Fig 2: Live SARS-CoV-2 Specifically Infects ChP Epithelium(A) 1 day post-infection (dpi) of day 110 ChP organoids with either live SARS-CoV-2 or mock and staining for two independent antibodies (Abcam ab252690 spike glycoprotein in magenta and GeneTex GTX632604 in green) directed to the viral spike protein. Specific staining is only seen in the SARS-CoV-2 infection condition, with co-staining for ACE2 (arrows). Scale bars: 100 µm.(B) Quantification of infected cells staining positive for viral spike protein in ChP tissue infected with SARS-CoV-2 (n = 3 independent infections) compared with mock (n = 2 independent infections). Data are shown as mean with error bars representing SD.(C) Staining for viral spike protein in mixed identity day 117 telencephalic organoids at 1 dpi showing staining only in ChP tissue. Scale bar: 100 µm.(D) Staining for viral spike protein in day 124 mixed identity telencephalic organoids displaying adjacent cortical and ChP tissues at 2 dpi and 4 dpi. Scale bars: 100 µm.(E) Staining for viral spike protein in pure day 48 cortical organoids infected with either SARS-CoV-2 or mock showing no specific staining in either condition. Scale bars: 100 µm.(F) Staining for viral spike protein in day 156 ALI-COs infected for 2 days with 10 times the dose used for ChP or mixed-identity organoids. Note sparse staining of a neuron (white arrow) that is positive for MAP2 and a glial cell (yellow arrow) that is positive for GFAP. Scale bars: 50 µm.

Fig 3: Fluorescence microarray images illustrating binding of monoclonal antibodies to the CoV SeroAssay. (a) CR3022 SARS-CoV-1 antibody from Creative Biolabs binding to the nCoV(ii) and SARS antigens, (b) 40021-MM07 HKU1 antibody from Sino Biological binding to HKU1 antigen, (c) 40069-MM23 MERS antibody from Sino Biological binding to the MERS antigen, and (d) GTX632604 SARS-CoV-2 antibody from Genetex binding to the nCoV(i) and nCoV(iii) antigens.

Fig 4: Spike from Omicron-BA.1 and Omicron-BA.2 incorporate less efficiency into viral particles relative to hCoV-19 and Delta pseudoviruses. A. Concentrated pseudotyped viral particles with the indicated SARS-CoV-2 spike were lysed and equally loaded on an SDS-PAGE gel, followed by western blotting using an a-spike GTX632604 (Genetex) and anti-p24 (NIH repository) antibodies. The lower panel represents a Western blot with p24 for an equal load of viruses. Arrowheads indicate spike proteins. B. Intensity analysis of spike bands using image J, normalized to p24 levels and shown relative to the hCoV-19 spike levels set to 100%. Two independent experiments were performed. Bar graphs show mean values ± SD error bars of two independent experiments. Statistical significance of our study was determined by a two-tailed Student's t-test - P = 0.001. Error bars show standard deviation.