Transplanted TGF-β1 deficient progenitors have decreased reconstitutive capacity with no sign of inflammatory/autoimmune disease. (A) Analysis of reconstitutive capacities of Lin⁻ BM cells from 8- to 10-day-old TGF-β1^+/+ and TGF-β1^−/− mice. T-depleted Lin⁻ cells (1 × 10⁵, 2 × 10⁵, 4 × 10⁵, and 8 × 10⁵) from male TGF-β1^+/+ and TGF-β1^−/− mice were transplanted into lethally irradiated CF-1 × Sv129 female mice (10 mice per group). Graphs represent the percentage of donor-derived cells (percentage of Y) in peripheral blood (PB) at 6 weeks (left) and 24 weeks (right) after transplantation (5 mice per group). An example of 2 independent experiments is shown (5 mice per dose of cells; *P < .05). The contribution of donor-derived cells is determined by quantifying chromosome Y sequence in PB of reconstituted irradiated mice in comparison to an autosomal sequence (titine). (B) Serum reactivity from mice that received a transplant with T-depleted Lin⁻ BM cells from TGF-β1^+/+ and TGF-β1^−/− mice. Sera were collected at week 3 after transplantation. Reactivity was tested in an ANA stain as described by Oak et al³⁹  on the human epithelial cell line Hep2. Antibody binding activity was shown with an anti–mouse immunoglobulin G FITC conjugate. Fluorescence was analyzed with an immunofluorescence microscope. MRL/lpr lupic mice were used as a positive control and TGF-β1^+/+ mice as a negative control.