Conclusions
This study unveiled that NA fusion protein promotes MPP and lineage-committed progenitor engraftment via extending long-term multi-lineage haematopoiesis.
Material and methods
300 sorted MPPs (Lin- CD48- c-kit+ Sca1+ CD135+ CD150- ) were mixed with 5 × 105 total BM helper/competitor cells and injected into irradiated recipients. For secondary transplantation, 5 × 106 total BM cells from primary recipient mice were injected into lethally irradiated recipients. NA-MPP recipient mice were sacrified for flow cytometric analysis of bone marrow progenitors at indicated time points. Sorted MPPs and myeloid progenitors were used for RNA-seq library preparation.
Methods
300 sorted MPPs (Lin- CD48- c-kit+ Sca1+ CD135+ CD150- ) were mixed with 5 × 105 total BM helper/competitor cells and injected into irradiated recipients. For secondary transplantation, 5 × 106 total BM cells from primary recipient mice were injected into lethally irradiated recipients. NA-MPP recipient mice were sacrified for flow cytometric analysis of bone marrow progenitors at indicated time points. Sorted MPPs and myeloid progenitors were used for RNA-seq library preparation.
Results
We showed that NA-expressing MPPs achieved significantly longer multi-lineage haematopoiesis (>44-week) than natural MPPs (20-week). NA upregulated essential genes regulating long-term haematopoiesis, cell cycle, epigenetic regulation and responses to stress in MPPs. These molecular traits are associated with the earlier appearance of a Sca1- c-kit+ myeloid progenitor population, and more abundant cellularity of lineage-committed progenitor as well as bone marrow nucleated cells. Further, the NA-derived primary bone marrow cells, which lack NA-LSK cells, successfully repopulated secondary multi-lineage haematopoiesis over 20 weeks. Conclusions: This study unveiled that NA fusion protein promotes MPP and lineage-committed progenitor engraftment via extending long-term multi-lineage haematopoiesis.