In vitro actions on hemopoietic cells of recombinant murine GM‐CSF purified after production in Escherichia coli: Comparison with purified native GM‐CSF

Abstract

Recombinant murine GM‐CSF produced in Escherichia coli was purified to homogeneity and tested in parallel with purified native GM‐CSF. Both recombinant and native GM‐CSF stimulated granulocyte and/or macrophage colony formation by adult and fetalmouse progenitor cells, and with adult marrow cells the specific activity of the recombinant GM‐CSF (25 × 108 U/mg) was similar to that of the native form (15 × 108 U/mg). At high concentrations (> 200 U/ml), both forms of GM‐CSF also stimulated eosinophil colony formation by adult marrow cells and, at very high concentrations (> 800 U/ml), megakaryocyte and some erythroid and mixed‐erythroid colony formation. Recombinant GM‐CSF was as effective in s..