Human parainfluenza virus type 1 regulates cholesterol biosynthesis and establishes quiescent infection in human airway cells
Fig 2
hPIV1, but not hPIV3 establishes quiescent infection in human airway cells.
A549 or HPBE cells were mock-, hPIV1-, or hPIV3-infected at an MOI of 5 and cultured for up to 15 days. (A) Infectious progeny virions released into the medium for 24 h at various time points were titrated (n = 3). *P≤0.05. Accumulated NP proteins in cell lysates at each time point were determined by Western blotting. (B) De novo protein synthesis in A549 cells was determined by radio-immunoprecipitation after 3 h labeling with 35S-Met/Cys at 2 and 15 dpi. Radiolabeled viral HN and NP (or HN and N) were immunoprecipitated with specific mAbs or polyclonal serum. (C) Released and 35S-Met/Cys radio-labeled virus from A549 cells was purified by sucrose gradient centrifugation and analyzed by a Personal Molecular Imager after SDS-PAGE. The same samples were also tested for the presence of NP protein by Western blotting.