Spatiotemporal interplay of severe acute respiratory syndrome coronavirus and respiratory mucosal cells drives viral dissemination in rhesus macaques

Mucosal Immunol. 2016 Jul;9(4):1089-101. doi: 10.1038/mi.2015.127. Epub 2015 Dec 9.

Abstract

Innate immune responses have a critical role in the control of early virus replication and dissemination. It remains unknown, however, how severe acute respiratory syndrome coronavirus (SARS-CoV) evades respiratory innate immunity to establish a systemic infection. Here we show in Chinese macaques that SARS-CoV traversed the mucosa through the respiratory tract within 2 days, resulting in extensive mucosal infiltration by T cells, MAC387(+), and CD163(+) monocytes/macrophages followed by limited viral replication in the lung but persistent viral shedding into the upper airway. Mucosal monocytes/macrophages sequestered virions in intracellular vesicles together with infected Langerhans cells and migrated into the tonsils and/or draining lymph nodes within 2 days. In lymphoid tissues, viral RNA and proteins were detected in infected monocytes upon differentiation into dendritic cells (DCs) within 3 days. Systemic viral dissemination was observed within 7 days. This study provides a comprehensive overview of the spatiotemporal interactions of SARS-CoV, monocytes/macrophages, and the DC network in mucosal tissues and highlights the fact that, while these innate cells contribute to viral clearance, they probably also serve as shelters and vehicles to provide a mechanism for the virus to escape host mucosal innate immunity and disseminate systemically.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Differentiation
  • Cell Movement
  • Cells, Cultured
  • Coronavirus / physiology*
  • Dendritic Cells / immunology*
  • Dendritic Cells / virology
  • Humans
  • Immune Evasion
  • Immunity, Innate
  • Macaca mulatta / immunology*
  • Macrophages / immunology*
  • Macrophages / virology
  • RNA, Viral / immunology
  • Respiratory Mucosa / immunology*
  • Respiratory Mucosa / virology
  • Severe Acute Respiratory Syndrome / immunology*
  • T-Lymphocytes / immunology*
  • T-Lymphocytes / virology
  • Viral Load
  • Virus Replication
  • Virus Shedding

Substances

  • RNA, Viral