Abstract: The present invention relates to recombinant human interleukin-3 (hIL-3) variant or mutant proteins (muteins). These hIL-3 muteins contain amino acid substitutions and may also have amino acid deletions at both the N- and C- termini. The invention also relates to pharmaceutical compositions containing the hIL-3 muteins and methods for using them. Additionally, the present invention relates to recombinant expression vectors comprising nucleotide sequences encoding the hIL-3 muteins, related microbial expression systems, and processes for making the hIL-3 muteins using the microbial expression systems. Included in the present invention are deletion mutants of hIL-3 in which from 1 to 14 amino acids have been deleted from the N-terminus, and from 1 to 15 amino acids 119 to 133 have been deleted from the C-terminus, and which also contain amino acid substitutions in the polypeptide.

Abstract: The present invention relates to recombinant human interleukin-3 (hIL-3) variant or mutant proteins (muteins) in which segments of the polypeptide sequence of the human IL-3 polypeptide have been replaced by segments of the murine (mouse) interleukin-3 (mIL-3) polypeptide to form human/murine chimeric hybrid polypeptides. The human/mouse IL-3 may have amino acid deletions at the N-terminus or the C-terminus or at both the N- and C- termini and in some cases may also contain additional amino acid substitutions or deletions. The human/murine IL-3 muteins retain at least one biological activity of native hIL-3 and may also exhibit an improved side effects profile such as a reduction in the stimulation of leukotriene release or histamine release. The invention also relates to pharmaceutical compositions containing the h/m IL-3 hybrids and methods for using them.

Abstract: The present invention relates to recombinant human interleukin-3 (hIL-3) variant or mutant proteins (muteins) in which segments of the polypeptide sequence of the human IL-3 polypeptide have been replaced by segments of the murine (mouse) interleukin-3 (mIL-3) polypeptide to form human/murine chimeric hybrid polypeptides. The human/mouse hybrid IL-3 may have amino acid deletions at the N-terminus or the C-terminus or at both the N- and C- termini and in some cases may also contain additional amino acid substitutions or deletions. The human/murine IL-3 muteins retain at least one biological activity of native hIL-3 and may also exhibit an improved side effects profile such as a reduction in the stimulation of leukotriene release or histamine release. The invention also relates to pharmaceutical compositions containing the h/m IL-3 hybrids and methods for using them.