Role of GM-CSF signaling in cell-based tumor immunization.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a potent adjuvant in cancer vaccination; however, the specific role of endogenous GM-CSF remains unknown. We performed cell-based vaccination in 2 tumor models. First, we vaccinated C57BL/6 mice lacking either GM-CSF, IL-5, or beta-common chain (betac), a receptor subunit essential for GM-CSF and IL-5 signaling, with melanoma cells engineered to produce GM-CSF.