Figure 7.

Anatomical distribution of M regs after administration to syngeneic or allogeneic recipients. 5 × 10⁶ CD45.2⁺ M regs were administered to recipients by iv injection and their presence in various tissues was detected by flow cytometry at 24 hours, 1, 2, and 4 weeks postinfusion. Data are representative of three independent experiments. (a) Gating strategy to identify live CD45.2⁺ M regs within the pool of CD11b⁺ MHC II⁺ cells. The position of the CD45.2 gate was set according to the fluorescence-minus-one (FMO) isotype control in each case. (b) Tissue distribution of CD45.2⁺ B6 M regs and CD45.2⁺ BALB/c M regs in CD45.1⁺ B6 recipients at 24 hours postinfusion. Both syngeneic and allogeneic M regs were found in the blood, spleen, liver, and lung. The “no cell” control group received an injection of 1 ml DPBS-containing 62 U/ml heparin. Data are representative of three independent experiments. (c) BALB/c M regs were readily detectable for up to 2 weeks in B6 recipients, albeit at a much lower frequency than at 24 hours postinfusion. Results representative of three independent experiments identifying M regs present in lung are shown.