Figure 4. Analysis of BMDCs in tumors recurring after local irradiation in WT/Tie2-GFP-BMT mice.

A, Representative confocal microscopy images of fluorescence immunohistochemistry in tumors recurring after 20Gy of radiation versus non-irradiated size-matched (control) tumors. Note localization of GFP expression (green) in CD11b⁺ cells outside vessels (blue, see arrows) but not in CD31⁺CD11b⁻ vascular endothelial cells (red). B,C, Quantification of BMDCs: Overall myeloid cell infiltration (CD11b⁺) and CD31⁺ microvascular density were not significantly changed, but the total number of Tie2⁺ BMDCs increased in irradiated tumors (B). These represented mostly Tie2⁺CD11b⁺ TEMs, the majority of which were also CD31⁺ but had peri-vascular location; in contrast the number of vessel-incorporated Tie2⁺CD31⁺CD11b⁻ EPCs was negligible and not different in tumors grwoing after irradiation (C). (*denotes p<0.05).