Fig. 2

CTLA-4-Ig suppresses Staphylococcus aureus-induced CD80 and CD86 levels on B cells in vitro. a Purified CD19⁺ B cells were stimulated with SAC (Staphylococcus aureus Cowan strain, SAC) or anti-IgM (5 μg/ml) plus anti-CD40 (1 μg/ml) antibodies in the presence of CTLA-4-Ig (100 μg/ml) or Ctrl-Ig (100 μg/ml) for 2 days. The expression of CD80, CD86, and CD69 was measured by RT-q-PCR, and GAPDH level was used to normalize the readout. After deducing the value of the medium control, the value of the control-Ig-treated B cells obtained from each donor was considered to be 100% for calculation of the relative level. Each dot represents one donor (n = 7~8). b The effect of CTLA-4-Ig on the level of CD80, CD86, or CD69 on the surface of the B cells was analyzed using flow cytometry (n = 4). The percentage of positive cells in each experiment is shown. c CD19⁺ B cells were stimulated as described in a. After acidic elution to remove bound CTLA-4-Ig, the CD80 and CD86 on the surface of the treated cells were examined using immunofluorescence staining. The percentage of positive cells in each experiment is shown (n = 4)