Lung macrophage scavenger receptor SR-A6 (MARCO) is an adenovirus type-specific virus entry receptor

PLoS Pathog. 2018 Mar 9;14(3):e1006914. doi: 10.1371/journal.ppat.1006914. eCollection 2018 Mar.

Abstract

Macrophages are a diverse group of phagocytic cells acting in host protection against stress, injury, and pathogens. Here, we show that the scavenger receptor SR-A6 is an entry receptor for human adenoviruses in murine alveolar macrophage-like MPI cells, and important for production of type I interferon. Scavenger receptors contribute to the clearance of endogenous proteins, lipoproteins and pathogens. Knockout of SR-A6 in MPI cells, anti-SR-A6 antibody or the soluble extracellular SR-A6 domain reduced adenovirus type-C5 (HAdV-C5) binding and transduction. Expression of murine SR-A6, and to a lower extent human SR-A6 boosted virion binding to human cells and transduction. Virion clustering by soluble SR-A6 and proximity localization with SR-A6 on MPI cells suggested direct adenovirus interaction with SR-A6. Deletion of the negatively charged hypervariable region 1 (HVR1) of hexon reduced HAdV-C5 binding and transduction, implying that the viral ligand for SR-A6 is hexon. SR-A6 facilitated macrophage entry of HAdV-B35 and HAdV-D26, two important vectors for transduction of hematopoietic cells and human vaccination. The study highlights the importance of scavenger receptors in innate immunity against human viruses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoviridae Infections / immunology
  • Adenoviridae Infections / metabolism
  • Adenoviridae Infections / virology*
  • Adenoviruses, Human / immunology
  • Animals
  • Humans
  • Immunity, Innate
  • Lung / immunology
  • Lung / metabolism
  • Lung / virology*
  • Macrophages / immunology
  • Macrophages / metabolism
  • Macrophages / virology*
  • Macrophages, Alveolar / immunology
  • Macrophages, Alveolar / metabolism
  • Macrophages, Alveolar / virology*
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Protein Binding
  • Receptors, Immunologic / genetics
  • Receptors, Immunologic / metabolism*
  • Receptors, Immunologic / physiology*
  • Virus Internalization*

Substances

  • MARCO protein, human
  • Marco protein, mouse
  • Receptors, Immunologic