Cytokine secretion of mB7-H1-stimulated T cells.

(A) NW-purified T cells were cultured with immobilized control immunoglobulin (○) or mB7-H1Ig (▪, 10μg/mL) in the presence of precoated anti-CD3 (2μg/mL). The mAb to CD28 (▵, 2.5 μg/mL) was used in soluble form. Supernatants were collected at days 1, 2, and 3 on the culture, and indicated cytokine concentrations in the supernatants were determined by sandwich ELISA (Pharmingen). Data represent one experiment of 3. Error bars represent the SD of the mean of triplicate T-cell culture wells. (B) Effect of B7-H1 costimulation on IL-2 production. The levels of IL-2 were determined in the supernatants, in which purified T cells were cultured in the presence of 2.5 μg/mL anti-CD28, 10 μg/mL mB7-H1Ig, or anti-CD28 plus mB7-H1Ig (♦) in the precoated plate with immobilized anti-CD3 (1 μg/mL). Supernatants were collected at 18, 24, 36, and 48 hours, and IL-2 concentrations in the supernatants were determined by sandwich ELISA. Data present one experiment of 3. Error bars represent the SD of the mean of triplicate T-cell culture wells.