Subsets of CD1c+ DCs: Dendritic Cell Versus Monocyte Lineage

• Main Authors: Lukas Heger, Thomas P. Hofer, Venetia Bigley, I. Jolanda M. de Vries, Marc Dalod, Diana Dudziak, Loems Ziegler-Heitbrock
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2020-09-01
• Series: Frontiers in Immunology
• Subjects: DC2; CD1c; CD172; CD301; CD14; dendritic cells
• Online Access: https://www.frontiersin.org/article/10.3389/fimmu.2020.559166/full

Currently three bona fide dendritic cell (DC) types are distinguished in human blood. Herein we focus on type 2 DCs (DC2s) and compare the three defining markers CD1c, CD172, and CD301. When using CD1c to define DC2s, a CD14+ and a CD14− subset can be detected. The CD14+ subset shares features with monocytes, and this includes substantially higher expression levels for CD64, CD115, CD163, and S100A8/9. We review the current knowledge of these CD1c+CD14+ cells as compared to the CD1c+CD14− cells with respect to phenotype, function, transcriptomics, and ontogeny. Here, we discuss informative mutations, which suggest that two populations have different developmental requirements. In addition, we cover subsets of CD11c+CD8− DC2s in the mouse, where CLEC12A+ESAMlow cells, as compared to the CLEC12A−ESAMhigh subset, also express higher levels of monocyte-associated markers CD14, CD3, and CD115. Finally, we summarize, for both man and mouse, the data on lower antigen presentation and higher cytokine production in the monocyte-marker expressing DC2 subset, which demonstrate that the DC2 subsets are also functionally distinct.