Existence of CD8α-Like Dendritic Cells with a Conserved Functional Specialization and a Common Molecular Signature in Distant Mammalian Species

Abstract

Material

The equivalents of human blood and spleen dendritic cell subtypes can be generated in vitro from human CD34+ stem cells in the presence of fms-like tyrosine kinase 3 ligand and thrombopoietin

“…However, it has recently been shown that the CD8 1 cDCs in mouse and the BDCA3 1 cDCs in human blood uniquely express XCR1. 21,31,32 The cultured CLEC9A 1 DC also expressed this molecule (Figure 1d). CLEC9A is therefore unique to spleen and blood CD141 1 DCs 16,24 and was thus used as a marker to distinguish this subset in subsequent experiments.…”

Cutting Edge: Expression of XCR1 Defines Mouse Lymphoid-Tissue Resident and Migratory Dendritic Cells of the CD8α+ Type

“…We focused on Xcr1, Clec9a, Cadm1, Clnk, and Rab7b (5430435G22Rik), because these genes are expressed selectively in CD8a + -type DCs from mouse spleen, human blood, and sheep lymph (4,5). CLEC9A, XCR1, and CADM1 contribute to confer their specific functions on spleen CD8a + DCs by promoting the cross-presentation of dead cell-associated Ags, the priming of CD8 + T cells, and the induction of IL-22 in CD8 + T cells (6,10,15,16).…”

“…This marker, the chemokine receptor XCR1, is also specifically expressed by human blood BDCA3 + DCs and sheep lymph CD26 + DCs and conserved during evolution (5,6). Thus, the community of the researchers working on DCs may consider using the term "XCR1 + DCs" to designate CD8a + -type DCs in a consistent manner across all mammalian species and tissues to further implement the definition of a universal nomenclature for mouse and human DC subsets (19).…”

“…XCR1 was previously described as exclusively expressed on mouse spleen CD8a + DCs and human blood BDCA3 + DCs. In this article, we showed that LT-resident CD8a In mouse skin, DCs make up epidermal Langerhans cells (LCs) and three major subsets of dermal DCs: (4,5) and on their efficiency for Ag cross-presentation (5-9). We proposed a universal classification of DCs in five major subsets irrespective of tissues and species: monocytederived inflammatory DCs, LCs, plasmacytoid DCs, CD11b + -type DCs, and CD8a + -type DCs (1).…”

“…Moreover, the relationships between LT-resident CD8a + DCs and CD103 + mig-DCs or CD103 + int-DCs need to be confirmed. The chemokine receptor XCR1 is specifically expressed by CD8a + -type DCs in mouse spleen, human blood, and sheep lymph (4)(5)(6)(7)10). The function of XCR1 was first unveiled by the group of R. Kroczek (10), who showed that CD8 + T cell cross-priming depends on their ability to secrete the XCR1 ligand XCL1 in experimental models where either the OVA coupled to an anti-CD205 Ab or OVA-expressing allogeneic pre-B cells are administrated in vivo.…”