Fig. 2.

Effect of freshly isolated bone marrow stromal cells (BMSCs) on T cell proliferation. Non-haemopoietic mesenchymal stem cell-enriched cells, defined as CD45^–/CD106⁺ cells, were sorted immediately (gate 1) from the recipient of intrabone marrow-bone marrow transplantation (IBM-BMT) + IBM-donor lymphocyte infusion (DLI), IBM-BMT + intravenous (i.v.)-DLI or IBM-BMT alone (without DLI) after the staining of cells with fluorescein isothiocyanate-anti-CD45 and phycoerythrin-anti-10⁶ monoclonal antibodies (mAbs). Haemopoietic cells in the bone marrow (BM), defined as CD45⁺/CD106^– cells, were also obtained by a cell sort (gate 2). Graded numbers of CD45^–/CD106⁺ BMSCs (3 × 10²−6 × 10³), CD45⁺/CD106^– haemopoietic cells (1 × 10³) or whole BM cells (1 × 10³−3 × 10⁴) were added to the culture of one-way mixed leucocyte reaction where 2 × 10⁵ responder CD4⁺T cells from BALB/c mice were stimulated with 12 Gy irradiated stimulator spleen cells (2 × 10⁵ cells) from B6 mice in a 96-well flat-bottomed plate in a total volume of 0·2 ml and cultured for 96 h. The cultures were pulsed with 0·5 μCi of [³H]-TdR for the last 16 h of the culture period. This figure shows the representative result of three experiments. The data are expressed as mean counts per minute ± standard deviation of three mice (separately cultured BMSCs obtained from the recipient).