Common lymphoid progenitor-independent pathways of innate and T lymphocyte development

All lymphocytes are thought to develop from common lymphoid progenitors (CLPs). However, lymphoid-primed multi-potent progenitors (LMPPs) are more efficient than CLPs in differentiating into T cells and group 2 innate lymphoid cells (ILC2s). Here, we have divided LMPPs into CD127− (LMPP-s) and CD127+ (LMPP+s) subsets and compared them with Ly6D− and Ly6D+ CLPs. Adult LMPP+s differentiated into T cells and ILCs more rapidly and efficiently than other progenitors in transplantation assays. The development of T cells and ILC2s is highly active in the neonatal period. Neonatal CLPs are rare and, unlike prominent neonatal LMPP+s, do not efficiently differentiate into T cells and ILC2s. ILC2s generated in the neonatal period are long-lived and persist in adult tissues. These results suggest that some ILCs and T cells may develop from LMPP+s via CLP-independent pathways. Here, we have divided LMPPs into CD127- (LMPP-s) and CD127+ (LMPP+s) subsets and compared them with CLPs.