Newly Found Rat CD103− Dendritic Cells Represent a Highly Immunogenic Subpopulation of Type-2 Conventional Dendritic Cells, Corresponding to Known Dendritic Cell 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. cDC1, cDC2, newly found CD103- dendritic cells (newAPC), and HIS36+ macrophages were sorted from thymic and spleens of male Lewis strain rats. mRNA was extracted and analyzed with Clariom™ S Assay, rat.