Two subsets of blood, secondary lymphoid organ, non-lymphoid tissue parenchyma classical dendritic cell (cDC) subsets have been identified in humans, which are known as CD1c/BDCA-1+ cDCs and CD141/BDCA-3/Thrombomodulin+ cDCs. CD1c/BDCA-1+ cDCs are the most prominent subset found in human blood, while CD141/BDCA-3/Thrombomodulin+ cDCs represent a very small population. Phenotypically, these two subsets differ not only in the high level expression of either CD1c/BDCA-1 or CD141/BDCA-3/Thrombomodulin, but CD1c/BDCA-1+ cDCs also uniquely express SIRP alpha/CD172a and the chemokine receptor, CX3CR1. In contrast, CD141/BDCA-3/Thrombomodulin+ cDCs uniquely express CLEC9a, IGSF4A/SynCAM1/Necl2, DEC-205/CD205, and the chemokine receptor, XCR1. Both subsets express low levels of CD11b/Integrin alpha M, and lack expression of CD1a and the lineage markers characteristic of other immune cell types including CD3, CD14, CD19, CD20, and CD56. Functionally, CD1c/BDCA-1+ cDCs preferentially activate CD4+ T cells, while CD141/BDCA-3/Thrombomodulin+ cDCs are more proficient at cross-presenting antigens to CD8+ T cells, and promote Th1 cell differentiation and cytotoxic T cell responses.
Human and Mouse Dendritic Cell Subsets Poster