Figure 7. In vivo reconstitution of PMNs at the tissue site restores experimental BP in C4^–/– mice.

C4^–/– mice were injected i.d. with pathogenic anti-mBP180 R530 IgG alone or in conjunction with IL-8 (50 ng/injection) or PMNs (5 × 10⁵ cells) and were examined 12 hours after IgG injection. MPO activity assay showed significantly higher levels of PMN recruitment in the lesional skin of WT mice injected with pathogenic IgG, C4^–/– mice coinjected with IL-8, and C4^–/– mice coinjected with PMNs compared with C4^–/– mice injected with pathogenic IgG alone as well as the nonlesional skin of WT and C4^–/– mice injected with control IgG. Tissue MPO activity at the injection sites was expressed as relative MPO activity. Three independent experiments were performed per group. n = 6 per group. **P < 0.01 versus C4^–/– mice injected with pathogenic IgG alone; Student’s t test for paired samples.