FIG. 2.

Blockade of CTLA-4 at the time of immunization with HKC results in a significant increase in the numbers of neutrophils that infiltrate the CneF-injected sponges. The experimental design is similar to that described in the legend to Fig. 1, but the mice in this experiment were treated intraperitoneally with either anti-CTLA-4 IgG or control IgG 1 day before immunization, the day of immunization, and days 1 through 5 after immunization with HKC, CneF-CFA, or saline-CFA. Cells were collected from the sponges and stained with GR-1-FITC 24 h after injection of the sponges with saline or CneF. Flow cytometric analysis was done on the cells collected from the sponges.