Global transcriptome analysis of T-competent progenitors in the bone marrow.

T cells are known to develop in the thymus. However, molecular events that control the transition from hematopoietic progenitor cells in the bone marrow to T precursor cells seeded in the thymus remained poorly defined. Our recent report showed that osteocalcin (Ocn)-expressing bone cells in the bone marrow have major impact on T cell immunity by regulating T progenitor development in the bone marrow (Yu et al., 2015) [1]. Selective endogenous depletion of Ocn+ cells by inducible diphtheria toxin receptor expression (OcnCre;iDTR) led to reduction of T-competent common lymphoid progenitors (Ly6D− CLPs) in the bone marrow and loss of T cells in the thymus. Expression of the Notch ligand DLL4 by Ocn+ cells in the bone marrow ensures the production of Ly6D− CLPs, and expression of chemotactic molecules CCR7 and PSGL1 to enable subsequent thymic seeding. These data indicate that specific mesenchymal cells in bone marrow provide key molecular drivers enforcing thymus-seeding progenitor generation and thereby directly link skeletal biology to the production of T cell based adaptive immunity. Here we present the transcriptome profiles of Ly6D− CLPs derived from Ocn+ cells deleted mice (OcnCre+;iDTR) compared to those derived from control littermates (OcnCre−;iDTR). These data are publically available from NCBI Gene Expression Omnibus (GEO) with the accession number GSE66102.