Human Skin Dendritic Cell Subsets Overview
In normal human skin, four phenotypically distinguishable CD11c+MHC class II+ subsets of dendritic cells have been characterized. These include epidermal Langerhans cells, CD14+ dermal dendritic cells, CD1a+CD1c/BDCA-1+ dermal dendritic cells, and CD1a+CD141/BDCA-3+ dermal dendritic cells. The largest population of human dermal dendritic cells is the CD1a+CD1c/BDCA-1+ subset, which is the human counterpart of mouse CD11b+Langerin/CD207- dermal dendritic cells. CD1a+CD1c/BDCA-1+ dermal dendritic cells are commonly identified based on the expression of CD1a, CD1c/BDCA-1, SIRP alpha/CD172a and CD11b/Integrin alpha M, and lack of expression of CD14 and CD141/BDCA-3. In contrast, human CD1a+CD141/BDCA-3+ dermal dendritic cells are the least abundant subset and are considered to be the human counterpart of mouse CD11b-Langerin/CD207+CD103/Integrin alpha E+ dermal dendritic cells. Similar to CD1a+CD1c/BDCA-1+ cells, CD1a+CD141/BDCA-3+ dendritic cells express high levels of CD1a, CD11b/Integrin alpha M, and SIRP alpha/CD172a, and lack expression of CD14, but they also express high levels of CD141/BDCA-3 and are the only human dermal dendritic cell subset that expresses XCR1, CLEC9a, and IGSF4A/SynCAM1/Necl2. This subset of dermal dendritic cells has been reported to be particularly efficient at priming CD8+ T cells. Like the two previously described subsets of dermal dendritic cells, human epidermal Langerhans cells also express high levels of CD1a and lack expression of CD14. Additionally, they also express Langerin/CD207 and are the only dendritic cell subset in the human skin to express EpCAM/TROP1 and E-Cadherin. The final dendritic cell subset found in human skin is the CD14+ subset. These cells lack expression of CD1a and express high levels of CD14. Together, the presence of multiple dendritic cell subsets in the skin are thought to allow subset-specific functional specialization under different conditions or in response to distinct stimuli.
Human and Mouse Dendritic Cell Subsets Poster