MSC-mediated activation of ovalbumin-specific T-T hybridomas. (A) C57BL/6 MSCs, DC2.4 or MEF (5 × 104 cells) were cocultured for 20 hours with ovalbumin-specific MHC class II-restricted T-T hybridomas (MF2.2D9; 105 cells) in the presence of increasing doses of soluble ovalbumin. Where indicated, recombinant mouse IFNγ (50 ng/mL final) was added to the cocultures. After 20 hours, supernatant was collected and tested for IL-2 release by ELISA. Means of triplicates ± standard deviations of 1 of 5 representative experiments are shown. (B) Same as panel A, except that clonal MSCs obtained by limiting dilution from the initial preparation were used. (C) Same as panel A, except that distinct polyclonal C57BL/6-derived MSC preparations were used. Means of triplicates ± standard deviations of 1 of 2 representative experiments are shown.
