Transcriptome profiles of mouse and human monocyte and dendritic cell subsets (human data)

Dendritic cells (DCs) are critical in mediating immunity to pathogens, vaccines, tumors and tolerance to self. Significant progress has been made in the study of DC subsets in murine models but the translation of these findings to human DC immunobiology has not been fully realized. Murine splenic CD8+ DC and CD103+ DC possess potent antigen cross-presenting capacity. Although recent evidence points to human blood CD141+ DCs as the functional equivalent of CD8+ DC, the precise identity of the human migratory cross-presenting DC has remained elusive. We performed phenotypic and functional analyses to interrogate the DC compartment of human non-lymphoid tissues and identified three distinct subsets: i) CD141high DCs, ii) CD1c DCs and iii) CD14+ DCs. Only CD141high DCs were capable of cross-presenting soluble antigen. Comparative transcriptome analysis of steady state monocyte and DC subsets between mouse and human confirmed conservation between species, aligning the following subsets together: i) human CD141high DCs with mouse CD8+ and CD103+ DCs, ii) human CD1c+ DCs with mouse CD4+ DCs and iii) human CD14+ DC with mouse monocyte subsets. The lack of positive association between human CD1c+ DCs and mouse non-lymphoid tissue CD11b+ DCs highlights heterogeneity and predicts the existence of a monocyte-like cell within the CD11b+ DCs.