Adeno-associated virus 2 infection requires endocytosis through the CLIC/GEEC pathway

Cell Host Microbe. 2011 Dec 15;10(6):563-76. doi: 10.1016/j.chom.2011.10.014.

Abstract

Adeno-associated viruses (AAVs) are nonpathogenic, nonenveloped, single-stranded DNA viruses in development as gene therapy vectors. AAV internalization was postulated to proceed via a dynamin-dependent endocytic mechanism. Revisiting this, we find that infectious endocytosis of the prototypical AAV, AAV2, is independent of clathrin, caveolin, and dynamin. AAV2 infection is sensitive to EIPA, a fluid-phase uptake inhibitor, but is unaffected by Rac1 mutants or other macropinocytosis inhibitors. In contrast, AAV2 infection requires actin cytoskeleton remodeling and membrane cholesterol and is sensitive to inhibition of Cdc42, Arf1, and GRAF1, factors known to be involved in the formation of clathrin-independent carriers (CLIC). AAV2 virions are internalized in the detergent-resistant GPI-anchored-protein-enriched endosomal compartment (GEEC) and translocated to the Golgi apparatus, similarly to the CLIC/GEEC marker cholera toxin B. Our results indicate that-unlike the viral entry mechanisms described so far-AAV2 uses the pleiomorphic CLIC/GEEC pathway as its major endocytic infection route.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Cell Line
  • Clathrin / metabolism*
  • Dependovirus / physiology*
  • Endocytosis*
  • Endosomes / metabolism
  • Endosomes / virology*
  • Golgi Apparatus / metabolism
  • Golgi Apparatus / virology*
  • Humans
  • Parvoviridae Infections / metabolism
  • Parvoviridae Infections / physiopathology*
  • Parvoviridae Infections / virology
  • Protein Transport
  • Virus Internalization

Substances

  • Clathrin