Dendritic cells in developing and adult zebrafish arise from different origins and display distinct flt3 dependencies.

Dendritic cells (DCs) are key cellular components of the immune system and perform critical functions in innate and acquired immunity. In mammals, it is generally believed that DCs originate exclusively from hematopoietic stem cells (HSCs). Using a temporal-spatial resolved fate-mapping system, here we show that in zebrafish, DCs arise from two sources: dorsal aorta-born endothelium-derived hematopoietic progenitors (EHPs) and HSCs.

Endoderm-Derived Myeloid-like Metaphocytes in Zebrafish Gill Mediate Soluble Antigen-Induced Immunity.

Immune cells in the mucosal barriers of vertebrates are highly heterogeneous in their origin and function. This heterogeneity is further exemplified by the recent discovery of ectoderm-derived immune cells-metaphocytes in zebrafish epidermis. Yet, whether non-hematopoiesis-derived immune cells generally exist in barrier tissues remains obscured.

An Ectoderm-Derived Myeloid-like Cell Population Functions as Antigen Transporters for Langerhans Cells in Zebrafish Epidermis.

Tissue-resident macrophages (TRMs) are highly heterogeneous and engage in a wide range of diverse functions. Yet, the heterogeneities of their origins and functions remain incompletely defined. Here, we report the identification and characterization of an ectoderm-derived myeloid-like cell, which we refer to as metaphocyte.