Dendritic cells (DCs) comprise two functionally distinct subsets: plasmacytoid DCs (pDCs) and myeloid DCs (mDCs). pDCs are specialized in rapid and massive se- cretion of type I interferon (IFN-I) in response...Dendritic cells (DCs) comprise two functionally distinct subsets: plasmacytoid DCs (pDCs) and myeloid DCs (mDCs). pDCs are specialized in rapid and massive se- cretion of type I interferon (IFN-I) in response to nucleic acids through Toll like receptor (TLR)-7 or TLR-9. In this report, we characterized a CD56^+ DC population that express typical pDC markers including CD123 and BDCA2 but produce much less IFN-I comparing with pDCs. In addition, CD56^+ DCs cluster together with mDCs but not pDCs by genome-wide transcriptional profiling. Accordingly, CD56^+ DCs functionally resemble mDCs by producing IL-12 upon TLR4 stimulation and priming naive T cells without prior activation. These data suggest that the CD56^+ DCs represent a novel mDC subset mixed with some pDC features. A CD4^+CD56^+ hematological malignancy was classified as blastic plasmacytoid dendritic cell neoplasm (BPDCN) due to its expression of characteristic molecules of pDCs.However, we demonstrated that BPDCN is closer to CD56^+ DCs than pDCs by global gene-expression pro- filing. Thus, we propose that the CD4^+CD56^+ neoplasm may be a tumor counterpart of CD56^+ mDCs but not pDCs.展开更多
文摘Dendritic cells (DCs) comprise two functionally distinct subsets: plasmacytoid DCs (pDCs) and myeloid DCs (mDCs). pDCs are specialized in rapid and massive se- cretion of type I interferon (IFN-I) in response to nucleic acids through Toll like receptor (TLR)-7 or TLR-9. In this report, we characterized a CD56^+ DC population that express typical pDC markers including CD123 and BDCA2 but produce much less IFN-I comparing with pDCs. In addition, CD56^+ DCs cluster together with mDCs but not pDCs by genome-wide transcriptional profiling. Accordingly, CD56^+ DCs functionally resemble mDCs by producing IL-12 upon TLR4 stimulation and priming naive T cells without prior activation. These data suggest that the CD56^+ DCs represent a novel mDC subset mixed with some pDC features. A CD4^+CD56^+ hematological malignancy was classified as blastic plasmacytoid dendritic cell neoplasm (BPDCN) due to its expression of characteristic molecules of pDCs.However, we demonstrated that BPDCN is closer to CD56^+ DCs than pDCs by global gene-expression pro- filing. Thus, we propose that the CD4^+CD56^+ neoplasm may be a tumor counterpart of CD56^+ mDCs but not pDCs.