FIG. 3.

T cells were plated with 5 × 10⁴ homologous macrophages (Mø) per well, in the presence of CTLA4-Ig (5 μg/ml) or of the indicated antibodies (5 μg/ml). Antibodies used in this experiment were as follows: anti-human B7-1 (clone 37711.11), anti-human B7-2 (clone 37301.11), and an isotype-matched normal mouse IgG1 (control IgG1); all antibodies were obtained from R&D Systems. Cells were mock-infected (+Mø alone), stimulated with 10 ng of PMA per ml, or infected with PBj6.6 virus. Results shown are the mean values of three independent observations and are representative of three separate experiments yielding similar conclusions; error bars indicate the standard errors of mean values.