Figure 3.

Antiviral response in hPSC-derived pancreatic progenitors after SARS-CoV-2 infection

(A) SARS-CoV-2 virions are produced in pancreatic progenitors. (Left) Replication of virus was evaluated at 72 h post inoculation using RT-qPCR. Data are presented as the mean of viral RNA copies per milliliter ± SEM. (Right) Calculation of TCID₅₀/mL in collected samples by Reed and Muench and Plaque Assay methods. Colors of the dots indicate independent experiments (N = 3) corresponding to the RT-qPCR graph. Titer is presented as mean TCID₅₀/mL ± SEM. (Bottom) Table with TCID50 ± SD values from each replicate.

(B) Heatmap of normalized cytokine and chemokine levels in SARS-CoV-2-infected hPSC-derived pancreatic spheroids compared to the mock control. Protein levels were measured 24–96 h post infection using Luminex assay. See also Table S1.

(C) CXCL1 and IL-2 protein levels in the cell culture medium of SARS-CoV-2-infected or mock control human pancreatic spheroids at 24–96 h post infection, measured by Luminex. Data are presented as mean ± SEM. The p values were calculated by unpaired two-tailed Student’s t test. N = 4 independent experiments.

(D) Apoptotic cells within SARS-CoV-2-infected (red) pancreatic progenitors. Apoptosis was assessed by cleaved Caspase 3 staining (green) 7 days post infection. DAPI marks nuclei. Maximum intensity projection of image captured by the Zeiss Lightsheet 7 microscope is shown. SARS-CoV-2 Nc+, cleaved CASP3+ double-positive cells are marked by asterisks, and magnified on the right. Scale bar = 50 μM (left) and 10 μM (right panels). N = 3 independent experiments.

(E) Quantification of cleaved Caspase 3+ cells within SARS-CoV-2 Nc+ and non-infected pancreatic progenitors, performed on spheroid images captured by Zeiss Lightsheet 7. Data are shown as mean % cleaved Caspase 3+ cells ±SEM, and unpaired two-tailed t-test was used to count the p-value. N = 3 independent experiments.

(F) Example of multinucleated clusters with strong continuous SARS-CoV-2 nucleocapsid (red) signal, suggesting syncytia formation. Apoptotic cells were observed within these clusters (cleaved CASP3, green, marked by the asterisk). DAPI stains nuclei. Scale bar = 10 μM.