Current Approaches on Viral Infection: Proteomics and Functional Validations

Zheng, Jie; Tan, Boon Huan; Sugrue, Richard; Tang, Kai

To functionally study host proteins associated with virions, siRNA-mediated transcript knockdown is utilized to validate the roles of host proteins involved in virus infection. In one study, highly purified RSV particles were analyzed by proteomic approach, and a total of 25 host proteins were identified to be associated with virions (Radhakrishnan et al., 2010) . Among those cellular components, two heat shock proteins, e.g., hsc70 and hsp90, were further selected to examine their effects on virus infection. RSV-infected cells were transfected with either sihsc70 or sihsc90 at 20 hpi. The transfected cells were then fixed and stained with anti-hsc70, anti-hsc90, and antiviral fusion protein (anti-F). In both the sihsc70 and sihsc90 treated groups, obvious reductions in hsc70 and hsp90 staining signals visualized by immunofluorescence imaging were observed, accompanying with decreased viral fusion protein expression. In another study, Spurgers et al. (2010) applied LC-MS/MS and siRNA screening to identify and validate the host proteins associated with Filoviruses (ebola viruses and marburgvirus). The specific knockdown of HSPA5 and ribosomal protein L18 (RPL18) greatly affected ebola virus and marburgvirus infection. qRT-PCR was also applied to confirm the reduced host gene expressions at the transcript level.