A transforming growth factor–β–induced protein stimulates endocytosis and is up-regulated in immature dendritic cells

Abstract

Dendritic cells (DCs) exhibit distinct functional properties at immature and mature states. To identify genes preferentially regulated in monocyte-derived immature DCs (imDCs), 13 000-element microarrays were hybridized with RNA isolated from imDCs, mature DCs (mDCs), monocytes, and macrophages and a TGF-␤-induced protein (␤ig-h3) was identified as being most prominently up-regulated in imDCs. By polymerase chain reaction (PCR), little ␤ig-h3 mRNA was detected in monocytes and macrophages, but it was abundant in imDCs. On DC activation with LPS, ␤ig-h3 mRNA became diminished, and in tissues, ␤ig-h3 mRNA was abundantly expressed in lymphoid-rich tissues such as the spleen, bone marrow, small intestines, and colon. ␤ig-h3 was expressed in 293T cells and purified as a 70-kDa protein and, by Western blotting, ␤ig-h3 was predominantly detected in the medium of imDCs. We demonstrate that ␤ig-h3 binds to macrophages and imDCs but not to mDCs and activates the Rac GTPase in macrophages, stimulating macrophage membrane ruffling and enhancing macrophage endocytosis. imDC endocytosis was also inhibited by purified anti-␤ig-h3 antibodies. Therefore, ␤ig-h3 appears to be selectively up-regulated in imDCs to regulate antigen uptake through endocytosis. (Blood. 2006;107:2777-2785)

MicroRNA Quantitation During Dendritic Cell Endocytosis Using Imaging Flow Cytometry: Key Factors and Requirements

“…1B). The results showed that DCs cultured without LPS had relatively lower internalization ratios, in contrast to the previously published findings for proteins [28,29]. However, most DCs cultured with LPS had relatively higher internalization ratios (Fig.…”

Effects of porcine epidemic diarrhea virus on porcine monocyte-derived dendritic cells and intestinal dendritic cells

“…In addition, immature Mo-DCs are more susceptible than mature Mo-DCs to infection by CV777. Endocytosis in immature Mo-DCs is significantly higher than in mature Mo-DCs (Cao et al, 2006), and the major receptor Aminopeptidase N (CD13) (Hansen et al, 1998) in immature Mo-DCs occurs at a higher level than in mature Mo-DCs. These may be the reasons why immature Mo-DCs are more susceptible than mature Mo-DCs to CV777.…”

Polymorphonuclear Neutrophil-Derived Ectosomes Interfere with the Maturation of Monocyte-Derived Dendritic Cells

“…Recently, ␤ig-h3, a protein expressed by iDCs and macrophages, has been shown to be involved in phagocytosis and suppressed during maturation of DCs. Whether PMN-Ect suppress the expression/production of ␤ig-h3 remains an intriguing hypothesis (39). The comparisons between the expression of costimulatory and HLA class II molecules on iDCs induced by either apoptotic PMNs or PMN-Ect show divergent trends as well.…”