RETROVIRALLY-PRODUCED ERYTHROPOIETIN EFFECTIVELY INDUCES DIFFERENTIATION AND PROLIFERATION OF J2E ERYTHROID-CELLS

The J2E erythroid cell line terminally differentiates in response to r ecombinant human erythropoietin (rHu-epo). Here we demonstrate that re trovirally produced monkey erythropoietin (Zen-epo) is also capable of inducing the final maturation steps of J2E cells in a dose-dependant manner. The hormone committed J2E cells to a pathway of accelerated pr oliferation, haemoglobin synthesis and morphological changes including enucleation. However, only 6 h exposure to Zen-epo was required to in itiate maximum haemoglobin synthesis 72 h later. Significantly, the sy nthesis of haemoglobin was achieved by concomitantly activating globin production, haem synthesis and iron uptake. Methylcellulose assays re vealed that the vast majority of clonogenic cells were able to respond to Zen-epo. These data show that retrovirally manufactured erythropoi etin is an effective stimulus for the erythropoietic development of J2 E cells in vitro.