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

Figure 7

Regulating SOD expression in plasma cells promotes anti-CoV Ab induction. (a–f) PCs were isolated from the spleen of immunized mice and treated with additional conditions in the culture as denoted in the figures. CoV: 10 μg/ml. MTL: 1% Maotai liquor (contains 1% alcohol) in culture medium. HS: heat stress by placing cell culture vials in a water bath with indicated temperature for 1 h. Ethanol: 1%. Curves indicate SOD mRNA levels in sPCs (a, b). (c, d) sPCs were gated from the whole PCs. (e) Gated FACS plots show apoptotic sPC counts (Annexin V⁺ or Annexin V⁺ PI⁺). ATN: ATN224 (a SOD1 inhibitor; 3.5 μM). (f) Bars show summarized apoptotic sPC counts from 6 experiments per group. (g) Mice were immunized with CoV/Alum and boosting with CoV weekly for 6 weeks, and the additional conditions denoted in the figure. MTL: mice were gavage-fed with MTL (5 ml/kg of 53% MTL) together with each CoV boosting. HS: mice were treated with HS at each CoV boosting. ATN: mice were treated with ATN224 (4 mg/kg; i.p.) every other day in the entire experimental period. Ethanol: Mice were gavage-fed with ethanol (5 ml/kg of 53% ethanol). Sham HS: Mice were treated with sham HS. Bars show serum CoV-specific Ab levels. (h) Curves show serum CoV Ab levels in mice after CoV immunization and CoV boosting. , compared with the saline group (a, b, h) or with group B (f) or with the immunized alone group (g). ^#, compared with the MTL/HS group (h). Statistical methods: ANOVA followed by Dunnett’s test (a, b) or Bonferroni’s test (f–h). Each group of (g, h) consists of 10 mice.