Figure 1.

Effect of CD3/CD28 costimulation on NO production and Ca²⁺ signaling in T cells from 11 control and 19 lupus donors. NO production was monitored by DAF-FM fluorescence (A) while [Ca²⁺]_c and [Ca²⁺]_m levels were assessed by Fluo-3 (B) and Rhod-2 fluorescence (C), respectively, in CD3⁺/annexin V⁻ cells. D, Detection of CD3⁺/annexin V⁻ cell population with elevated Δψ_m, [Ca²⁺]_c, and [Ca²⁺]_m as well as and NO production. Following CD3/CD28 costimulation, Δψ_m was measured by TMRM fluorescence (FL-2); [Ca²⁺]_c and [Ca²⁺]_m levels were assessed by Fluo-3 (FL-1) and Rhod-2 fluorescence (FL-2), while NO production was monitored by DAF-FM fluorescence (FL-1) gated on CD3⁺/annexin V⁻ cells. Values in dot plots indicate mean channel FL-1 and FL-2 fluorescence, respectively. Results are expressed as RF values with respect to those of unstimulated cells normalized at 1.0 (100%). Data present mean ± SE. Error bars are occasionally covered by data symbols. Values of p reflect differences between 19 lupus and 11 control donors.