Fig. 2

MMF and MPA inhibited viral RNA levels of HCoV-229E and HCoV-OC43. Cells were infected with HCoV-229E (MOI = 0.35) or HCoV-OC43 (MOI = 0.35), and treated with different concentrations of MMF or MPA for 24 h. a–f The cells were harvested for qRT-PCR assay with specific primers, relative quantification was performed and normalized to the housekeeping gene GAPDH (n = 3). *P < 0.05, **P < 0.01, ***P < 0.001 vs. virus control (Con), one-way ANOVA with Holm-Sidak multiple comparisons test. g–j The cells were fixed and intracellular viral double strand RNA (dsRNA) was detected with immunofluorescence (IF) assay. Green particles represent dsRNA and the blue ones represent cell nucleus. The quantitative study on immunofluorescence was comparison of the total fluorescence values of each experimental group with the control group and analyzed by Image J software