siRNA-mediated knockdown of Snapin inhibits Ca²⁺ influx and HIV replication.

<p>Jurkat cells that were transfected with Snapin-specific siRNA or control siRNA were suspended in (A) Ca²⁺-free medium with 10 mM EGTA or (B) Ca²⁺-containing medium. After 30 s, OKT3 was added. The FL5/FL4 ratio was monitored using a flow cytometer. (C) NFAT Luc reporter plasmid and pBMN lacZ were transfected into Jurkat cells that were transfected with Snapin-specific siRNA or control siRNA. Cells were treated for 3 hr with or without PHA and PMA prior to measurement of luciferase activity. The experiments were repeated three times; values shown are the average ± SE. Data from cells without treatment were assigned a value of 1 and were used to calculate the fold activation. Transfection efficiencies were normalized to a co-transfected lacZ plasmid. (D) SupT1 cells that were transfected with Snapin-specific siRNA or control siRNA were challenged with replication incompetent HIV-1-Ea. P24^gag levels in culture supernatants were assayed from four wells 48 hr after HIV-1 challenge. P24^gag levels were normalized for cell number using XTT assay. Data are presented as the average ± SE per 10⁶ cells. Similar results were observed in three independent experiments. * indicates <i>p</i><0.05 by <i>t</i> test.