Figure 4

MDSC-inducing cell lines produce increased GM-CSF, IL-6, TNFα, and VEGF. Protein secretion of these cytokines by HNSCC cell lines was measured in supernatants using ELISA techniques to confirm gene expression findings. Mean protein levels shown (two independent experiments each run in triplicate), +SEM. Of note, cell line USC-HN2 was recently established and characterized in our laboratory from a the tumor of a patient with recurrent oral cavity squamous cell carcinoma¹ and found to be a strong producer of immune modulatory factors associated with MDSC induction.