DCreg suppression assays

We used in vitro T cell suppression assays to assess the function of our DCreg, as noted [7, 8]. Briefly, OVA-pulsed, irradiated DC10 (1000 rads) were titrated into round-bottom 96-well tissue culture plates with optimized numbers of irradiated OVA-presenting DC-LPS (4×10³ cells/well) and CD4⁺ Teff cells (1×10^{5 T} cells/well; 1:1, 1:3 or 1:9 DC10:T cell ratios) purified as noted above. We used ³H-thymidine uptake assays to assess T cell proliferation, as determined by liquid scintillation counting. We have previously reported that our Th2-phenotype Teff (i.e., CD4⁺CD25^loFoxp3^-) cells are also CD44^hiCD69⁺CD62L^lo, and secrete IL-4, -5, -9 and -13 [25].