Superoxide Dismutase Prevents SARS-CoV-2-Induced Plasma Cell Apoptosis and Stabilizes Specific Antibody Induction

Figure 3

Assessment of CoV-exposure-induced sPC apoptosis. (a, b) Plasma cells were isolated from CoV-immunized mouse spleen by FACS and cultured in the presence of CoV (1 μg/ml) for 24 h to activate sPC (a, b). (c) sPC, ACEd-PC, and nPC were exposed to CoV or saline in the culture for 24 h as denoted above each subpanel. Gated FACS plots show apoptotic sPC frequency. ACE2d: ACE2-deficient plasma cells (from ST2-deficient mice); nPC: plasma cells were isolated from the naïve mouse spleen; CoV/Ab: CoV and CoV Ab were mixed at a ratio of 1 : 1 before adding to the culture. (d) Violin plots show summarized apoptotic sPC counts. (e) sPCs were analyzed by RNAseq. Heatmap shows apoptotic related gene activities in plasma cells. The data of each row were obtained from one sample. (f–j) sPC protein extracts were analyzed by Western blotting. Immunoblots show indicated protein levels. (k) Immunoblots show plasma cells express ACE2, the CoV receptor. (ANOVA followed by the Dunnett’s test), compared with group A. The group labels in (b) are the same as those in (a). The data represent 6 independent experiments.