Dendritic Cells (DC) Facilitate Detachment of Squamous Carcinoma Cells (SCC), While SCC Promote an Immature CD16(+) DC Phenotype and Control DC Migration.

In the inflammatory mucosal microenvironment of head and neck SCC (HNSCC), DC express CD16 and are usually in direct contact with tumor cells. Mucosal and inflammation-associated DC develop from monocytes, and monocyte-derived DC are used in HNSCC immunotherapy. However, beyond apoptotic tumor cell uptake and presentation of tumor antigens by DC, HNSCC cell interactions with DC are poorly understood.

Squamous carcinoma cells influence monocyte phenotype and suppress lipopolysaccharide-induced TNF-alpha in monocytes.

Bacteria and chronic inflammation are present in squamous cell carcinoma of the head and neck (HNSCC), but their roles in the pathogenesis of HNSCC are unclear. Our studies described here revealed that human monocytes co-cultured short term with HNSCC cells were more likely to express CD16, and CD16(+) small mononuclear cells were common in HNSCC specimens. In addition, we identified monocytes as the primary source of LPS-induced IL-6 and TNF-alpha in the monocyte-HNSCC co-cultures.