Effect of iPTH treatment on HSPC expansion in T cell-replete and T cell–deficient mice. (A-C) Effects of iPTH on the relative frequency of LSK cells in WT mice, TCRβKO mice, and TCRβKO mice previously subjected to adoptive transfer of T cells. Lin⁻ cells were gated and analyzed for Sca-1 and c-Kit expression using isotype control settings. Left panels: Representative flow cytometric dot plots from 1 mouse per group. Black box represents c-Kit⁺ Sca-1⁺ cells. Parent population is Lin⁻. Data are expressed as percentage of total Lin⁻ cells. Right panels: Mean ± SEM for each group. Data are expressed as percentage of total BM mononucleated cells (BMMCs). (D-F) Effects of iPTH on the relative frequency of CD150⁻CD48⁻ LSK cells (ST-HSPCs/MPPs) and CD150⁺CD48⁻ LSK cells (LT-HSPCs) in WT, TCRKO, and TCRβKO mice previously reconstituted with T cells. Left panels: Representative flow cytometric dot plots from 1 mouse per group using the SLAM receptors CD150 and CD48. Parent population is Lin⁻Sca1⁺c-Kit⁺. Upper boxes represent LT-HSPCs; and lower boxes, ST-HSPCs + MPPS. Right panels: Mean ± SEM for each group. Data are expressed as percentage of BMMCs. n = 10 mice per group. *P < .05 versus the corresponding vehicle-treated group. **P < .01 versus the corresponding vehicle-treated group.