Fig. 3.

Myeloid-COX-2 KO tumors display a modified immune microenvironment with less suppression of T lymphocytes. Flow cytometric analysis of enzymatically digested spontaneous tumors indicated that total TAM and CD3⁺CD8⁺ CTLs, as a percentage of tumor immune cells, were inversely correlated in (A) spontaneous WT^neu tumors (n = 10) but not in (B) spontaneous myeloid-COX-2 KO^neu tumors (n = 9). Flow cytometry of digested orthotopic tumors revealed (C) reduced TAM density and (D) enhanced T-cell density in myeloid-COX-2 KO host tumors compared with WT hosts (n = 4–6). The proportion of both (E) CD3⁺ CD4⁺ T lymphocyte and (F) CD3⁺ CD8⁺ CTL populations was increased in myeloid-COX-2 KO tumors compared with WT tumors (n = 7). No difference was observed between genotypes in the proportion of CD4⁺CD3⁺ T cells positive for (G) IL-4, (H) interferon γ or (I) FOXP3 (n = 3–4). Data are mean ± SEM. **P < 0.01, n.s. = not significant.