Fig. 3

MSC mitochondria and PGE2 cooperate in the suppression of HNT CD4⁺ T cell responses. A Purified HNT CD4⁺ T cells were activated with anti-CD3 and anti-CD28 mAbs and cultured in the presence of MSC-A or absence. Indomethacin or vehicle was added to tissue culture media and cells cultured for 4 days. Absolute numbers of harvested T cells. B Day 4 activated HNT CD4⁺ T cells were restimulated with PMA and ionomycin in the presence of brefeldin A and production of intracellular IFNγ was assessed by FACS. Percentage of cytokine producing T cells is indicated. C CD25 expression on day 4 activated T cells was assessed by FACS. Mean fluoresce intensity (MFI) minus that of the isotype controls is indicated. D Isolated mitochondria from MSC-A were transferred by mitoception to naïve HNT CD4⁺ T cells. 12 h later, mitocepted or mock mitocepted HNT CD4⁺ T cells were activated with anti-CD3 and anti-CD28 mAbs and cultured during 4 days in the presence or absence of PGE2 (at a concentration of 1 or 10 ng/ml). Absolute numbers of harvested HNT CD4⁺ T cells. E Day 4 activated HNT CD4⁺ T cells were restimulated with PMA and ionomycin in the presence of brefeldin A and production of intracellular IFNγ was assessed by FACS. Percentage of cytokine producing T cells is indicated. F Expression of CD25 and CD40L in activated HNT CD4⁺ T cells. Mean fluorescence intensity (MFI) minus that of the isotype controls is indicated. Values are represented as mean ± SEM. Data from 3 independent experiments is presented in panels A to F