Description
The respiratory system is a complex network of many cell types, including subsets of macrophages and dendritic cels, that work together to maintain steady-state respiration. Due to limitations in acquiring cells from healthy human lung, these subsets remain poorly characterized transcriptionally and phenotypically. We set out to systemically identify these subsets in human airways, by developing a schema of isolating large numbers of cells by whole lung bronchoalveolar lavage. Six subsets of phagocytic antigen presenting cells were consistently observed, which varied in their ability to internalize bacterial particles. Subsets could be further separated by their inherent capacities to upregulate CD83, CD86, and CCR7. Whole genome transcriptional profiling revealed a clade of true dendritic cells distinct from a macrophage/monocyte clade. Each clade, and each member of both clades, could be discerned by specific genes of increased expression, which would serve as markers for future studies in healthy and diseased states.