Fig. 5: MERS-CoV pseudotyped viruses are permissive in cells stably expressing ΔcytDPP4.
HEK293T stable cell lines expressing either full-length DPP4 ((HEK293TwtDPP4) or cytoplasmic tail-deleted DPP4 (HEK293TΔcytDPP4) were used to assess. a Cell surface expression and MERS-CoV S1 binding (scale bar = 50 µm), b Expression levels of wtDPP4 and ΔcytDPP4 by Western blot, and (c) confirmation of the cytoplasmic tail deletion in ΔcytDPP4 using reverse transcription PCR (RT-PCR) with two distinct primer sets, “Set1” primers were designed to amplify the both full-length DPP4 and ΔcytDPP4 sequence, while “Set2” primers include a forward primer binding site located immediately downstream of the cytoplasmic tail region, allowing amplification only of ΔcytDPP4. d Dual staining of ΔcytDPP4 (red) and SARS-CoV-2 spike S1 protein (green) to visualize colocalization (yellow), white square indicates zoomed area, scale bar = 10 µm. e Dual staining of ΔcytDPP4 (red) and MERS-CoV spike S1 protein (green) to visualize colocalization (yellow), white square indicates zoomed area, scale bar = 10 µm, (f) and (g) Percentage of relative pseudovirus infection in HEK293TwtDPP4 and HEK293TΔcytDPP4 stable cell lines and cells transiently expressing wtDPP4 or ΔcytDPP4 respectively, N = 3, bar graphs represent mean ± SD, ns non-significant, * p < 0.05; ** p < 0.01; *** p < 0.001.
