FIG. 3.

BDC12-4.1 CD4SP cells convert into Teffs and Tregs upon antigen recognition in vitro. CD4⁺CD8⁻ (CD4SP) thymocytes from BDC12-4.1.RAG^KO mice were FACS-sorted and cultured in the presence of TDS from Ins2^KO NOD mice. The stimulation lasted for 48 h in the absence (without [w/o]) or presence of 50 μg/mL B:9-23 peptide (Ins1 or Ins2 sequence), B:9-23(1) and B:9-23(2), respectively. For control, plate-bound anti-CD3 (1 μg/mL) plus anti-CD28 (0.5 μg/mL) were used to stimulate the cells. Cells were consequently stained and analyzed by flow cytometry after gating on CD4⁺CD8⁻ for the expression of CD44 and CD62 L (A) or CD25 and Foxp3 (B). Cell supernatant was quantified with ELISA for the presence of four cytokines: IL-10, IL-4, IFN-γ, and TGF-β1 4 days after stimulation (C). (A high-quality color representation of this figure is available in the online issue.)