siRNA directed at Gβ₁ but not Gβ₂ enhances TCR-stimulated IL-2 mRNA increases in Jurkat cells.

<p>Expression of Gβ mRNAs in primary naïve (A) and memory (B) human CD4⁺ T cells grown in TH1 or TH2-promoting conditions, and Jurkat T cells (C) treated with Gβ₁ siRNA (si β₁) or NT siRNA (si NT). The primary cells and, where indicated, the Jurkat cells, were stimulated with plate-bound anti-CD3 and soluble anti-CD28 for three days in the presence of the indicated siRNAs. Values represent means ± SE (N = 3). (D) Representative immunoblot (left) and quantification (right) of the effects of Gβ₁ and Gβ₂ siRNAs on the protein levels of Gβ₁ and Gβ₂ in Jurkat cells. Jurkat cells were treated with the indicated siRNAs for 3 days. Values represent means ± SE (N = 3). (E) Gβ₁ siRNA but not Gβ₂ siRNA potentiated TCR-stimulated IL-2 mRNA increases in Jurkat cells. Jurkat cells were stimulated with plate-bound anti-CD3 and soluble anti-CD28 for 3 days in the presence of the indicated siRNAs. Values represent the means ± SE from 17 experiments. The data were normalized to the values for TCR-stimulated cells treated with NT siRNA. (F and G) A second Gβ₁ siRNA also potentiated TCR-stimulated IL-2 mRNA increases. Values represent the means ± SE from 7 experiments. The data were normalized to the values for TCR-stimulated cells treated with NT siRNA. (F) Gβ₁ mRNA was measured in stimulated cells. All mRNA levels were determined by qPCR. **, <i>p</i> < 0.01; ***, <i>p</i> < 0.001.