Fig 4. LCMV DI particle production is impaired in the absence of a functional PPXY domain.

(A-B) Equivalent PFUs of WT, Z Y88F, Z Y88E, or Z Y88A rLCMV (range 25 to 2.5 x 10⁴ PFUs) were inoculated onto monolayers of Vero E6 cells and a standard plaque assay was performed. Representative images of crystal violet-stained wells are shown in (A). Inhibition of standard infectious virus-induced cytopathic effect by DI particles at each dose was determined by measurement of the mean pixel intensity of each well using Image J software (B). The data in (B) are representative of the mean ± SEM relative to rLCMV WT (at 250 PFU per well) from 3 independent experiments and were tested for statistical significance with a two way ANOVA and Holm-Sidak’s test for multiple comparisons. (B) *p < 0.05; ***p < 0.001; ****p < 0.0001, as determined by the indicated statistical tests.