Head and neck squamous cell carcinomas (HNSCCs) are associated with abnormal cell-mediated immunity at the primary tumor site. We investigated tumor-derived cytokines as factors underlying such abnormalities. Cytokine mRNA and protein of eight HNSCC-derived cell lines were tested; reverse transcription PCR results indicated the presence of mRNAs for interleukin 1 alpha(IL-1 alpha) and transforming growth factor alpha (8 of 8); transforming growth factor beta and IL-1 beta (7 of 8); and IL-4 and IL-6 (4 of 8). IL-2, IFN-gamma and tumor necrosis factor alpha mRNA were not detected. Supernatants from sir of these cell lines were analyzed by ELISA; IL-1 alpha, IL-1 beta, and IL-6 were found to be markedly increased compared to human papillomavirus-16-immortalized human oral keratinocytes. To determine whether the cell line findings are applicable to primary tumors, we performed immunohistochemical analysis on tumor specimens from 12 patients with invasive HNSCC. Universal intracellular production of IL-1 alpha, IL-1 beta, and IL-6 protein was detected. We conclude that the aberrant elaboration of biologically active IL-1 and IL-6 may contribute to altered immune status in HNSCC patients.