Figure 2

Accumulation kinetics and quantification of iNOS⁺subset (P1a). A. Primary tumors were 400 mm³ in size when they were harvested and weighed. The absolute numbers of tumor-infiltrating leukocytes were determined by flow cytometry. Results are expressed as the average number of cells per gram of tumor tissue and were obtained from two separate experiments with 4–5 mice. Error bars represent mean and SD B. To determine the time course of expansion of the iNOS⁺ cell subset in the tumor and spleen, mice with various tumor sizes (from 50 mm³ to 400 mm³) were sacrificed and the absolute number were calculated per gram of tumor tissue or per spleen. C. In all of the tested samples the iNOS⁺ cell subset (gated on R1 + R2) was identified as CD11b⁺ Gr-1^dim cells (R2) within SSC^hi subfraction (R1). D. The quantification of the iNOS⁺ cell subset was carried out following the gating strategy shown in C. Error bars = SD, n = 4–5 mice per group. The above experiments were repeated twice with similar results.