Fig. 1 | Signal Transduction and Targeted Therapy

Fig. 1

From: Peptidic defective interfering gene nanoparticles against Omicron, Delta SARS-CoV-2 variants and influenza A virus in vivo

Fig. 1The alternative text for this image may have been generated using AI.

SARS-CoV-2 DIG construction, expression and antiviral activity in cells. a Construction of SARS-CoV-2 DIG (CD2100 and CD3600). Dotted lines show the internal deletion in the wild-type HKU001a (SARS-CoV-2). The three solid-line sequences linked together were inserted into phw2000 vector to generate CD2100 and CD3600. b DIG RNA expression in 293 T, Calu-3 and HK-2 cells (n = 3). After 24 h plasmid transfection, RNA expression in cells was measured by RT-qPCR. c The antiviral activity of DIG (1.0 µg ml−1) in HK-2 cells (n > 6). SARS-CoV-2 (B.1.1.63) was added to DIG-transfected cells for viral replication. At 48 h post infection, the viral titers in cell supernatants were measured by plaque assay. d Does-dependent antiviral activity of CD3600. CD3600 or PHW (1.0 µg, 0.5 µg, or 0.25 µg ml−1) were transfected to HK-2 cells one day before viral infection. Viral titers in cell supernatants were measured at 48 h post infection. e, f Antiviral activity of CD3600 during multi-cycle viral replication after viral passage (n = 3). The supernatant viruses (50 PFU) collected from HK-2 cells, transfected with PHW or CD3600 and then infected with SARS-CoV-2, were passaged in VeroE6-TMPRSS2 (VeroE6-T) cells. The viral titers in supernatants were determined at 24 h and 72 h post infection. g Supernatant CD3600 RNA copies of PHW- and CD3600-treated virus (n = 3) were determined at 72 h post infection. h Representative images of viral particles of PHW- or CD3600-treated SARS-CoV-2. Viruses (50 PFU of PHW or CD3600) were cultured in VeroE6-T and then were harvested at 72 h post infection for RT-qPCR and TEM assay. White arrows indicated the small spherical particles. Black arrows indicated the wild-type virus. Scale bars, 200 nm. i The broad-spectrum antiviral activity of CD3600 (0.5 µg ml−1) against SARS-CoV-2 variants in HK-2 cells (n = 4). PFU (%) was the plaque number of CD3600-treated virus normalized to the plaque number of PHW-treated virus. Data were presented as mean ± SD of independent biological samples. * indicates P < 0.05 and ** indicates P < 0.01. P values were calculated by the two-tailed Student’s t test

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