Figure 4.

The effect of phosphonoacetic acid treatment on viral host shutoff and MHC class I down-regulation. H-2^b MEFs were either left uninfected or infected overnight with MHV-68 (10 pfu per cell) and exposed or not to 100 μg/ml phosphonoacetic acid (PAA), starting 1 h before infection. (A) Cells were assayed for total cellular protein synthesis by [³⁵S]methionine labeling, followed by SDS/PAGE of total protein extracts. (B) Cells from parallel cultures were stained for surface MHC class I expression, using anti-H-2K^b (filled curves), or were stained with secondary antibody alone (open curves). Equivalent results of the H-2K^b staining were obtained by using anti-H-2D^b.