Fig. 3.

Nucleolin increases viral protein and replication. A. Western blot determination, in triplicate, of NCL and viral proteins in Caco-2 cells control and NCL-KD infected with mock and SARS-CoV-2 (MOI 0.01) for 48 h. β-actin: loading control. B. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), using primers against N-protein, to determine the viral titer in the supernatant of Vero E6 and Caco-2 control and NCL-KD cells at the indicated time points, following SARS-CoV-2 infection (MOI 0.001). Four independent infection experiments and qRT-PCR were performed. C. Cell titer glow assay, in triplicate, to determine cell viability at 48h of Vero E6 control and NCL-KD cells (1 × 10⁴ cells/well in 96 well plate) following viral infection (MOI 0.001 and 0.01). The viral inoculums were removed after 1 h of incubation in both replication and survival assays. Cell viability is represented as percentage relative to non-infected cells. The student t-test was performed. NS: not significant. *P < 0.05, **P < 0.01 and ***P < 0.001.