Fig. 2.

SARS-CoV-2 replication in NP is non-productive. (A) IF staining for SARS-CoV-2, with anti-dsRNA (green), in cryosections of 5 d.p.i. NP (MOI 0.1). Nuclei were counterstained with DAPI (blue). ZIKV-infected NP (MOI 0.5 for 2 h, 3 d.p.i) and SARS-CoV-2-infected CM (MOI 0.1 for 1 h, 2 d.p.i) were used as positive controls for dsRNA labeling and SARS-CoV-2 infectivity, respectively. Scale bar: 50 µm (B) Detection of SARS-CoV-2 SP by WB. Protein extracts from Vero cells (MOI 0.1 for 24 h) were used as positive control. Gel loading was assessed by beta-actin staining. (C) Real-time qRT-PCR of genomic and subgenomic RNA levels of SARS-CoV-2 in the supernatants of NP 5 d.p.i. SARS-CoV-2-infected Vero cells were used for comparison. (D) Plaque forming units’ assay from the supernatants of the NP at 2 and 5 d.p.i (MOI 0.1). Data was plotted as average plus standard error. (E) Multiplex luminex assay for IL-7 and TNF-α from the supernatant of NP collected 5 d.p.i. (*p < 0.05, **p <  0.01). Collected data corresponds to an exposure of NP from 3 different cell lines (Table 1) to SARS-CoV-2 (PANGO lineage B.1, Nextstrain clade 20C) in one experimental infection. Each donor data point corresponds to the average of a duplicate technical measurement and is connected within the different experimental groups (cell lines). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)