (Caveolin 1) SB - IM MH - Animals MH - Blood-Brain Barrier/*virology MH - Caveolae/*virology MH - Caveolin 1/genetics MH - Cell Line MH - Central Nervous System/virology MH - Encephalitis Virus, Venezuelan Equine/*physiology MH - Encephalitis Virus, Western Equine/*physiology MH - Endothelial Cells/virology MH - Male MH - Mice, Inbred C57BL MH - *Transcytosis MH - *Virus Internalization MH - Virus Replication PMC - PMC7018649 OTO - NOTNLM OT - IFNAR OT - Venezuelan encephalitis virus OT - alphavirus OT - blood-brain barrier OT - caveola-mediated transcytosis OT - caveolin-1 OT - in vivo animal model OT - transcytosis assay OT - type I interferon OT - western equine encephalitis virus EDAT- 2020/02/13 06:00 MHDA- 2020/10/21 06:00 PMCR- 2020/02/11 CRDT- 2020/02/13 06:00 PHST- 2020/02/13 06:00 [entrez] PHST- 2020/02/13 06:00 [pubmed] PHST- 2020/10/21 06:00 [medline] PHST- 2020/02/11 00:00 [pmc-release] AID - mBio.02731-19 [pii] AID - mBio02731-19 [pii] AID - 10.1128/mBio.02731-19 [doi] PST - epublish SO - mBio. 2020 Feb 11;11(1):e02731-19. doi: 10.1128/mBio.02731-19.