Spinoculation triggers dynamic actin and cofilin activity that facilitates HIV-1 infection of transformed and resting CD4 T cells

J Virol. 2011 Oct;85(19):9824-33. doi: 10.1128/JVI.05170-11. Epub 2011 Jul 27.


Centrifugal inoculation, or spinoculation, is widely used in virology research to enhance viral infection. However, the mechanism remained obscure. Using HIV-1 infection of human T cells as a model, we demonstrate that spinoculation triggers dynamic actin and cofilin activity, probably resulting from cellular responses to centrifugal stress. This actin activity also leads to the upregulation of the HIV-1 receptor and coreceptor, CD4 and CXCR4, enhancing viral binding and entry. We also demonstrate that an actin inhibitor, jasplakinolide, diminishes spin-mediated enhancement. In addition, small interfering RNA (siRNA) knockdown of LIMK1, a cofilin kinase, decreases the enhancement. These results suggest that spin-mediated enhancement cannot be explained simply by a virus-concentrating effect; rather, it is coupled with spin-induced cytoskeletal dynamics that promote receptor mobilization, viral entry, and postentry processes. Our results highlight the importance of cofilin and a dynamic cytoskeleton for the initiation of viral infection. Our results also indicate that caution needs to be taken in data interpretation when cells are spinoculated; some of the spin-induced cellular permissiveness may be beyond the natural capacity of an infecting virus.

Publication types

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

MeSH terms

  • Actin Depolymerizing Factors / metabolism*
  • Actins / metabolism*
  • CD4 Antigens / metabolism
  • CD4-Positive T-Lymphocytes / virology*
  • Cells, Cultured
  • Centrifugation / methods*
  • HIV-1 / physiology*
  • Humans
  • Receptors, CXCR4 / metabolism
  • Receptors, HIV / metabolism
  • Up-Regulation
  • Virology / methods*
  • Virus Internalization*


  • Actin Depolymerizing Factors
  • Actins
  • CD4 Antigens
  • CXCR4 protein, human
  • Receptors, CXCR4
  • Receptors, HIV