FIGURE 5.

Expression of ACE2 and TMPRSS2 at the taenia choroidea. (A) Shows a DIC image of the interface between the human choroid plexus of the lateral ventricle and the brain parenchyma (i.e., taenia choroidea), as well as stainings for ACE2 (green), the glial marker GFAP (red), and the nuclear marker DRAQ5 (blue). The white rectangle indicates the location of the high power magnification micrograph showing ACE2 expression in ependymal cells at the ventricular surface. The immunoreactivity for ACE2 is much higher in plexus epithelial cells than in ependymal cells or astrocytic processes. (B) Shows a corresponding section as a DIC image and with stainings for TMPRSS2 (green), the glial marker GFAP (red), and the nuclear marker DRAQ5 (blue). Compared to the strong staining for TMPRSS2 in the plexus epithelial cells, astrocyte processes are weakly stained. All images are single optical sections (pinhole size 1 AU). Scale bars: 50 μm.