Figure 1

Immunohistochemistry of tumor-bearing lungs of mice 24 hours after immunotherapy with either IL-2 alone (left panel) or IL-2 and effector T cells from wt mice (middle panel) or PKO mice (right panel). Lungs were frozen and sections were cut and stained with control IgG, anti-CD4, anti-CD8, anti-NK1.1, anti-MAC-1, or anti-GR-1 Abs.