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 fetal mouse progenitor cells, and with adult marrow cells the specific activity of the recombinant GM-CSF (25 X 10(8) U/mg) was similar to that of the native form (15 X 10(8) U/mg). At high concentrations (greater than 200 U/ml), both forms of GM-CSF also stimulated eosinophil colony formation by adult marrow cells and, at very high concentrations (greater than 800 U/ml), megakaryocyte and some erythroid and mixed-erythroid colony formation. Recombinant GM-CSF was as effective in stimulating the proliferation of the GM-CSF-dependent cell line FD as the native molecule. Both recombinant and native GM-CSF were able to induce partial differentiation in colonies of WEHI-3B myeloid leukemic cells. Recombinant GM-CSF competed effectively for the binding of 125I-labeled native GM-CSF to hemopoietic cells, and antiserum to recombinant GM-CSF also neutralized the biological activity of native GM-CSF. The bacterially synthesized GM-CSF was a slightly more effective stimulus for megakaryocyte colony formation than the native molecule. The demonstration that purified bacterially synthesized GM-CSF is biologically active in vitro now permits studies to be undertaken on the in vivo effects of this material.

Neonatal Infection of Mice With Lactate Dehydrogenase-elevating Virus Results in Suppression of Humoral Antiviral Immune Response but does not Alter the Course of Viraemia or the Polyclonal Activation of B Cells and Immune Complex Formation

“…These conclusions are further supported by the finding that plasma LDV titres are also higher in infected mice during the first several weeks of age, a period which coincides with a high proportion of LDV-permissive macrophages being present in the peritoneum and with the time period when peritoneal macrophages exhibit self-sustained growth (Metcalf et al, 1992). Furthermore, repeated injection of chronically infected mice with IL-3/GM-CSF, which is known to stimulate macrophage generation (Metcalf et al, 1987(Metcalf et al, , 1992, raised their plasma LDV levels more than I0-fold.…”

“…2) without significantly affecting the total number of macrophages harvested from the mice. Similarly, repeated injection of mice with IL-3/GM-CSF, which has been shown to cause an up to 15-fold increase in the number of macrophages in the peritoneum (Metcalf et al, 1987) increased LDV viraemia in persistently infected mice. Thrice-daily intraperitoneal injection of two 4-week LDV-infected AKXD-20 mice with 200 units of IL-3/GM-CSF for 7 days increased their plasma LDV titre from 105.5 and 10 +.5 IDso/ml to 107.0 and 10 s° IDso/ml of plasma, respectively.…”

Differential Expression of Interferon Alpha and Beta Induced with Newcastle Disease Virus in Mouse Macrophage Cultures

“…However, preparation of poly(A) + RNA from bone marrow macrophages requires large amounts of M-CSF during cell culture and is thus limited by the supply with pure material isolated from CM. In this respect, the availability of cloned human M-CSF (Kawasaki et al, 1985) which has great homology to murine L cell M-CSF (Boosman et al, 1987) and is active on mouse cells (Metcalf, 1986), could facilitate this supply.…”

The biological consequences of excess GM-CSF levels in transgenic mice also lacking high-affinity receptors for GM-CSF

“…5,6 The GM-CSF receptor is a heterodimer composed of a low-affinity specific ␣-chain and a signaling ␤-chain (␤c) which is shared in common by the specific ␣-receptor chains for IL-5 and IL-3. 5 Most evidence indicates that the ␤-chain initiates signaling events 5 but there has been one report of membrane transport responses initiated by the ␣-chain.…”