Fig. 2.

S proteins of North/West- and West-African MERS-CoV isolates from dromedary camels efficiently bind to DPP4. 293T cells expressing the indicated S proteins or no S protein at all (Control) were successively incubated with soluble DPP4 containing a C-terminal Fc tag (sol-DPP4-Fc) and AlexaFluor488-conjugated anti-human antibody, before DPP4 binding to the respective S protein was analyzed by flow cytometry. Presented are the combined data of three independent experiments for which sol-DPP4-Fc binding to MERS-S EMC was set as 100%. Error bars indicate the standard error of the mean (SEM). Statistical significance was tested by one-way analysis of variance with Sidak's posttest (p > 0.05, not significant, ns; p ≤ 0.01, **).