FIG. 7.

Effect of overexpression of CD147 on MeV infection in CHO-K1 cells. (A) Expression of human CD147 on CHO/CD147 cells was confirmed by flow cytometry with anti-human CD147 antibody. (B) CHO/CD147 and CHO/pCAG cells (3 × 10⁴ cells each) were incubated with MeV-EGFP at an MOI of 4.0 at 37°C for 1 hour. The MOI corresponded to that estimated for B95a cells. After the incubation, cells were washed three times with medium containing fusion block peptide. At 48 hpi, cells were observed by confocal fluorescence microscopy. (C) CHO/CD147 and CHO/pCAG cells (3 × 10⁴ cells each) were incubated with MeV-EGFP at an MOI of 1.0 at 37°C for 1 hour. After incubation, the cells were washed thrice with a medium containing fusion block peptide. At 48 hpi, we counted the number of GFP-positive cells by using a confocal fluorescence microscope. Data are means plus SEM. *, P = 0.0004 (Student's t test). (D) CHO/CD147 and CHO/pCAG cells (3 × 10⁴ cells each) were incubated with MeV-luc at an MOI of 4.0 at 37°C for 1 hour. After the incubation, cells were washed three times with medium containing fusion block peptide. The luciferase activity of infected cells was measured at 48 hpi. The white and black bars represent the infectivities to CHO/pCAG and CHO/CD147 cells, respectively. Luciferase assays were performed in triplicate. Data are means plus SEM. *, P = 0.022 (Student's t test). (E) CHO/CD147 and CHO/pCAG cells (3 × 10⁴ cells each) were incubated with MeV-luc in the presence of anti-CD147 antibody at an MOI of 4.0 at 37°C for 30 min. After the incubation, cells were washed three times with medium containing fusion block peptide. The luciferase activity of infected cells was measured at 48 hpi. The white and black bars represent the infectivities to CHO/pCAG and CHO/CD147 cells, respectively. (−), infection without antibody, as a negative control; (+), infection with anti-CD147 antibody. Luciferase assays were performed in triplicate. Data are means plus SEM. **, P = 0.035 (Student's t test).