Characterization of dendritic cells in differentiated thyroid cancer.

In this study, the types and localization pattern of dendritic cells (DCs), the expression of chemokines on carcinoma cells and of the relevant receptors on DCs, and the adhesion molecules expressed on vascular endothelial cells and DCs were examined in thyroid carcinomas. Papillary carcinoma had a higher frequency of CD1a(+) immature DCs than other thyroid tumours. Macrophage inflammatory protein (MIP)-3 alpha was expressed strongly on the majority of papillary carcinoma cells and weakly on a minority of follicular carcinoma cells. DCs positive for chemokine receptor-6 (CCR-6) were densely accumulated in papillary carcinoma. DC-SIGN(+) DCs were accumulated in papillary carcinoma but rarely in follicular carcinoma. A binding assay for DC-SIGN-mediated adhesion of isolated DCs revealed significant inhibition of DC adhesion to papillary carcinoma tissues by neutralizing antibodies against intercellular adhesion molecule-2 or DC-SIGN. These results clearly indicated marked differences between papillary carcinoma and follicular carcinoma in the accumulation of immature DCs, in MIP-3 alpha expression on carcinoma cells, and in the frequency of CCR-6(+) DCs and DC-SIGN(+) DCs.