FIGURE 6.

Effect of CRAC/Orai1 channel blocker (BTP2) on intracellular Ca²⁺. CD4⁺ T cells of wild type mice were preincubated with BTP2 (10 μM) for 1 h, after which cells were washed and coincubated with Fluo-4 AM (3 μM) and Rhod-2 AM (2.5 μM) for 30 min, and the mitochondrial-to-cytosolic Ca²⁺ ratio was determined. A, Amplitude of intracellular Ca²⁺ response at the IS with BTP2 in wild type CD4⁺ T cells after a 15 min coculture with Hybridoma 145-2C11 APCs (n = 15–19 cells, 15–30 min following IS formation). B, Amplitude of total intracellular Ca²⁺ response with BTP2 in wild type CD4⁺ T cells. C, Comparison of relative mitochondrial-to-cytosolic Ca²⁺ ratio at the IS versus total cell in wild type CD4⁺ T cells (n = 35 cells). *p < 0.05.