The adhesion molecules, l-selectin and sialyl lewis x, relate to the formation of the follicular dendritic cell-lymphocyte cluster in the mantle zone

Glycosyltransferase and sulfotransferase gene expression profiles in human monocytes, dendritic cells and macrophages

Using a focused glycan-gene microarray, we compared the glycosyltransferase (GT) and sulfotransferase gene expression profiles of human monocytes, dendritic cells (DCs) and macrophages (Mphis), isolated or differentiated from the same donors. Microarray analysis indicated that monocytes express transcripts for a full set of enzymes involved in the biosynthesis of multi-multiantennary branched N-glycans, potentially elongated by poly-N-acetyl-lactosamine chains, and of mucin-type Core 1 and Core 2 sialylated O-glycans. Monocytes also express genes involved in the biosynthesis and modification of glycosaminoglycans, but display a limited expression of GTs implicated in glycolipid synthesis. Among genes expressed in monocytes (90 out of 175), one third is significantly modulated in DCs and Mphi respectively, most of them being increased in both cell types relative to monocytes. These changes might potentially enforce the capacity of differentiated cells to synthesize branched N-glycans and mucin-type O-glycans and to remodel cell surface proteoglycans. Stimulation of DCs and Mphis with lipopolysaccharide caused a general decrease in gene expression, mainly affecting genes found to be positively modulated during the differentiation steps. Interestingly, although a similar set of enzymes are modulated in the same direction in mature DCs and Mphis, cell specific genes are also differentially regulated during maturation, a phenomenon that may sustain functional specificities. Validation of this analysis was provided by quantitative real-time PCR and flow cytometry of cell surface glycan antigens. Collectively, this study implies an important modification of the pattern of glycosylation in DCs and Mphis undergoing differentiation and maturation with potential biological consequences.

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.