Human rOPN increases RSV titers in a dose-dependent manner.

<p>(A) HEK-293 cells were treated with increasing concentrations of human recombinant OPN (rOPN) (0 to 200 ng/ml) four hours before infection. Cells were infected with 0.1 MOI of RSV-L19F and infectious media was replaced with fresh media containing the appropriate concentration of rOPN. Supernatants were collected 24 hpi and viral titers were determined by plaque assay. (B) HEK-293 cells were treated with 100 ng/ml at different time points: before, during or immediately after the infection. Supernatants were collected 24 hpi and viral titers were determined by plaque assay. Result of a representative experiment is shown. * p < 0.05, ** p < 0.01, **** p < 0.0001. (C) Hep-2 or HEK-293 cells were infected with 0.1 MOI of RSV-KL19F or RSV-KL19F in the presence of 100 ng/ml of rOPN. After 24 hours, the infected HEp-2 or HEK-293 cells were gated for RFP-expression (RSV + cells).