Table 1

Inhibition of spontaneous metastasis formation by immunization with the soluble B7.2-IgG fusion protein plus irradiated 4T1 tumor cells or by irradiated 4T1 cells expressing the transfected H-2IAd and B7.1 genes (4T1/IA/B7.1)

BALB/c mice were inoculated s.c. with 1 × 105 4T1 breast tumor cells. On day 7, when tumors reach ∼0.5 cm in diameter, mice were inoculated s.c. with murine recombinant B7.2-IgG fusion protein (100 μg) admixed with 4 × 106 irradiated (15,000 r) 4T1 tumor cells (B7.2-IgG/TC) or irradiated 4T1/IA/B7.1 tumor cells. Immunizations were repeated on days 14 and 21. On day 35 of tumor growth mice were sacrificed and lung metastases were counted.

TreatmentNo. of mice per groupMedian no. of metastasis/lung (range)
Control720 (5–37)
B7.2-IgG + TC85 (2–7)a
4T1/IA/B7.194 (0–10)a
  • a Significantly (P < 0.05) differs from the control group according to Mann-Whitney test.