Panel A: C57BL/6J PerC cells were cultured with (left to right) anti-CD3, anti-CD3 + 33, 100, or 300 ng/ml EPO. Graph depicts the average of three independent experiments that yielded similar results. Panel B: EPO has no effect on spleen (SP) T cell activation, yet when PerC cells are co-cultured with SP cells suppression and the EPO effect were observed. C57BL/6J SP cells cultured at 1.0 ×105 cells/well with (left to right) CM, anti-CD3, anti-CD3 + 200 ng/ml EPO and graded numbers of C57BL/6J PerC cells.