FIG. 4.

Effects of various virus gene deletions on accumulation of cell surface MHC class II in infected CIITA-transfected U373-MG cells. Replicate 25-cm² flask cultures of His16 (A) or His 28 (B) cells were mock infected or exposed to 10 PFU of the indicated viruses per cell. The genes disrupted in each virus strain are indicated above the bars. At 14 h after infection, cells were harvested, fixed in paraformaldehyde, and analyzed for cell surface MHC class II expression by FACS. MHC class II cell surface mean fluorescence values are shown for cells reacted with PE-conjugated anti-HLA-DR.