Analysis was performed with the Living Image software (v2.50, Xenogen). Lethally irradiated (9 Gy) C57BL/6 WT recipients received adoptive transfer of a total number of 1×107 BM cells that were either a 1:1 or a 1:20 mixture of
Thy1.2−Foxp3-eGFP WT to Thy1.2+Foxp3-eGFP OT-II, respectively. Chimeric mice were analyzed at 8–10 wk BMS-354825 mouse after transfer. The C57BL/6 (H-2b) into BALB/c (H-2d) acute GvHD model was performed as described elsewhere 35. In addition, some groups received 0.5×106 sorted Treg cells from WT or OT-II mice with a purity of >95%. Thy1.1+ Treg cells from either WT or OT-II donors were co-cultivated in round-bottom 96-well plates with MACS-enriched CFSE-labeled Thy1.2+ T cells at the indicated ratios under stimulatory conditions applying RPMI 1640 supplemented with 10% FCS, 2 mM glutamine and antibiotics, 100 IU/mL rh-IL2, and 1.5 μL T-cell expander beads (anti-CD3/anti-CD28, Dynal). After 4 days of co-culture, proliferation was assessed by flow cytometry determining CFSE dilution
on live Thy1.2+ T cells. Dead cells were identified by counterstaining with 4′,6-diamidino-2-phenylindol. Averages and SD or SEM were calculated with Graphpad Prism®. Group data were compared with the two-tailed unpaired t-test. Similarity between two sequenced TCR repertoires was statistically measured by the Morisita-Horn index 58. This index ranges between 0 (complete dissimilar) and 1 (identical) and is comparatively resistant to sample size. Proportional Euler diagrams were generated using the program VennMaster, which is Rebamipide available at http://www.informatik.uni-ulm.de/ni/staff/HKestler/vennm/doc.html. INK 128 mouse The authors thank Andreas Krueger and Oliver Pabst for discussions and carefully reading the MS. The authors thank Mathias Herberg, Georgios-Leandros Moschovakis, Sebastian Seth, Henrike Fleige, Sabrina
Woltemate, Kerstin Püllmann, Monika Bischoff, Anna Smoczek, Frano Malinarich, Manuel Winter, and Vijaykumar Chennupati for help. They also acknowledge the assistance of the Cell Sorting Core Facility of the Hannover Medical School. The authors are grateful to Véronique Guidicelli and the IMGT® team for their helpful collaboration and the analysis of nucleotide sequences on the IMGT/HighV-QUEST web portal, prior to its public availability. This work was supported by grants from the Deutsche Forschungsgemeinschaft SFB621-A14 (IP), and Deutsch-Französische Hochschule/Université franco-allemande DFH-UFA G2RFA 104-07-II. L. F. is supported by Hannover Biomedical Research School. Conflict of interest: The authors declare no financial or commercial conflict of interest. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors.