The last abundant subset of thymic DCs is represented by B220 plasmacytoid DCs (pDCs) which also rise extrathymically and transfer peripheral antigens from the periphery to the thymus to mediate selection processes.
All these thymic DC subsets were shown to participate in antigen transfer. Nevertheless, only tDCs and mDCs were observed to utilize transferred TRAs for indirect presentation which led to the processes of central tolerance.