Fig. 4

Leukocyte infiltration in Renca-MUC1 tumors treated with radiation and vaccine. Tumor sections obtained from the experiment described in Fig. 3 were also stained by IHC for CD45⁺ leukocytes, CD4⁺ T_H cells, and CD8⁺ CTL and cells positive for these markers are shown (arrows). Control tumors showed minimal immune cell infiltration. Radiation showed focal infiltration of CD45⁺, CD4⁺, and CD8⁺ cells. Following radiation and vaccine, a massive infiltration of CD45⁺, CD4⁺, and CD8⁺ cells was observed in areas of tumor destruction. The extent of tumor destruction and immune infiltration was greater with Vaccine + Rad sequence than with Rad + vaccine sequence. All magnifications X40