Newly found rat CD103- dendritic cells are the highly immunogenic conventional DC2 subpopulation, corresponding to the known DC subsets in mice and humans.

Dendritic cells (DCs), the primary antigen-presenting cells, have traditionally been identified by CD103 molecules in rats, whereas mouse and human DCs are identified by CD11c molecules. However, this history does not preclude the existence of CD103- DCs in rats. To explore this possibility, we examined MHCII+ cells in rat spleen and thymus, identifying a novel population of CD103-MHCII+CD45R-CD172a+ cells. These cells are negative for CD103 and B cell marker CD45R, but positive for the type-2 conventional DC (cDC2) marker CD172a. Transcriptomic analyses revealed that they represent a subpopulation of cDC2.