Figure 1.

Human ACE2 detection in the lungs of HIS-DRAGA mice.

(a) Amplified RT-PCR products using hACE2 primers (upper panel) and mACE2 primers (lower panel) on RNA samples extracted from human lung (lane 1), from lungs of four non-infected HIS-DRAGA mice (lanes 2–5), and from lungs of 2 non-HIS-reconstituted DRAGA mice (lanes 6–7). NC, negative RT-PCR control (lane 8). (b) hACE2 protein expression on alveolar and bronchiolar epithelia as indicated by binding of S1 (RBD)-mFcγ2a recombinant chimeric protein revealed by a goat anti-mouse IgG-FITC conjugate in lung sections from two HIS-DRAGA male mice and one HIS-DRAGA female mouse. Lower panels show S1 (RBD)-FITC staining, and upper panels show S1 (RBD)-FITC and DAPI (nuclei) co-staining. Shown are enlargements of alveolar epithelia (right panels). (c) Lung section from human lung stained as in panel b. (d) Lung sections from two non-HIS reconstituted DRAGA mice stained as in panel b.