Rabies virus-induced apoptosis involves caspase-dependent and caspase-independent pathways

Virus Res. 2006 Nov;121(2):144-51. doi: 10.1016/j.virusres.2006.05.002. Epub 2006 Jun 30.

Abstract

Previously, it has been shown that the laboratory attenuated rabies virus CVS-B2C, but not the wild-type virus SHBRV, induces apoptosis in mice and the induction of apoptosis is mediated by viral glycoprotein. Induction of apoptosis by CVS-B2C limits the spread of the virus in the CNS. In the present study, we characterized the pathways by which CVS-B2C induces apoptosis. BSR cells were infected with CVS-B2C or SHBRV and harvested at different time points for detection of apoptosis by immunofluorescence and flow cytometry. Apoptosis was detected only in cells infected with CVS-B2C, but not SHBRV. Caspase activity and expression of several apoptotic proteins were analyzed by fluorometric assay and Western blotting. Activation of caspase-8 and -3, but not of caspase-9, was observed in CVS-B2C-infected cells. In addition, the level of expression of Apaf-1 did not change. Furthermore, PARP was cleaved confirming activation of downstream caspases. All these data suggest that CVS-B2C infection activates the extrinsic, but not the intrinsic, apoptotic pathway. In addition, AIF, a caspase-independent apoptotic protein was up-regulated and translocated from the cytoplasm to the nucleus post-infection, suggesting that apoptosis induced by CVS-B2C also involves the activation of a caspase-independent pathway.

Publication types

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

MeSH terms

  • Animals
  • Apoptosis Inducing Factor / metabolism
  • Apoptosis*
  • Apoptotic Protease-Activating Factor 1 / metabolism
  • Blotting, Western
  • Caspase 3 / metabolism
  • Caspase 8 / metabolism
  • Caspases / metabolism*
  • Collagen / metabolism
  • Cricetinae
  • Flow Cytometry
  • In Situ Nick-End Labeling
  • Rabies / virology*
  • Rabies virus / physiology*
  • Up-Regulation

Substances

  • Apoptosis Inducing Factor
  • Apoptotic Protease-Activating Factor 1
  • Collagen
  • Caspase 3
  • Caspase 8
  • Caspases