Table 1.

Coinjection of tumor-derived Gr1+CD11b+ cells increases incidence of tumor outgrowth in immunodeficient mice

Tumor challengeIncidence of tumor outgrowth (%) *
DoseCancer cells onlyCancer cells and Gr1+CD11b+ cells from tumor-free miceCancer cells and Gr1+CD11b+ cells from tumor-bearing mice
1 × 1040/6 (0)0/8 (0)4/8 (50)
5 × 1041/6 (17)2/8 (25)8/8 (100)
2.5 × 1056/6 (100)8/8 (100)8/8 (100)
  • * C57BL/6 Rag1−/− mice were injected s.c. with PRO4L cells and sorted Gr1+CD11b+ cells at 10:1 ratio at indicated doses from tumor-bearing mice in 200 μL PBS on the back. PRO4L cells alone and Gr1+CD11b+ cells from tumor-free Rag1−/− mice were used as controls. Tumor outgrowth was assessed 30 d after tumor challenge. The data were pooled from two independent experiments.

  • P < 0.05, compared with the groups “Cancer cells only” or “Cancer cells and Gr1+CD11b+ cells from tumor-free mice” at a dose of 5 × 104.