Reconstructing human DC, monocyte and macrophage development in utero using single cell technologies

The repertoire of dendritic cells (DCs), monocytes and macrophages in adult humans is diverse and we are appreciating this to a greater extent as high throughput methods, such a single-cell RNA sequencing, become widely adopted and scalable. This powerful lens of analysis is also beginning to shed light on prenatal immunology, allowing us to chart the emergence, tissue distribution and developmental regulation of DCs, monocytes and macrophages during early human life. In this review, we will integrate recent insights from studies of the developing immune system into our understanding of adult DC, monocyte and macrophage organization, illustrating where insights from early life both affirm and challenge current understanding.