Circulating lymphoid committed progenitors after allogeneic stem cell transplantation in humans

Lymphoid committed CD34+lin-CD10+CD24- progenitors undergo a rebound at month 3 after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the absence of acute graft-versus-host disease (aGVHD). Here, we analyzed transcriptional programs of cell-sorted circulating lymphoid committed progenitors and CD34+Lin-CD10- non lymphoid progenitors in 11 allo-HSCT patients having (n=5) or not developed (n=6) grade 2 or 3 aGVHD and in 7 age-matched healthy donors. Major deregulated pathways included protein synthesis, energy production, cell cycle regulation and cytoskeleton organization. Notably, genes from protein biogenesis, translation machinery and cell cycle (CDK6) were over-expressed in progenitors from patients in the absence of aGVHD compared with healthy donors and patients affected by aGVHD. Expression of many genes from the mitochondrial oxidative phosphorylation metabolic pathway leading to ATP production were more specifically increased in lymphoid committed progenitors in absence of aGVHD. This was also the case for genes involved in cell mobilization such as those regulating Rho GTPases activity. In all, we show that circulating lymphoid committed progenitors undergo profound changes in metabolism favoring cell proliferation, energy production and cell mobilization after allo-HSCT in humans. These mechanisms are abolished in case of aGVHD or its treatment, indicating a persistent cell-intrinsic defect after exit from bone marrow. Transcriptome analysis of 2 cell populations CD34+lin-CD10+CD24-(TSP) and CD34+lin-CD10- (CD10) from peripheral blood of 11 patients that underwent Hematopoietic transplantation (5 with acute Graft versus Host Disease) and 7 Healthy controls,