Fig. 1: Improved intrathymic human T cell differentiation in NSGW41hIL7 mice.

a Scheme of BAC constructs for the generation of NSGW41hIL7 mice. b Abundance of hIL-7 transcript in bone marrow (BM), spleen, and thymus from humanized NSGW41 or NSGW41hIL7 mice. c hIL-7 protein levels in bone marrow, thymus, and serum isolated from non-humanized NSGW41 (black) or NSGW41hIL7 mice (red, top) and from NSGW41 or NSGW41hIL7 mice that have received human CD34⁺ HSPCs 26-38 weeks before (bottom). Gray lines indicate the limit of assay sensitivity. d Scheme of transplantation experiments. e Numbers (top) and fold-change (bottom) of human (h)CD45⁺ cells in thymi of humanized NSGW41 or NSGW41hIL7 mice at the indicated time points after humanization. Fold-changes were calculated by dividing hCD45⁺ thymocyte numbers from humanized NSGW41hIL7 mice by the thymocyte numbers from humanized NSGW41 mice. This was conducted separately for each experiment and the results pooled. f Analysis of CD4 and CD8 expression on hCD45⁺ thymocytes from NSGW41 or NSGW41hIL7 mice that have received human HPSCs 15 (left) or 26 (right) weeks before. g Composition of thymocyte subsets in NSGW41 or NSGW41hIL7 mice at the indicated time points after humanization. Frequencies of DN populations were significantly decreased in NSGW41hIL7 compared to NSGW41 counterparts (week 15 and 18: P < 0.01 and week 32: P < 0.001). h Numbers of B cell subsets in the bone marrow of NSGW41 or NSGW41hIL7 mice 26–32 weeks after humanization. i Kinetics of the appearance of human CD45⁺ cells (hCD45⁺, top) and hCD3⁺ T cells within human leukocytes (bottom) in the blood after humanization. b, c, e, h, i Each dot represents an individual mouse. Boxes and whiskers indicate quartiles and median.