Figure 1.

Chemical or biological compounds trigger arthritis in SKG mice. (A) Arthritis scores of 6-mo-old SKG mice maintained in the indicated environment. SPF-born nonarthritic SKG mice were foster nursed to non-SPF BALB/c mice at 7 d of age or transferred to the non-SPF environment at 8 wk of age. (B) 5 × 10⁷ splenocytes, 10⁸ thymocytes, or 5 × 10⁶ BM cells prepared from each nonarthritic SPF SKG mouse were adoptively transferred to individual 6-wk-old nude or SCID mice. BM cells were T cell depleted by treatment with anti–Thy-1, anti-CD4, and anti-CD8 antibodies and rabbit complement before transfer. Arthritis scores 6 mo after transfer are shown. (C) Arthritis scores of SPF SKG mice 5 mo after administration of indicated compounds. SKG mice between 8 and 12 wk of age maintained in the SPF environment were treated as follows: i.p. injection of 2 mg zymosan, 1 μg LPS, 200 μg ConA, 500 μl pristane, 1 mg CP, or 150 μl PBS; i.v. administered with 400 ng PTX on days 0 and 2; i.p. 150 μg poly(I:C) or 150 μl PBS three times per week for 17 wk, 10 nmol CpG or non-CpG once per week for 4 wk; and i.v. with 0.3 mg agonistic anti-CD40 or control rat IgG on days 0, 7, and 14.