Figure 4
Humanized 4C2 (4C2h) sustains similar neutralizing activity and biochemical characters to 4C2. (A) SPR analysis of the MERS-RBD binding to 4C2h. The kinetic profile is shown. (B) Flow cytometric assay showing the blocking by 4C2h of the binding between MERS-RBD and hCD26 on the cell surface. (C, D) In vitro neutralization tests of 4C2h using the pseudotyped (C) and the live (D) viruses. The non-neutralizing antibody 2H8 or an irrelevant antibody L2 was used as the negative controls. The data are from four independent experiments, and mean ± SD is presented. (E, F) Protective efficacies of 4C2h in vivo. Ad5-hCD26-transduced BALB/c mice were treated intravenously with a single dose of antibody one day before (E) or after (F) the MERS-CoV challenge. Virus titers in the lungs were measured at 3 and 5 dpi and are expressed as PFUs per gram of lung tissue. n = 3 mice/group. *P< 0.05. LOD represents limit of detection.
