CTLA4 blockade and GM-CSF combination immunotherapy alters the intratumor balance of effector and regulatory T cells
J. Clin. Invest. Sergio A. Quezada, et al. 116:1935 doi:10.1172/JCI27745 [Go to this article.]

Figure 3
Gvax/anti-CTLA4 combination therapy induces tumor infiltration and rejection without permanently impairing Treg function. Immunofluorescence microscopy of 8-μm-thick sections from 15-day-old tumors from untreated mice (A and B) and mice treated with Gvax/anti-CTLA4 (C). Tumor sections were fixed in acetone and stained with anti-CD4–FITC (green), anti-CD8–PE (red), and anti-Foxp3⁺ APC (pink). Samples were analyzed with a Leica Microsystems inverted confocal microscope with a ×20 water immersion objective. The data are representative of 3 independent experiments with 3 mice/group. (D) In parallel experiments, mice (n = 10 mice per group) were monitored for tumor growth and rejection upon treatment with Gvax/anti-CTLA4 combination therapy. (E) CD4⁺CD25⁺ Tregs from tumor-draining lymph nodes of Gvax/anti-CTLA4–treated mice or naive mice were tested for their ability to suppress CD4⁺CD25^– T cell proliferation in vitro.