A bioactive designer cytokine for human hematopoietic progenitor cell expansion

M Fischer, J Goldschmitt, C Peschel… - Nature …, 1997 - nature.com
M Fischer, J Goldschmitt, C Peschel, JPG Brakenhoff, KJ Kallen, A Wollmer, J Grötzinger…
Nature biotechnology, 1997nature.com
Efficient expansion of hematopoietic progenitor cells requires, at least, the simultaneous
stimulation of the receptors c-kit and gp130. While c-kit is activated by SCF; gp130, in cells
which do not express sufficient amounts of IL-6R, can be activated by the complex of soluble
IL-6R (slL-6R) and IL-6. The therapeutic use of IL-6/sIL-6R, however, has been hampered by
the high concentrations of the sIL-6R protein required. We have designed a fusion protein of
sIL-6R and IL-6, linked by a flexible peptide chain, that was expressed to high levels. On …
Abstract
Efficient expansion of hematopoietic progenitor cells requires, at least, the simultaneous stimulation of the receptors c-kit and gp130. While c-kit is activated by SCF; gp130, in cells which do not express sufficient amounts of IL-6R, can be activated by the complex of soluble IL-6R (slL-6R) and IL-6. The therapeutic use of IL-6/sIL-6R, however, has been hampered by the high concentrations of the sIL-6R protein required. We have designed a fusion protein of sIL-6R and IL-6, linked by a flexible peptide chain, that was expressed to high levels. On gp130 expressing cells the fusion protein turned out to be fully active at 100 to 1,000-fold lower concentration than the combination of unlinked IL-6 and IL-6R. The fusion protein was used to effectively expand human hematopoietic progenitor cells ex vivo in a dose dependent fashion.
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