title: Spinoculation triggers dynamic actin and cofilin activity that facilitates HIV-1 infection of transformed and resting CD4 T cells.
abstract: 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.
authors.affiliation: Department of Molecular and Microbiology, George Mason University, VA 20110, USA.
authors.forename: Jia
authors.initials: J
authors.lastname: Guo
authors.forename: Weifeng
authors.initials: W
authors.lastname: Wang
authors.forename: Dongyang
authors.initials: D
authors.lastname: Yu
authors.forename: Yuntao
authors.initials: Y
authors.lastname: Wu
mesh_terms: D051339:Actin Depolymerizing Factors / Q000378:metabolism*; D000199:Actins / Q000378:metabolism*; D015704:CD4 Antigens / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000821:virology*; D002478:Cells, Cultured; D002498:Centrifugation / Q000379:methods*; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D019718:Receptors, CXCR4 / Q000378:metabolism; D015728:Receptors, HIV / Q000378:metabolism; D015854:Up-Regulation; D014773:Virology / Q000379:methods*; D053586:Virus Internalization
chemical_list: D051339:Actin Depolymerizing Factors; D000199:Actins; D015704:CD4 Antigens; C527276:CXCR4 protein, human; D019718:Receptors, CXCR4; D015728:Receptors, HIV