20-2b2 inhibited the activation of T cells <i>in vitro</i>.

<p>(A–C) The PBMCs of healthy donors were cultured with an anti-CD3 Ab (OKT3) (A), PHA (B), or PWM (C) in the presence (red symbols) or absence (black) of 20-2b2 (50% SN). (D) PBMCs were pre-treated with medium (black) or 20-2b2 (red) at 37°C. Cells were washed three times and cultured with PHA two hours later. Cell proliferation was measured two days later. Values are shown as the mean ± SD of triplicate cultures. Data are representative of more than three (A–C) and three (D) independent experiments. *<i>p</i><0.01, **<i>p</i><0.001 by the Student's <i>t</i>-test.