Cytokine secretion by primary T cells in the presence of B7-H2Ig.

(A) Purified T cells were stimulated by precoated high (500 ng/mL) (left panels) or suboptimal doses (40 ng/mL) (right panels) of anti-CD3 mAb in the presence of immobilized B7-H2Ig, B7-H1Ig, or control Ig (5 μg/mL). Anti-CD28 mAb was used at 5 μg/mL in soluble form. Supernatants were collected at the indicated time points after stimulation and assayed for cytokines using sandwich ELISA. (B) Purified T cells were stimulated by precoated suboptimal (40 ng/mL) (right panels) or high doses (500 ng/mL) (left panels) of anti-CD3 mAb in the presence of the indicated concentration of immobilized control Ig or B7-H2Ig. Supernatants were collected at 48 hours after stimulation and assayed for IL-2 and IL-10 using sandwich ELISA.