Fig. 6.

Treatment of Calu3 cells with HP-BCD inhibit SARS-CoV-2 replication and cytokine production. Calu-3 cells were treated with the indicated concentrations of HP-BCD for 1 h, the cells were washed and then cultured in HP-BCD-free culture medium. A) After 72 h, cell viability was measured using cell-titer blue kit. B) Total cholesterol concentration was measured after 1 h treatment by amplex red reagent. C-E) The cells were treated or not with 20 mM HP-BCD for 1 h, washed, and the medium substituted by culture medium. Then, the cells were infected with SARS-CoV-2 (A2 isolate; MOI of 0.1). After 24 or 48 hpi, and the concentration of virus RNA (N2 log copy numbers; C) or infectious particles (PFU) (D) released in the supernatants were measured by qRT-PCR and plaque assay, respectively. The percentage inhibition of both RNA and PFU released by HP-BCD treated, in relation to untreated cells, was calculated and demonstrated in (E). F) mRNA expression corresponding to IL-6, TNF-α and CCL2 were evaluated in the cell lysates, at 48 hpi, by qRT-PCR; individual mRNA fold induction obtained from infected untreated cells (closed symbols) and infected HP-BCD-treated cells (open symbols), in each individual experiment, are indicated. The data are representative of four independent experiments. * represents p < 0.05; **p < 0.01, according to paired t-test statistical analysis.