Figure 3.

Antibody targeting of PTCH1 blocks influenza infection. Antibody binding to the surface of (A) control or (B) influenza-infected MDCK cells was evaluated using flow cytometry. PTCH1 staining (brown) is selectively exposed on the surface of influenza-infected cell. Matched isotype controls (green) and influenza-hemagglutinin (Blue) antibodies provided controls negative and positive controls for staining, respectively. (C) MDCK cells were infected with influenza A/Udorn/72 in the presence of absence of PTCH1 antibodies (brown bars) or isotype-matched control antibodies (green). Note that the antiviral effects of PTCH1 antibodies are more prominent at a low multiplicity of infection (MOI), suggesting PTCH1 antibodies inhibit a late stage of the viral life cycle.