FIG. 2.

Binding of MNV-1 P dimer to murine macrophages is inhibited by the monoclonal antibody A6.2 in a dose-dependent manner. P dimer (+) or buffer (−) (100 μg) was incubated with the indicated concentrations of A6.2 or isotype control (IgG1) for 1 h at 37°C. RAW 264.7 cells (2 × 10⁶), resuspended in host cell medium containing anti-FcγR MAb 2.4G2, were added and incubated for 1 h on ice. Unbound P dimer was washed off, and equal numbers of RAW 264.7 cells were analyzed by SDS-PAGE and Western blotting. (a) Quantitative analysis was performed, measuring the relative intensities of the P-domain-specific bands from three independent experiments. The limit of detection was set to background intensity levels. Statistical analysis was performed using the t test; **, P < 0.01. The error bars indicate standard errors. (b) The P-domain-specific band in a representative Western blot probed with a polyclonal antibody against MNV-1.