Figure 4.

Inhibition of CD38 enzymatic activity by a natural anthocyanin. Cells were infected with respiratory syncytial virus (RSV) [multiplicity of infection (MOI) of 1] for 2 hr. Where indicated, some samples were pretreated with kuromanin (100 μ m) for 20 min. Mock‐infected cells were added as control. After infection, cells were washed, incubated in fresh medium and, where indicated, kuromanin was re‐added. (a) RSV‐infected monocyte‐derived dendritic cells (MDDCs), at 20 hr, were harvested and incubated with 0·1 mm NGD ⁺. Generation of ADPR was measured by high‐performance liquid chromatography (HPLC). Quantitative measurements were inferred by comparing the peak area of the samples with the calibration curve for peak area of standard compound. Values were expressed as the percentage of the peak area and are the mean ± standard error of the mean (SEM) of three independent experiments. (b) RSV‐infected MDDCs were harvested at the indicated time‐points, and total RNA was extracted. The kinetics of mRNA expression for all genes analysed was evaluated by real‐time quantitative reverse transcription–polymerase chain reaction (qRT–PCR). The mRNA transcripts were normalized with respect to the endogenous reference sample. Data were expressed as fold increase versus mock‐treated cells at 4 hr and are mean ± SEM of five experiments. (c) RSV‐infected MDDCs were collected at 20 hr p.i. and viral copies for each sample were determined byRT –PCR (mean ± SEM of two experiments).