Fig. 2.

CD4⁺ and CD25⁺ cells but not CD8⁺ cells are responsible for enhancement of pulmonary metastasis induced by immunization with SEREX-defined wild-type antigen. BALB/c mice were injected i.p. with anti-CD4 mAb (25-μl ascites, a), anti-CD25 mAb (250 μg, b), or anti-CD8 mAb (25-μl ascites, c) 2 days before tumor challenge. Mice treated with anti-CD4 mAb and anti-CD8 mAb injection were also treated with the respective mAb every 7 days. Mice were injected with 1 × 10⁶ CMS5m cells intravenously. Biweekly immunization with plasmids encoding Dna J-like 2 commenced 5 days after tumor challenge. Pulmonary metastatic nodules were counted with a dissecting microscope 28 days after tumor challenge. Data are mean ± SD; n = 5. These experiments were repeated three times with similar results.