Toll-like receptor interference in myeloid dendritic cells through head and neck cancer

Background: In head and neck squamous cell carcinoma (HNSCC) the secretion of various immunosuppressive mediators contributes to large-scale effects on the immune functions. The influence of HNSCC on the Toll-like receptor (TLR) expression profiles of human myeloid dendritic cells (MDCs), which have been identified in human solid tumor tissue of the head and neck, was analysed. Materials and Methods: MDCs were isolated from peripheral blood by 'magnetic bead separation' and subsequently incubated with supernatants of HNSCC permanent cell lines. TLR expression profiles were investigated using flow cytometry and SDS-PAGE. Results: Human MDC from peripheral blood were found to express all human TLRs except TLR4 and TLR9. Incubation of MDC with supernatants of HNSCC resulted in an increased expression of TLR7. Conclusion: The data suggest an interference of TLR7 expression through HNSCC and provide novel evidence of TLR alterations as a potential tumor promoting event in head and neck cancer.